NC0025453_Environmental assessment_20011231

CT9905
REVIEW AGENCY COMMENTS AND RESPONSES
12/13/00ForwardHUA
Town of Clayton
Environmental Assessment for WWTP Expansion
TOWN OF CLAYTON
WWTP EXPANSION
ENVIRONMENTAL ASSESSMENT
FORWARD
MAY 2 5 2001
May 23, 2001
RE:
Dear Mr. Wicker:
If you have any questions, please feel free to call me at 919-733-5083 ext. 366
Raleigh. NC 27699-16171617 Mail Service CenterDivision of Water Quality
http://www.enr state nc us
Sincerely,
Michael C. Wicker
Hobbs, Upchurch, and Associates, PA
290 S.W. Broad Street
Post Office Box 1737
Southern Pines, North Carolina 28388
Environmental Assessment (EA) for the
Town of Clayton Wastewater Treatment Plant Upgrade
Johnston County
Michael F Easley
WV Governor
William G Ross Jr
Department of Environment and Natural Resources
Kerr T Stevens
Division of Water Quality
The Division of Water Quality (Division) and the Department of Environment and Natural
Resources have completed the review of the January 2001 Environmental Assessment (EA) for
the “Town of Clayton Wastewater Treatment Plant Upgrade" in Johnston County.
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NCDENR
Customer Service
[phone]
1-877-623-6748
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Milt Rhodes
Interim DWQ SEPA CoordinatorI
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Once the final version of the document is completed, please send me one copy. Once the
Division has reviewed the final version and all concerns have been adequately addressed, I will
draft a Finding of No Significant Impact and request an additional seven copies for distribution
through the State Clearinghouse for a 30 day public review period.
Please give careful consideration to the recommendations provided by the NC Wildlife Resources
Commission in the attached letter. The Division encourages the applicant to work directly with
the NC Wildlife Resources Commission prior to finalizing project plans. Additionally, the Division
of Water Quality, NPDES permitting unit has provided additional comments that should be taken
into consideration upon preparation of the final version of the document
To:
Through:
From:
Subject:
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The NPDES Unit of the Division of Water Quality discussed concerns regarding the FA.
as well as other issues, during the meeting held with Town officials and their
consultants, April 25, 2001. The following comments represent the potential problems
the Town may face with the expansion to 2.5 MGD. As long as the Town is aware ol the
problems discussed below, the NPDES Unit has no objection to the proposed project.
I have reviewed the Environmental Assessment (EA) submitted by Hobbs, Upchurch,
and Associates on behalf of the Town of Clayton. The EA represents the flow expansion
of the Little Creek Wastewater Reclamation Facility from 1.9 MGD to 2.5 MGD.
Milt Rhodes
Local Government Assistance Unit
DIVISION OF WATER QUALITY
May 22, 2001
Town of Clayton - Little Creek Wastewater Reclamation Facility
Environmental Assessment
NPDES No. NC0025453
Johnston County
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Susan A. Wilson. Environmental Engineer/.
NPDES Unit A
As discussed in the meeting, depending on the timing of the expansion and the
proposed formation of the Group Compliance Association, there are two different
pathways to compliance with Clayton’s nutrient load allocation to the Neuse River
basin, which are outlined below:
1. Resolution and formation of the proposed Compliance Association for the Neuse Basin.
Should the proposed Compliance Association be contractually formed (with Clayton
as a member in good standing) at the date of permit application for the expansion to
2.5 MGD, the Town will not have to meet the individually limited total nitrogen (TN)
load of 21,400 Ibs/year and will not be required to design for a nitrogen limit
equivalent to 3.5 mg/1 TN referred to in 15A NCAC 2B .0234 (8). However, the
Division is unaware at this time what may be required for the Town to comply with
conditions that may be stipulated by the Compliance Association for expanding
facilities. We encourage the Town to contact Glenn Dunn and/or other Local
Government members of the proposed Compliance Association. Additionally, a total
phosphorus limit of 2 mg/1, based on a quarterly average will be required if the
Compliance Association is formed. All other limits presented in the speculative
limits letter dated July 10, 2001 are correct and will be applicable regardless of any
Compliance Association.
2. No formation of a Compliance Association. If no Compliance Association has been
formed, the Town will be subject to the individual total nitrogen load of 21.400
David A. Goodrich. Supervisoi^^
NPDES Unit
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The current EA states that “...nutrient removal projects are for later consideration and
are not part of the proposed project ....” The Town of Clayton should be aware that
proceeding forward without nutrient removal could be problematic, whether or
not a compliance group is formed.
To address all eventualities, the EA should reflect both possible paths and
evaluate each accordingly (including analyses of alternatives).
The EA should clearly document the Town’s future (20 year) planning. This should
include an explanation as to how this expansion phase fits into long range planning
efforts. Also, the Division is interested in how the county and other local governments
will be involved with Clayton’s future efforts.
Ibs/year and the Town will be required to design for an equivalent nitrogen limit of
3.5 mg/1. Current treatment technologies for total nitrogen removal may not allow
the Town to comply with the total nitrogen load. Therefore, it may be necessary that
Clayton acquire additional allocation from nonpoint sources through the Wetlands
Restoration Fund. The Town will be required to obtain (make payment) for 30 years
allocation at, or prior to, renewal of a permit for 2.5 MGD.
Bobby Blowe, Construction Grants & Loans
Ken Schuster/Tim Baldwin, RRO/WQ
Furthermore, a revised model for nutrient effects on the Neuse River is currently under
review by the Division and ERA. Additionally, EPA is currently running a separate
model for nutrient effects on the Neuse River. It is possible that upon Phase II review of
the nutrient TMDL for the Neuse River Basin, nitrogen loads may be reduced even
further. It is imperative that the Town plan for future nutrient reduction either
via increased treatment capability and/or effluent flow reduction.
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NCDENR
MEMORANDUM
TO:
FROM:
RE:
DATE:
Thank you for the opportunity to respond.
Attachments
s/EN!</
Michael F. Easley, Governor
William G. Ross Jr., Secretary
Milt Rhodes
Division of Water Quality
/1101 Environmental Assessment, Town of Clayton, WWTP
Expansion, Johnston County
North Carolina
Department of Environment and Natural Resources
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Melba McGee
Environmental Review Coordinator
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March 7, 2001
The Department of Environment and Natural Resources has completed
its review of the subject proposal. This department asks that careful
consideration be given to the attached recommendations. The applicant
is encouraged to work directly with the N.C. Wildlife Resources
Commission prior to finalizing project plans.
1601 Mail Service Center, Raleigh, North Carolina 27699-1601
Phone:[phone] \ FAX: 919 - 715-3060 \ Internet: www.enr.state.nc.ir
AN EQUAL OPPORTUNE Y X AEHRMATIVE ACTION EMPLOYER - 50% RECYCLED , 10% POST CONSUMED PAH
252522
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TO:
FROM:
DATE:March?, 2001
SUBJECT:
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Mailing Address
Town of Clayton WWTP Expansion Environmental Assessment (EA), Johnston
County, North Carolina. Project Number: 1101.
li_Tjorth Carolina Wildlife Resources Commission §
Charles R. Full wood, Executive Director
• Division of Inland Fisheries • 1721 Mad Service Center - Raleigh
Tdeohone- <919) 733-3633 ext. ?R 1 - Fax: r9i^71^7Mt 21
The subject EA describes intentions to increase capacity of Clayton’s Wastewater
Treatment Plant from 1.9 mgd to 2.5 mgd by upgrading facilities on the existing Plant site,
astewater receiving tertiary treatment would continue to be discharged to the Neuse River at
the same location. The large number of rare, threatened, and endangered amphibian, fish, and
mollusk species m the streams of the project area (particularly Swift Creek) are noted in the
environmental document.
PAGE 01/0103/06/2001 22:57
t wi?16 Carolina Wildlife Resources Commission has reviewed the project for impacts
401 of the Clean Water Act (as amended), and North Carolina General Statutes (G.S. 113-131 et
seq.).
■ . W*e >C<XP,eCt secondary and cumulative impacts to be the primary adverse effects of the
project. Added sewer capacity usually serves to stimulate development in a given service area,
mcreasmg ground disturbance, incremental wetland loss, impervious surface area, and water
quabty decline The EA points to Clayton’s Watershed Protection Plan and Strategic Growth
P an as means of countering these effects We noticed that these plans specify only 30 ft buffers
along streams. Given the sensitivity of proximal streams with their prevalence of listed biota we
rewmmend that vegetated streamside buffers be a bare minimum of 50 ft. in width A 50 ft ’
butter width should also be consistent with the Neuse Buffer Rules.
Thank you for the opportunity to comment on this project. If you have questions
regarding these comments, please call me at [phone].
Melba McGee
Office of Legislative and Intergovernmental Affairs
Bennett Wynne
Habitat Conservation Program
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July 23, 2001I
Re:
Dear Mr. Rhodes:
NCDENR-DWQ Comments
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The NPDES Unit provided comments based on their concerns with regard to the more
stringent nutrient limits, specifically those for total nitrogen, and the ultimate ability for the
Town of Clayton to meet these limits with the flow expansion of the Little Creek Wastewater
Reclamation Facility to 2.5 MOD.
The Environmental Assessment that has been prepared is for a wastewater facility upgrade
project. An Authorization to Construct was received by the Town of Clayton on May 24.
2001 for upgrades to the existing wastewater treatment facility. These upgrades are located
on the existing plant site and have very little environmental impact from construction. While
it is recognized that these approved improvements will help to facilitate the re-rating to 2.5
MOD, additional measures to reduce Total Nitrogen are necessary and will be addressed in
the submittal for an Authorization to Construct for the re-rating of the plant. This submittal
will follow the approval of the Environmental Assessment and the NPDES request for the
expansion to 2.5 MOD. It should be noted that the environmental impacts of this flow
Southern Pines, NC • Telephone [phone] • Fax [phone] • e-mail: [e-mail]
Myrtle Beach • Nags Head • Raleigh • Charlotte
In response, Hobbs, Upchurch & Associates provides the following information in order to
adequately address the comments.
Mr. Milt Rhodes
Division of Water Quality
Planning Branch
1621 Mail Service Center
Raleigh, NC 27699-1621
Environmental Assessment Comment Response
Town of Clayton - Little Creek Wastewater Reclamation Facility Upgrade
Johnston County
NPDES Permit NC0025453
HUA Project No. CT9905
Hobbs, Upchurch & Associates, PA.
Consulting Engineers
300 S.W. Broad Street • Post Office Box 1737 • Southern Pines, NC 28388
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Thank you for your letter dated May 23, 2001, which included comments from the NCDENR-
Division of Water Quality (DWQ) and the NC Wildlife Resources Commission. The concerns
have been addressed in the Environmental Assessment; however, from these comments, it was
clear that clarification was necessary for each agency. This correspondence has been prepared
to address these issues so that the environmental review process can proceed as expeditiously as
possible.
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It is further recognized, however, that the comments from the NPDES Unit are more
proactive in nature and are requesting that the Town recognize and plan for these lower
limits, which will be associated with both the implementation of the Neuse Rules and the
NPDES permit modification process for the increased flows. The Town of Clayton does
recognize this eventuality and has been and continues to evaluate and study all alternatives
for nutrient reduction.
Nutrient Offset Payments
The Neuse Rules allow for wastewater dischargers to individually or collectively
reduce their respective nitrogen loadings through nutrient offset payments. If a
permitted wastewater discharger chooses this option, they are required to have
made an offset payment in an amount that is great enough to cover nitrogen
reduction for a period of 30 years. In addition, these payments are required to be
made prior to a NPDES permit reissuance.
The Environmental Assessment contains an Alternatives Analysis for the purpose of
demonstrating both the economic and environmental feasibility of each alternative open to
the Town of Clayton. Based on the comments from DWQ, an additional discussion of the
nutrient reduction options allowed under the Neuse River Basin Rules is also needed. The
following paragraphs provide this discussion.
While this represents an option, the costs must be weighed against those costs for
the addition of a nutrient removal system at the wastewater treatment facility.
The primary difference in the level of these costs is that the entire nutrient offset
payment must be made at the time of the application for the permit modification,
whereas, the costs for the nutrient removal can be spread over a number of years.
Therefore, the option of using nutrient offset payments is still one that is feasible;
however, the immediate costs would certainly be greater than other options
available to the Town.
Town of Clayton EA Comment Response
July 23, 2001
expansion are addressed in this Environmental Assessment since the speculative discharge
limits are presented and evaluated. The discharge of Total Nitrogen is set at 21,400 Ibs/yr;
therefore, the direct impacts of the increased discharge from 1.9 MGD to 2.5 MOD to the
Neuse River from Total Nitrogen are minimal.
A Nutrient Removal Study was performed for the Town of Clayton by I he
Wooten Company and was completed in October 2000. In this study, numerous
alternatives were discussed; including the use of the nutrient offset payments.
Based on this study, the calculated total nitrogen annual mass permit limit at a
flow rate of 2.5 MGD is 26635.87 lb TN/yr. At the nutrient offset payment rate
of 200 percent of the cost at $11.00 lb TN/yr, Clayton would need to make a
minimum payment in excess of $3,455,000.00 in order to operate the facility at
2.5 MGD with a nitrogen discharge limit of 26635.87 lb TN/yr. (26635.87 -
21,400 = 5235.87 lb TN/yr for 30 years).
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Clayton is very interested in this option and has consistently expressed its
willingness to participate in this kind of alliance with the other wastewater
dischargers in the lower Neuse River Basin when the opportunity becomes
available.
The current Lower Neuse Basin Association was established in 1994 upon the
execution of a Memorandum of Agreement (MOA) with the DWQ in order to
design and implement a water quality monitoring program in the Neuse River.
This association, however, has not yet reached an agreement with DWQ with
regard to the collective nutrient loadings as has been done in the Tar-Pamlico
Basin.
If such an agreement can be reached, the participation in this association would be
one of the most feasible options for the Town; however, they are proceeding with
all necessary projects under the assumption that this alternative will not be
available to them within the time frame during which they will apply for the
NPDES permit modifications to increase the plant flow to 2.5 MOD.
While this represents an alternative to the Town of Clayton, it is not one that is
realistic given the situation with most all dischargers in the Neuse Basin. Clayton
would have to identify an entity with excess allocation, which is willing to trade
some portion of it to Clayton in exchange for some unknown rate of payment.
This is considered a very unlikely option for the Town.
Town of Clayton EA Comment Response
July 23, 2001
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Nutrient Trading
Another option allowed by the Neuse Rules is the trading of nutrient allocations
between discharge facilities within the basin. This requires one facility to
voluntarily agree to trade some portion of its nutrient allocation to another facility
and for the two to enter into an agreement for the long-term commitment of this
allocation transfer at an agreed upon rate.
Basin Associations
Under the rules, a group of wastewater dischargers can collectively come together
to form an association for the purposes of working jointly to reduce their
collective nutrient loadings to the Neuse River. The association members must
enter into an agreement with the Division of Water Quality to establish annual
loading goals for the totality of the nutrient loading for all members. The
Environmental Management Commission must then formally approve the
agreement for it to in effect. Each individual discharger that is a member of the
association would not be subject to an individual total nitrogen limit but rather the
group’s discharges could not exceed the total allocation calculated for the
association. Each individual discharge would also have a quarterly total
phosphorus limit of 2.0 mg/L.
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3.Land Application
The third option of land application
facilities plan. Exhaustive efforts
Do nothing (no action)
The first alternative of no action remains an unacceptable option to all parties
involved due to the inevitable restrictions on residential, commercial, and
industrial growth in the Town’s wastewater service area, and a risk of future
NPDES permit renewals with more stringent limits than the current facilities are
capable of achieving. As previously stated, the Town of Clayton is within 2-3
years of achieving flow rates, which would result in sewer moratoriums in the
area.
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Town of Clayton EA Comment Response
July 23, 2001
was evaluated extensively in the original 201
were made to locate adequate disposal sites in
the 201 area. Although site characteristics were conducive to the actual disposal
design criteria, it was impossible to locate sufficient land area within an
approximate 5 mile distance of the Town on even a semi-contiguous basis, i.e..
perhaps half the land area in one site and the remainder distributed among two or
three separate sites in reasonable proximity. Further, at that time given the flow
projections and then anticipated application rates, the amount of land to be located
was approximately half of what would be required at this juncture. Accelerated
residential development demand pressure has made the land in the Clayton area
even more expensive and more difficult to obtain and locate. Therefore, the
Regional Wastewater Treatment System
The second option of optimizing operation of the existing wastewater treatment
plant is currently being accomplished. While the Town currently sends 600,000
gpd to the Central Johnston County Regional Wastewater Treatment Plant
(CJCRWWTP) from its industrial area, this facility does not have the capacity to
accept additional flows from Clayton. Treatment levels at this facility would be
the same as those being faced at Clayton’s Little Creek plant. Therefore, Clayton
would still need to purchase into the expansion of the CJCRWWTP in much the
same level as is needed for its facility. The costs for this option are contained in
the Environmental Assessment and are estimated at $5,740,000.00 for only a
600,000 gpd commitment. The Town would still be required to incur the costs to
upgrade their 1.9 MOD WWTP to the nutrient removal levels required by 2003.
While this is a feasible option, this option is not the best option at this time. It
requires more cost to the Town of Clayton, requires more extensive construction
impacts for the conveyance system, expansion of the Johnston County facilities,
and still requires construction at the Town of Clayton WWTP for nutrient
removal. The Regional WWTP options appear more attractive in the future
should additional growth in the Town of Clayton area require more extensive
expansions to the facilities beyond 2.5 MOD.
Based on the above discussion, the following paragraphs represent the
modifications to the original Alternatives Analysis contained in the
Environmental Assessment.
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Town of Clayton EA Comment Response
July 23, 2001
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Treatment Optimization
The optimization of treatment to limit nutrient loading to the Neuse River is the
primary goal of the rules. The other alternatives discussed are used to supplement
treatment and to provide a resource for the restoration of wetlands and riparian
areas within the basin. If a facility were able to meet the stringent nitrogen limits
established, then it would be in compliance with the discharge requirements.
Treatment optimization can come through the upgrade of existing facilities by the
installation of nutrient removal systems, through the use of land application
practices, or through wastewater reuse, to name several alternatives. Each of
these can also be used in combination with nutrient offset payments, basin
associations, or nutrient trading to achieve the required limits.
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This alternative represents the most feasible alternative to the Town of Clayton
and the one with which they are proceeding. To that end, the Town was recently
awarded a grant for the purpose of the construction of a wastewater reuse project.
It will allow treated effluent to be sent to the Pine Hollow Golf Course, a 150-acre
18-hole public course, for use as irrigation water. Based on initial calculations for
an irrigation rate of approximately 150,000 gpd, this reuse component will result
in an estimated total nitrogen reduction of 1,351 lb TN/yr. This project is
demonstrative of the Town’s aggressive pursuit for all available options to meet
the stringent nutrient limits imposed by the Neuse Rules. The estimated cost of
this reuse project is $733,000.00. Using this option in concert with the nutrient
offset payments could also amount to a savings to the Town of $891,660.00, if
those payments were elected as the means of providing for the necessary nitrogen
reduction.
In addition as stated in the Nutrient Removal Study, additional biological and
chemical treatment to reduce nitrogen will be necessary at the existing wastewater
treatment facility. These units would include anaerobic/anoxic basins, recycle
pump stations, chemical addition from existing caustic, alum, polymer, and
chlorine facilities, and supplemental methanol treatment, if necessary. The
treatment plant design will be optimized to remove nitrogen and phosphorus. The
preliminary construction costs for the necessary upgrades are estimated at
$5,417,000.00 from the Wooten Study.
The upgrade project for which this Environmental Assessment has been prepared
does include components necessary for the reuse project. Specifically, through
the upgrades to the existing clarifiers and oxidation ditches, these treatment
components will also be evaluated for optimal operation and used to achieve the
maximum level of nutrient removal possible.
The preliminary route of the forcemain to transport the effluent to the Pine
Hollow Golf Course follows within existing road rights-of-way and will utilize
the golf course’s existing irrigation system. These measures will minimize al
impacts associated with the construction of this reuse project.
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Treatment Optimization
The alternative of optimizing operation of the existing wastewater treatment plant
is currently being accomplished. The evidence indicates that the facility will meet
current and immediately renewed NPDES permit limits at the proposed design
flow capacity of 2.5 MOD. This option continues to divert 600,000 gpd to the
CJCRWWTP from the industrial area while continuing to serve the Town of
Clayton residential and commercial district and the additional flow from the
County residents and commercial enterprises near Cleveland. The flow rating of
the WWTP would be increased to 2.5 MOD. The treatment optimization would
be used in conjunction with the wastewater reuse project and would require the
addition of biological and nutrient removal at the plant. The estimated costs for
the upgrade and optimization of the plant combined with the addition of the BNR
components are $6,147,000.00. This does represent one of the most feasible
options for the Town, as it will allow the use of multiple of projects either already
designed or funded, while also accomplishing the necessary nutrient reduction
that was required by 2003 for the existing 1.9 MOD WWTP. The above costs
include approximately $5 million dollars of cost to reduce nitrogen regardless of
the expansion of the WWTP to 2.5 MOD. The cost of this option may be reduced
during design by the conversion of the existing trickling filter plant structures to
anoxic/aeration basins or fermentation tanks. The estimated costs consider the
construction of all new structures for conservative cost estimating. Because the
existing units can be modified and upgraded for relatively minor construction
costs and all the construction can be accomplished on the existing site without
Wastewater Reuse
The fourth alternative involves the reuse of wastewater and is considered to be a
feasible option for limited portions of Clayton’s effluent. The Town has just
recently received a grant for the construction of a wastewater reuse project where
effluent will be set to the Pine Hollow Golf Course for use as inigation water. The
initial estimates indicate that the implementation of this project will take
approximately 0.15 MGD of Clayton’s discharge and divert it to the golf course.
The cost estimate for this project based on the Wooten Study is $733,000.00;
however, additional alternatives must be used in conjunction with this project in
order to enable the Little Creek treatment facility to operate at the eventual
expanded flow of 2.5 MGD.
Town of Clayton EA Comment Response
July 23,2001
viability of this option is virtually nil. As an illustrative example land application
of wastewater at 1” per acre per week requires approximately 750 acres of welted
area to irrigate the entire amount necessary to eliminate the discharge.
Additionally 225 million gallons of storage lagoons would be needed to store
wastewater during inclement weather. The recent example of the Town of Garner
land application treatment facility being closed to divert their wastewater to the
City of Raleigh system indicates the unattractiveness of this option to an area
where residential growth is utilizing desirable land. The cost estimates for this
alternative are also contained in the Environmental Assessment and are estimated
to exceed $17,000,000.00.
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In summary, the Town of Clayton does recognize and is planning for the known eventuality
of the reduction in the nitrogen limits for their discharge to the Neuse River. This evident by
the completion of the Nutrient Removal Study and the recent grant commitment received for
the wastewater reuse project. The Town also understands that it must be able to demonstrate
the effect that all of these projects, including the plant upgrade, will have on their ability to
remove adequate amount of nitrogen from their effluent at the time of the re-rating of the
plant and will be prepared to do so to the satisfaction of the DWQ.
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Town of Clayton EA Comment Response
July 23, 2001
extensive construction impacts this option appears the most cost-effective
environmentally feasible option for the Town to expand their WWTP to current
needs, postpone the threat of sewer moratorium, and address the TN limit by
2003. Should the DWQ not permit these improvements to the level of treatment
required to meet the TN limit (approximately 2.8 ppm, 2.99 ppm with reuse
credit), then the Town of Clayton will purchase the extra TN required from the
Restoration Fund.
At this time, however, the treatment plant upgrades are of primary concern in this
Environmental Assessment. These upgrades are necessary not only to provide for the
wastewater treatment needs of the community but to optimize the operations of the plant in
preparation for the wastewater reuse project and the eventual increase in flows that will be
requested later through the NPDES permit modification process.
The Division of Water Quality has expressed concern that the expansion to 2.5 MOD does
not consider a 20-year planning period. To reiterate this expansion is not intended for a 20-
year planning period. The Town of Clayton recently has been threatened with a sewer
moratorium by the Division of Water Quality for exceeding allocations to the WW fP. While
flows have not yet exceeded the 80/90 rule requirements, everyone acknowledges that the
growth in the Town of Clayton sewer service area will require additional capacity in the near
future. The Town of Clayton recognized that the existing 1.9 MOD WWTP was required to
meet TN requirements by 2003 and have addressed this by the Nutrient Removal Study by
the Wooten Company. In addition Hobbs, Upchurch & Associates, P.A. have evaluated the
optimization of the existing facility and concluded that 2.5 MOD is a feasible flow through
the existing WWTP with minor modifications. The Town recognized that for the costs of the
upgrade and nutrient removal projects that the Town could expand the NPDES permit to 2.5
MOD at the existing site. The Town also recognizes that this expansion may be no more
than a 5-year “solution” if growth continues in the area as is currently being seen. 1 he Town
is preparing to enter into a 20 year planning period evaluation of the sewer needs of the
Town of Clayton. As discussed on several occasions in our meetings with DWQ this
planning will include additional reuse projects and cooperation with Johnston County to meet
the sewer needs of both governmental entities. The Town and the County already operate in
a spirit of cooperation, with intergovernmental agreements for sewer connections. 1 he Town
and County both interchange flow where is feasible to reduce the costs of conveyance. The
20-year plan will certainly continue this evaluation of these options. The proposed expansion
to 2.5 MOD allows the Town of Clayton to prepare and implement such a 20-year plan. The
implementation of such plans is often a 5-year process.
NC Wildlife Resources Commission Comments
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Steve Biggs, Town of Clayton
Tim Simpson, Town of Clayton
James Warren, Town of Clayton
Michael Wicker, P.E., Hobbs, Upchurch
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The primary comment received from this agency was in reference to the Town of Clayton’s
streamside buffers requirements set forth in their protective ordinances. A memorandum was
sent directly to Mr. Bennett Wynne for clarification of the Town’s requirements. Mr. Wynne
responded with a memorandum stating that the clarification provided by Hobbs, Upchurch &
Associates adequately addressed the concerns of the NC Wildlife Resources Commission.
Copies of these memoranda are attached for reference.
Eight copies of the final Environmental Assessment for the Little Creek Wastewater Treatment
Facility upgrades are included with this transmittal, each with a copy of this correspondence and
associated attachments addressing the final concerns. Please notify me as soon as possible upon
the drafting of the Finding of No Significant Impact and submittal to the State Clearinghouse so
that I can immediately notify the Town for planning purposes. Thank you for your prompt
consideration and review.
Town of Clayton EA Comm^^Response
July 23, 2001
Sincerely,
Hobbs, Upchurch & Associates, P.A.
Angelaki. Mettlen
Water/Waste water Division
02: 42 2b2b22973b tJ WYNHt
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FROM:
DATE;July 3, 2001
SUBJECT;
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Melba McGee
Office of Legislative and Intergovernmental Affairs
Angie Mettlen
Hobbs, Upchurch & Associates, P. A
Bennett Wynne
Habitat Conservation Program
Mailing Address: Division of Inland Fisheri.
Telephone:
North Carolina Wildlife Resources Commission
• Charles R. Fullwood, Executive Director
07/03/2001
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ICS •1721 Mail Service Center • Raleigh, NC 27699-1721
[phone] ext- 281 • Fax: [phone]
Follow-up on our March 7, 2001 comments re: Town of Clayton WWTP
Expansion Environmental Assessment (EA), Johnston County, North Carolina.
Project Number: 1101.
Thank you for the opportunity to further comment on this project. If you have questions
please call me at [phone].
Per a fax received July 3, 2001, project consultants have clarified that the Town of
Clayton’s Watershed Protection and Strategic Growth Plans require streamside buffers a
minimum of 55 ft. in total width. This exceeds the Neuse Buffer Rules total width requirement of
50 ft. and will afford listed aquatic species some additional protection. Based on this clarification,
we now concur with the EA
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Memo
I FAX NUMBER:252-522-9736TO:Bennett Wynne
HUA PROJECT #CT9905FROM:
DATE:July 3,2001
RE:
MESSAGE:Bennett-
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North Carolina Wildlife Resources
Commission
Habitat Conservation Program
Angie Mettlen
Hobbs, Upchurch & Associates, P.A.
Per our telephone discussion on Monday, July 2, 2001, the following infonnation is provided as a
response to the NC Wildlife Resources Commission comments with regard to the referenced
Town of Clayton Environmental Assessment.
As we discussed, Mr. Milt Rhodes of the NCDENR-DWQ would like to have your concurrence
that this information addresses your concerns when we resubmit the Environmental Assessment
for continuation of review through the State Clearinghouse. A facsimile with your comments
will be sufficient to serve this purpose. My fax number is [phone].
Your assistance is greatly appreciated. If you have any questions or need additional information,
please feel free to contact me at [phone].
P.O. Box 173]
SOOS. IV. BroadStred
Southern Pines, North Carolina 2838^
[phone] FAX [phone].
Response: The Town Clayton’s buffer requirements are consistent with those of the Neuse
Buffer Rules. These Rules require a total 50-foot buffer to be maintained along streams. Thirty
feet of this buffer area is required to be maintained as completely vegetated, where the remaining
20 feet can be used for utility easements, etc. as specified by the approved usages outlined in the
Neuse Rules. The Town of Clayton requires a total streamside buffer area of 55 feet; a
minimum of 35 feet for a vegetative buffer (this was just increased within the last month from 30
feet) and the balance of 20 feet for approved usage such as utility easements, etc. as outlined
above. Based on this information, Clayton’s buffer requirements are actually more stringent than
those required by the Neuse Buffer Rules.
NC Wildlife Resources Commission Comments
Town of Clayton Wastewater Treatment Plant Upgrade/Expansion Environmental Assessment
Johnston County, North Carolina
Wildlife Project No: 1101
9 | iW Hobbs, Upchurch
■■■| ■ & Associates, P.A.
■ Consulting Engineers
Wildlife Comment: “We noticed that the [Town’s Watershed Protection and Strategic Growth
Plans] specify only 30 ft. buffers along streams. Given the sensitivity of the proximal streams
with their prevalence of listed biota, we recommend that vegetated streamside buffers be a bare
minimum of 50 ft. in width. A 50 ft. buffer width should also be consistent with the Neuse
Buffer Rules.”
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February 14, 2000
FEB 1 6 2000
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RE:
Dear Mr. Wicker:
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James B. Hunt, Jr., Governor
Bill Homan, Secretary
Kerr T. Stevens, Director
State of North Carolir^
Department of Environment
and Natural Resources
Division of Water Quality
1617 Mail Service Center, Raleigh, North Carolina 27699-1617 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post-consumer paper
The Division of Water Quality (Division) has completed it’s initial review of the December 29,
1999 Environmental Assessment (EA) for the “Town of Clayton Wastewater Treatment Plant
Upgrade” in Johnston County. There are a number of issues that need to be addressed prior to
proceeding to the next level of review. These items are identified on the attached pages. Once
the EA has been amended to address our concerns, please forward eight copies of the document
to me for an internal review by the Department of Environment and Natural Resources.
As a first step in revising the document, the Town of Clayton needs to apply to the NPDES Unit
for speculative limits for the wastewater treatment plant (WWTP) expansion. The NPDES Unit
is aware of the EA and that speculative limits will need to be provided for the EA process to
continue. The NPDES Unit is therefore anticipating a speculative limits request from the Town
for this project and have figured this request into their upcoming workload.
Environmental Assessment (EA) for the
Town of Clayton Wastewater Treatment Plant Upgrade
Johnston County
Michael C. Wicker
Hobbs, Upchurch, and Associates, PA
290 S.W. Broad Street
Post Office Box 1737
Southern Pines, North Carolina 28388
If you need any clarification regarding the comments provided, please contact me at 919-733-
5083, ext. 567.
Sincerely,
Gloria F. Putnam
Environmental Specialist
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Information on prime farmlands is included in the revised EA.Comment 7:
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Predicted
Comment 15: The source for this information has been identified and cited.
Comment 18: The comparative statement has been removed.
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Page Two
December 1 3, 2000
Town of Clayton Environmental Assessment
Comment 10: The reference to the table containing fecal coliform data has been
clarified and labeled.
Comment 11: The information included in the first draft of the EA for the Town of
Clayton covered additional references and data which went beyond the scope of this
current project and its projected effects. The information, which was not relevant to
this particular project, has been removed.
Comment 13: Specific impact statements are included in Section E:
Environmental Effects of the Proposed Project.
Comment 17: The statement claiming that the increase in the Town of Clayton’s
discharge will have insignificant impacts to the use of the Neuse River by the Town
of Smithfield and Johnston County has been supported using current data.
Comment 12: Impacts from the proposed increased discharge from the Town of
Clayton are discussed based on their own significance.
Comment 9: The map referenced by this comment was an older map created prior
to the Town’s discharge point being moved from Little Creek to the Neuse River and
has been removed from the Exhibits Section. The map noted in Comment 1 shows
the location of the current discharge point.
Comment 16: There will not be any pipeline construction other than that which is
contained entirely on the grounds of the WWTP site. This statement has been
removed.
Comment 6: There is only one water body within the area adjacent to the project
site. Detailed information on this stream. Little Creek, is included in the document.
Comments: The various terms used in previous draft have been clarified and all
appropriate terminology has been defined.
Comment 5: Wetlands issues have been clarified in this revised EA. This proposed
project will not impact any wetlands.
Comment 14: The project site area for this proposed expansion project has been
clarified. All construction will take place entirely on the current WWTP site.
Comment 21: The locations of the exhibits are referenced accordingly.
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I Attachments
Page Three
December 13, 2000
Town of Clayton Environmental Assessment
Michael C. Wicker, P.E.
Environmental Division Manager
Comment 24: Based on a review of the most recent data, there are no mollusk
populations in the Neuse River downstream of the Town’s discharge point.
Steve Biggs, Town of Clayton
Tim Simpson, Town of Clayton
James Warren, Town of Clayton
Russell Byrd, Hobbs, Upchurch
Comment 19: The buffer size, as contained in the Town’s Watershed Management
Plan, is the same (minimum of 30 ft.) regardless of the development density.
Additional setbacks, yard footage, and permitted density restrictions are also included
in the Town’s Plan regarding cluster development.
Comment 20: The paragraph regarding wastewater treatment and disposal has been
moved to Section B: Purpose and Need for the Project.
Comment 22: This map has been removed and replaced by those maps denoted in
Comment 1.
Comment 23: A cover sheet with appropriate contact information has been included
in the document.
Sincerely,
Hobbs, Upchurch & Associates, P.A.
Upon review of this revised Environmental Assessment, please contact either myself or
Angie Mettlen of this office immediately if you should have any additional questions or need
more copies of this report. We understand additional copies will be requested upon
completion of your initial review. Thank you for your prompt consideration and review.
February 1, 2001
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Re:
I Dear Mr. Rhodes:
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Associates, P.A.rch,
a:I co:
Attachments
L
Mr. Milt Rhodes
NCDENR-Division of Water Quality
1617 Mail Service Center
Raleigh, NC 27699-1617
Sincerely,
Hobbs, Opel
Angell
Water!
Southern Pines, NC • Telephone [phone] • Fax [phone] • e-mail: [e-mail]
Myrtle Beach • Nags Head • Raleigh • Charlotte
Town of Clayton WWTP Upgrade - Environmental Assessment
Johnston County
HUA Project No. CT9905
xluiT
rater Division
Hobbs, Upchurch & Associates, P.A.
Consulting Engineers
300 S.W. Broad Street • Post Office Box 1737 • Southern Pines, NC 28388
Steve Biggs, Town of Clayton
Tim Simpson, Town of Clayton
James Warren, Town of Clayton
Russell Byrd, HUA-Raleigh
Please find attached eight (8) copies of the revised Environmental Assessment for the Town
of Clayton WWTP upgrade for internal DENR review^ as requested by Mr. Jeff Masten,
SEPA Coordinator. This Environmental Assessment has been prepared for the increase of
the wastewater treatment permit from the existing 1.9 mgd capacity to 2.5 mgd capacity and
has been revised based upon comments received from the Division of Water Quality dated
February 14, 2000. Please note that the wastewater will be tertiary treated in an advanced
wastewater treatment facility and all portions of the proposed project will be constructed
solely on this existing WWTP site. The treated wastewater will continue to be discharged to
the Neuse River. The permitted increase to 2.5 mgd will be requested upon completion of the
EA process. With regard to the prior review of this document, there were 24 comments
noted. Copies of this initial review letter and the subsequent correspondence specifically
addressing each of the comments are also attached for reference purposes.
As you proceed with the internal DENR review of this revised Environmental Assessment,
please feel free to contact me immediately should have any questions or need more copies ol
this report. Thank you for your prompt consideration and review.
CT9905
EXECUTIVE SUMMARY
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Town of Clayton
Environmental Assessment for
The expansion will involve minor modifications to existing structures and equipment at
the existing wastewater treatment plant located next to Little Creek near US 70 in the
Town of Clayton. The construction on this previously disturbed ten-acre site should
disturb less than one acre. An engineering study by Hobbs, Upchurch & Associates, P.A.
indicates that the existing wastewater treatment design is capable of treating 2.5 mgd to
the expanded permit limits with minor modifications to pumps, plant piping and
hydraulics, aeration capacity and treatment unit optimization without extensive
construction activities.
An alternatives analysis including do nothing, land application, conveyance to the City of
Raleigh wastewater treatment system, and conveyance to the Johnston County
wastewater system were evaluated in addition to the selected alternative. The alternative
selected is the most cost effective, environmentally feasible alternative.
The increase in the permitted capacity will not have any significant effects on the
environment.
The Town of Clayton located in Johnston County, NC is proposing to increase their
existing NPDES permit discharge NC0025453 from 1.9 mgd to 2.5 mgd. The existing
discharge from their wastewater treatment plant is located on the Neuse River, WS-IV
NSW CA between SR 1700 and NC 42 in northwest Johnston County.
^^TP Expansion
CT9905
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Town of Clayton
Environmental Assessment for P Expansion
The Town Council of the Town of Clayton retained the firm of Hobbs, Upchurch and
Associates to prepare an amendment to the existing NPDES permit. Clayton is served by
one wastewater treatment plant owned and operated by the Town with discharge into the
Neuse River. This plant currently serves the Clayton Municipal Limits, the east Clayton
industrial area, the East Clayton Elementary School area and collection facilities which
serve the to the I40/NC 42 interchange area, and the Cleveland Community (service
area). This expansion project will service this same area.
The facility averaged 1.35 mgd in 1998, which is approximately 72% of the permitted
capacity. The facility averaged 1.32 calendar year 1999, which approximately 69% of
the permitted capacity. The evaluation of the existing treatment units predicts that the
effluent limits can be achieved with the existing treatment at the increase of flow to 2.5
mgd with some additional improvements to the facility.
The recommended improvements consist of the following and will be constructed
entirely on the existing WWTP site:
Improvements to the Influent Pump Station and Headworks Structure
Increased Aeration and mixing in the existing Oxidation Ditches by the addition of one
new aerator and new effluent weirs
Improved Hydraulics and Baffling in the existing Clarifiers and relocation of Polymer
feed lines to aid in settling
Increase Sludge Pumping Capabilities in the existing Sludge Return Pump Station and
retum/waste lines
Evaluation of the incorporation of the existing clarigester, trickling filter and clarifier as a
nutrient removal units. A Study has been completed on further means of biological
nutrient removal by the construction of additional treatment units as well evaluation of
reuse water on adjacent golf course property to reduce the TN loadings in the effluent.
These proposed nutrient removal projects are for later consideration and are not part of
the proposed project considered in this EA. Improvements to the mixing and aeration in
the oxidation ditches will be incorporated into the nutrient removal design.
Except for the above recommendations, no further improvements appear to be needed to
increase the design size of the WWTP to 2.5 mgd. The effluent pump station, force main
and gravity outfall are already capable of the increased capacity.
Following presentation of the report, the Town of Clayton Town Council authorized the
preparation of an environmental assessment and application for an NPDES permit
increase to 2.5 mgd in order to address future wastewater treatment and disposal for the
Clayton waste water service area. The objectives of the amendment to existing permit are
to develop a plan for achieving compliance with receiving stream effluent limits or
otherwise dispose of the Town’s wastewater and to accommodate growth in the Clayton
wastewater service area while minimizing the impact on the environment.
PURPOSE AND NEED FOR THE PROPOSED PROJECT
CT9905
HUA Page 4 12/13/00
An agreement between the Town of Clayton and Johnston County is intended to permit
the Town and the County to effectively utilize their respective wastewater treatment
capacities. The agreement states that the Town of Clayton can divert up to 600,000 gpd
of wastewater flow from the East Clayton Industrial Park to the county system and in
return will receive a similar daily quantity of wastewater flow from the western 140/142
interchange area portion of Johnston County.
The Clayton service area is defined by two major drainage basins, the Little Creek basin
and the Neuse River basin. After examination in a 1997 study by McKim and Creed of
existing users, zoning, current land use and development patterns in and surrounding the
Town of Clayton, it was determined that the major contributions to long-term growth will
be primarily from residential development and secondarily from industrial expansion.
The service population in 1997 was approximately 11,250. Industrial locations are found
mainly along the US Highway 70 corridor with the most prominent being the East
Clayton Industrial Park.
Town of Clayton
Environmental Assessment for WWTP Expansion
Johnston County owned facilities currently serve the I40/NC 42 interchange area, which
is comprised predominantly of light commercial developments and several residential
subdivisions. Wastewater flows from this area are transported by Johnston County
owned utilities to the Town of Clayton’s wastewater treatment plant. In trade for this
treatment of flow, the County transports wastewater from the East Clayton Industrial
Park to the Johnston County regional wastewater treatment plant located in Smithfield
during periods of peak flow. The Glen Laurel residential development and the Caterpillar
industrial site are also jointly utilized by both facilities.
The last population projections from the State of North Carolina indicate that Johnston
County grew from a population of 81,306 in 1990 to 99,215 in 1996. The estimated
population in 2016 is 141,563. The Town of Clayton grew from a population of 4,756 in
1990 to 6,810 in 1996. Using the same growth rate of approximately 43%, the Town’s
An amendment to the 201 Facilities Plan was prepared by McKim and Creed on behalf of
the Town of Clayton in 1993 and an expansion from 1.5 mgd to 1.9 mgd with tertiary
treatment was designed and bid. The Little Creek Water Reclamation Facility was
expanded and upgraded in 1987 to 1989 and again in 1998 to 1999 with the all the new
facilities commissioned in May1999. The scope of improvements were consistent with
the Clayton 201 Wastewater Facilities Plan, and the treatment facilities were planned to
provide adequate service to Clayton and its environs through the year 2007. Explosive
growth in Wake County, and its attendant effect in western Johnston County have
resulted in the treatment facilities nearing their design capacity much sooner than has
been forecast. In addition, the anticipation of much more stringent effluent limitations
for receiving streams in the Neuse River Basin have necessitated the comprehensive
review and evaluation of wastewater treatment and disposal options for the Town for the
foreseeable future.
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CT9905
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12/13/00Page 5HUA
2016 projected population would be 9,738. The County growth is occurring rapidly in
the I40/NC42 and Cleveland Community, which are also served by the Clayton system.
Town of Clayton
Environmental Assessment forwBl' T P Expansion
The existing NPDES permit allows a 1.9 mgd discharge of tertiary treated wastewater to
the Neuse River at a point between SR 1700 and NC 42. The Neuse River is classified as
WS-IV NSW CA in this area. The summer 7Q10 for the Neuse River is 186 cfs at this
location. The City of Raleigh WWTP discharge is approximately 9 miles upstream and
As more people live and work in the Neuse River Basin, more wastewater will continue
to be generated. Treatment and disposal of this wastewater will be accomplished either
by enlarging or creating more wastewater treatment plants or by constructing more on­
site wastewater systems such as septic systems. Because the basin s surface waters have
a limited capacity to assimilate wastewater, the level of treatment at wastewater
treatments will need to continue to improve in order to hold the line on the amount of
pollutants leaving the plants as the flow of wastewater to them increases. Also, while on­
site wastewater systems can provide a very effective means of disposing and treating
wastewater from individual homes or commumties, they can also pose environmental
risks if not properly installed and maintained.
The design capacity of the LCWRF, and its current permitted flow rate, are set at 1.9
MGD. The influent flow to the LCWRF for averaged 1.35 and 1.32 MGD, respectively
in 1998 and 1999. This is 69 to 71 percent of its permitted capacity. When the influent
flow reaches an annual average of 80 percent of the plants capacity, or 1.52 MGD at the
currently permitted flow capacity, the Town must begin planning and design of new
capacity in order to avoid a moratorium or other actions. Once the Town begins such a
process, they can apply for a waiver to allow the plant to accept up to 90 percent of its
currently permitted flow rate or 1.71 MGD. Additionally the Raleigh Regional Office of
the DWQ has expressed concern that sewer permit allocations to the LCWRF are
approaching 100% of the permitted capacity. While it may be several years before these
allocated flows become actual flows, DWQ has chosen to withhold additional sewer
permits at such time as 100% of the capacity is allocated. At the current growth in the
system the Town has 2 - 3 years in which to plan and develop additional flow capacity.
The purpose of this environmental assessment and NPDES permit expansion is to begin
the rerating of the existing WWTP to the expanded capacity of 2.5 mgd. The engineering
evaluation by Hobbs, Upchurch indicate that the existing facilities with minor
modifications are capable to treat to this design flow. By achieving this expansion with
existing facilities the Town of Clayton should be able to continue serving the expected
growth within the next 2-3 year period during which the Town can begin a full 201
Facilities Plan Update for a 20 year plan for wastewater needs. The purpose of the 201
Facilities Plan study will be to determine the most cost effective means for future
wastewater treatment and disposal which will meet water quality standards and
accommodate future growth of the Clayton wastewater service area.
CT9905
Monitor
c.ALTERNATIVES ANALYSIS
HUA Page 6 12/13/00
The following speculative effluent limits (dated July 10, 2000) have been given for the
expanded wastewater treatment facility by the Division of Water Quality:
Town of Clayton
Environmental Assessment for WWTP Expansion
Speculative Effluent Limitations
(2.5 MGD Flow)
: J
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Monitor
Monitor
Monitor
BODs mg/I
NHj-N mg/1
DO mg/1
Fecal Coliform per 100 ml
TSS mg/1
Total Residual Chlorine ug/1
Cadmium ug/I
Chromium ug/1
Copper ug/1
Nickel ug/I
Lead ug/1
Zinc ug/1
Silver ug/1
Cyanide ug/1
Total Phosphorus mg/1
pH NTV
Winter
To
2
6
200
30
28
Neuse River
Summer
5
1
6
200
30
28________
Monitor
2
6-9
2
6-9
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the City of Smithfield Water Plant intake is downstream in the critical area designation of
the River.
A Total Nitrogen Limit of 21,400 Ib/year is given as a mass loading on annual basis for
the Town. The mass limit may be waived if the Town is a member of an approved
trading coalition for the Neuse River Basin. Per the Neuse River Basin Rules, the
expansion of the WWTP would also result in a Total Phosphorus limit drop to 1 mg/1
unless the Town is a member of the Association. A copy of these Speculative Limits is
included as Exhibit 3.
An alternatives analysis for the wastewater treatment options has been considered for the
Town of Clayton. The 201 Facilities Plan amended in 1993 by McKim and Creed on
behalf of the Town of Clayton addressed several of the options at such time and
concluded that the best alternative for the Town was the upgrade and expansion of the
existing facility with a discharge to the Neuse River. The wastewater treatment facility
CT9905I’TP Expansion
I 1. Do nothing (no action).
2.
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I 5. Modify the existing wastewater treatment facility for preliminary treatment and flow
equalization (only) and discharge into the City of Raleigh wastewater treatment plant.
I 6. Modify the existing wastewater treatment facility for preliminary treatment and flow
The following alternatives have been considered for this expansion request:I
1. Do nothing (no action).
2.
12/13/00Page?HUA
I
Town of Clayton
Environmental Assessment for
equalization (only) and discharge into the Central Johnston county Regional
Wastewater Treatment Plant (CJCRWWTP).
3. Modify the existing wastewater treatment plant and convey to a separate site(s) for
equalization and disposal by land application.
was expanded to 1.9 mgd with an additional 0.6 mgd diverted to the Johnston County
Wastewater Treatment Plant. Both the Clayton and Johnston County wastewater service
areas have seen tremendous growth and are approaching their capacity. Some of the
same alternatives have been considered for this WWTP expansion as previously
considered in 1993. The following general options for wastewater treatment and disposal
were considered in 1993:
4. Divert flow as necessary from the east Clayton area to the Central Johnston County
Regional Wastewater Treatment Plant, and upgrade and expand the Clayton WWTP
to treat the remaining waste stream and discharge to the Neuse River with effluent
limits of 10/4/2 and future effluent limits of 5/2/2.
In 1993 alternative number 4 above was the selected alternative. All of the recommended
improvements in the 1993 analysis were completed in 1999. Despite this implementation
the WWTP flows are approaching the permitted limit and additional analysis is required.
Optimize operation of the existing wastewater treatment plant and continue to
discharge to the Little Creek with initial effluent limits of 10/4/2 and future effluent
limits of 5/2/2.
Divert flow as necessary from the east Clayton area to the Central Johnston County
Regional Wastewater Treatment Plant, and upgrade and expand the Clayton WWTP
to treat the 2.5 mgd of the remaining waste stream and discharge to the Neuse River
with effluent limits of 5 -' = /<- 8»t>5 1 '■’□Tw Cs--'—'J; •«
3. Modify the existing wastewater treatment plant and convey to a separate site(s) for
equalization and disposal by land application.
CT9905
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Town of Clayton
Environmental Assessment for WWTP Expansion
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The second option of optimizing operation of the existing wastewater treatment plant is
currently being accomplished. The evidence indicates that the facility will meet current
and immediately renewed NPDES permit limits at the proposed design flow capacity of
2.5 mgd. This option continues to divert 600,000 gpd to the CJCRWWTP from the
industrial area while continuing to serve the Town of Clayton residential and commercial
district and the additional flow from the County residents and commercial enterprises
near Cleveland. The flow rating of the WWTP would be increased to 2.5 mgd. This
option will be a “stopgap” measure to allow the Town to continue planning for longer
term needs without the expenditure of significant Town resources.
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The first option of no action is not acceptable to the Clayton Town Council due to the
inevitable restrictions on residential, commercial, and industrial growth in the Town’s
wastewater service area, and a risk of future NPDES permit renewals with more stringent
limits than the current facilities are capable of achieving. As previously stated, the Town
of Clayton is within 2-3 years of achieving flow rates, which would result in sewer
moratoriums in the area.
4. Modify the existing wastewater treatment facility for preliminary treatment and flow
equalization (only) and discharge into the City of Raleigh wastewater treatment plant
5. Modify the existing wastewater treatment facility for preliminary treatment and flow
equalization (only) and discharge into the Central Johnston county Regional
Wastewater Treatment Plant (CJCRWWTP).
The fourth option involves conversion of the existing Town of Clayton wastewater
treatment plant to a pump station and flow equalization facility and construction of a
The third option of land application was evaluated extensively in the original 201
facilities plan. Exhaustive efforts were made to locate adequate disposal sites in the 201
area. Although site characteristics were conducive to the actual disposal design criteria,
it was impossible to locate sufficient land area within an approximate 5 mile distance of
the Town on even a semi-contiguous basis, i.e., perhaps half the land area in one site and
the remainder distributed among two or three separate sites in reasonable proximity.
Further, at that time given the flow projections and then anticipated application rates, the
amount of land to be located was approximately half of what would be required at this
juncture. Accelerated residential development demand pressure has made the land in the
Clayton area even more expensive and more difficult to obtain and locate. Therefore, the
viability of this option is virtually nil. As an illustrative example land application of
wastewater at 1” per acre per week requires approximately 750 acres of wetted area to
irrigate the entire amount necessary to eliminate the discharge. Additionally 225 million
gallons of storage lagoons would be needed to store wastewater during inclement
weather. The recent example of the Town of Gamer land application treatment facility
being closed to divert their wastewater to the City of Raleigh system indicates the
unattractiveness of this option to an area where residential growth is utilizing desirable
land.
CT9905
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12/13/00Page 9HUA
Town of Clayton
Environmental Assessment for Expansion
The wastewater plan options have been thoroughly reviewed and analyzed on the basis of
environmental impact and cost. The options of no action at the existing wastewater
treatment plant are not viable in that the effluent limits cannot be achieved while
accommodating imminent growth and sewer service demands, and the Town would be
subject to citations and penalties.
The most cost effective alternative is to continue to divert the east Clayton area flows to
the Johnston County wastewater treatment facilities and upgrade the Town of Clajrton
WWTP to 2.5 mgd for treatment and discharge to the Neuse River. The minor
modifications necessary to the Town of Clayton WWTP result in a much lower cost than
the other alternatives evaluated. These figures evaluated in order to arrive at this
conclusion are included as Exhibit 4.
The fifth alternative is similar to alternative 4 in that the treatment plant would be
converted to a pump station and flow equalization facility and raw wastewater would be
conveyed to the Central Johnston County Regional Wastewater Treatment Plant.
Required improvements would include expansion of the influent works and preliminary
treatment and modifications to the influent pump station, construction of approximately
twelve miles of 16” force main and one mile of 30” gravity interceptor sewer and a
metering and chemical addition station. The routing would generally follow US Rt. 70 to
the Neuse River at Smithfield. The existing Neuse River interceptor sewer has
insufficient capacity for this additional flow, which necessitates the parallel new 30
interceptor sewer. In addition the Central Johnston County Treatment Plant would
require upgrading and expansion to accommodate the additional flow at more stringent
effluent limitations, (5 mg/1 BOD, 21 mg/1 ammonia nitrogen, and 1 mg/1 total
phosphorous), that would be occasioned by any request for flow increase. This facility is
also experiencing growth and the agreement with the Town of Clayton and Johnston
County to trade flow during peak flow periods appears to be the best cooperative
arrangement at this time.
force main to the City of Raleigh Neuse River wastewater treatment plant. Modifications
at the plant would consist of expanding the influent works and preliminary treatment, and
modifying the influent pump station. Conveyance to Raleigh would include
approximately nine miles of 16” force main and a metering and chemical addition station.
In addition, a one time capital charge payable to the City of Raleigh is required to reserve
treatment capacity. Discussions with the City of Raleigh regarding the diversion of Town
of Clayton wastewater have proven unsuccessful. In addition the costs of this alternative
are higher than the costs of the proposed expansion at the Town of Clayton wastewater
treatment facility. This alternative was considered and rejected in the 1993 analysis as
well.
An assessment of the impact of the proposed project on the environment has been
completed. Long-term impacts from the project appear to be positive or non-detrimental.
CT9905
D.EXISTING ENVIRONMENTAL CHARACTERISTICS
and
1.Topography
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Town of Clayton
Environmental Assessment for WWTP Expansion <i
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The following sections will discuss the existing environmental characteristics of Johnston
County, the Town’s wastewater service area, and the Wastewater Treatment Plant
(WWTP) site. The proposed expansion project will consist of construction activities
located solely on the grounds of the existing WWTP (project site). A map illustrating
the locations of the Town limits, extraterritorial limits and utility service area is
included as Exhibit 5. An additional map showing the location of the WWTP
the discharge point to the Neuse River is included as Exhibit 6.
Most of the county is in the Neuse River basin. A considerable part of the county,
however, is actually drained by the major tributaries of the river. Some of the tributaries
have headwaters outside of the county. Most of the county is well drained. Several
areas, however, are generally poorly drained. They include areas east of Smithfield,
between Stancil’s Chapel and Kenly, east of Benson and in the Neuse River valley and
other large stream valley.
Short-term impacts during construction involving dust, noise, and air quality will be
mitigated by careful design, and construction methods and procedures.
Elevation ranges from 75 feet above sea level, where the Neuse River leaves the county
at the Wayne County line, to more than 370 feet at the North Carolina State University
Experiment Station, which is near the Wake County line. Relief varies considerably.
The Neuse River bottom has very little relief. The large interstream areas in the eastern
and southern parts of the county also are nearly level and have low relief. Relief varies
from 20 to 60 feet along the edges of the stream valleys that dissect these areas. In the
northern and western parts of the county, the interstream divides are relatively narrow
and relief in the adjoining stream valleys varies from 50 feet to more than 150 feet.
Soils in the Piedmont region formed in the residues of crystalline bedrock. Soils in the
Coastal Plain region formed in sediments deposited several million years ago by the
ocean and streams. The flood plains along the Neuse River consist of relatively recent
deposits of sediments that are not as highly weathered as the sediments in the Coast Plain
region.
About 65 percent of Johnston County is in the middle and upper parts of the Southern
Coastal Plain physiographic region. The northern 20 percent of the county is in the
Southern Piedmont physiographic region. The area of transition between the two regions
is known as the “Fall Line.” About 15 percent of the county is on the flood plains and
terraces along the Neuse River and its tributaries.
Clayton s service area lies along the “fall-line,” the ill-defined border between the
Piedmont and Coastal Plains provinces. Thus, there is much about the appearance of the
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Environmental Assessment for
Felsic igneous comples
Mica Gneisses and schist
Coast plain sediments
Floodplain alluvium
The first category is igneous (volcanic) origin; the second, metamorphic; and the third
and fourth are sedimentary deposits.
Geology and Mineral Resources
The geology of the Clayton service area can be classified into four categories:
The “mica gneiss and schist” complex into which the granite intruded was originally a
volcanic-sedimentary sequence that varied greatly in type, composition, and areal
distribution, and is probably of early Paleozoic Age. This complex also included some
slates. (“Schist” refers to metamorphic rocks which have a banded or layered structure;
The surface drainage of the Clayton service area can be classified as good, because of the
available relief and well-drained soils. Only limited areas immediately adjacent to the
Neuse River and Little Creek are subject to natural flooding or could be classified as
poorly drained.
The following discussion is excerpted and summarized from N.C. Department of Water
Resources Ground-Water Bulletin No. 2, Geology and Ground Water in the Goldsboro
Area, North Carolina.” By Richard D. Pusey (1960); and N.C. Department of Natural and
Economic Resources Report “Region J Geology: A Guide for North Carolina Mineral
Resources Development and Land Use Planning,” W.F. Wilson and P. A. Carpenter,III
(1975).
area that would be characteristic of either region. There is a considerable portion of the
area that can be characterized as broad ridges with very moderate slopes, while on the
other hand immediately off the broad ridges and intruding into the ridges are narrow
eroded areas having steep slopes. Thus the topography does in many places change
dramatically within a fairly short horizontal distance. Relief between hill tops and valley
floors is approximately 200 feet within the wastewater service area. This is generally
greater than for the surrounding areas, particularly that to the east. The area slopes in
general toward the southeast at approximately 10 feet per mile. A composite
topographic map is included as Exhibit 7.
The “felsic igneous complex” is a granite intrusion into mica gneiss. This intrusion is
probably of Paleozoic Age (190 to 400 million years ago). The granite is fairly resistant
to erosion and forms an upland of knobby hills covered by a thin veneer of saprolite (soil
residual formed by weathering rock). The granite is medium-grained to porphyritic
(containing larger crystals within fine-grained structure). This formation is itself intruded
by several diorite (a dense igneous rock) dikes, particularly south of Clayton. These
intrusions are probably of Triassic Age (155 to 190 million years ago).
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There is one active National Weather Service daily weather station in the wastewater
service area, which is located at the Agricultural Experiment Station west of Clayton near
the Wake County Line. This station was established in the mid 1950’s and has
continuous record since then. Although outside the wastewater service area, there is
schistose rock of igneous origin is called “gneiss.”) There is a variation in weathering
resistance of the complex, with the gneiss portion being more resiliant. The complex
slopes to the southeast at the rate of 10 feet per mile, and passes beneath coastal Plain
sediments in the southern part of Johnston County.
Climate
The climate of Johnston County, including the Clayton service area and the WWTP site,
can be categorized as temperate and humid. Mean annual temperature is approximately
61 °F, varying from a mean a minimum of 31°F in January to a mean maximum of 85° in
July. The average number of frost-free days is approximately 210. Typical annual
extremes are several days at or near 10°F in the winter and several days at or near 100°F
in the summer. The daily variation in temperature is typically around 20°F. The mean
annual humidity is approximately 70%, which, of course, varies daily with temperature,
although there is not much seasonal variation.
The Clayton WWTP site and outfall pipeline corridor to the Neuse River lie within the
transition zone between the Piedmont and coastal Plain physiographic provinces.
Features typical of both the Piedmont and Coastal Plain provinces are represented in the
area. Elevations vary from 330’ (msl) on the ridge on which Clayton is situated to 130’
(msl) at the Neuse River. Throughout this area, erosion has altered the original relief.
Most of the area is gently rolling to steep but depositional areas along streams are flat.
The natural surface drainage is generally medium to rapid and drainage tends toward the
northeast and south. Intersections occur with Little Creek and an unnamed creek, which
drains the east side of the Town of Clayton, their minor tributaries or upper watershed
drainage depressions, and the Neuse River.
The Coastal Plain sediments are of marine or alluvial terrace origin, and are of uncertain
age (post-Miocene). They are buff-colored, unconsolidated sands interlayered with clays
and containing some beds of predominantly quartz gravel. These deposits are only
several feet thick at their interface with the older rock formations, but they deepen rapidly
toward the south, attaining a depth of 60-90 feet in the extreme south of Johnston County.
Floodplain alluvium consists of all those materials deposited in the floodplain by periodic
flooding, which in this area consists of a fairly narrow corridor each side of the stream.
This material can be classified as dark brown to gray silt, sand, and clay with some
gravels and coarse boulders occasionally intermixed.
There have been no known mining or quarrying operations within the Town’s service
area or the WWTP site, and there are no known mineral concentrations of commercial
value other than potentially some sand/gravel or crushed stone for road building.
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Mean
Temp. (°F)
Avg. Max
Temp. (°F)
Avg. Min.
Temp. (°F)
Avg.
Rainfall
(In.)
RMS
Rainfall
(In.)
44
44
52
61
70
77
79
78
72
62
51
45
61
54
54
63
65
76
81
85
82
79
74
60
54
31
35
42
53
65
72
75
74
67
56
45
35
3.52
3.67
3.82
3.71
3.50
4.58
6.20
5.65
4.19
2.90
3.04
3.24
48.02
January
February
March
April
May_____
June
July
August
September
October
November
December
Annual
another active station at the Smithfield water plant, approximately 12 miles to the
southeast, with continuous record of approximately 57 years. The following table
summarized temperature and rainfall data for the Smithfield weather station.
1.5
1.7
1.5
1.8
1.6
2.6
3.0
3.3
2.3
2.8
1.9
1.5
Cloud cover is present during the majority of the year, which has a moderating effect on
temperatures. Approximately 107 and 142 days per annum are classified as "partly
As can be seen, both the average rainfall and variability are greatest in the summer and
early fall months, which reflect the fact that this rainfall is primarily from thunderstorms.
Thunderstorms, of course, are fairly limited in area so that the chance of receiving rainfall
from a particular storm at a particular point are much less than from a regional storm
system. The late summer and early fall rainfall variability also reflects seasonal variation
in regional storm systems originating from humcanes or other tropical depressions. The
data for the late fall, winter and spring months reflect the fact that this rainfall is
primarily from regional storm systems for which there is less areal and seasonal
variability in rainfall. The regional storms are primarily a result of frontal conflicts
between cold Canadian air with warm moist air from the Gulf. Due to the nature and
variability of the summer rainfall, and to greatly increased evaporation-transpiration due
to the rise in temperature, the summer months do not contribute to stream flow in any
way proportionate to the monthly rainfall averages. The traditional wet months are
December through May. Late September, October, and early November are the
traditional “drought” months (as can be seen from the October data, there is a fair chance
of having no rainfall in this month). Precipitation in the form of snow and sleet occurs
only for a few days each winter. Precipitation in amounts greater than a trace occurs
approximately 113 days each year, of which about 45 days have thunderstorm activity.
About 34 days have heavy fog.
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2.Soils
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Norfolk—Wagram Association
Appling—Louisburg Association
Chewacla—Wehadkee-Roanoke Association
The soils in the Clayton service area can be classified into four distinct categories
(following the SCS series):
cloudy” or “cloudy” respectively, leaving approximately 116 as “clear” days. The
prevailing wind is from the south-southwest at about 8 mph.
Town of Clayton
Environmental Assessment for WWTP Expansion
Included as Exhibit 8 are general soil maps of Johnston County and of the Clayton
service area. This mapping and the following discussion are taken largely from the
“General Soil Map, Johnston County, N.C.,” a publication of the Johnston County office
of the Soil Conservation Service.
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An examination of the soils is necessary to project the future development potential of an
area. Factors such as impermeable soils, high groundwater tables, hydric soils and
wetland areas affect the potential use of the land and therefore the projected waste water
needs. Some of Johnston County is considered swamp or wetland area and the
surrounding areas have high groundwater tables. These areas are limited for building
development because of structural conditions and limited ability of septic tanks to treat
individual domestic waste. These areas would need to be serviced with sanitary sewer or
the density requirements of growth will be limited. The following summaries from the
county soil surveys and the accompanying maps of the soils of the counties highlight the
areas were future development is possible and where development is limited.
Wastewater projections can thus be more clearly defined in these areas.
The Appling—Cecil Association covers the majority of the Town’s 201 Facilities
Planning Area. It was derived from the gneisses and schist, and is typical soil of the
Piedmont province. These soils are deep and well drained. They have moderate
permeability and susceptibility to erosion. Typically topography is rolling dissected hills.
The Appling soils make up about 35 percent of the association. They have light colored
sandy loam surfaces over yellowish red to yellowish brown firm clay subsoils, and
reoccur on ridges and gently sloping to moderately steep sideslopes. The Cecil soils
make up about 30 percent of the association. They have brownish colored sandy loam
surfaces over red firm clay to loam to clay subsoils, and occur on ridges and gently
sloping to steep sideslopes. Norfolk soils make up 15 percent of the association. They
have loamy sand surfaces over yellowish brown friable sandy clay loam subsoils, and
occur on ridges and on nearly level to sloping sideslopes. These soils are well suited for
agricultural production (tobacco, cotton, com, small grain, lespedeza, and pasture). They
are suitable for septic tank drainage systems with moderate limitation due to local
variances in permeability and slopes.
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Environmental Assessment for
The Town of Clayton WWTP site is located next to Little Creek, adjacent to the Town of
Clayton Cemetery on PaD, Pacelot soils which percolate slowly because of clay content.
^^TP Expansion
In summary, the great majority of the soil in the Clayton service area is well suited either
for agriculture or for urban or suburban development, although there may be local
variations due to slope or permeability for septic tank systems.
The Appling-Louisburg Association is confirmed primarily to the area immediately
adjacent to the river. It is derived from the gneisses and porphyritic granite, and is typical
of the Piedmont province. These soils are in general shallower than the Appling—Cecil
Association, and may have rock outcrops. They are well to excessively drained, have
moderate to rapid permeability and moderate susceptibility to erosion. The Appling soils
have been discussed previously. The Louisburg soils occur on moderate to steep slopes.
They have brown stoney sandy loam surfaces, and stoney sandy loam subsoils, light
yellowish brown in the upper part and yellowish brown in the lower part. Below the
subsoil is partially decomposed light yellowish brown gneiss and gramte rock. These
soils occur on slopes ranging from 6 to 50 percent. The soils in this association are
generally considered good for agriculture and are suitable for septic tank drainage
systems where local variations in permeability and slope permit.
The Chewacla—Wehadkee—Roanoke Association is confined primarily to the river
stream bottomlands since it is derived from flood-bourne sediments. These are generally
poorly-drained unconsolidated sands and clays. They are moderately to slowly
permeable and have slight to moderate resistance to erosion. In Johnston County about
40 percent of this association is made of Roanoke soils, which have loam surfaces over
gray firm to very firm clay subsoils. Wehadkee soil makes up another 20 percent of the
association. They have sandy loam surfaces over gray friable sandy clay loam subsoils.
Most of this association is in forest. The soils being subject to overflow have poor
drainage and it is difficult to obtain suitable drainage outlets. Thus the use of these lands
has severe limitations for all urban uses.
The Norfolk-Wagram Association covers the bulk of the remaining area. It is derived
from coastal sedimentation and is typical of the upland Coastal Plain province. These
soils are deep and are well-to excessively-drained. They have rapid to very rapid
permeability and slight to moderate susceptibility to erosion. Typical topography is flat
top divides and gentle to moderate slopes. The Wagram soils make up about 60 percent
of this association. They have light colored loamy sand surfaces, 20 to 40 inches thick,
over yellowish brown friable sandy clay loam subsoils, and occur on nearly level ridges
and gently sloping to sloping short side slopes. The Norfolk soils discussed above make
up about 30 percent of the association. The sand surface is normally less than 20 inches
thick. These soils are well suited for agriculture production (tobacco, cotton, com,
peanuts, small grain, and pasture), especially tobacco. They are subject to wind erosion.
They are suitable for septic tank drainage systems with only slight limitations.
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3.Land Use
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Environmental Assessment for WWTP Expansion
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The Town of Clayton’s population grew from a 1990 population of 4,756 to 6,810, a 43%
growth. Using the same growth rate predicted for the County projects the Town
population to close to 10,000 in 2016.
In 1777, the town of Smithfield was established by an act of legislature on the site of the
farm of Captain John Smith. The farm had been an important center for the tobacco
trade. Tobacco was shipped by barge down the Neuse River to New Bern and then was
shipped to England. The town is still an important center for the tobacco industry.
Johnston County was the scene of the last major battle of the Civil War. The battle was
fought in the Bentonville area, which is in the southern part of the county.
Johnston County is in the east-central part of North Carolina. The County has a total area
of 510,138 acres, or 797 square miles. This total includes 1,075 acres of bodies of water
larger than 40 acres. About half of the land area is used as farmland. About 52 percent
of the county, or 265,344 acres, meets the requirements for prime farmland. Areas of
prime farmland are scattered throughout the county but are mainly in the Norfolk-
Goldsboro-Rains general soil map unit.
History and Development
The Tuscarora Indians were the original inhabitants of the Johnston County area. Settlers
from England did not arrive in significant numbers until after the Tuscarora were
defeated in battle by the British in the early part of the 18th century. The county was
organized in 1746 from Craven County. It was named in honor of Gabriel Johnston, a
former royal governor of the colony. Originally, it had a much larger land area than it
does now. It extended as far east as Kinston and as far west as Reidsville.
In 1980, the County had a population of 70,599, mostly in rural areas. One-third of the
population was in the nine towns in the county. Smithfield, the largest town and county
seat, had a population of 7,288. Selma had a population of 4,762; Clayton, 4,091;
Benson, 2,792; Kenly, 1,433; Four Oaks, 1,049; Princeton, 1,034; Pine Level, 935; and
Micro 438 (21). Raleigh, the State capitol, is about 30 miles west in Wake County. In
1990 the population of Johnston County grew to 81,306 and by 1996 to 99,215. This
growth rate of 22% is expected to continue with a projected 2016 population of 141,563.
Much of this growth will occur in western Johnston County near Clayton and the
Cleveland area because of the urban influence of the City of Raleigh.
Until the middle of the 19th century, Smithfield was the only significant town in the
county. The other towns developed later, mainly as stops along the railroad.
Construction of the railroad began prior to the Civil War.
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Town of Clayton .
Environmental Assessment for
Within the geographic area encompassing the Clayton service area, there are only two
existing units of local government which have legal authority to own, operate, and
maintain publicly owned waste treatment works: the Town of Clayton and the County of
Johnston.
The County of Johnston has financed the sewer collection and pumping facilities for the
outside industries. The County has legal authority to own, operate, and maintain public
sewer facilities in any portion of the County, incorporated or unincorporated. It is the
only existing unit of government, which could provide wastewater collection and
treatment services throughout the entire area.
The Town of Clayton, at present, operates and mainUins all of the publicly owned
wastewater collection, interceptor, and treatment system. The Town, in fact, owns all of
the system except for collection and pumping facilities serving the outside industries.
The Town’s collection system serves the majority of the incorporated area. The Town
has legal authority to provide sewer service to areas outside of Town only if: 1) The
facilities were financed privately and dedicated to the Town; or 2) the out-of-Town
A I P Expansion
Until the 20th century, agriculture and lumber were the only industries in the county.
During the early part of the 20th century, a few textile mills were established in some of
the towns. Agriculture did not become highly mechanized until after World War II. This
mechanization caused a sharp decrease in the number of persons employed on farms. It
did not, however, cause a significant decrease in the population of the county because
new industries moved into the county. These industries created new jobs for those people
that were displaced from farm work.
The Johnston County Health Department has authority under state statutory to regulate
septic tank systems of 3000 gpd or less throughout the entire County. The Health
Department has promulgated local regulations, which are empowered through County
ordinance. Approval for residential developments (subdivisions, mobile home parks, and
housing developments) requires a soils survey by the Soils Conservation Service, a
topographic survey, and percolation tests. Lot sizes are required to be 40,000 square foot
minimum for dwellings served by on-site wells (10 or more lots) and 20,000 square foot
minimum for dwellings served by community water supplies. Lots with slopes exceeding
15 percent are prohibited. (The Health Department also regulates the construction of on­
site water systems. Community water systems, defined as serving 10 or more
connections, are regulated by the North Carolina Public Water Supply Section.)
The population of the county increased by over 17,000 from 1960 to 1987. About 80,425
people lived in the county in 1987. Urbanization is increasing in the county and will
undoubtedly continue to increase. It is the result of increased industrial employment; the
convenient location of major transportation corridors such as Interstate 95, Interstate 40,
and U.S. Highway 70; and the close proximity of the county to Raleigh and the Research
Triangle Park. Many persons who live in Johnston County commute to work in Raleigh
or at the Research Triangle Park. Most of the new housing in the county is in the
northern and western parts of the county near the Wake County line.
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4.Wetlands
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Environmental Assessment for WWTP Expansion
has legal authority to provide sewer service to areas outside of Town only if: 1) The
facilities were financed privately and dedicated to the Town; or 2) the out-of-Town ‘
facilities were a necessary part of the facilities serving the in-Town population, or were
shown to be profitable and passed by referendum of the incorporated voters, in which
case the Town’s general tax funds could be used for construction.
In the area outside the Town’s extra-territorial limits, the County of Johnston has
authority to regulate subdivison of land and enforce the building code. It also has
authority to zone, but does not do so. Building Code enforcement is limited to permitting
and inspection of electrical and insulation construction. The County also enforces a
Mobile Home Park Ordinance, which outlines requirements for streets and parking,
mobile home spaces (including tie-down provisions), and utilities (including refuse
collection and street lighting). The County also enforces a Flood Damage Prevention
Ordinance, which requires permits and flood-proofing provisions for all structures
proposed within designated flood-prone areas in the unincorporated portion of the
County.
Wetlands provide a variety of functions and values, which are important to environmental
protection and enhancement. Historically, wetlands have been considered unimportant or
worthless. Much of the time they were considered useful only when drained or filled.
During the last 20 to 30 years, scientists and policy makers have become more aware of
the values of wetlands to landowners and the general public. These values include water
storage for flood protection, bank/shore line stabilization to prevent erosion, pollutant
removal through settling and filtration, wildlife habitat enhancement by habitat and travel
corridor areas, aquatic life breeding grounds, and recreation/education value for
hunting/fishing or ecological studies.
Wetlands are areas that are covered by water or have waterlogged soils for long periods
during the growing season. Plants growing in wetlands are capable of living in saturated
soil conditions for at least part of the growing season. Wetlands such as swamps and
marshes are often obvious, but some wetlands are not easily recognized because they are
dry during part of the year. Some of these wetlands include bottomland forests, pocosins,
pine savannas, bogs, wet meadows, potholes, and wet tundra.
All area within this boundary is subject to the Town’s authority in zoning, subdivision of
land, and building code enforcement. Most of the extra-territorial land has been zoned R-
20, which restricts use to agriculture, single family residential development (20,000
square foot lots minimum), and other low density uses. Therefore, any developer
proposing other uses within this area must obtain re-zoning approval.
The Town zoning ordinances require the developers to adhere to buffer zones pending the
zoning class. The buffer zones include landscape plans to limit the visual and physical
impacts of developments on the surroundings. The applicable zoning ordinances are
included as Exhibit 9.
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Town of Clayton
Environmental Assessment for
Increased awareness of value of wetlands has resulted in a number of wetland regulations
and programs designed to protect wetlands and the benefits they provide. Section 404 of
the Clean Water Act of 1972 provides the primary legislative authority behind Federal
efforts to regulate the use of wetlands. This section requires that a permit be obtained
from the Corps of Engineers prior to undertaking any activity that will result in the
discharge of dredged or fill materials into waters of the United States, including wetlands.
Section 401 of the Clean Water Act requires that the States insure that any issued Federal
permits comply with State Water Quality Standards. Therefore, the State of North
Carolina must issue a certification for each Corps of Engineer 404 permitted activity.
They are primarily concerned with the importance of wetlands to the protection of water
quality and have taken a proactive role in this certification program by evaluating each
wetland project based on the values and uses of the impacted wetland. The previously
mentioned values associated with wetlands are rated for each specific site and an overall
rating of the wetland is determined. Also, the project itself is evaluated. Whenever
possible, wetland disturbance is avoided, minimized, or mitigated by the restoration or
creation of disturbed or new wetland areas.
Because the Neuse River spans two physiographic provinces - the coast and the lower
Piedmont — the river basin contains a wide array of natural communities, both upland and
wetland. The basin contains the full array of estuarine wetland communities, such as Salt
Marsh, Brackish Marsh and Estuarine Fringe Loblolly Pine Forest. The basin also
contains a few good examples of Tidal Freshwater Marsh, notably at the junction of the
Trent and Neuse rivers near New Bern. In addition, the northernmost Pine Savanna
natural communities remaining in good condition are here; these are located in Croatan
National Forest.
Nonriverine-forested wetlands are prominent in the lower part of the basin. Pamlico
County, in particular, contains high-quality remnant stands of Nonriverine Swamp Forest
and Nonriverine Wet Hardwood Forest. Often mixed with the nonriverine hardwood
forests are communities of pocosin vegetation, such as Pond Pine Woodland, High
Pocosin, Bay Forest and Low Pocosin. This association is especially notable in the
Croatan National Forest.
The importance of wetlands to the Neuse River area can be easily determined by the
wetland inventory maps within the area. Much of Johnston County can be classified as
wetlands, and, therefore, the potential for development of residential, commercial and
industrial sties must follow the limitations set in the regulatory permitting. Therefore, the
potential wastewater projections from specific areas can be affected by the acreage of
wetlands present. As the implementation of extensions of services is developed into
currently undeveloped areas, wetland impacts must be considered. Nationwide 12
General Permits allow the utility line installations. It is the development that generates
the need for the service extensions that could be restricted because of the presence of
wetlands.
CT9905
The WWTP site, which is also the project site, does not contain any wetlands.
5.Prime or Unique Agricultural Lands
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Environmental Assessment for WWTP Expansion
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In 1987, about 153,885 acres in Johnston County was used for crops and pasture. Of this
total, 32,737 acres was used for permanent pasture or hayland; 86,621 acres for row
crops, mainly com, soybeans, tobacco, and sweet potatoes; and 13,589 acres for close
growing crops, such as wheat, oats, sorghum, barley, and cereal rye, much of which was
double cropped with soybeans.
The total acreage used for crops and pasture in the county has gradually decreased as
more land has been used for urban development. Such development is converting several
hundred acres per year to urban land.
Pastureland
Johnston County has about 24,000 acres of improved pasture and hay land. It has about
16,800 acres of mixed fescue, native grass, and clover used for pasture and about 7,200
acres of hybrid bermudagrass used for pasture or hay. Most of the bermudagrass is used
for hay. The pastures of fescue native grass, and fescue-clover are mainly in areas of
poorly drained and somewhat poorly drained soils on the Coastal Plain and the well
Cropland
In Johnston County, agriculture has always been the mainstay of the economy because of
the large acreage of well-suited soils and the favorable climate. The county is a leading
producer of tobacco and sweet potatoes, both statewide and nationwide. It has a variety
of soils that are suited to a number of different crops in addition to traditional staple
crops.
Tobacco and sweet potatoes are the most important cash crops, even though they are
planted on an acreage several times smaller than that used for com and soybeans. Com,
soybeans and small grain are grown mainly as rotation crops on these soils. Hybrid
bermudagrass commonly is grown for hay on these soils.
A variety of riverine communities are represented in the basin, although they are not as
mature and high quality as those in the Roanoke River Basin. Examples of cypress-Gum
Swamp and Bottomland Hardwood communities are located on the Neuse floodplain
upstream of New Bern in northwestern Craven County and below Smithfield in Johnston
County. In the Piedmont, some of the best examples of Piedmont/Mountain Swamp
forest were destroyed by the creation of Falls Lake, but remnants of this rare natural
community still exist in streams above the flooded portion of the lake.
The county has been following a nationwide trend toward larger farms and farming
operations and fewer farms and farmers. Despite this trend, the county has 1,713 farms,
which is the largest number of individual farms of any county in the state. The average
farm size is about 137 acres. Most farmers are increasing their acreage by renting or
sharecropping.
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Environmental Assessment for Expansion
Prime Farmland
Prime farmland is one of several kinds of important farmland defined by the U.S.
Department of Agriculture. It is of major importance in meeting the nation’s short- and
long-range needs for food and fiber. The acreage of high-quality farmland is limited, and
the U.S. Department of Agriculture recognizes that government at local, state, and federal
levels, as well as individuals, must encourage and facilitate the wise use of our nation s
prime farmland.
Prime farmland soils usually get an adequate and dependable supply of moisture from
precipitation or irrigation. The temperature and growing season are favorable. The
acidity level of the soils is acceptable. The soils have few or no rocks and are permeable
to water and air. They are not excessively erodible or saturated with water for long
Cultivated Cropland Runoff
Significant acreages of cropland are being converted to roads and other urban uses.
Reduced cropland acreages combined with improved erosion control techniques
including no-till farming are reducing the pollution contribution from cropland in the
Neuse basin.
Prime farmland soils, as defined by the U.S. Department of Agriculture, are soils that are
best suited to producing food, feed, forage, fiber, and oilseed crops. Such soils have
properties that are favorable for the economic production of sustained high yields of
crops. The soils need only to be treated and managed using acceptable farming methods.
The moisture supply, of course, must be adequate, and the growing season has to be
sufficiently long. Prime farmland soils produce the highest yields with minimal inputs of
energy and economic resources. Farming these soils results in the least damage to the
environment.
drained, sloping soils on the Piedmont. The native grasses in these pastures consist of
broomsedge bluestem, crabgrass, common bermudagrass, and switch cane. The hayfields
and pastures of hybrid bermudagrass are mainly in areas of the well drained to
excessively drained, sandy soils on the Coastal Plain. The acreage of bermudagrass is
increasing because the grass is well suited to the sandy soils that are extensive throughout
the county.
Prime farmland soils may presently be in use as cropland, pasture, or woodland, or they
may be in other uses. They are used for producing food or fiber or are available for these
uses. Urban or built-up land, public land, and water areas cannot be considered prime
farmland. Urban or built-up land is any contiguous unit of land 10 acres or more in size
that is used for such purposes as housing, industrial, and commercial sties, sites for
institutions or public buildings, small parks, golf courses, cemeteries, railroad yards,
airports, sanitary landfills, sewage treatment plants, and water control structures. Public
land is land not available for farming in national forests, national parks, military
reservations, and state parks.
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6.Public Lands and Scenic, Recreational, and State Natural Areas
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Most of the soils of the service area have a potential for one or more kinds of recreation
development. Soils on floodplains are well suited to some kinds of recreation because
they generally occur as long, winding areas along streams and adjacent to scenic uplands.
An onsite assessment of the height, duration, and frequency of flooding should be made
in these areas before recreation facilities are developed.
periods and are not subject to frequent flooding during the growing season. The slope
ranges mainly from 0 to 6 percent.
Town of Clayton
Environmental Assessment for WWTP Expansion
In its Strategic Growth Plan, the Town of Clayton has recognized the importance of
preserving existing farmland. The Town has identified 5,000 acres of land within its
extraterritorial jurisdiction and has committed to working with Johnston County and the
NC Department of Agriculture to continue establishing development policies and
utilizing current zoning ordinances to ensure their preservation. A copy of the Town’s
Strategic Growth Plan is included as Exhibit 10.
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The Town owns the all of the land encompassing the WWTP site. Due to the fact
that its current use restricts this land from being classified as prime farmland, no
such land exists on the project site.
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acidity level of the soils is acceptable. The soils have few or no rocks and are permeable
to water and air. They are not excessively erodible or saturated with water for long ‘
Picnic areas are attractive natural or landscaped tracts that are subject to heavy foot
traffic. Most of the vehicular traffic, however, is confined to access roads. The best soils
are firm when wet and not dusty when dry, are not subject to flooding during the period
of use, and do not have slopes and stones that greatly increase the cost of leveling sites or
of building access roads.
Playgrounds are areas used intensively for baseball, football, badminton, and similar
organized games. Soils suitable for this use should be able to withstand intensive foot
traffic. The best soils are nearly level and have a surface free of coarse fragments and
Camp areas are used intensively as sites for tents and small camp trailers and for the
accompanying activities of outdoor living. Little preparation of the site is required, other
than shaping and leveling for tent and parking areas. Camp areas are subject to heavy
foot traffic and limited vehicular traffic. The best soils are gently sloping, are not subject
to flooding, have a surface that is firm after rains and not dusty when dry, and do not perc
slowly (water does not percolate through the soil slowly).
The amount of land used for recreation is rapidly increasing in Johnston County,
including the Clayton service area. Among the larger recreation uses are canoeing the
scenic rivers, hunting and fishing the gamelands and waterways.
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Water Resources (Surface and Groundwater)10.
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Town of Clayton
Environmental Assessment for
As Johnston County, including the Clayton service area and the WWTP site, is
largely rural in nature, there are no existing noise level concerns.
Water for industry and for most of the towns in the county is supplied by deep wells or by
the Johnston County water plant, which obUins water from the Neuse River. Water is bit
There are no recreational facilties located on the WWTP plant site; therefore, there
are none located on the project site.
Prior to the construction of the current WWTP and its outfall pipeline, the entire route
was surveyed and a review of records of the Department of Cultural Resources indicated
no archaeological sites have been identified along or near the areas and route of this
original project. In addition, no structures of historical significance have been
identified in these areas by the State Office of Historic Properties.
Expansion
Ground water in the county is used for domestic and industrial purposes and for
irngation. Water supplies for homes and industries are generally adequate. Most
households in rural areas get their water from wells that are sunk into sediments in the
Coastal Plain region or into the crystalline bedrock in the Piedmont region. Generally,
the water from these wells is good quality. The water from wells bored into slate or
phyllite rocks, however, has a high content of iron and sulfur.
Currently, there are no air quality concerns in Johnston County, including the
Clayton service area and the WWTP site. These areas are influenced principally by
the greater Raleigh urban area, local industries and local farming practices.
Paths and trails are used for local and cross-country travel on foot or horseback. I he
design and layout should require little or no cutting and filling. The best soils are at least
moderately well drained, are firm when wet, are not dusty when dry, are not subject to
flooding more than once during the period of use, have slopes of less than 15 percent, and
have few or no rocks or stones on the surface.
Ground water is present throughout Johnston County and the Clayton service area, but
with the exception of low-lying floodplain and wetland areas, the groundwater table is
usually located no closer than 10-15 feet from the surface. Groundwater is supplied from
storage in fractured granite, phyllite and mica gneiss strata. Most water supply wells are
drilled to depths of 100-200 feet on carefully selected sites and provide low yields.
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Town of Clayton
Environmental Assessment for WWTP Expansion
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Two aquatic habitat types occur in the Clayton service area, including those areas
adjacent to the WWTP site and the outfall pipeline corridor to the discharge point at the
Neuse River. These are small streams and their tributaries and a major river.
The surface hydrology of Clayton service area is dominated by the Neuse River. The
Neuse watershed at the point of the N.C. 42 bridge east of Clayton contains
approximately 1140 square miles (including the majority of Orange, Durham, and Wake
counties and the northern half of Durham and all of Raleigh). :
Streams: Southwest of the WWTP site, Little Creek has a 15-20’ base channel with a
steady, somewhat tannic malodorous base flow approximately 1” deep and a gravelly
bottom. The channel banks are steep and the stream margins are wooded. Wetlands
appear to be limited to the depressional areas within the floodplain adjacent to the outfall.
The upper reach of the northeastern creek has a 5’ - 10’ base with 5’ - 7’ banks and a
steady, clear base flow approximately 6” deep in a cobble bottom. The stream gradient
appears to be high with much urban debris deposited and some minor odor. Accelerated
erosion of the banks was evident. Extensive additional disturbance is created by
agricultural/silvicultural practices, powerline easements and a commercial farming
operation. Both overbank areas are fairly high suggesting limited potential for adjacent
wetlands except in minor depressional areas. Approaching the Neuse River confluence,
this creek broadens to a 15-20’ base channel with 6-8’ high banks and a steady, clear
base flow approximately 1 ’ deep on a sand and gravel bottom. The stream gradient is
much flatter and a distinct pool and riffle pattern develops. The overbank areas remain
high and wetlands appear to be limited to minor depressional areas within the stream’s
floodplain.
plentiful for irrigation. Most of the water for irrigation is obtained from excavated pond
reservoirs or from embankment ponds. These sources are not adequate to supply water to
all of the cropland in the county and are expensive to develop. As a result, only high-
value crops, such as tobacco, small fruits, and vegetables, are irrigated.
There are no gaging stations on any of the tributaries in the Clayton service area.
However, a study by W.L. Yonts, “Low-Flow Measurements of North Carolina Streams,”
N.C. Department of Water and Air Resources, 1971, estimates average stream flow in
this area to be between 1.1 and 1.2 cfs/square mile of drainage basin. Assuming 1.15
cfs/square mile, the runoff from the area constitutes about 32% of the rainfall received.
Major river: The Neuse River has an 80-100’ base with steady, turbid flow (depth not
determined) and a silty sand bed. The WWTP discharge is located at a wide
(approximately 1000’), straight floodplain section gently sloping to high alluvial terraces
on the south bank and uplands on the north bank. Due to the moderately well to
somewhat poorly drained nature of the adjacent soils (USDA, 1978-82) significant areas
of wetlands were not be encountered during construction of the previous plant
expansions.
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Town of Clayton
Environmental Assessment for
History of Nutrient Issues in the Neuse Basin
Eutrophication became a water quality concern in the lower Neuse River Basin in the late
Due to the excellent relief and the fairly steeply sloped tributaries, natural flooding is not
a general problem and is restricted to areas immediately adjacent to Little Creek and the
Neuse.
^fc/TP Expansion
There is no significant regulation of diversion of streamflow within the Clayton service
area. There are a significant number of farm ponds, which are used for stock watering
and for supplemental irrigation during periods of drought, as well as some sport fishing.
However, these are all small. Old Barnes Pond, with surface area of approximately ten
(10) acres, is the largest impoundment within the area.
The previous subsections on soils and ecology have pointed out the general
characteristics of the groundwater storage basin in the Clayton service area: the upper
soil, deep and well-drained, derived from an intermixture of ancient coastal sediments
and deeply weathered volcanic rock residuals; the underlying saprolite layer, very old,
deeply weathered (50-60 feet) metamorphic rock, intruded by more erosion-resistant rock
of volcanic origin; and finally the deep unweathered parent materials, containing
numerous fractures from the expansion and cooling under volcanic force. Over millions
of years the erosive power of water moving over and through these materials has cut into
and altered their layered structure, and since the underlying materials were fairly
resistant, the surface streams were concentrated, resulting in a drainage system of fairly
steep, banked tributaries, between which is left a fairly level upland.
The avenues thus created for groundwater movement are initially downward due to the
good infiltration rate into the soil, and then laterally and vertically in the weathered rock,
and finally along fracture planes in the parent crystalline rock.
Neuse River Basin
The Neuse River originates northwest of Durham and flows southeasterly for over 150
miles past Raleigh, Smithfield, Goldsboro and Kinston before it reaches its estuary
around New Bern. The Neuse River’s watershed encompasses nearly 6200 square miles
over 19 counties. A few miles above New Bern, the river takes on estuarine
characteristics as it widens but remains shallow (< 5 m), frequently resulting in minimal
discharge and long hydraulic residence times. The Neuse River estuary stretches to the
southeast for 25 miles until it reaches Cherry Point (Minnesott Beach on the north side),
where it turns to the northeast and continues for another 20 miles before meeting Pamlico
Sound. Estuarine salinity varies vertically and horizontally with saltwater inflow from the
sound, meteorological conditions (wind and precipitation), and river discharge (Pinckney
et al., 1997). Up-estuary advancement of saline water along the bottom occurs in the
growing season during low to moderate discharge and prevailing southwest winds.
Saltwater advance typically persists until heavy winter rains result in high river discharge
that drives the salt wedge back into the sound.
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Town of Clayton
Environmental Assessment for WWTP Expansion
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plentiful for irrigation. Most of the water for irrigation is obtained from excavated pond
reservoirs or from embankment ponds. These sources are not adequate to supply water to
all of the cropland in the county and are expensive to develop. As a result, only high-
value crops, such as tobacco, small fruits, and vegetables, are irrigated.
1
The surface hydrology of Clayton service area is dominated by the Neuse River. The
Neuse watershed at the point of the N.C. 42 bridge east of Clayton contains
approximately 1140 square miles (including the majority of Orange, Durham, and Wake
counties and the northern half of Durham and all of Raleigh). :
There are no gaging stations on any of the tributaries in the Clayton service area.
However, a study by W.L. Yonts, “Low-Flow Measurements of North Carolina Streams,”
N.C. Department of Water and Air Resources, 1971, estimates average stream flow in
this area to be between 1.1 and 1.2 cfs/square mile of drainage basin. Assuming 1.15
cfs/square mile, the runoff from the area constitutes about 32% of the rainfall received.
Major river: The Neuse River has an 80-100’ base with steady, turbid flow (depth not
determined) and a silty sand bed. The WWTP discharge is located at a wide
(approximately 1000’), straight floodplain section gently sloping to high alluvial terraces
on the south bank and uplands on the north bank. Due to the moderately well to
somewhat poorly drained nature of the adjacent soils (USDA, 1978-82) significant areas
of wetlands were not be encountered during construction of the previous plant
expansions.
Two aquatic habitat types occur in the Clayton service area, including those areas
adjacent to the WWTP site and the outfall pipeline corridor to the discharge point at the
Neuse River. These are small streams and their tributaries and a major river.
Streams: Southwest of the WWTP site. Little Creek has a 15-20’ base channel with a
steady, somewhat tannic malodorous base flow approximately 1” deep and a gravelly
bottom. The channel banks are steep and the stream margins are wooded. Wetlands
appear to be limited to the depressional areas within the floodplain adjacent to the outfall.
The upper reach of the northeastern creek has a 5’ - 10’ base with 5’ - 7’ banks and a
steady, clear base flow approximately 6” deep in a cobble bottom. The stream gradient
appears to be high with much urban debris deposited and some minor odor. Accelerated
erosion of the banks was evident. Extensive additional disturbance is created by
agricultural/silvicultural practices, powerline easements and a commercial farming
operation. Both overbank areas are fairly high suggesting limited potential for adjacent
wetlands except in minor depressional areas. Approaching the Neuse River confluence,
this creek broadens to a 15-20’ base channel with 6-8’ high banks and a steady, clear
base flow approximately 1 ’ deep on a sand and gravel bottom. The stream gradient is
much flatter and a distinct pool and riffle pattern develops. The overbank areas remain
high and wetlands appear to be limited to minor depressional areas within the stream’s
floodplain.
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Town of Clayton
Environmental Assessment for
The avenues thus created for groundwater movement are initially downward due to the
good infiltration rate into the soil, and then laterally and vertically in the weathered rock,
and finally along fracture planes in the parent crystalline rock.
Due to the excellent relief and the fairly steeply sloped tributaries, natural flooding is not
a general problem and is restricted to areas immediately adjacent to Little Creek and the
Neuse.
I P Expansion
The previous subsections on soils and ecology have pointed out the general
characteristics of the groundwater storage basin in the Clayton service area: the upper
soil, deep and well-drained, derived from an intermixture of ancient coastal sediments
and deeply weathered volcanic rock residuals; the underlying saprolite layer, very old,
deeply weathered (50-60 feet) metamorphic rock, intruded by more erosion-resistant rock
of volcanic origin; and finally the deep unweathered parent materials, containing
numerous fractures from the expansion and cooling under volcanic force. Over millions
of years the erosive power of water moving over and through these materials has cut into
and altered their layered structure, and since the underlying materials were fairly
resistant, the surface streams were concentrated, resulting in a drainage system of fairly
steep, banked tributaries, between which is left a fairly level upland.
History of Nutrient Issues in the Neuse Basin
Eutrophication became a water quality concern in the lower Neuse River Basin in the late
Neuse River Basin
The Neuse River originates northwest of Durham and flows southeasterly for over 150
miles past Raleigh, Smithfield, Goldsboro and Kinston before it reaches its estuary
around New Bern. The Neuse River's watershed encompasses nearly 6200 square miles
over 19 counties. A few miles above New Bern, the river takes on estuarine
characteristics as it widens but remains shallow (< 5 m), frequently resulting in minimal
discharge and long hydraulic residence times. The Neuse River estuary stretches to the
southeast for 25 miles until it reaches Cherry Point (Minnesott Beach on the north side),
where it turns to the northeast and continues for another 20 miles before meeting Pamlico
Sound. Estuarine salinity varies vertically and horizontally with saltwater inflow from the
sound, meteorological conditions (wind and precipitation), and river discharge (Pinckney
et al., 1997). Up-estuary advancement of saline water along the bottom occurs in the
growing season during low to moderate discharge and prevailing southwest winds.
Saltwater advance typically persists until heavy winter rains result in high river discharge
that drives the salt wedge back into the sound.
There is no significant regulation of diversion of streamflow within the Clayton service
area. There are a significant number of farm ponds, which are used for stock watering
and for supplemental irrigation during periods of drought, as well as some sport fishing.
However, these are all small. Old Barnes Pond, with surface area of approximately ten
(10) acres, is the largest impoundment within the area.
CT9905
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The Neuse River was listed as one of the 20 most threatened rivers in the United States
because of the frequency, magnitude and areal extent of phytoplankton blooms
(American Rivers, Washington, D.C. 1996). As a result of these phytoplankton blooms
and chlorophyll a levels. North Carolina placed the Neuse River estuary on its 1994,
1996 and 1998 303(d) impaired waters lists. Controlling nutrients is the most direct way
to reduce chlorophyll a concentrations, and the science indicates nitrogen is the main
nutrient of concern in the estuary.
Town of Clayton
Environmental Assessment for WWTP Expansion
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Dissolved Oxygen
Dissolved oxygen distributions for the mainstem gradually decrease in concentration
along the mainstem until the river widens into the estuary at New Bern. At this point,
concentrations return to near the level at Falls and remain at that level to the mouth.
Excursions below the criterion for dissolved oxygen are few with exceptions being at the
Askin and Narrows sites.
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In 1993, DWQ completed the Neuse River Basinwide Water Quality Management Plan,
which recognized the reductions in total phosphorus loading that had been achieved
through the phosphate detergent ban and the NSW strategy. Furthermore, the reduction in
phosphorus loading greatly reduced algal blooms in the river and freshwater, uppermost
portion of the estuary. However, the plan recognized that eutrophication was still a
problem in much of the estuary. The plan indicated that a water quality model of the
estuary would be developed, and that addressing eutrophication in the estuary was a
priority (NCDEM, 1993). During July, September, and October 1995, extensive fish kills
occurred in the Neuse estuary, primarily from New Bern to Minnesott Beach. Millions of
menhaden, as well as flounder, croaker and rock fish were killed. DWQ conducted
extensive water quality sampling in the areas of the fish kills. The sampling showed the
water was often hypoxic only 1 to 2 meters below the surface. The results also showed a
prevalence of algal blooms. In sum, the 1995 fish kills and threat of Pfiesteria led to a
review of water quality and management actions to expedite nutrient loading reductions
in the system.
Phosphorous
The phosphorus concentrations leaving Falls Lake were very low, but they increase at the
Clayton site. There is a gradual decrease to Fort Barnwell where the concentration again
increases. Another decrease occurs in the estuary from Thurman to the mouth.
1970s and early 1980s through the proliferation of nuisance algal blooms (Paerl J983,
1987; Stanley 1983; Christian et al. 1986). A prevalence of algal blooms in the freshwater
portion of the basin prompted a special Division of Water Quality (DWQ) investigation
of the Neuse River beginning in 1979 (Tedder et al., 1980). This study found that
phytoplankton growth in the Neuse was not limited by the major nutrients of nitrogen or
phosphorous. Similar conclusions derived from other studies led to a ban on phosphate
detergent and classification of the lower basin as nutrient sensitive water (NSW); both
actions were instituted in January of 1988. One requirement of the NSW strategy was that
all new and expanding NPDES dischargers, as well as existing ones with design flows
greater than 0.05 MGD, must meet a quarterly average phosphorus limit of 2 mg/1.
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Town of Clayton
Environmental Assessment for
Total Nitrogen
Total nitrogen concentrations show a similar pattern to total phosphorus. Nitrogen is very
low from Falls Lake; increases suddenly at Clayton, below Raleigh’s wastewater
treatment plant (1995 data); decreases to Fort Barnwell; increases slightly at Streets
Ferry; and gradually decreases in the estuary from New Bern to the mouth.
ftWTP Expansion
Fecal Coliform Bacteria
Fecal coliform bacteria behave differently than most other water quality parameters, and
these differences must be considered when using them to evaluate water quality.
Available information was reviewed to identify potentially impaired waters and locate
potential sources of pollutants in order that targeting efforts and appropriate management
strategies can be developed. As sampled in the ambient monitoring system, fecal
coliform bacteria are most useful as a screening tool to estimate the cumulative inputs
from multiple sources, but in some instances can be used to locate a single large source of
bacteria. Summary fecal coliform information is listed on page 28 and is taken from
the Neuse River Basin Plan published by the Division of Water Quality in the table
entitled, “Fecal Coliform Summary Data for the Neuse River Basin near Clayton 1991 to
1995”. The primary screening tool used in establishing priority is the geometric mean.
Sites with 10 or more fecal coliform samples within the last 5 years, that have a
geometric mean exceeding 200/100 ml, are considered highest priority. This information
was reflected in the Use Support Rating for the various streams or rivers.
Summary of Nutrient Loading from the Town of Clayton’s Discharge
As previously mentioned the Town of Clayton WWTP discharges 1.9 mgd into the Neuse
River between SR 1700 and Hwy 42 bridges. The classification of the Neuse at this
location is WS-IV NSW CA. The 7Q10 flow is 186 cfs. The designations reflect the
nutrient problems mentioned as well as the presence of a water supply downstream. All
of the previous reviewed studies on the River in this area attribute water quality impacts
to upstream effects of the much larger dischargers such as the City of Raleigh WWTP
and the urban growth in the greater Raleigh area. The additional 0.6 mgd and 25 Ibs/day
of BOD to the Town of Clayton WWTP discharge is a small percentage increase (0.5%)
of flow to the Neuse and a small percent in the cumulative pollutant loading for BOD.
There will be no increase in the allocated Nitrogen loading and the Ammonia and
Phosphorus loadings will not increase because of the more stringent limit of 1 mg/1 in the
new NPDES permit rather than the existing 2 mg/1 for each parameter in the existing
NPDES permit. There is 205.25 mgd of permitted flow from major dischargers in the
Neuse River. With a BOD standard of 5 mg/1 this is approximately 8559 Ibs/day
permitted for discharge. The increase of 25 Ibs/day of BOD for the Town of Clayton
WWTP constitutes 0.29% of this total. The total discharge at 2.5 mgd will be 260
Ibs/day BOD, 20.8 Ibs/day Ammonia, 20.8 Ibs/day TP, and 58.6 Ibs/day TN( 21,400
Ibs/yr).
CT9905
Fecal Coliform Summary Data for the Neuse River Basin near Clayton 1991 to 1995
14 7 50.0 9/12/94 10/25/95
14 293.6at 8 57.1 9/12/94 10/25/95
WS-V-NSW 02 5.8
IWS-IV NSW 02 14 ST G G
NSW 02 0.7
02 27.1 ST
CNSW 02 12
WS-IV NSW 02 25.8 G G
at
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208757
0
208750
0
G
F
Little
Cr.G-
F/G
F
Neuse
R.
Neuse
R
Neuse
R
27-
43-12
27-
(49.5)
27-
(41.3)
27-
(41.7)
27-
(38.5)
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1
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(36)
Neuse River at NC Hwy
42 near Clayton, NC
Neuse River
Smithfield, NC
WS-IV
CA
WS-V-NSW
Neuse
R.___
Neuse
R.
Town of Clayton
Environmental Assessment for WWTP Expansion
s'“
Monitored Freshwater Streams in the Neuse River Basin near Clayton
Neuse
R, nr
Clayton,
NC
Neuse
R., nr
Clayton,
NC
Neuse
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Smithfle
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Lit.Cr @
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Neuse
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SR
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Johns.
iftlII
| Total ?- . I C, Geometic
A 4Mem.
257.0
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Town of Clayton
Environmental Assessment for Expansion
There are also many small dischargers in this subbasin, and 5 dischargers with greater
than 1.5 MGD design flow. The largest of these is the Raleigh Neuse River WWTP, with
a design flow of 60 MGD. Aquatic toxicity data (self-monitoring) at wastewater
Water Quality Overview
Data collected from the 63 DWQ benthic macroinvertebrate sites in this subbasin
suggested that this subbasin has severe water quality problems. Fisheries information
also suggested some water quality problems in this subbasin, with 6 out of the 9 sites
sampled in 1995 were assigned a Fair rating. Fish tissue data from two sites (Lake
Wheeler, Neuse River) found no elevated levels of heavy metals or pesticides.
The entire Neuse River was declared Nutrient Sensitive Waters in 1988 at about the time
a statewide phosphate detergent ban went into effect. Water chemistry data from the
1993 Neuse Basin Plan revealed major reductions in instream phosphorus concentrations
below Raleigh’s wastewater treatment plant and lesser, but measurable, reductions in
phosphorus downstream (although nitrogen loading was unaffected by the phosphorus
reduction efforts and has been the subject of recent revisions to the NSW strategy for the
basin).
Macroinvertebrate data from one site (Neuse River near Clayton) suggest that new
restrictions and other management strategies have improved water quality for aquatic life
up to 1991. Improvements also were observed for the Neuse River at US 64 (Raleigh)
from 1986-1995. The Neuse River from NC 64 (Raleigh) to SR 1201 (western Johnson
County above Goldsboro) was assigned a Good bioclassification in 1995 based on
macroinvertebrate collections. Water chemistry data for the last five years suggest few
water quality problems in the larger streams and the Neuse River, although urban streams
(like Pigeon House Branch) may have low dissolved oxygen and elevated concentrations
of copper and zinc.
Urban stormwater runoff, and to a lesser extent, agricultural runoff and effluent from
wastewater treatment plants are the main contributors to water quality degradation in this
subbasin. In this regard, the Town of Clayton has put in place both a Watershed
Management Plan and a Strategic Growth Plan to combat these effects of development.
The Town’s Watershed Management Plan is included as Exhibit 12.
Subbasin Description
Many streams in this subbasin are impaired by urban stormwater runoff. The western
portion of the subbasin (generally west of Smithfield and 1-95) lies within the piedmont
physiographic region. The piedmont streams are underlain by rock formations that cause
smaller streams to have a tendency to dry up under low flow conditions. This reduces
their ability to assimilate wastewater and places stress on aquatic life. The eastern
portion of the subbasin is located in the coastal plain physiographic region. The two
regions are divided by the fall line, which runs roughly parallel to 1-95. A map of this
subbasin is included as Exhibit 11.
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Swift Creek’s headwaters near Cary and Raleigh were rated Poor to Fair based on benthic
macroinvertebrates, but showed gradual recovery downstream. The most pollution-
intolerant benthic macroinvertebrates did not appear until the most downstream site and
were not abundant an any of the Swift Creek sites. Fish sampling in the middle reach of
the creek (at SR 1525) showed a decline from Good-Excellent in 1991 to Fair in 1995.
Urban Stormwater Runoff
Water quality impacts from population growth and development are major water issues in
this subbasin. These impacts occur both locally, as borne out by the following benthic
macroinvertebrate data, and all the way to Neuse estuary through nutrient contributions
from runoff and wastewater treatment plants. As previously mentioned, the Town of
Clayton has instituted a Watershed Management Plan and a Strategic Growth Plan in
response to these and other issues surrounding growth concerns.
treatment plants show substantial improvements in effluent toxicity over a 10-year
period. The Clayton WWTP failed numerous tests, but greatly increased their dilution
by relocating the discharge from Little Creek to the Neuse River in April 1996. In
addition they constructed tertiary filters and an ultraviolet disinfection system. They are
now passing all toxicity tests.
Classifications of Neuse River and Its Tributaries Located in Johnston County
Swift Creek
Swift Creek is a moderate-sized stream that flows from Cary into the Neuse River near
Clayton. The creek is impounded at two locations in its upper third to form Lake Benson
and Lake Wheeler. Swift Creek is under pressure from growth and yet it still supports
populations of rare, threatened and endangered mussels downstream of Lake Benson.
There will be no direct impacts to Swift Creek because of this project.
Lower Swift Creek, SR 1501
This site is in the most downstream portion of Swift Creek, in an area intermediate
between the piedmont and coastal plain ecoregions. Some downstream recovery has
occurred, with a Good benthic rating in both 1991 and 1995. However, water quality in
this portion of the stream is threatened by a variety of ongoing or planned activities.
Downstream of Lake Benson, the Town of Gamer is proposing to discharge wastewater
into the City of Raleigh collection system to eliminate the need for its present wastewater
spray field near the creek. The Neuse River Foundation Creek Keeper for Swift Creek
has identified the Eastside Septic Company sludge site and the Town of Gamer’s
wastewater treatment plant spray site as two significant sources of nonpoint source
pollution in the lower Swift Creek. In addition, there are numerous activities being
planned that will likely increase growth, development and nonpoint source pollution
loading to the creek. For example, the proposed path of the outer loop (1-540) runs
through the lower Swift Creek watershed, and there is a proposed interchange with 1-40
just east of the creek. There is also a proposed Clayton Bypass and proposed widening of
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Town of Clayton
Environmental Assessment for WWTP Expansion
NC 42. New water districts will be providing another growth incentive by making public
water available to properties in the area.
The potential impact of upstream sources also has changed during this time period.
Several small wastewater treatment plants on Perry Creek have ceased discharge since
1988 and connected into Raleigh’s WWTP system. Also a ban on phosphate detergent
was instituted in 1988. The Raleigh WWTP (a 60 MGD plant located upstream of this
station) observed a 55% reduction in effluent phosphorus concentration after the ban was
put into effect (EHNR, 1991). Additionally, according to personnel from the DWQ
Raleigh Regional Office, the plant is using an odor controller that also precipitates
phosphorous, reducing their phosphorus levels in the effluent to an average of less than 1
mg/1. Water chemistry data taken from this site suggest a lowering of total phosphorus
from yearly averages of 0.46-0.91 mg/1 between 1980 and 1987 to yearly averages of
0.16-0.29 mg/1 between 1988 and 1991.
The Neuse River near Clayton has been sampled during the summer eight times since
1983. Consistent Good-Fair ratings were obtained from 1983 to 1990, although EPT taxa
richness was much lower in the first sample (1983). The bioclassification improved to
Good in 1991 and 1995.
One site is upstream of the Raleigh WWTP. The first collection (December 1986)
followed a fish kill that was caused by a spill of dairy wastes into a tributary stream. The
Fair rating, therefore, may have not represented normal conditions in this part of the
Neuse River. This site was upgraded to Good-Fair in 1991, and further upgraded to
Good in 1995. There was no difference in EPT taxa richness between 1991 and 1995, but
the abundance of several intolerant species (Macrostemum, and Isonychia) resulted in a
decrease in the Biotic Index.
Neuse River (Falls Lake Dam to Smithfield)
Scouring during high flow appears to have reduced total taxa richness values in 1989 and
1995, but variety and abundance of pollution-intolerant aquatic insect larvae has
remained fairly stable. A slight improvement in water quality was indicated by the lower
biotic index in 1991 and 1995 (5.8-5.9), plus the abundance of an intolerant mayfly
(Isonychia') during 1995. The fauna continued to be dominate by heptageniid mayflies
(Ephemeroptera) and hydropsychid caddisflies (Trichoptera). Stoneflies (Plecopterd)
remained sparse, usually absent, at this site. Burlington Industries was a discharger to the
river upstream of this site at the time of sampling. This facility failed 2 out of 21 self­
monitoring tests from January 1991 to June 1995. In 1995, Burlington terminated its
former textile operations at its Wake County plant.
There are no direct impacts of the proposed project on this stream. Indirect
impacts could occur from the growth in the service area.
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There will be no direct impacts to Swift Creek because of this project.
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Lower Swift Creek, SR 1501
This site is in the most downstream portion of Swift Creek, in an area intermediate
between the piedmont and coastal plain ecoregions. Some downstream recovery has
occurred, with a Good benthic rating in both 1991 and 1995. However, water quality in
this portion of the stream is threatened by a variety of ongoing or planned activities.
Town of Clayton
Environmental Assessment for WWTP Expansion
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Urban Stormwater Runoff
Water quality impacts from population growth and development are major water issues in
this subbasin. These impacts occur both locally, as borne out by the following benthic
macroinvertebrate data, and all the way to Neuse estuary through nutrient contributions
from runoff and wastewater treatment plants. As previously mentioned, the Town of
Clayton has instituted a Watershed Management Plan and a Strategic Growth Plan in
response to these and other issues surrounding growth concerns.
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Classifications of Neuse River and Its Tributaries Located in Johnston County
Swift Creek
Swift Creek is a moderate-sized stream that flows from Cary into the Neuse River near
Clayton. The creek is impounded at two locations in its upper third to form Lake Benson
and Lake Wheeler. Swift Creek is under pressure from growth and yet it still supports
populations of rare, threatened and endangered mussels downstream of Lake Benson.
Swift Creek’s headwaters near Cary and Raleigh were rated Poor to Fair based on benthic
macroinvertebrates, but showed gradual recovery downstream. The most pollution-
intolerant benthic macroinvertebrates did not appear until the most downstream site and
were not abundant an any of the Swift Creek sites. Fish sampling in the middle reach of
the creek (at SR 1525) showed a decline from Good-Excellent in 1991 to Fair in 1995.
treatment plants show substantial improvements in effluent toxicity over a 10-year
period. The Clayton WWTP failed numerous tests, but greatly increased their dilution
by relocating the discharge from Little Creek to the Neuse River in April 1996. In
addition they constructed tertiary filters and an ultraviolet disinfection system. They are
now passing all toxicity tests.
Downstream of Lake Benson, the Town of Gamer is proposing to discharge wastewater
into the City of Raleigh collection system to eliminate the need for its present wastewater
spray field near the creek. The Neuse River Foundation Creek Keeper for Swift Creek
has identified the Eastside Septic Company sludge site and the Town of Gamer’s
wastewater treatment plant spray site as two significant sources of nonpoint source
pollution in the lower Swift Creek. In addition, there are numerous activities being
planned that will likely increase growth, development and nonpoint source pollution
loading to the creek. For example, the proposed path of the outer loop (1-540) runs
through the lower Swift Creek watershed, and there is a proposed interchange with 1-40
just east of the creek. There is also a proposed Clayton Bypass and proposed widening of
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NC 42. New water districts will be providing another growth incentive by making public
water available to properties in the area.
The Neuse River near Clayton has been sampled during the summer eight times since
1983. Consistent Good-Fair ratings were obtained from 1983 to 1990, although EPT taxa
richness was much lower in the first sample (1983). The bioclassification improved to
Good in 1991 and 1995.
Town of Clayton
Environmental Assessment for WWIP Expansion
The potential impact of upstream sources also has changed during this time period.
Several small wastewater treatment plants on Perry Creek have ceased discharge since
1988 and connected into Raleigh’s WWTP system. Also a ban on phosphate detergent
was instituted in 1988. The Raleigh WWTP (a 60 MGD plant located upstream of this
station) observed a 55% reduction in effluent phosphorus concentration after the ban was
put into effect (EHNR, 1991). Additionally, according to personnel from the DWQ
Raleigh Regional Office, the plant is using an odor controller that also precipitates
phosphorous, reducing their phosphorus levels in the effluent to an average of less than 1
mg/1. Water chemistry data taken from this site suggest a lowering of total phosphorus
from yearly averages of 0.46-0.91 mg/1 between 1980 and 1987 to yearly averages of
0.16-0.29 mg/1 between 1988 and 1991.
Neuse River (Falls Lake Dam to Smithfield)
Scouring during high flow appears to have reduced total taxa richness values in 1989 and
1995, but variety and abundance of pollution-intolerant aquatic insect larvae has
remained fairly stable. A slight improvement in water quality was indicated by the lower
biotic index in 1991 and 1995 (5.8-5.9), plus the abundance of an intolerant mayfly
(Isonychia) during 1995. The fauna continued to be dominate by heptageniid mayflies
(Ephemeroptera) and hydropsychid caddisflies (Trichoptera). Stoneflies (Plecopteraj
remained sparse, usually absent, at this site. Burlington Industries was a discharger to the
river upstream of this site at the time of sampling. This facility failed 2 out of 21 self­
monitoring tests from January 1991 to June 1995. In 1995, Burlington terminated its
former textile operations at its Wake County plant.
One site is upstream of the Raleigh WWTP. The first collection (December 1986)
followed a fish kill that was caused by a spill of dairy wastes into a tributary stream. The
Fair rating, therefore, may have not represented normal conditions in this part of the
Neuse River. This site was upgraded to Good-Fair in 1991, and further upgraded to
Good in 1995. There was no difference in EPT taxa richness between 1991 and 1995, but
the abundance of several intolerant species (Macrostemum, and Isonychia) resulted in a
decrease in the Biotic Index.
There are no direct impacts of the proposed project on this stream. Indirect
impacts could occur from the growth in the service area.
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Environmental Assessment for WWTP Expansion
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1993-1997 Actions
1997 Use Support Rating
1995 WQ Observations
Waterbody /Location
Classification
1992 Use Support Rating
Reason(s) for Impairment
1993 Planned Strategy
Little Creek at SR 1562 in Johnston County
C
PS
Sediment, urban nonpoint source pollution
Eliminate the Clayton WWTP discharge
Continue existing NPS programs
The Clayton WWTP discharge was relocated to the Neuse R.
ps —
Benthos rating declined from Good-Fair 1991 to Fair in 1995
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Little Creek
Little Creek is the only waterbody located adjacent to the WWTP site, the location of the
proposed project. This stream is a tributary to Swift Creek near its confluence with the
Neuse River. It flows near the edge of downtown Clayton. A table reprinted from the
Neuse River Basin Plan is provided below (page 34) which details the most current
Classification and Use Support Ratings for Little Creek.
The direct impacts to Little Creek by the proposed project will occur only during
construction and will be minimized by erosion control methods implemented to
control runoff. Indirect impacts may occur because of growth in the service area.
Based on the above analysis, the existing water quality of the Neuse River is not
significantly impacted from the immediate effects of the current 1.9 mgd Town of
Clayton NPDES discharge. This is substantiated by the fact that monitoring
downstream of the Town’s discharge by the Division of Water Quality indicates that
the Neuse River water quality improves by the SR 1201 station. The increased flow
of 2.5 mgd (2% of the stream flow ) should not significantly alter these impacts. The
additional 0.6 mgd constitutes only 0.5% of the 7Q10 of the Neuse at this location.
Fish tissue samples were collected at two sites in this subbasin by DWQ. Metals
contaminants remained below levels of concern at both stations except for mercury,
which was detected at levels above EPA and/or FDA criteria in longnose gar collected
from the Neuse River near Smithfield and in one largemouth bass sample from Lake
Wheeler. DWQ organics analyses were performed on channel catfish, bluegill, and carp
samples collected from the Neuse River near Smithfield in 1992. DWQ results show
eleven contaminants were detected and except for PCBs remained below levels of
concern. PCBs were detected in all three species at levels above the EPA screening value
of 0.01 ppm.
Neuse River at SR 1201
This site is downstream of the Town of Clayton WWTP and the Johnston County
WWTP. This portion of the Neuse River is characterized by a sandy substrate and
frequently turbid water. The Neuse River Basin Plan stated that in spite of such habitat
problems, the invertebrate community suggested that the river at SR 1201 is the highest
quality site on the Neuse River. Most of the macro invertebrates collected were
associated with snag habitats.
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Town of Clayton
Environmental Assessment for >^wTP Expansion
A more detailed investigation of the watershed is needed to
determine the causes and sources of impairment sufficient to
develop a restoration plan. This watershed has been targeted by
the NC Wetlands Restoration Program for riparian zone and
wetlands restoration (NCDWQ, 1998)'
Loblolly-shortleaf. This forest type covers 70,946 acres,
loblolly pine and shortleaf pine. Common included trees ;
oak, gum, hickory, and yellow-poplar.
Longleaf-slash. This forest type covers 7,319 acres. It is more than 50 percent longleaf
pine or slash pine or both. Common included trees are oak, hickory and gum.
Oak-pine. This forest type covers 62,214 acres. It is more than 50 percent hardwoods
and more than 25 percent pines. Common included trees are upland oaks, gum, hickory,
and yellow-poplar. If left undisturbed, this forest type develops into a forest of
predominantly oak and other upland hardwoods. The understory usually consists of
hardwood seedlings and saplings, which are more tolerant of shade than pine seedlings
and saplings. In shaded understory, hardwoods compete for light and moisture so
strongly that few pine seedlings are able to survive. If mature stands of pine are cut, the
dense understory of young hardwoods becomes dominant.
Oak-hickory. This forest type covers 40,257 acres. It is more than 50 percent oaks and
hickory. Common included trees are elm, maple, and yellow-poplar.
Forested land is an ideal natural land cover for the protection of surface water quality.
Forests slow the flow of water, and their root systems absorb nutrients and hold the soil.
Rainwater soaks into forest soils and recharges the groundwater, which provides the
baseflow for streams. According to land cover data presented in the Neuse River Basin
Plan, Chapter 2, the acreage of forestland decreased by almost seven percent from 1982
to 1992. Minimizing forest clearing and utilizing forested land as buffers along
waterways to filter pollutants and absorb nutrients is strongly recommended and a key
component of the nutrient sensitive waters strategy for the basin
Commercial forests cover 253,935 acres, or about 50 percent of the land area of Johnston
County. Commercial forest is land that is producing or is capable of producing crops of
industrial wood and that has not been withdrawn from timber production. Loblolly pine
is the most important timber species in the county because it grows fast, is adapted to the
soil and climate, brings the highest average sale value per acre, and is easy to establish
and manage.
For purposed of forest inventory six forest types are identified in Johnston County,
including the Clayton service area. They are described in the following paragraphs.
. It is more than 50 percent
are pond pine, red oak, white
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7 own of Clayton
Environmental Assessment for WW'I'P Expansion
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There are no forested lands on the existing WWTP site. There are no direct impacts
of the proposed project to forest land.
Rare Aquatic and Aquatic-Related Species
The Neuse River basin contains many rare plants and animals. Five animals of aquatic or
wetland habitats are federally listed. Of these, the manatee, loggerhead (turtle), piping
plover and bald eagle are found primarily in estuarine habitats, whereas the dwarf
wedgemussel occurs in the Piedmont and upper Coastal Plain. Of the three wetland
plants that are federally listed, one (seabeach amaranth) occurs along the coast, one
occurs in freshwater areas in the tidewater zone (Virginia jointvetch), and one occurs
scattered over the Coastal Plain (rough-leaf loosestrife). Especially noteworthy are the
number of state-listed mollusk species, nearly all of which are freshwater mussels.
Oak-gum-cypress. This forest type covers 47,579 acres. It is bottom-land forest,
consisting predominantly of tupelo, blackgum, sweetgum, oaks, southern cypress, or a
combination of these species. Common included trees are cottonwood, willow, ash, elm,
hackberry, and maple.
Elm-ash-cottonwood. This forest type covers 25,620 acres. It is more than 50 percent
elm, ash, or cottonwood. Common included trees are willow, sycamore, beech, and
maple.
Bottomland forests: Three types of bottomland forest were identified adjacent to the
project route. These are piedmont alluvial forest, piedmont levee forest and piedmont
bottomland forest. The piedmont alluvial forest was noted along the northeastern creek
and its larger tributaries in areas of steeper channel gradient. The piedmont levee forest
occurs generally from the major powerline crossing on the northeastern creek to the
Neuse River shore. Piedmont bottomland forest was noted between the levee forest and
toe of the floodplain on the northeastern creek and along the Little Creek floodplain
adjacent to the existing WWTP. Again, most of these areas exhibited serious alteration
from past cultural practices. In much of the northeastern creek’s floodplain, for example,
forest cover was non-existent or limited to the channel bank due to agricultural,
silvicultrual and powerline easement related disturbances.
Upland forests: Two types of upland forest were identified adjacent to the project route.
These are mesic mixed hardwood forest and dry mesic oak/hickory forest (NCNHP).
These communities have been substantially altered and impacted by past land-use
practices and occur in limited locations on slopes and drainage divides near the
northeastern creek which drains the east side of Clayton. Although generally clear cut,
cutover or selectively thinned for merchantable timber, some mature examples of various
species were noted on the steeper side slopes adjacent to the project area.
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Environmental Assessment for
Another aquatic vertebrate species endemic to North Carolina is the Carolina madtom
(Noturus furiosus). Like the Neuse River waterdog, this small fish lives only in the
Neuse and Tar basins. Among the other rare fishes in the Neuse basin, the Roanoke bass
(Ambloplites cavifrons) and Carolina darter {Etheostoma collis} have restricted ranges,
being limited mainly to the Piedmont and upper Coastal Plain of southern Virginia and
North Carolina.
\^^1P Expansion
Rare Aquatic Animals - Vertebrates
The manatee (Trichechus manatus} is a sporadic visitor to estuarine waters in the basin.
The species does not breed in the state but individuals are sighted every few years, even
as far inland as New Bern. The American alligator (Alligator mississippiensis') is present
in the lower Neuse Basin, primarily in Croatan National Forest and Cherry Point Marine
Corps Air Station. Loggerhead turtles (Caretta caretta) nest along coastal beaches and
forage in the ocean and in most of the sounds. Estuaries and tidal marches are the
preferred habitat for the other rare aquatic reptiles in the basin - diamondback terrapin
(Malaclemys terrapin) and Carolina salt marsh snake (Nerodia sipedon williamengelsi).
An especially significant aquatic amphibian is the Neuse River waterdog (Necturus
lewisi), which is endemic to the Neuse and Tar systems in the upper Coastal Plain and
lower Piedmont.
Significant Natural Heritage Areas and Aquatic Habitats
Swift Creek. This stream in Southern Wake and Johnston counties contains eleven rare
animals; one rare fish and ten rare mussels, including the Federally Endangered dwarf
wedgemussel. Although there are several protected areas along the stream above Lake
Wheeler, all of the rare animals live in the creek below Lake Benson, where there are no
lands protected along the creek banks. Thus, protection efforts are greatly needed
downstream of Lake Benson.
There are no direct impacts from the proposed project to Swift Creek.
Little River. Beginning in Franklin County, the Little River flows through Wake,
Johnston and Wayne counties. It contains twelve rare animals; three fishes, one
Rare Aquatic Animals - Mollusks
Good water quality in the Neuse River Basin is critical to the survival of a large number
of rare freshwater mussels. Fourteen species of rare freshwater mussels, plus one rare
snail [panhandle pebblesnail (Somatogyrus virginicus)] are known from the Neuse Basin,
and one species, the dwarf wedgemussel (Alasmidonta heterodori) is federally-listed as
Endangered. The majority of the Neuse Basin mollusks, including the dwarf
wedgemussel, inhabit small streams. Many of the larger rivers in the state, such as the
main stem of the Neuse, no longer support populations of rare mussels because of high
amounts of sedimentation and pollution. Most populations of the rare mollusk species
occur in the Piedmont and upper Coastal Plain, in rapidly developing areas such as the
Research Triangle. The future of the populations is uncertain.
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Middle Creek. This tributary in southern Wake and Johnston counties contains eleven
rare animals, two fishes, one amphibian and eight mussels, including the Federally
Endangered dwarf wedgemussel. Most of the creek flows through private, unprotected
lands.
There are no direct impacts from the proposed project to Middle Creek
Town of Clayton
Environmental Assessment for WWTP Expansion
Moccasin Creek. This stream runs along the boundaries of Wake, Franklin, Nash and
Johnston counties and contains one rare amphibian and four rare mussel species, one of
which is the Federally Endangered dwarf wedgemussel. Except for a very small nature
preserve in Johnston County, there are no protected lands along this creek; thus,
protection efforts are greatly needed.
There are no direct impacts from the proposed project to Moccasin Creek
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In addition, there are no shellfish beds or fish habitats located at or adjacent to the
WWTP site. Therefore, there do not appear to be any direct impacts from the
proposed project on any endangered or rare aquatic animal species.
As detailed in the December, 1998 Neuse River Basinwide Plan, the main stem of the
Neuse River does not support populations of rare aquatic animals, such as the dwarf
wedgemussel. Therefore, there are no known rare or endangered mollusks or
shellfish beds directly downstream of the Town’s discharge point.
amphibian and eight mussels, including several populations of the Federally Endangered
dwarf wedgemussel. The only protected site along the river is Mitchells Mill State
Natural Area in Wake County. A reservoir, which will impact some of the rare species,
will be constructed on the river downstream from Mitchells Mill State Natural Area.
Aquatic species would benefit from protection efforts along the River.
There are no direct impacts from the proposed project to Little River.
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I nETrichechus manatus
SCNecturus lewisi
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State Federal
Ambioplites cavifrons
Etheostoma collis
Lam petra aepyptera
Notropis bifrenatus
Noturus furiosus
SR
SC
SC
SC
SC
SR
SR
SR
Lynceus gracillicornis
Procambarus medialis
Procambarus plumimanus
Abbreviations: E = Endangered; T = Threatened; PT = Proposed Threatened
T(S/A) = Threatened Due to Similarity of Appearance; SC = Special Concern
C = Candidate; SR = Significantly Rare
Alligator mississippiensis
Caretta caretta______________
Malaclemys terrapin_________
Nerodia sipedon williamengeisi
Alasmidonta heterodon
Alasmidonta undulata
Anodonta implicata
Elliptio ianceolata_____
Elliptio marsupiobesa
Elliptio roanokensis
Fusconaia masoni_____
Lampsillis cariosa_____
Lampsillis radiata____
Lasmigona subviridis
Liqumia nasuta_______
Somatogyrus virginicus
Strophitus undulatus
Villosa constricta_____
Villosa delumbis
T
T
SC
SC
T(S/A)
T
MAMMALS
Manatee
AMPHIBIANS
Neuse River Waterdog
FISHES___________
Roanoke Bass______
Carolina Darter_____
Least Brook Lamprey
Bridle Shiner_______
Carolina Madtom
REPTILES____________
American Alligator______
Loggerhead____________
Diamondback Terrapin
Carolina Salt Marsh Snake
MOLLUSKS_________
Dwarf Wedgemussel
Triangle Floater_____
Alewife Floater______
Yellow Lance________
Cape Fear Spike_____
Roanoke Slabshell
Atlantic Pigtoe_______
Yellow Lampmussel
Eastern Lampmussel
Green Floater_______
Eastern Pondmussel
Panhandle Pebblesnail
Squawfoot__________
Notched Rainbow
Eastern Creekshell
CRUSTACEANS
Graceful Clam Shrimp
Tar River Crayfish
Croatan Crayfish
E
T
SC
T
T
T
T
T
T
E
SC
Sr
T
SR
SR
Rare Aquatic Animal Species in the Neuse River Basin
(Source: NC Natural Heritage Program, 1997)__________ _____________
Listing Status:
Common Name Scientific Name
Town of Clayton
Environmental Assessment for^^VTP Expansion
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Environmental Assessment for WWTP Expansion
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Inaturally established grasses and forbs, including
; are goldenrod, beggarweed, partridgepea.
Wild herbaceous plants are native or ]
weeds. Examples of wild herbaceous plants
and pokeweed.
Habitat for openland wildlife consists of cropland, pasture, meadows, and areas that are
overgrown with grasses, herbs, shrubs, and vines. These areas produce grain and seed
crops, grasses and legumes, and wild herbaceous plants. The wildlife attracted to these
areas include bobwhite quail, mourning doves, songbirds, cottontail, red fox, and deer.
Coniferous plants furnish browse and seeds. Examples of coniferous plants are pine and
cedar.
Habitat for wetland wildlife consists of open, marshy or swampy shallow water areas.
Some of the wildlife attracted to such areas are ducks, geese, herons, redwing blackbirds,
muskrat, mink, raccoon, and beaver.
Habitat for woodland wildlife consists of areas of deciduous plants or coniferous plants
or both and associated grasses, legumes, and wild herbaceous plants. Wildlife attracted
to these areas include wild turkey, woodpeckers, squirrels, gray fox, raccoon, deer and
bear.
Grain and seed crops are domestic grains and seed-producing herbaceous plants.
Examples of grain and seed crops are com, wheat, oats, barley, rye, millet, buckwheat,
soybeans, cowpeas, and sunflowers.
The kind and abundance of wildlife depend largely on the amount and distribution of
food, cover, and water. Wildlife habitat can be created or improved by planting
appropriate vegetation, by maintaining the existing plant cover, or by promoting the
natural establishment of desirable plants. The elements of wildlife habitat are described
in the following paragraphs.
Hardwood trees and woody understory produce nuts or other fruit, buds, catkins, twigs,
bark, and foliage. Examples of these plants are oak, poplar, sweetgum, dogwood,
hickory, blackberry, and blueberry. Examples of fruit-producing shrubs that are suitable
for planting on soils rated good are Russian-olive, autumn-olive, and crabapple.
Wetland plants are annual and perennial, wild herbaceous plants that grow on moist or
wet sites. Examples of wetland plants are smartweed, wild millet, rushes, sedges,
cutgrass, cattail, and reeds.
Grasses and legumes are domestic perennial grasses and herbaceous legumes. Examples
of grasses and legumes are fescue, lovegrass, switchgrass, clover, bahiagrass, trefoil, and
crownvetch.
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Town of Clayton
Environmental Assessment for Expansion
The food and habitat requirements of the major kinds of wildlife in the service area are
discussed in the following paragraph.
Beaver. Beavers eat plant foods only, mostly bark, roots, tender twigs, and green plants.
Their choice food is the tender bark, or cambium, of alder, ash, birch, cottonwood,
hornbeam, maple, pine, sweetgum, and willow. Beaver also eat the tender shoots of
elder, honeysuckle, grass, and weeds. Acorns and com are also choice foods. The chief
feeding areas are within 150 feet of water.
Squirrel. Fox squirrels are restricted mainly to the Sandhills area, but gray squirrels are
plentiful throughout the county. Their choice foods are acorns, beechnuts, black cherries,
com, hickory nuts, mulberries, pecans, pine mast, and the fruit of blackgum and
flowering dogwood.
Dove. Doves eat browntop millet, com, Japanese millet, pokeberry seeds, common
ragweed, grain sorghum, the seeds of pine and sweetgum, and other kinds of seeds.
Doves do not eat insects, green leaves, or fruits. They drink water daily.
Deer. Deer eat acorns, clover, cowpeas, greenbrier, honeysuckle, annual and shrub
lespedezas, oats, rescue-grass, rye, ryegrass, soybeans, and wheat. They need an
adequate supply of surface water for drinking, and wood areas, 500 acres or more in size,
for cover.
Duck. Ducks eat acorns, beechnuts, browntop millet, com, Japanese millet, and the seeds
of smartweed. These foods must be covered by water to be readily available to ducks.
Occasionally, ducks feed on acorns and grains on dry land.
Otter. Otters are primarily carnivorous. Their principle food is fish, mainly the coarse,
undesirable species. They also each crayfish, water beetles, water birds, clams, and,
occasionally, water-loving mammals. Swamps, rivers, streams, and lakes are the habitat
of otters.
Bobwhite. Bobwhites eat acorns, beechnuts, blackberries, browntop millet, wild black
cherries, com, cowpeas, dewberries, annual and shrub lespedezas, milo, mulberries,
panicgrass, pecans, common ragweed, soybeans, pine seeds, and the fruit of flowering
dogwood and sweetgum. They also eat many insects. Their food must be close to
sheltering vegetation.
Rabbit. Rabbits eat clover, winter grasses, and other succulent vegetation. They also eat
waste grain, bark, and twigs. They especially need cover, such as blackberry or plum
thickets or honeysuckle patches.
Raccoon. Raccoons eat a wide variety of foods. Among their favorite vegetable foods
are acorns, chufa, greenbrier, grapes, persimmons, pokeberries, com, hollyberries, and
pecans. Favorite animal foods are frogs, crayfish, grasshoppers, insects, and small
mammals. Raccoons inhabit bottom lands and swamps where den trees are plentiful.
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Turkey. Turkeys thrive only in large blocks of woodland, generally 1,000 acres or more
in size. They need surface water daily for drinking. They often roost over water in the
overhanging branches of large trees. Their choice foods are insects, acorns, beechnuts,
blackberries, browntop millet, chufa, clover, com, cowpeas, wild grapes, hackberries,
mulberries, oats, paspalum seeds, pecans, pine mast, rescuegrass, rye, wheat, and the fruit
of blackgum and flowering dogwood.
Among the fifty-two rare wetland plants in the Neuse Basin, three are federally-listed as
Threatened or Endangered. The rough-leaf loosestrife (Lysimachia asperulifolia), which
is found in savannas and pocosin ecotones, is restricted to southeastern North Carolina
and adjacent South Carolina. In Virginia and other states north of North Carolina, the
Federally Threatened Virginia jointvetch (Aeschynomene virginicd) grows in tidal
freshwater marches; in this state, however, the species is found mostly in ditches and
other moist disturbed soil. The seabeach amaranth (Amaranthus pumilus) grows on sand
flats, near the ends of barrier islands. Its seeds are carried in ocean water to other
beaches and flats. Because the species is an annual and occurs in the ever-changing
environment of sand flats, populations of seabeach amaranth fluctuate tremendously from
year to year. Probably the most imperiled rare plant in the basin is the Godfrey’s
sandwort (Minuartia godfreyi\ which is State Endangered. The only extant population in
North Carolina is in a tidal marsh near New Bern, and within its range in the southeastern
states it is known from only a few locations. Most of the other rare plants in the Neuse
Rare Wetland and Bottomland Animals and Plants
The Neuse River Basin contains many dozens of other rare animals and rare plants,
dependent on wetlands or open water for their existence. The bald eagle (Haliaeetus
leucocephalus} is a Federally Threatened species that nests mainly in estuarine habitats,
but it also nests in the Piedmont at large reservoirs such as Falls Lake. It forages for
fishes on both fresh and brackish waters of lakes, large rivers and sounds. The Federally
Threatened piping plover (Charadrius melodus} nests on barrier islands and sand flats,
and it forages on tidal flats and shores. Many other state-listed bird species nest in
coastal regions and feed in tidal marshes or in estuaries; these include herons, egrets,
ibises, pelicans, terns and skimmers.
Animals: Notorus fuiossus (Carolina madtom) is known to exist in the Neuse River and
its tributaries ranging from the middle piedmont into the lower coastal plain. This
species is state listed as special concern.
Endangered Species
Plants: Adjacent to the Neuse River floodplain near Tippett’s Chapel and SR 2509,
approximately four miles northwest of the project area Scutellaria australis (Southern
Skull Cap) was identified in 1957 and is currently a candidate for state listing as a
threatened species. Also, along the road right-of-way on SR 2551 near the Neuse River
(approximately eight miles northwest of the project area) exists Rhus michauxii
(Michaux’s sumac) which is a federally listed endangered species.
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There are no rare or endangered wildlife species
PREDICTED ENVIRONMENTAL EFFECTS OF PROJECTE.
1.
The existing climate
Soils2.
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Town of Clayton
Environmental Assessment for
^^TP Expansion
’ ------ ‘ ; or habitats located on the current
WWTP site. There are no anticipated direct impacts from the proposed project.
Climate
The proposed project will not affect existing climate of the area,
is not too harsh for the construction of the project.
Less than one acre will be disturbed during construction. Erosion control methods will
be specified and implemented. There will be no changes to soils in the Clayton service
area or at the WWTP site as a result of this project.
Topography
There will be no changes to existing topography by the construction on the existing
WWTP site. The proposed construction involves less than a 10-acre site with less than a
total of 1 acre of disturbed area. The existing topography may be influenced in the
Town’s service area by changes in land use. As discussed later in this section, these
secondary impacts are more heavily influenced by the urban growth demands of the
region than the proposed WWTP expansion.
Basin grow in wet soils of savannas, pocosins and flatwoods, and are only indirectly
affected by water quality and quantity.
The Clayton service area has undergone substantial disturbance and impact throughout
post-Columbian history. Virtually the entire Clayton service area has been intensively
utilized or impacted by agricultrual/silvicultural practices, residential development and
roadway construction. Many of the drainage features exhibit evidence of alteration due
to channelization, sedimentation and erosion. A description of project and adjacent
habitats is presented below. Although lacking the precise components to be classified as
natural communities (NCNHP, 1990) due to human alteration, several habitat types are
generally described in light of their potential natural conditions.
Significant Natural Heritage Areas: Terrestrial and Wetland
Neuse River/Brogden Bottomlands; Cowbone Oxbows; and Sage Pond/Neuse. Rivgr
Floodplain. These are the three most important sites in the floodplain of the Neuse in
southeastern Johnston County. The floodplain is remarkably wide (up to 4 miles) in this
part of the basin; even though much of the floodplain forests have been cut over,
considerable acreage still remains in swamp and bottomland forest. This portion of the
river contains several oxbow lakes, which are rare in North Carolina. No parts of this
natural area are in public or otherwise protected ownership; thus, protection efforts are
greatly needed.
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3.Land Use
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The project will involve no direct changes in land use in the vicinity of the WWTP
site. Indirect changes in land use, which could occur over some period of time
would include residential and possibly commercial and industrial development due
to the eventual increase in the availability of utility service.
Although a 10% factor has been included for commercial and industrial growth, large
water using industries can have a great and unforeseen impact on wastewater flows in any
given area. This potential will be addressed when planning collection line sizes and in
long-range planning of wastewater capacity.
In planning for wastewater collection, transmission and treatment, it is prudent to
consider long-range wastewater projections beyond 20 years in some cases. This would
be particularly applicable when designing major outfall lines, which should have a useful
life span of 50 years or more. These can more cheaply be upsized during initial
construction than paralleled or replaced later to provide increased capacity. In order to
determine the maximum loads, which might ever be carried by a particular transmission
line, the concept of ultimate build-out is useful. The service area is predominantly rural,
in spite of high growth in certain areas. Ultimate build-out of the entire area would mean
that no land was left for agricultural uses. While ultimate build-out is considered less
than desirable by some, large metropolitan areas such as Raleigh are closer to realizing
this build-out potential than could have been imagined 20 years ago. Most of Johnston
County however, will remain as forested or agricultural land based on the projections of
the Office of State Planning. When taken as microcosms, most residential developments
represent ultimate build-out of small areas. Close reference to parcel lines and dwelling
units show more clearly the extent to which relatively high-density development has
occurred in certain areas.
In order to estimate ultimate build-out sewer flows, several factors have been considered.
One major consideration in estimating these flows is the presence or absence of
wastewater service. If no wastewater service is made available, ultimate build-out would,
hopefully, be less due to the need to provide larger lots to accommodate long-term septic
tanks. The suitability of soils and presence of wetlands and unsuitable percolating soils
should have a large bearing on the density of residential development allowed without
sanitary sewer service.
Permeable, well-drained areas depict soil types, which support septic tank use. The
loamy soils are more moderate and are more restrictive of long-term septic tank use. The
silty or clayey areas are classified as having severe limitations toward the use of septic
tanks. In order to promote development in strategic areas, it would be wise to provide
sanitary sewer service in areas where septic tanks are least desirable. These areas should
not be allowed to densely develop without sewer service due to the probability of future
septic tank failure. In order to estimate the ultimate residential development and
expected wastewater generation, in the event that the area governments provides no
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Town of Clayton
Environmental Assessment for
sanitary sewer service, these soil classifications can be utilized to establish an allowable
density of development.
Urban stormwater runoff
In addition to the increased flow of stormwater from urban lands, stormwater contains a
wide array of pollutants that adversely affect aquatic life and can render water unsuitable
for swimming and other recreation. Urban runoff can include automobile residues (oil,
grease, abraded tire material, etc.), yard fertilizer and pesticides, animal wastes and other
pollutants.
Acreage of these various classifications contained within each county can be calculated.
Additionally, acres considered to be “buildable” can be determined by subtracting the
acres of Class A and Class B hydric soils, and the acres of land already built upon, from
the total acres of each sewer shed. In order to calculate potential wastewater production,
development densities can be applied to amounts of available soil classifications to
determine the number of possible dwellings. These numbers can then be multiplied by an
average of 2.7 persons per dwelling and an estimated wastewater production of 85 gpdpc.
This method can show a potential wastewater production without sanitary sewer service.
Once again, while this will probably never happen, certain sewer sheds might
approximate the flow numbers projected for that particular shed. Should the local county
or municipal governments elect never to provide wastewater service in highly developing
areas, flows approaching those calculated could ultimately be generated in selected sewer
sheds. These flows would be treated through septic tanks with a varying degree of
effectiveness. Failing septic tank areas would be subjecting groundwater and surface
water to contamination. These areas, once developed without sanitary sewer service,
would be difficult to sewer if the need ever arose.
The proposed project for Clayton includes the hydraulic expansion of the existing
wastewater treatment plant. This system serves the flows from the Cleveland area which
will need to be increased to account for the additional flows from the previously
unsewered parts of this community where the existing soils and density of housing does
not support the continued use of septic tanks. The elimination of failing septic tanks will
prevent further environmental degradation to the groundwater and surface recharge
waters and the potential health problems from such failure.
Urban land cover
As population increases, so does the amount of urban land area. This change in land
cover appears to be happening at the expense of forest and cultivated croplands. Urban
land includes roads, parking lots, houses, shopping centers, schools, driveways and other
impervious surfaces. Stormwater flows much more rapidly from impervious land than
from agricultural or forestland and causes scouring, erosion and reduced aquatic habitat
quality in receiving streams. In addition, there is less ground water recharge, and thus
small streams in urban areas may have much reduced flows during dry summer periods
than their counterparts with forested watersheds.
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4.Wetlands
5.Prime Agricultural Lands
6.Public Lands, Scenic and Recreational Areas
7.Archaeological and Historical Sites
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As this proposed WWTP expansion project is confined to the current plant site, no
prime farmland will be affected directly or indirectly by the construction and
subsequent operation of this project.
Because no archaeological sites or structures of historical significance are located on
the WWTP site, this proposed project construction and subsequent operation will
not impact any resources of historic significance. The property is adjacent to the
Town of Clayton cemetery; however there is a tree buffer area and construction activity
and traffic along the access roadway will be monitored during construction to avoid
conflicts with funeral activity.
No public lands other than the existing WWTP site will be affected directly or
indirectly; therefore, the project will involve no adverse impacts to any scenic or
designated recreational areas. The Neuse River is frequently used for recreational
activities such as boating, hunting and fishing. The proposed wastewater discharge will
not impair any of these uses.
The continued urban growth in the county does affect the amount of prime farmland
converted to other uses; however the secondary impacts from the expansion of the
WWTP are minimal compared to the economic influences of residential growth from the
overflow of population growth in the Raleigh and Triangle area. However, as previously
stated, the Town of Clayton has recognized the importance of preserving land for
agricultural use and has put in place a Strategic Growth Plan which will encourage that
this is accomplished. Such a plan will minimize what little secondary impacts that may
occur as result this expansion and current residential growth.
These secondary impacts from changes in land use are beyond the scope of one
individual project such as this; however, the Town of Clayton zoning ordinances,
particularly the Watershed Protection Plan and the Strategic Growth Plan, along
with the Neuse River Basin Rules, address the nonpoint source pollution impacts of
continued development. The Town has addressed these issues by implementing
density development restrictions and stream buffer requirements and requiring the
implementation of stormwater controls.
All the construction and subsequent operation of the proposed plant expansion will be
contained on previously disturbed areas of the WWTP site, which does not include any
wetlands. Therefore, the proposed project will have no wetland disturbance.
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Town of Clayton
Environmental Assessment for
Current noise levels at the Clayton WWTP are minimal due to judicious selection of
equipment and enclosing structures. The expanded future operation of this facility
will result in no additional noise generation. During construction noise levels from
construction could be elevated in the vicinity of the work site. This will be minimized by
restricting the work hours to 8 am- 5 pm Monday - Friday and coordinating activities
with the nearby cemetery.
Little Creek
The direct impacts to Little Creek by the proposed project will occur only during
construction and will be minimized by erosion control methods implemented to
control runoff. Erosion at construction sites is a significant source of sedimentation in
streams and rivers. Even the best sediment control measures are only about seventy
Local air quality is influenced principally by the greater Raleigh urban area, local
industries and local farming practices. This project will involve no direct or indirect
impacts on long-term air quality. Dust and equipment engine exhaust generated during
the construction period could cause short-term degradation of air quality in the vicinity of
the work site. Should the increase in the size of the standby generator exceed the
minimum kilowatt production required by the Division of Air Quality, then an air quality
permit may be needed. The maximization of the treatment processes and improved
aeration should minimize any odor generation at the facility.
Groundwater Quality
No direct or indirect impacts to groundwater quality resulting from the project are
anticipated. Shallow groundwater levels may be manipulated temporarily in very
limited locations during construction. Groundwater levels will return to normal
immediately following construction and, therefore, should not be adversely impacted on a
short-term or long-term basis.
Neuse River and Its Tributaries Located in Johnston County
There are no direct impacts of the proposed project on these water bodies. Indirect
impacts could occur from the growth in the service area. In addition, the existing
water quality of the Neuse River has not significantly impacted from the immediate
effects of the current 1.9 mgd Town of Clayton NPDES discharge. This is
substantiated by the fact that monitoring downstream of the Town’s discharge by
the Division of Water Quality indicates that the Neuse River water quality improves
by the SR 1201 station. The increased flow of 2.5 mgd (2% of the stream flow )
should not significantly alter these impacts. The additional 0.6 mgd constitutes only
0.5% of the 7Q10 of the Neuse at this location.
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The Neuse River, classified WS-IV NSW CA serves as the primary raw water supply
source for the Town of Smithfield and Johnston County approximately 1 river miles
downstream from the proposed outfall as well the City of Goldsboro approximately 45
miles downstream. The proposed increase in Town’s permitted flow will not impair
these uses. This is illustrated by the Town’s current performance in meeting its discharge
limits, by the fact that the Town has not failed toxicity tests in the recent past, and from
monitoring data on the Neuse River showing water quality improvement downstream of
the Town’s discharge point. The proposed increase in the permitted discharge is
relatively small and based on the speculative discharge limits set the Division of
Water Quality, the resulting discharge of 2.5 mgd and its cumulative effects will not
produce a significant increase in nutrient loading on the Neuse River and, therefore,
should not cause a degradation in the raw water quality currently seen by the Town
of Smithfield and Johnston County at their respective intakes.
Water supply needs
As the population increases, so will the need for water. As more water is used, more
wastewater is generated. Also, as water is removed from a stream or river for water
supply purposes, the reduced flow can result in the reduction of the assimilative capacity
of the water body for accepting effluent from wastewater treatment plant. Water supplies
in the upper basin come from a combination of surface water impoundments and wells in
the upper and middle basin. The lower basin is served almost exclusively by wells.
Major aquifer levels are currently dropping and further increases in use will cause
continued reduction.
percent effective (Section A, Chapter 4-B.l Neuse River Basinwide Water Quality Plan,
December, 1998), and they could be much worse depending on how well the measures
were designed, installed and maintained. During construction of this expansion
project, every effort will be made to employ the use of best management practices to
maximize sediment and erosion control and minimize any impacts to the Little
River, adjacent to the WWTP site. Indirect impacts may occur because of growth
in the service area.
More importantly, this project will help prevent any proliferation of small private
discharges to the Neuse in this vicinity, which might occur in response to development
pressure. These small discharges are historically not managed and operated as well as
municipal discharges.
In addition, the Watershed Protection Plan adopted by the Town of Clayton limits
developments to 2 dwellings per acre or 24% built upon area with curb and gutter or 3
dwellings per acre or 36% built upon area without curb and gutter. For all development
with the Town, a minimum of 30-foot vegetative buffer is required from streams and
stormwater controls must implement BMPs to minimize runoff.
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Town of Clayton
Environmental Assessment for W
W^^^xpansion
Eutrophication of Receiving Waters
The magnitude of the nutrient wasteload in the proposed discharge will not appreciably
increase eutrophication of the Neuse River. The allocated nitrogen loading will remain
the same as currently permitted and the phosphorus loading will drop with the lower
concentration limit for Total Phoshporus.
Wastewater Treatment and Disposal
As previously stated, the proposed increase of 600,000 gpd to the existing NPDES
Permit should not have significant effects on the Neuse River. The existing treatment
produces an excellent effluent, which is compliant with the existing NPDES permit. The
proposed increase can be treated to the tentative effluent limits previously given by the
Division of Water Quality to the Town of Clayton for a discharge of 2.5 mgd. The
existing wastewater treatment plant is capable of these treatment limits with minor
modifications. An increase of 600,000 gpd results in a permitted increase of 25 Ibs/d of
BOD, an increase of 150 Ibs/d of TSS, a decrease of 11 Ibs/d of ammonia, and a decrease
of 11 Ib/d of phosphorus at the new limits of 2.5 mgd, 5 ppm BOD, 1 ppm ammonia, 30
ppm TSS, 1 ppm TP. The annual nitrogen loading will remain the same per the Neuse
River Basin Rules and the NPDES permit. It is also noted that with the new filters the
existing treatment plant averages less than 5 ppm on the TSS so the above increase is
skewed.
Reduction of Urban Point and Nonpoint Source Pollution
Several keys to reduce pollution and stream erosion from urban areas include minimizing
impervious surfaces to slow runoff, promoting filtration and infiltration of the water
before it reaches a creek or storm drain inlet, keeping pollutants out of the runoff, and
encouraging local governments to consider water quality impacts during long-range
planning. The Town of Clayton has stormwater ordinances that serve to minimize
the impacts of new development on water quality.
In summary, the actual construction activites involved in this project will have no
significant impact on the water resources in the area of the WWTP site. Secondary,
or indirect, and cumulative effects are more targeted toward the operation of the
plant expansion itself. Based on the information provided in this section, this small
increase in the permitted flow from the Town’s WWTP to the Neuse River will not
have any detrimental effects on the water quality. In addition, the Town has been
very progressive in implementing numerous plans, policies and ordinances; they
include their Watershed Management Plan, Strategic Growth Plan, and Zoning
Ordinances. These combined will help to significantly decrease any secondary or
cumulative effects from further growth and development in the Clayton service area
that may be raised as concerns from the increase in the WWTP capacity.
CT9905
G.REFERENCES
Needs Survey for the Town of Clayton, McKim & Creed Engineers, 1997.
1999 Capital Improvements Plan, Town of Clayton, July 1999.
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Neuse Letter, North Carolina Cooperative Extension Service, September 1997.
H.EXHIBITS (See Attached)
I.STATE AND FEDERAL PERMITS REQUIRED
An amendment to the existing NPDES permit issued by the Division of Water Quality
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Soil Survey of Johnston County, North Carolina, USDA, Soil Conservation Service,
October 1994.
Neuse River Basinwide Water Quality Plan, NCDENR, Division of Water Quality, Water
Quality Section, December 1998.
Town of Clayton Wastewater Treatment Plant Upgrade Evaluation, Hobbs, Upchurch &
Associates, P.A., June 1999.
Addendum No. 1 to Amendment No. 1 to Clayton 201 Wastewater Treatment Facilities
Plan, McKim & Creed Engineers, April 1993.
Amendment No. 1 to Clayton 201 Wastewater Treatment Facilities Plan, McKim & Creed
Engineers, November 1992.
Town of Clayton
Environmental Assessment for WWTP Expansion
Appropriate erosion control during construction, and operation within permitted
limitations will mitigate any negative impact to water supplies. The Town of Clayton has
implemented these rules into their existing zoning requirements and has adopted a
Watershed Management Plan and a Strategic Growth Plan, and therefore, any additional
nonpoint source impact, such as stormwater runoff, as a result of this expansion project
will be effectively mitigated through these measures.
File Correspondence, Staff Reports, Raleigh Regional Office, NCDENR, Division of
Water Quality, October 1999.
will be required to increase the flow from 1.9 mgd to 2.5 mgd and issue new permit limits
at the expanded flow. An authorization to construct permit from the Division of Water
Quality will be required to re-rate the WWTP to a design capacity of 2.5 mgd. Plans and
specifications for the minor plant modifications and the recent engineering evaluation by
Town of Clayton Zoning Ordinance, Town of Clayton Planning Department, January
1993.
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If required by the increase in the standby generator requirements, an Air Quality Permit
from the Division of Air Quality will be obtained. If the disturbed area is greater than one
acre on the construction site then an Erosion and Sedimentation Plan will be submitted to
the Division of Land Quality.
Expansion
Hobbs, Upchurch & Associates, P.A. have been submitted for review to approve this
increase in design capacity.
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Attachment 12/13/00HUA
PREPARED BY
HOBBS, UPCHURCH & ASSOCIATES, P.A.
300 S.W. BROAD STREET
SOUTHERN PINES, N.C. 28388
DECEMBER 2000
TOWN OF CLAYTON
WWTP EXPANSION
ENVIRONMENTAL ASSESSMENT
EXHIBITS
Town of Clayton
Environmental Assessment for WW^Hsxpansion
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EXHIBITS
Exhibit 1: Wastewater Treatment Plant Evlauation
I Exhibit 2: NPDES Permit Information
Exhibit 3: NPDES Speculative Limits
I Exhibit 4: Alternatives Analysis Figures
Exhibit 5: Map of the Town Limits Including the WWTP Site and Discharge Point
I Exhibit 6: Map of the Town’s Extraterritorial Limits and Utility Service Area
Exhibit 7: Composite Topographic Map
Exhibit 8: Soil Maps
Exhibit 9: Town of Clayton Zoning Ordinances
Exhibit 10: Town of Clayton Strategic Growth Plan
I Exhibit 11: Subbasin Map
Exhibit 12: Town of Clayton Watershed Management Plan
Exhibit 13: Nutrient Removal Study, The Wooten Company, October 2000
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12/13/00AttachmentHUA
Town of Clayton WHr
Environmental Assessment for WW fP Expansion
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JUNE, 1999
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WASTEWATER TREATMENT PLANT
UPGRADE EVALUATION
Performed by
HOBBS, UPCHURCH & ASSOCIATE, P.A.
/tWWx■ : UAL \ 2
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INTRODUCTION
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LCWRF Uprate Feasibility Study
. A related issue concerns upcoming limits for nutrients, especially nitrogen, in all
• discharges to the Neuse River Basin. The draft NPDES permit for the LCWRF would
establish a limit for total nitrogen at 21,400 pounds on an annual mass basis. Under
Special Condition A.(5) of the permit, the mass limit can be waived if the Town is a
member of an approved nutrient trading coalition for the Neuse River Basin. The Town
of Clayton has expressed interest in joining such a coalition, however the status of a
Neuse River Basin Coalition, and on the Neuse River Basin Nutrient Management
Strategy itself, is currently up in the air. The original strategy was challenged in court,
bringing in the USEPA. The State of North Carolina DENR and the USEPA are in the
process of reviewing the Strategy and the modeling that forms the basis of the goals of
the program.
Under a tentative agreement with the U.S. EPA on a total maximum daily load (TMDL)
for total nitrogen for the Neuse River Estuary, North Carolina has committed to consider
initiating a new round of rulemaking for the Neuse River Basin. The N.C. Division of
Water Quality (DWQ) has agreed to reconsider its 30% nitrogen reduction goal for the
Neuse Estuary by July 1,2000, and to prepare a draft revision of its currently submitted
TMDL and, if the new TDL requires it, initiate rulemaking to implement the new TMDL
by March 31, 2001. In the meantime, the Neuse River Nutrient Sensitive Waters
Management goals and rules adopted in August 1998 will continue to be implemented,
except for wastewater discharge permit allocations, which may have to be revised.
The TMDL calculates the point source share of baseline loading delivered to the Neuse
Background
The municipal wastewater treatment plant for the Town of Clayton is the Little Creek
Water Reclamation Facility (LCWRF). This facility provides secondary biological and
tertiary treatment to the Towns wastewater and discharges the treated effluent to the
Neuse River. The current draft NPDES permit for the LCWRF, effective April 1, 1999,
establishes the rated design capacity at a monthly average of 1.9 Million Gallons per Day
(MGD).
The Town of Clayton is experiencing continued growth, both in terms of population and
in industrial capacity. Current average day flows (ADF) to the LCWRF are running at
1.35 MGD (1998 figures). This is about 72 percent of the permit limits of 1.9 MGD. By
law, the Town is required to begin planning and design of a new or upgraded treatment
capacity when the ADF reaches 80 percent of the permit limit, which in this case would
be 1.52 MGD. Although the Town’s flow is not yet at this point, it is prudent to begin
evaluating alternatives at this time. Allocations to permitted sewers are past the limit.
Agreement with the County allows trading of allocations with approximately 200,000
B ■ gpd of capacity left. The current increase in flow of200,000 gal/yr shows that only one
" year remains before the 80% mark may be reached and three (3) years before permit
• limits are exceeded.
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The Purpose of this Study
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Estuary to be 2.34 million pounds per year and, to achieve a 30% reduction, allocates
point sources a total yearly loading at the estuary of 1.64 million pounds. According to
the TMDL submission, the Neuse NSW rules probably will not accomplish a point source
reduction to the TMDL level. Additional rulemaking to revise point source allocations is
expected soon, and NPDES wastewater discharge permits in the Neuse River Basin will
not be reissued until the Environmental Management Commission provides guidance to
DWQ on the issue.
Initial discussions with the NPDES Permits section at DWQ indicated that a desk top
study would be sufficient for the goals of this study, that is to demonstrate that the
existing facility could be uprated to 2.5 MOD and still meet its NPDES discharge limits.
This is contingent upon the current satisfactory operation of the LCWRF, meeting or
exceeding all of its discharge limits.
Regardless of the outcome of the current review, it is certain that there will be some form
of nutrient strategy implemented for the Neuse River Basin, and that an allowance for a
nutrient trading coalition will be a key part of the strategy. Prior to the current situation,
a tentative charter for a trading coalition was in the process of being developed. An
element of the initial draft was to set charges for the purchase and sale of nutrient
“credits”. The charges for purchasing additional nutrient credits were to be $22 per
pound of total nitrogen (TN) over the discharger’s mass limit as set by the NPDES
permit The Town of Clayton was concerned with the cost impacts of the nutrient trading
charges versus the costs of Biological Nutrient Treatment and Reuse Strategies at the
Town’s wastewater facilities on their plans to expand treatment capacity to meet future
needs.
The purpose of this study is to evaluate the technical and economic feasibility of
increasing the rated capacity of the existing LCWRF from the current permitted level of
1.9 MGD to as much as 2.5 MGD. The goal is to develop a program which would allow
the existing facilities to be uprated at minimal capital cost The study would include
initial review with the DENR NPDES Permitting Section leading to an approval in
principal of the technical feasibility of the facility uprating. The proposed modification
of the NPDES permit, including Environmental Assessments, etc., would then be pursued
with the NC DENR DWQ as part of a separate project.
Due to the twin pressures of the Towns growth and the increasing costs of meeting
effluent criteria, the Town of Clayton has begun to review various alternatives to meeting
future wastewater treatment needs. In the long term, the Town is considering the
construction of a new reclamation facility at a site owned by the Town adjacent to the
Neuse River, expansion and upgrades at the existing facilities, wastewater reuse or
joining with a regional facility and getting out of the treatment business altogether.
In the short term, the Town is exploring the feasibility of increasing the rated capacity of
the existing LCWRF to as high as possible, and at least up to 2.5 MGD.
I
CURRENT CONDITIONS
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♦
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Page 3
HUA/ Town of Clayton
LCWRF Upraie FeastbllUy Study
Recent Operating Records
NPDES Permit Limitations. An important consideration in evaluating the feasibility of
Existing Little Creek Water Reclamation Facility Units
The LCWRF currently consists of the following unit processes:
I ■
■ Final Disinfection
- Ultraviolet (UV) (Newly Online)*
- Chlorination (Previously existing, now for backup only)*
- -De-chlorination (Sulfur Dioxide) (Previously existing, now for backup only)*-
■ Effluent Pumping to Neuse River •
■ Waste Activated Sludge (WAS) Pumping
■ Aerobic Digestion .. -
■ Sludge Conditioning (Alum, Polymer and Magnesium Hydroxide)
■ Sludge Thickening (Drum Thickener)
■ Sludge Storage
■ Sludge Dewatering (Drying Beds)
■ Sludge discharge (Truck transfer to final disposal)
■ Trickling Filter Plant (Separate Train)
- Influent Pumping Station
- Clarigester (Combined clarifier and anaerobic digester)
- Rock Media Trickling Filter
- Final Clarifier
The tertiary facilities have recently been constructed and placed into operation, including
the tertiary shallow bed filters and the UV disinfection facility. The operating records
discussed below therefore do not include the operational impacts of these units except for
the months of April and May when these units were placed into operation.
Screening
Mechanically cleaned bar screen
- Manual bar rack (By-pass)
■ Grit Removal
■ Flow Measurement (Parshall flume)
■ Influent Pumping
■ Secondary biological treatment
- Extended aeration using oxidation ditches (2)
- Final sedimentation basins (2) with optional chemical addition
■ Return Activated Sludge (RAS) Pumping
■ Tertiary Sand Filters (2 Shallow bed ABW Filter Beds) (Newly Online)
LCWRF Effluent Quality.
TABLE 1 - NPDES PERMIT LIMITATIONS
PARAMETER
*
Condition A.(5) arc met, as described in the previous section.
Page 4
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HUA/ Ttnm of Clayion
LCWRF Uprate Feasibility Study
The summary in Table 1 illustrates the tightening of limitations for BOD5 and NH3-N to
take effect after April 1, 1999.
1.9 MOD
10.0 Mg/1
20.0 Mg/1
30.0 Mg/1
4.0 Mg/1
8.0 Mg/1
28 pg/1
21,400 Ib/yr
2.0 Mg/1
200/100 ml
To 3/31/99
(PartA.l)
Monthly Average
Monthly Average
Monthly Average
Monthly Average
Monthly Average
Monthly Average
Flow
BOD5 (Summer)
BOD5 (Winter)
Total Suspended Residue (TSS)
NH3-N (Summer)
NH3-N (Winter)
Total Residual Chlorine (Cl)
Total Nitrogen (TN)
Total Phosphorus (TP)
Fecal Coliform (FC)
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uprating a facility is whether the existing facility is meeting or, hopefully, exceeding its
effluent discharge limits. A copy of the LCWRF draft NPDES permit (Permit No.
NC0025453) is provided in Appendix A. The effluent limitations in Part A.(l) and Part
A.(2) of the permit are summarized in Table 1. Part A.(l) of the permit is effective
through March 31, 1999 while Part A.(2) will become effective April 1, 1999. The
permit renewal process for the LCWRF, along with all other discharge permits in the
Neuse River Basin, has been placed temporarily on hold until the TMDL review is
completed, as described previously.
IJ
1.9 MOD ..
5.0 Mg/1
10.0 Mg/1
30.0 Mg/1
2.0 Mg/1
4.0 Mg/1
28 pg/l
21,400 lb/yr* Annual mass load
2.0 Mg/1
200/100 ml
PERMIT LIMITATIQNS
After 4/1/99 Sample Type
(Part A.2)
Copies of the monthly reporting forms for the twelve months of 1998 are provided in
Appendix A following the NPDES permit draft. The reported monthly averages of each
of the critical effluent parameters for the LCWRF are summarized in Table 2 for 1998.
Quarterly Average
Monthly Average
The (•) denotes that the annual mass limitation of 21,400 pounds of tool nitrogen (TN) may be waived if the conditions of Special
PARAMETER
MONTH
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I May 1999 the following results have been observed:
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Page 5
BODS
6.10
4.11
5.5
4.2
7.3
TSS
17.71
5.33
1.4
1.2
1.6
TN
6.29
5.76
1.5
1.9
0.8
FC
63
27
FC
(N/lOOml)
30
30
30
HUA/ Toym of Clay tort
LCWRF Uprate Feasibility Study
1.35
1.32
1.39
BOD5
(Mg/1)
7.5
7.1
8.0
TSS
(Mg/1)
<18.3
<18.5
<18.1
Cl
(Mg/1)
3.9
4.0
3.9 .
TP
1.93
3.14
Averages:
Annual
Summer
Winter
Flow
(MOD)
NH3-N
2.99
1.43
Flow
1.23
1.13
NH3-N
(Mg/1)
Dec 97
Jan 98
Feb
Mar
Apr
May
June
July
Aug
Sep
Oct
Nov 98
0.962
1.272
. .1.575
1.474
1.281
1.431
1.40
1.24
1.331
1.413
1.156
1.184
12.3
20.6
. 14.1
19.5
15.8
14.7
16.9
17.2
15.6
<24
25.3
<24
4.8
3.6
4.8
3.4
2.3
5.0
4.4
4.1
2.0
1.7
2.7
58
45
10
24
S
10
24
59
27
42
41
15
5.1
7.0
- 7.5
11.7
578“
4.0
4.2
3.8
3.6
3.3
4.9
5.4
1.3
1.1
1.4
2.4
TT
0.8
0.7
<0.5
2.2
0.7
0.6
1.6
5.2
7.0
8.7
12.1
"W
7.6
6.3
5.4
6.8
8
6.4
7.1
1.3
0.3
0.6
0.6
KT
3.3
1.7
0.5
3.2
2.6
1.5
1.2
TABLE 2 - RECORDED EFFLUENT PARAMETER^
treatment to 4 BOD, 5 TSS, <1 NH3-N, 4 TN, 2 TP, and 14 FC is the best to be expected
from the existing system. This should be sufficient to meet the existing draft permit
limits. A few critical parameters are discussed in more detail below.
TN TP
(Mg/1) (Mg/1)
Flow. The design capacity of the LCWRF, and its current permitted flow rate, are set at
1.9 MOD. The influent flow to the LCWRF for 1998 averaged 1.35 MOD on an annual
MONTH
April
May
As the system stabilizes, results should continue to improve; however, state of the art
Note: . .The months within the box arc the summer months defined by the permit
In comparing the two tables above, it is evident that the LCWRF is meeting or exceeding
. all of its effluent pennit limitations in Part A.(l). However, the current facilities, if
operated in the same manner, would not meet the limitations in Part A.(2) for summer
BOD5. The addition of the tertiary filters to the plant train will result in a further
improvement in effluent quality.
During startup and initial operation of the tertiary filters and UV disinfection in April and
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TABLE 3 - RAW WASTEWATER STRENGTHS
PARAMETER
MEDIUM STRONG
x
x
UX
Page 6
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HUA/ T<nm of Clayton
LCWRF Upraif Feasibility Study
1) Annual Averages for 1998
2) Ref.: Metcalf & Eddy, “Wastewater Engineering", 3rd Edition,, p-109.
145 Mg/1
350 Mg/1
219 Mg/1
16.7 Mg/1
25.4 Mg/1
6.8 Mg/1
120
250
100
12
20
4
220
500
x220
25
40
8
350
1000
350
50
85
15
LCWRF
(1)
BODS
COD
TSS
nh3-n
TN
TP
!
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The low organic strengths of the raw wastewater could be caused by the large
contributions from industrial sources. Recent influent samples indicate that the organic
x
x
One additional note regarding flows - a major portion of the existing flow rates to the
LCWRF originate from the two principle industrial sites, both of which are pumped to
. the Towns system at the upper end of the O’Hara/Durham Outfall. A significant portion
of this industrial flow can be diverted^ if needed, to the Johnston County system. This
would free up a considerable proportion of the existing LCWRF capacity, and thus
provide several more years for planning and development of additional treatment
capacity. This may not be politically or economically desirable, but it does indicate that
the Town has several options at its disposal to avoid or delay a moratorium.
Raw Wastewater Strengths; Results of 1998 data indicate that the majority of the raw
.wastewater constituent concentrations are indicative of a relatively weak strength
wastewater. However, the total suspended solids (TSS) levels are more typical for a
medium strength wastewater. This can be seen more clearly in the following Table 3:
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basis. This is 71 percent of its permitted capacity. When the influent flow reaches an
annual average of 80 percent of the plants capacity, or 1.52 MGD at the currently
permitted flow capacity, the Town must begin planning and design of new capacity in
order to avoid a moratorium or other actions. Once the Town begins such a process, they
can apply for a waiver to allow the plant to accept up to 90 percent of its currently
permitted flow rate or 1.71 MGD. Additionally the Raleigh Regional Office of the DWQ
has expressed concern that sewer permit allocations to the LCWRF are approaching
100% of the permitted capacity. While it may be several years before these allocated
flows become actual flows, DWQ could choose to withhold additional sewer permits at
. such time as 100% of the capacity is allocated. Additional challenges by the Town to this
policy should be made to the Director of DWQ, as it is only the Director’s Office which
can deny issuance of permits. At the current growth in the system the Town has 2-3
years in which to plan and develop additional flow capacity. The purpose of this report is
to determine if some of that additional capacity can be obtained by an uprating of the
existing facilities.
TYPICAL STRENGTHS (Mg/1) (2)
WEAK
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Summary
TABLE 4 - LCWRF OPERATIONAL SUMMARY
PARAMETER
VALUES (1)
1) Reported Annual or Seasonal AveragesI
Poge 7HUA/ Town of Clayton
LCWRF Upratt FeaslbllUy Study
1.5 Mg/1
30/100 ml
2.0 Mg/1
200/100 ml
5.0 Mg/1
10.0 Mg/1
2.0 Mg/1
4.0 Mg/1
28.0 |xg/l
Table 4 below combines and summarizes the data in the Tables 1 and 2 for ease of
comparison.
1.35 MOD
7.1 Mg/1
8.0 Mg/1
5.5 Mg/1
1.2 Mg/1
1.6 Mg/1
<18.3 jxg/1
16,145 Ibs/yr
Flow
BODj Summer
BODs Winter
TSS
NH3-N Summer
NH3-N Winter
Cl Residual
TN
Meets or Exceeds
Will not meet future
Meets or Exceeds
Meets or Exceeds
Meets or Exceeds
Meets or Exceeds
Meets or Exceeds
Will not meet future
@1.9
Meets or Exceeds
Meets or ExceedsTP
Fecal Coliform
1.90 MOD
10.0 Mg/1
20.0 Mg/1
30.0 Mg/1
4.0 Mg/1
8.0 Mg/1
28.0 p.g/1
21,400 Ibs/yr
The foregoing discussion demonstrates that the existing treatment imits at the LCWRF
have been consistently meeting and exceeding their effluent limitations in force through
Total Nitrogen. The draft NPDES permit includes a limitation of 21,400 pounds of
nitrogen per year. At current average daily flows (1.35 MOD) and average effluent total
nitrogen levels (TN = 3.9 Mg/1), the LCWRF is discharging a total of 16,145 pounds per
year of TN, well below the permit limit At the rated flow capacity of 1.90 MOD and the
same TN concentration, the load would be 22,556 pounds per year, just over the proposed
cap. At 1.90 MOD, the LCWRF would have to remove TN to an annual average of 3.70
Mg/1. In order to uprate the flow capacity of the facility to 2.5 MOD and still meet the
proposed TN limitation, the effluent concentration can be no more than 2.81 Mg/1.
Once the tertiary ABW filters are placed on-line, the LCWRF will be able to consistently
meet the new Part A.(2) limitations for BOD5 and may also be able to meet the more
restrictive TN limitations at its current rated flow capacity. This must be confirmed
through actual operation, since the additional flow to the oxidation ditches will reduce the
detention time required for denitrification.
1998 EFFLUENT PERMIT LIMITATIONS COMMENT
To 3/31/99 After 4/1/99
• . . Astrength is increasing as more domestic flow is added to the Town s system: The original
design calculations for the biological process at the plant assumed a BOD5 of 220 Mg/1,
which is a typical medium strength wastewater, and should still be used in future
considerations.
EVALUATION OF UNIT CAPACITIES
Peak Flows
Period ADF Peak Flow Peak Factor
PageS
The peak flows above are the maximum daily flows, not the peak instantaneous flows.
Treatment facilities should be designed on the basis of maximum day flows.
HUA/Tovn of Clayton
LCWRF Upeate Feasibility Study
The purpose of this study is to determine whether the existing facilities can be
economically uprated to handle 2.5 MGD while still meeting permit limitations
It is fully anticipated that, with the new tertiary facilities on line, the LCWRF will be
fully capable of consistently meeting and exceeding all the effluent limitations. The only
question at this time is whether the full plant (with the tertiary filters on line) will be able
to meet the TN limitation at the full rated capacity of 1.90 MGD. Once the tertiary filters
are on-line, operational experience will indicate if operating practices need to be
modified to improve TN removal.
1.38
1.32
1.47
2.07
1.86
2.37
1.50
1.41
1.61
Annual
Summer
Winter
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The evaluation of the feasibility of uprating the LCWRF will proceed on a unit by unit
basis, beginning with the headworks. The units will be evaluated both for their hydraulic
capacity and for their treatment capacity. The treatment capacities will be evaluated on
the basis of the proposed ADF of 2.5 MGD and the existing raw wastewater
characteristics. Hydraulic capacities will be evaluated on the basis of the peak flows
expected for an ADF of 2.5 MGD. Typically, a peaking factor of 2.5 is used for
calculating peak flows. This is a very general rule of thumb which does not take into
consideration the fact that peaking factors are directly related to the contributing
population nor the fact that pumped flows are not peaked. Since a very significant
•proportion of the influent flow to the LCWRF is pumped flow, it is prudent to perform a
more critical analysis of peak flows.
March 31,1999. The current plant operations will also meet the proposed limitations to
take effect after April I, 1999 with the exception of the Summer BOD5. Current
operations result in an average summer BOD5 of 7.1 Mg/1, which meets the current limit
of 10.0 Mg/1 but will not meet the proposed limit of 5.0 Mg/1 after April 1, 1999.
The calculation of peak flows should be based on strong empirical data, both in general
terms and for specific systems. The historical flow record for the Town of Clayton, as
summarized from the monthly report forms (MR-1) for 1998 in Appendix A, yields the
following annual and seasonal peak factors, on a monthly average basis:
I
Page IIHUA/ Ttnen of Clayion
LCWRF Upratc Feasibility Study
M&E
M&E
0.95
0.84
1.0
0.46
Okay
Okay
(Hydraulic Retention)
Recycle Ratio 0.75 - 1.50
Solids Yield 0.4 - 0.8
Ref: M&E, Wastewater Engineering, 3rd Edition, Table 10-5, p-550.
The current F:M ratios are somewhat low relative to typical industry standards, due to the
low influent BOD5 levels, as discussed above, however, these will improve as more
domestic wastewater is added to the system. The MLSS levels are at the high side of the
Ten State Standards and at mid-range per M&E, but both well within acceptable
operating limits. The mean cell residence times (MCRT) are higher than typically seen.
Current sludge wasting rates are averaging 23,700 GPD with an average sludge solids of
4,445 Mg/1 MLSS and a corresponding MLVSS assumed at 80 percent of MLSS or about
3*556 Mg/1.
In order to bring the MCRT down to 30 days, either the sludge wasting rate can be
increased or the MLSS reduced. Since the MLSS levels are a result of operational
experience and best practice for the Clayton wastewater characteristics, it is more
reasonable to adjust sludge wasting rates. In order to get the MCRT down to 30 days, the
sludge wasting rate, at an ADF of 2.5 MOD, could be increased to 34,000 GPD from the
present level of 23,700 GPD. At this rate, the observed solids yield (Y) increases to 0.58
pounds of VSS produced per pound of BOD5 consumed, which is more comfortably
within the typical range of 0.4 to 0.8 Ib/lb. The sludge pumping capacities will be
checked at the higher wasting rates.
The remaining organic loading parameters in Table 5 are within acceptable ranges.
A theoretical analysis was undertaken to determine impacts of the higher flow rates on
nitrification and denitrification processes within the aeration basins. This analysis
indicated that the existing aeration volumes were adequate to continue nitrification rates
in the basin to result in an estimated ammonia level of 0.62 Mg/1 which is very close to
the current recorded levels. The analysis also indicated that denitrification would also
continue as before with little impact These are highly theoretical calculations and should
be confirmed through operational studies in the field.
Finally, the existing aeration systems were evaluated for adequacy at an ADF of 2.5
MGD. With an influent BOD5 level of 147 Mg/1 and an influent TKN of 34 Mg/1, the
oxygen requirements are calculated as 6,764 pounds of O per day. With an influent
BODj level of 220 Mg/1 and an influent TKN of 35 MG/1, the oxygen requirements are
calculated as 9,890 pounds of O2 per day. Per Baker Hughes these type aerators transfer
3.5 lbs O2 per HP per day. At this rate, a total of 120 Hp is required at the lower loadings.
Per our calculations 200 Hp is required at the higher loadings without a denitrification
credit. The present two oxidation ditches are equipped with two - 50 Hp units and two -
25 Hp units for a total connected capability of 150 Hp. This is barely enough to meet the
calculated loads, at the higher influent loadings with a denitrification credit. The report
from Baker Hughes and the HUA spreadsheet are attached for reference.
I
Final Clarifiers
TABLE 6 - FINAL CLARIFIERS OPERATING PARAMETERS
Parameter
Value @5.8 MGD
439 I
1036
16.7
39.4
6,631
15,650
Ref: M&.E, Wastewater Engineering, 3rd Edition, Table 10-12, p-588
Page 12
The final clarifiers are a key element in the biological treatment system and must be
designed in conjunction with the aeration basins. Table 6 below presents typical
operating criteria used in the design of final clarifiers for extended aeration type activated
sludge systems. The actual operating values for each parameter are presented for the
ADF of 2.5 MGD and for the projected peak flow of 5.8 MGD.
Conclusions. The existing oxidation ditches are capable of handling 2.5 MGD with no
reduction in BOD5 removal, nitrification efficiency and no apparent loss of denitrification
capability. The oxygen transfer efficiency of the existing aerators will be marginal
however at higher BOD loads approaching the design conditions of 220 Mg/1.
Supplemental aeration by the addition of new 40 Hp aerators or fine bubble diffusers and
a blower system may be necessary if BOD increases continue. The only improvements
noted, not related to the uprating, is the need for a better means of controlling and
distributing flows out of the two aeration basins.
Overflow Rate (Gpevto)
Average Flow
Peak Flow
Weir Loading (gpd/fo
Average Flow
Peak Flow
The M&E recommended criteria are slightly more conservative for the overflow rate and
the solids loading rate that can be applied but more forgiving for peak weir loading. The
Ten State Standards provided maximum values at peak flows only. The two most
important criteria, and the ones most often used for design, are the overflow rate, which is
200-400
600-800
1000
10,000
20,000
15,000
M&E
M&E
HUA/ To*n of Clayton
LCWRF Upeate FeasibUUy Study
M&E
M&E
Ten States
M&E
M&E
Ten States
u
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Solids Loading Cb/Day/Ft2)
Average Flow 5-24
Peak Flow 34
Ten States
Criteria_____
Source
Operating Value
@2.5 MGD
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Page 13
I HUA/ Toxm of Clayton
LCWRF Upeate Feasibility Study
closely tied to the upflow velocity, and the solids loading rate. The weir ^feing criteria
is less often used.
Baker Hughes (EIMCO) reviewed the existing installation and proposed re-rating. They
concur the clarifiers can be re-rated but recommend that Stamford Baffles and energy
dissipating inlets (EDI) be incorporated into each clarifier for enhanced performance
during peak flow events..
These comparisons indicate that the final clarifiers, as they are currently configured, will
provide marginal operation at the higher peak flows. This may result in floc carryover as
well as some “burping” of solids over the weirs during peak flows. This will result in
more rapid blinding of the tertiary filters, however this can be handled by increasing the
backwash indexing cycle. Plant personnel have noted that the backwash return rate
contribution of250 gpm increases the instantaneous rate to the clarifiers. It may be
necessary to return the backwash to the head works to help dampen these effects.
The chemical addition facilities at the LCWRF have the capability to feed alum and
magnesium hydroxide to the aeration basin flow distribution box ahead of the final
clarifiers to provide enhanced coagulation and sedimentation. This facility will enable
the operation of the clarifiers to be modified to improve floc formation, solids capture
and sludge thickening at the higher loadings. In addition, it is suggested that field tests be
undertaken to determine the potential improvements in floc formation and solids capture
through the addition of a polymer to the clarifier influent Polymer addition should be
provided at the clarifier inlet well to limit the turbulence after introduction of the
polymer. Any turbulence will tend to shear the polymer floc, which will not re-form.
Other improvements which should be evaluated include the installation of baffles at the
effluent weirs to prevent short circuiting and the carryover of resuspended solids from the
• hindered settling zone of the clarifiers during peak flow periods.
Conclusions. The existing clarifiers will be capable of handling the flows at a design
capacity of 2.5 MOD. However, clarifier performance will need to be enhanced to ensure
good performance during the anticipated peak flows. This enhancement could be
provided by modification of the chemical addition facilities, including the use of polymer
The overflow rates at the higher flows will be slightly over the recommended maximums
for both references. The peak overflow rates will be significantly higher than the
maximum recommended by M&E.
Average day solids loadings are well within the recommended limits. Peak loading rates
will be about 16 percent over the M&E recommended maximum for peak flows but under
the maximum recommended by Ten States. It should be noted that the above operating
parameters were calculated using the current average MLSS of 4,556 Mg/1.
Weir loading rates at average flows are well within the recommended limits. Peak flow
loading rates are under the M&E criteria but are slightly higher than the Ten State
Standards recommended maximum.
Sludge Pumping
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Page 14
The return activated sludge (RAS) pumping and the waste activated sludge (WAS)
pumping are provided by a single pumping station with four pumps acting through a
single force main. Three pumps are dedicated to RAS and one to WAS.
The RAS pumps are rated at 600, 800 and 1000 GPM, and all discharge to the aeration
splitter box through a common main consisting of420 feet of 10 inch diameter D.I.P.
The maximum pumping capacity of the facility, with the three RAS pumps operating in
unison, is estimated to be 2,050 GPM or about 2.95 MGD. This will provide up to 118
percent recycle at an ADF of 2.5 MGD. The plant is currently recycling at about 95
percent of ADF. The existing RAS pumps are therefore capable of handling the
increased flow rates at an ADF of 2.5 MGD but will be pumping longer hours. This will
increase maintenance and reduce the expected lives of the pumps. When replaced, the
pumps should be upsized to handle the higher flows more efficiently.
The existing arrangement of the piping requires that the RAS and the WAS pumping
utilize the same force main. This means that the RAS pumping must be shut down while
the sludge is wasted to the digester. A more efficient arrangement will be to install a
separate sludge wasting line to the point at which the RAS and WAS piping separate.
This will require about 315 feet of 8 inch diameter D.I.P.
addition at the inlet wells, and the installation of baffles, energy dissipating inlets, and
repiping of return flows.
In addition, discussions with plant operating personnel have indicated that the hydraulics
of the older clarifier are problematic, causing difficulty in controlling flow through the
structure. A more detailed evaluation of the hydraulics through both clarifiers will
indicate where there are flow control problems and what measures can be undertaken to
improve control. Some additional piping modifications are necessary in the inlet well.
The RAS pump is adequate to handle the higher sludge wasting rates estimated for a
design flow rate of 2.5 MGD. The RAS force main should be separated from the WAS
main by installing a new length of 8 inch D.I.P. from the WAS pump discharge to the
point where the WAS line tees off to go to the aeration splitter box. This will require
HUA/ Town of Clayion
LCWRF Upraie Feasibility Study
The single WAS pump is rated at 250 GPM at 29 feet of TDH. This is equivalent to ■
. about 15,000 gallons per hour. Current sludge wasting rates are averaging 23,700 GPD
so the WAS pump is running an average of 1.6 hours per day. The sludge wasting rates
projected for the LCWRF at an ADF of 2.5 MGD are estimated to be 34,000 GPD which
will mean that the WAS pump must operate an average of 2.3 hours per day. The
existing pump is obviously adequate for the proposed higher flow rate.
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IConclusions. The WAS pumping facilities are adequate for the proposed higher design
flow rate of 2.5 MGD. The pumps may require additional maintenance however, and, as
they wear out, should be replaced with higher capacity units.
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about 315 feet of new force main.
Aerobic Digester
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TABLE 7 - AEROBIC DIGESTER OPERATING PARAMETERS
CommentParameter
Value
Okay0.15
Okay10-15 15(1)M&E
Okay2.94M&E2.3
I Both, okay
M&E40-50
I) Solids retention of 15 days is calculated for a digested sludge solids concentration of20.000 Mg/1 (2.0 percent)
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Page 15
Solids Loading
(lbs VSS/day/Ft3)
Solids Retention(d)
Ten States
O2 Requirements
(lbs OMb VSS / day)
Mixing (Hp/ioooFt3)
and (cfotflOOOFB)
VSS Reduction (%)
Winter
Summer
1.0
20-40
0.42
18.3
40
46
Assumed
Okay
0.1 -0.3
0.1 .
M&E
Ten States
Ten States
M&E
Operating Value
@2.5 MOD
Criteria______
Source
The aerobic digester is a 90,000 gallon tank equipped with a floating mixer and a blower
capable of applying 220 SCFM through a grid of difiusers. The digester operation will be
evaluated on the basis of solids loading, oxygen requirements and cell residence times for
a range of digester sludge solids levels. The calculations are based on a sludge wasting
rate of 34,000 GPD as calculated earlier, an average sludge solids concentration from the
final clarifiers of 8,324 Mg/1 as at present, and a minimum 40 percent reduction in
volatile solids in winter. Volatile solids are assumed to comprise 80 percent of the total
suspended solids or about 6,660 Mg/1. Average winter temperatures are taken as 158C
and maximum summer temperatures at 28.48C.
HUA/ To*n of Clayton
LCWRF UpraU Feasibility Study
The typical design criteria and the operating parameters for the digester at the ADF of 2.5
MGD are presented in Table 7. Total solids applied will average 2,200 Ibs/day at 2.5
MGD with about 1,755 Ibs/day of volatile suspended solids (VSS). Comparison of the
parameters in Table 7 with typically recommended criteria indicate that the existing
aerobic digestion facilities will be capable of handling solids produced at 2.5 MGD.
Assuming a solids retention rate of 90 percent, and a minimum 40 percent reduction in
volatile solids, the digested sludge solids will average 1,343 Ibs/day. At a digested
sludge solids concentration of 2.0 percent (20,000 Mg/1) dry solids, the average sludge
volume sent to thickening will be 8,050 GPD on a seven day basis. Since the thickener is
only operated five days a week, the average pumpage per day would be 11,270 GPD.
Thickening
Page 16
■' The thickened sludge is sent to a 360,000 gallon sludge holding tank. This tank is
equipped with a 30 Hp floating mixer and a 60 Hp diffused air blower capable of
delivering 1,100 SCFM. There is a sludge transfer pumping station with one pump rated
at 800 GPM at 32 feet TDH. This pump station lifts the stored sludge to the truck
loading bay.
Typically, WAS is thickened prior to digestion, primarily to reduce the volume of sludge
to be digested and thus reducing the size of digestion facilities required. The LCWRF
solids handling process puts the digester first, followed by thickening. The purpose may
have been to reduce costs since, at this size, the thickener is more costly per increment of
size than aerobic digestion. In any case, the digested sludge is first conditioned with the
addition of polymer and then sent to a drum thickener.
The sludge conditioning chemical feed systems consist of chemical storage tanks, mix
tanks, day tanks, diaphragm type metering pumps and piping to several application
points. The diaphragm metering pumps have a pumping range of from 6.3 to 62.5 GPD
of chemical solution. Depending upon the types of chemical used, and the solution
concentrations, the existing metering pumps, along with the storage tanks, mix and day
tanks, should be adequate to handle conditioning needs at the higher ADF of 2.5 MGD.
Currently the thickner is being operated at 32-40 hours per week. This would increase to
40-50 hours per week at 2.5 mgd
The sludge concentration in the sludge holding tank is reported to be 3.32 percent This
is somewhat lower than the 5.0 percent assumed in the O&M manual but well within
typical parameters for a drum thickener. Assuming a typical solids capture of about 90
percent through the thickener, about 1,209 lbs of dry solids are sent to the sludge storage
tank per day. At 3.32 percent solids, this equates to 4,365 GPD of sludge. The air
diaphragm pumps cannot adequately pump this thickness and need to be replaced with
rotary lobe or positive displacement pumps.
Conclusions. The drum thickener, sludge storage and pumping facilities will not be
significantly impacted by uprating the design ADF to 2.5 MGD. The total sludge
digestion, thickening, and storage approximates 40 days of storage at 2.5 mgd. This
coupled with the long MCRT should allow the Town to continue to meet 503 sludge
regulation parameters. New sludge transfer pumps need to be evaluated.
HUA/ T<nm of Clayton
LCWRF Uprate Feasibility Study
Conclusions. The aerobic digester tank, air blower system and floating mixer will be
capable of handling the solids produced from the plant at an uprated design ADF of 2.5
MGD.
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Dewatering
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Tertiary Filters
Effective SizeDepthMedia
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I TABLE 8 - TERTIARY FILTRATION OPERATING PARAMETERS
CommentOperating ValueParameter
Value
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Page 17HUA/ Tovn of Clayton
LCWRF Upraie Feasibility Study
M&E
M&E
0.80 to 1.20 mm
0.55 to 0.65 mm
1.0 to 1.1 mm
Okay
Okay
Media
Sand Depth (Inches) 10-12
Effective Size (mm) 0.35 - 0.60
9 inches
5 inches
6 inches
9 plus 5
0.55 - 0.65
Coarse Sand
• Silica Sand
Anthracite
Criteria_____
Source
The tertiary filtration facility is comprised of two shallow bed, automatic backwash
(ABW) filters, with integral backwash pumps, indexing, backwash hood and piping.
Each filter is 12’-6” wide by 48’-8” long with 47 cells. Total filtration area is 1,224
square feet The design filter media is a total of 20 inches deep and will consist of the
following:
The design filtration rate is listed as 2.2 GPM per square foot at average day flow with a
peak hydraulic loading rate of 5.5 GPM per square foot With both filters in operation,
these design rates are equivalent to 3.9 MGD average day flow and a peak hydraulic
capacity of 9.7 MGD. Comparison of the above design operating parameters with typical
recommended criteria is presented in Table 8.
The sludge dewatering facilities are kept as a standby resource, and consist of nine beds,
each 2,026 square feet in area. This would allow an application rate of about 0.06 lbs of
dry sludge solids per square foot per day, or about 22 lbs per square foot per year. This is
slightly higher than the maximum value of 20 Ibs/F^/yr recommended by M&E for
digested activated sludge. Since this facility is to be used only in case the land
application must be curtailed, the higher loadings are not considered to be a problem.
Conclusions. The sludge drying beds will not be impacted by the increased flow rating of
the plant The beds are used only as a standby. In any case, the beds will still operate
satisfactorily at the higher sludge throughputs expected, especially in summer months.
Final Disinfection
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Page 18
Final disinfection facilities consist of ultraviolet dismfection with the old system of
chlorination, followed by dechlorination using sulfur dioxide as a backup measure. The
dechlorination step is to reduce the residual chlorine in the effluent discharge to the
Neuse River to below 28 pg/1. The disinfection system has recently been upgraded with
the installation of ultraviolet radiation (UV) units in the first channel of the chlorine
contact chamber.
The data in Table 8 indicates that the tertiary ABW filters, as designed, will provide
adequate treatment at the higher flow rates. A review of the backwash rates are not
needed since the application rates are well within the filter’s operating parameters and the
backwash bridge mechanism speed can be modified to suit conditions within that range.
Conclusions. The tertiary filters will be able to handle the increased flows at an uprated
ADF of 2.5 MGD and will be operating comfortably within normal parameters.
Application Rate
(GPM/Ft2)
A typical feed rate for a secondary effluent is about 8 Mg/1 chlorine. At an ADF of 2.5
MGD, this equates to a feed rate of 167 Ibs/day. The maximum possible chlorine dosage
at 2.5 MGD would be 17.3 Mg/1. These dosages are well within the operating
capabilities of the existing system. With the addition of tertiary filtration, (and ignoring
the UV units for now) it is expected that chlorine demand will be less than 8 Mg/1.
Typical values for chlorine contact time are 15 to 45 minutes at ADF and no less than 15
minutes at peak flow. The chlorine contact tank was originally sized at approximately
78,000 gallons at a liquid depth of 6.9 feet. This permitted a detention time of 59 minutes
at 1.9 MGD. At 2.5 MGD, the detention time of the full chamber would be 45 minutes
HUA/Tovn of Clayton
LCWRF Upraie Feasibility Study
M&E
M&E
1.40 @2.5 MGD
3.35 @ 5.8 MGD
Okay
Okay
Okay, w/silica
Okay
Chlorination. The chlorination system centers around a chlorinator with a capacity of
500 Ibs/day of chlorine gas, fed by ton cylinders. Since 1-ton cylinders can feed only
about 360 Ibs/day of gas, the effective maximum application rate, without evaporators, is
360 Ibs/day.
M&E
Ten States
J
2-6
5 Max.
6
1.0- 1.1
!
Ultraviolet Radiation(UV). The UV system has been installed in the first channel of the
chlorine contact tank. Operational data indicates that the Trojan Unit is designed for
■ peak flow of 4.75 mgd. with redundancy in modules and lamps. Should problems with
fecal exist at peak flows of 5.8, the supplemental chlorine/SOi system may need to be
activated.
Anthracite Depth 12-20
Effective Size (mm) 0.8 - 1.5
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RECOMMENDATIONS
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Page 19HUA/ To*n of Clayion
LCWRF Uprate Feasibility Study
The conclusions discussed in the preceding section will be summarized on a unit by unit
basis below, along with an estimate of the probable cost of upgrades or modifications.
and the detention time at peak flow of 5.8 MGD would be 19 minutes. 1 he existing
chlorination facilities will be adequate to handle disinfection chores at the higher design
rating of 2.5 MGD.
Dechlorination. The LCWRF uses sulfur dioxide to reduce the residual chlorine levels
to meet the limits of the NPDES permit. A sulfonator rated at 100 Ibs/day feeds sulfur
dioxide gas from four manifolded 150 lb cylinders. At an ADF of 2.5 MGD and a
chlorine residual of up to 2.0 Mg/1, a maximum of 83.4 Ibs/day of SO2 would be required
to dechlorinate the effluent More typically, a residual of 1.0 Mg/1 would probably
require about 32 Ibs/day at 2.5 MGD and up to 74 Ibs/day at the peak flow of 5.8 MGD.
The existing dechlorination facility will be capable of handling demands at the higher
rating of 2.5 MGD.
Conclusions. The existing disinfection systems will be capable of handling the higher
flows at a design capacity of 2.5 MGD.
Effluent Pumping and Discharge.
The effluent pumping station is equipped with three pumps, each rated at 1,650 GPM at a
TDH of 158 feet A hydraulic analysis of the 16 inch diameter force main indicates that
one pump will actually discharge about 2,120 GPM (3.05 MGD) at a TDH of 104 feet
Two of these pumps in parallel will discharge 3,550 GPM (5.11 MGD) at 143 feet and all
three will discharge 4,460 GPM (6.42 MGD) at 176 feet of TDH.
Conclusions. The hydraulic calculations indicate that the existing effluent pumping
station and force main system has sufficient capacity to handle the anticipated peak flows
of 5.8 MGD at the uprated capacity.
Unit by Unit Summary
Headworks. The evaluation of the existing units in the headworks facilities did not yield
any obvious problems with regard to the uprate to 2.5 MGD. However, there are some
operating problems that are being addressed or need to be addressed. First is the
mechanically cleaned bar screen. The Town of Clayton is in the process of replacing this
unit for maintenance and operational reasons. The new unit will be sized to handle the
higher flow throughputs.
Second, the “tee” channel, whereby flow is diverted to the Trickling Filter plant influent
pump station, has poor hydraulic properties. Unless flow is physically diverted into the
Trickling Filter side channel, flow rates into that channel are not sufficient. This makes
flow control difficult and clumsy. A better system of flow diversion needs to be
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Page 20
■ Assuming that the detailed analysis confirms the desk top study performed here and by
Baker Hughes, the system aeration capacity will have to be upgraded. For budget
purposes, it is suggested that the overall horsepower ratings be increased by 40 percent,
from 150 Hp to 210 Hp. This can be accomplished by replacing the two 25 Hp units with
40 Hp motors and the two 50 Hp units in the newer oxidation ditch with 70 Hp units or
the closest available size.
The desk top analysis conducted in this study included a theoretical review of possible
nitrification and denitrification rates through the aeration basins at the higher design flow.
This review indicated that nitrification rates would not be negatively impacted and that
effluent ammonia levels would be very close to current levels. The analysis of possible
denitrification rates was more theoretical but did indicate that some denitrification would
still take place in the aeration basins. The apparent limiting factor in these calculations
was the low F:M ratios in the basins, due in part to the low influent BOD5 levels and
lower detention times.
Influent Pump Station. The existing influent pump station is a high maintenance and
inefficient operation. The control logic will need to be altered to run the existing pumps
in parallel in order to meet the peak capacity of 5.8 mgd at an ADF of 2.5 mgd. It is
recommended that the two (2) (60 Hp) pumps and two (40 Hp) pumps be replaced with
three (3) 75 Hp pumps with two operating pumps rated at peak flow and one for standby.
These pumps should be dry pit submersible pumps with VFD controls.
An alternate to changing the aerators would be to install supplemental fine bubble
diffusion in each ditch with a centrifugal blower.
The actual nitrification and denitrification rates that will be experienced at the lower
detention period of 18 hours should be determined through field tests at the LCWRF.
This could best be accomplished by pushing all flow through the new oxidation ditch and
clarifier during a test period of one to two months. The operating parameters through the
units would be intensively monitored, especially for nitrification and denitrification rates.
Actual operating constants can be determined at the shorter detention time. A longer test
period will also allow some experimentation with different operating regimes, such as
lower MLSS levels, return rates, etc. The test period could also be used to experiment
incorporated if the Trickling Filter plant is to continue to receive raw influent in parallel
with the oxidation ditches. This will be discussed in more detail below.
HUA/Tmm of Clayton
LCWRF Uprate Feasibility Study
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Other than the replacement of the mechanical bar screen, under another project, there are
no modifications recommended for the headworks.
Aeration Basins. The analysis indicated that the existing aeration capabilities would be
marginal at the higher flow rates and higher BOD loadings.. The analysis used some
typical and commonly accepted values for field transfer rates of oxygen to conduct the
analysis. The existing aeration power was determined to be marginal at the highest end
of the O2 transfer range.
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Page 21
HUA/ Town of Clayton
LCWRF Upeaie Feasibility Study
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with different chemical addition programs for enhancement of clarifier performance.
The down time for the older ditch and clarifier could also be put to good use in correcting
some flow split problems that have been experienced since the new train was put on line.
Final Clarifiers. The review of clarifier performance indicated that the two units
combined, as currently configured and operated, will provide marginal results at foe
higher loadings proposed. The unit operations can be improved by one or a combmation
of measures:
■ Chemical addition. Alum and MgOH are now provided but polymer addition should
■ B^fflfo^^eln^lation of baffles to reduce short circuiting and to reduce foe
potential for solids burping over foe effluent weirs. .
■ Modifying plant operations, such as reducing MESS levels m foe aeration basins and
thus reducing clarifier surface loadings.
■ The addition of Energy Dissipating Inlets and modification of inlet piping to more
evenly distribute flows.
Any one or more of foe above should improve clarifier operation sufficiently to handle
future flows. The installation of serpentine weirs or tube settler modules is not
recommended due to foe marginal improvements that can be expected, costs and higher
maintenance requirements.
Sludge Punwing. The existing RAS and WAS pumps will be capable of handling the
highfr sludZ flows at an uprated ADF of 2.5 MOD with the proviso that *e RAS pumps
will need to be upsized as they wear out For budget purposes, it is suggested that the
two smaller pumps be upsized to 1000 GPM units.
The WAS discharge should be provided with a separate force main. The
recommendation is to instafl approximately 315 feet of 8 inch D.I.P. from the existing
WAS pump discharge line to foe point in foe yard where foe RAS mam separates from
foe WAS line.
To provide a margin of safety, valving should be added either in the sludge pump station
valve chamber oHn the force main itself to allow crossing over from the RAS discharge
to the WAS main, in case the one WAS pump goes down.
Aerobic Digester. The existing digester is capable of handling the increased solids
wasted from the LCWRF at the higher design rating of 2.5 MOD. No modifications are
recommended.
Sludge Thickening and Storage. The sludge drum thickener and foe aerated sludge
storage tank will still be operating comfortably within normal operating ranges at foe
higher solids throughput expected for an uprated facility. The air diaphragm pumps need
to be replaced with rotary lobe or positive displacement pumps.
Cost Summary.
TABLE 9 - SUMMARY OF RECOMMENDATIONS AND COSTS
Unit Recommended Action Estimated Cost
Headworks
Page 22
Tertiary Filters. The new tertiary sand ABW filters are sufficiently sized to handle the
higher flows at 2.5 MOD and still operate within standard parameters. No modifications
are needed; however repiping the backwash to the headworks should help ease surges to
the clarifiers.
Final Disinfection. With the addition of UV capabilities, the LCWRF will be capable of
handling flows in excess of 2.5 MOD on an average basis. No modifications are needed.
Effluent Pumping and Discharge. The new effluent pumping station and 16 inch force
main have sufficient capacity to handle in excess of the 5.8 MGD peak flows that can be
expected for a design uprate to an ADF of 2.5 MGD. No modifications are therefore
needed.
The recommended actions and budget level estimates of the probable costs are provided
in Table 9. These costs are rough budget level estimates of probable costs that will be
incurred for each proposed action. Several of the proposed measures will make
maximum use of LCWRF staff, thus reducing costs. The costs of the new mechanical bar
screen were not included in the summary since the replacement of this unit is currently
being undertaken by the Town under a separate program.
The total of the cost estimates provided in Table 9 come to $590,000. Should the Town
of Clayton wish to pursue any of the suggested actions, a detailed scope of work will be
developed and a more refined estimate of the probable costs will be prepared.
Sludge conditioning facilities will also be capable of matching flows at the higher
throughputs.
HUA/ To\m of Clayton
LCWRF Uprate Feasibility Study
Replace Mechanical Bar Screen
Modify Flow Split to T.F. Plant
(Already budgeted)
See Below
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Standby Generation. The existing generator is sized to run the entire WWTP in order to
take advantage of peak savings. Should modifications to the Hp of aerators or pumps
cause the rating to be exceeded during peak conditions, additional power generation or
selective use at low flow conditions may be required.
Sludge Dewatering. The drying beds are used as standby facilities in case the sludge can
not be trucked out for extended periods. The operational parameters of the sand beds will
be marginal at the higher flow rating, but since the beds are used for emergencies only,
this is not considered a problem.
I
$150,000Influent Pump Stations new 75 Hp 2400 gpm submersible w/VFD
Aeration Basins
Clarifiers
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I Sludge Pumping
$15,000Install 600 If of 8inch DIP
$590,000Total Estimate of Probable Costs
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Page 23
ReRoute Backwash
Line
HUA/ Toun of Clayton
LCWRF Upeate Feasibility Study
$ 5,000
$25,000
$25,000
$50,000
$15,000
$10,000
$10,000
$ 7,500
Conduct Field Oxygen Transfer Rate Test
Upgrade Aerator Motors
Comprehensive Field Test of New Train
Replace Sludge Transfer Pumps
Upsize Two Smaller Pumps to 1000 GPM
Install 315 feet of 8 Inch DIP with Valving
Conduct Field Test of Chemical Enhancement -
Install Polymer Addition to Clarifiers
Install Baffling
Install Energy Dissipating Inlet
Improve Inlet flow Split Hydraulics
♦Recommendation at this stage would be to add blower and diffused aeration. Costs would be less than $100,000 to
aerate both basins.
$ 2,500
$250,000 *
$25,000
Discussion of the Trickling Filter Plant and Future Nutrient Limits
The trickling filter plant has not been included in the discussion so far. The intent was to
ensure that the main treatment units of the LCWRF will be capable of handling the
projected future flows at an uprated design capacity of 2.5 MGD on their own. The
preceding discussion has indicated that, with minor modifications, the main treatment
units of the LCWRF will be capable of meeting its April 1,1999 permit limitations at an
uprated design capacity of 2.5 MGD. The older trickling filter units will not be needed in
this regard.
A second reason for keeping the trickling filter units “in reserve” involves nutrient
limitations and nitrogen limits in particular. The status and outlook for nitrogen
limitations in the Neuse River basin are discussed below, followed by a discussion of the
possible adaptation of the trickling filter units to meet future nitrogen limitations.
Nitrogen Limits in the Neuse River Basin. The Neuse Strategy calls for an across the
board 33 percent reduction in the total nitrogen loading to the Neuse estuary. As part of
the strategy, total nitrogen limitations were established by the DENR DWQ section for
each point source discharger in the basin. These were established as total annual mass
limits. As discussed in the Introduction to this report, the limit for the Town of Clayton
discharge was set at 21,400 pounds per year. The limits could be waived if the Town
joined a nutrient trading coalition for the Neuse River Basin which had met EMC
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Page 24
As discussed in the Introduction, the LCWRF will not be able to meet the future limits
for total nitrogen (TN) as it is currently configured and operated. The Town has several
options for meeting future limits. These are:
requirements. As mentioned above, an attempt was made to set up such a coalition and
the Town of Clayton had expressed interest in joining. Due to legal action taken by the
Neuse River Keepers and other organizations (the *TMDL Lawsuit”) however, the status
of the trading coalition and of the new NPDES permit limitations is currently on hold.
The recent public workshop held to discuss the status of the TMDL calculations indicated
that the model review will not result in significant changes to the mass limits for most
dischargers, including the Town of Clayton. It is therefore prudent to assume that some
form of nitrogen limits will be included in the new permits and that some type of trading
coalition will be developed.
HUA/ r<n«*i of Clayton
LCWRF Uprale FeatlbUUy Study
J
1. Improve plant operations to meet future TN limits. This will require removing TN
down to 2.81 Mg/1 at an ADF of 2.5 MOD.
2. The existing site can be utilized for expansion of the facility to meet the existing
treatment levels with a reuse pump station added on the discharge line to pump
‘‘reuse” water to either dedicated land application sites, golf courses, parks,
cemeteries, etc. as irrigation water. This land application will allow the annual mass
loading to the Neuse River to be met without extensive nutrient removal equipment.
Every pound of nitrogen applied in the irrigation water is one less pound discharged
to the Neuse River.
3. Construct a new WWTP at the site owned by the Town near the Neuse River. At
current prices for treatment facilities with advanced treatment for nutrient removal, a
5.0 MOD plant, for instance, could cost up to $ 15 to $20 Million.
4. Join a nutrient trading coalition. This option will have the Town dependent on the
overall “bubble” provided by the coalition and to the terms developed by the
coalition’s charter for the purchase of additional nutrient “credits”. The costs of this
approach could be quite high. The draft charter that had been prepared (prior to the
TMDL lawsuit) set TN credit prices at $22 per pound per year, purchased for a 30
year period. At current discharge rates of 3.9 Mg/1 TN (1998 average reported) and
an uprated flow capacity of 2.5 MOD, the LCWRF will discharge about 29,700 Ibs/yr
or 8,300 Ibs/yr over the current limit To purchase 8,300 Ibs/yr of TN credits would
cost $5,478,000 for a 30 year “grant”.
5. Join a regional wastewater treatment facility, phase out the LCWRF altogether and
pump all waste to the regional plant The cost of this option is unknown, however
typical wholesale wastewater charges in the Triangle area have run from $1.25 to
$1.70 per 1,000 gallons with an up-front capacity charge also added in. Assuming the
minimum of $1.25 per 1,000 gallons, the cost to purchase wholesale treatment would
run about $1,140,000 per year at an ADF of 2.5 MGD. This does not include capital
and capacity charges that may be levied, nor does it include the costs of constructing
the pump station and force main and the annual operating and maintenance costs of
the pumping facilities (if owned by the Town). These costs are offset by the
elimination of the annual O&M costs of the LCWRF and by the avoided costs of
upgrading the facility further. Since the Town does have significant “sunk” costs in
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Page 25IHUA/To^m of Clayton
LCWRF Uprate Feasibility Study
the recent additions to the LCWRF, it may be preferable to send flows above the
present LCWRF capacity to the regional facility until such time as the LCWRF debt
is paid off, at which time it can be abandoned.
Option 2 will require the Town to continue to treat the wastewater to high levels and fmd
adequate acreage to land apply the effluent. At an application rate of 1 ac/week, 258
acres would be required for each 1 mgd applied.
Options 4 and 5 include varying degrees of loss of control over operation of the
wastewater utility. For instance, in Option 4, if the coalition does not meet its “bubble”
goal, a monetary penalty will be levied. How will this be distributed to the coalition
members? If Clayton is meeting its goal, yet the coalition does not, will Clayton
nonetheless have to share in paying the penalty? These issues, and others, will be
outlined in the coalition charter which has yet to be finalized or approved by the EMC.
In Option 5, there is no guarantee that the regional authority (or the utility providing
regional wastewater treatment service) will continue to provide that service should the
major member itself run into trouble. The fees charged for the service would also be a
continuing unknown factor.
There are obviously numerous unknowns in the above options. The following discussion
will explore the potential for using the Trickling Filter units to meet future TN limitations
as part of Option 1 above.
Potential Use of the Trickling Filter Plant One option considered when this desk top
■study was initiated, was the use of the trickling filter units for advanced nitrogen removal,
either as part of the main flow stream through the LCWRF or as a side stream operation.
There is significant precedence for such an operation. The system projected for the
LCWRF would be a separate denitrification facility using high rate plastic media placed
within the modified existing trickling filter units. The purpose of the modified units
would be to further denitrify the effluent to reduce the TN concentration to below the
2.81 Mg/1 goal anticipated for the future.
In general, the modifications would include gutting the interiors of the clarigester and the
trickling filter, removing all interior baffles, media and appurtenances. The clarigester
would be fitted with a sub-floor to support the plastic media, a rotating arm and aeration
ports to blow air up through the bottom and through the media. The trickling filter
bottom will be modified if needed and the current rotating arm replaced with a more
efficient unit. Side walls will be added to increase the total depth of the media to match
the elevation of the top of the former clarigester. Using both basins will provide a total
surface area of 3,338 square feet with total media depths ranging up to 20 feet The total
depth of media in both units will be calculated on the basis of application rates which will
be determined from more detailed studies. Total media volume could be up to 66,760
cubic feet. The process will require the addition of an auxiliary source of carbon, either
methanol or a form of acetate. Depending upon the biological kinetics of the resulting
system, the final clarifier may or may not be needed.
Some options that need to be evaluated for design include:
1.
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Addition of Baker Hughes (Eimco) Bardenpho
Page 26
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HUA/ Tovrt of Clayton
LCWRF Uprate Feasibility Study
The estimated costs for such a pilot scale study would range from $10,000 to $25,000
depending upon the scope of work to be undertaken and the amount of the work to be
performed by LCWRF staff
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The existing Carrousel System can be converted to the Baker Hughes (EIMCO)
Bardenpho Process by the addition of an anaerobic basin, and anoxic basin, and a
reaeration basin in order to biologically remove nutrients. This process may be able to
use the existing clarigester and trickling filter as the initial anaerobic and anoxic basins
prior to the existing Carrousel System followed by the construction of additional second
stage anoxic and reaeration.
These design criteria would be derived from pilot studies undertaken at the LCWRF,
preferably during the comprehensive field test of the higher flow rates through the new
oxidation ditch, as recommended above. The pilot studies would initially be conducted
as laboratory or bench scale studies. The study would be designed and set up by HUA
personnel and normal day to day operation and monitoring would be undertaken by
LCWRF staff under HUA supervision.
J
The pilot study, leading to the modification of the existing trickling filter units to a
denitrification facility, is recommended as one of the options to be considered for the
long term solution to the Town’s wastewater treatment issues. This option should be
considered after review of the LCWRF’s operating reports after bringing the ABW filters
on-line. If the new filters and the minor modifications to the existing main units are not
expected to be able to bring the total nitrogen limits down to the 2.81 Mg/1 goal, then the
option to modify the trickling filter units for effluent denitrification should be given full
consideration.
Full flow (main stream) or side stream operation. If full flow, the total application
rates would be 0.52 GPM/Ft2 and 1.09 Ibs/day TN per Ft3. Side stream flows could
be as low as 0.50 MOD in which case the application rates could be 0.22 GPM/Ft2
and 0.22 Ibs/day TN per Ft3.
2. Take flow from the secondary effluent, prior to the ABW filters, either as main
stream or side stream, and return the denitrified effluent to tertiary (now quaternary)
filtration. Alternatively, take the filtered effluent, again as either main stream or side
stream, to the trickling filter plant and return the denitrified effluent to final
disinfection.
3. Depth and type of plastic media.
4. Type and dosage of auxiliary carbon source, whether methanol or some form of
acetate.
5. Whether final clarification is needed, either prior to final disinfection or prior to sand
filtration.
I
Summary of Nutrient Removal Discussion.
I
I
I
I
I
I
I
I
Page 27
This process may be simulated by utilizing the existing structures and series operation of
the existing Carrousel Ditches.
HUA/ Town of Clayton
LCWRF Uprate Feasibility Study
It is recommended that the Town proceed with the process of re-rating the LCWRF to
approximately 2.5 mgd and to begin to initiate an NPDES permit expansion to 2.35 mgd.
The reason for the difference in the above flows is that the State Environmental Policy
Act requiring expansion of existing permits beyond 500,000 gpd increases to perform
extensive environmental assessment reviews by the State environmental agencies. This
process would add 1—2 years to the permitting process. The need for the re-rating of the
LCWRF is to meet short term goals and such a delay is not recommended for the extra
150,000 gpd increase to 2.5 mgd.
Additionally, the preliminary discussion of nutrient removal should be sufficient to meet
the existing nitrogen strategy and the subsequent pilot studies should allow the Town to
plan for the year 2003 deadlines to meet the more stringent nitrogen levels.
1
I
I APPENDIX A
1
I
I
I
Page IHUA/ Tbvm of Clayton
LCWRF Uprate Feasibility Study
Flow
91.6%
50.0%
5.1
1.1
1.4
2.3
5.0
CLAYTON WWTP
RECORDED WATER QUALITY DATA
78.3%
73.8%
86.7%
1.272
1.575
1.953
1.281
1.431
1.398
1.239
1.331
1.413
1.156
1.183
0.962
1.350
1.321
1.389
1.900
1.900
144.7
151.4
135.2
5
10
218.6
242.0
185.8
228
163
217
238
248
261
202
262
266
205
193
30
30
1.4
1.2
1.6
80.7%
95.2%
91.8%
92.6%
90.8%
25.4
28.7
20.5
3.6 '86.0%
3.3 88.5%
3.9 81.1%
49.5%
80.2%
7.5
6.5
8.2
9.0
8.6
6.6
0.3
0.6
0.6
1.5
1.9
0.8
2
2
93.3%
50.8%
68.3%
83.3%
86.0%
80.3%
94.8%
95.3%
94.1%
2
4
4.7
6.0
4.1
6.7
6.6
6.8
7.4
6.0
5.5
4.2
98.3%
98.3% •
98.5%
98.2%
98.7% •
98.2%
. 16.7
•16.5
16.9
0.5
2.2
0.7
0.6
1.6
1.3
14.5
15.1
14.4
17.1
• '16.8 . .
16.7
. 17.3
14.8
15.4
17.7
’23.0.
17.6
9.5
17.2
7.0
8.7
12.1
9.0
7.6
6.3
5.4
6.8
8.0
6.4
7.1
5.2
18.3
30.0
12.6
28.0
22.1
61.1
20.1
35.1
7.5
7.1
8.0
AVERAGES
ANNUAL
MKUMMER
WINTER .
NPDES PERMIT LIMITS
SUMMER
WINTER-
92.4%
90.7%
2.4 83.3%
• 3.3
0.8
0.5 97.0%
97.1%
85.1%
95.5%
96.6%
93.0%
92.6%
87.4%
83.3%
4.4 65.1%
4.1 85.4%
2.2 90.0%
1.8 97.1%
2.7 86.6%
4.8 86.3%
97.5%
98.3%
7.3 96.0%
93.6%
90.0%
85.4%
0.8 ' 88.1%
3.3
1.7
0.5
3.2
2.6
1:5
1.2
1.3
BODS
Influent Effluent
148
93
96
156
157
133
167
138
149
160
195
144
Month
(1998)
Jan
Feb
Mar
May
Juri
JuIJt*
Aug
s«O
Oct \
Nov
Dec
TN . TP
Influent Effluent %-Rem Influent Effluent %-Rem
3.6
4.8
3.4
TSS NH3-N
%-Rem Influent Effluent %-Rem . Influent Effluent %-Rem
95.3%
90.6%
87.4%
94.2%
95.2%
95.3%
96.8%
95.1%
94.6%
96.0%
96.4%
96.4%
7.0 96.9%
7.5 95.4%
140 11.7
5.8 97.3%
4.0
4.2
3.8
3.6
3.3
4.9
5.4, 97.4%
97.4%
r'1 1 1-J .•u
BODS DATA
Jul Sep Oct Nov DecJanFebMarAprMayJunAug
MONTH
200 -
50
0
150
d
2
m
Q
O
CO 100
I
I
I
1
I
I
I
I
I
2 o z
o a
CD
CO
CD
c
CD o
H
(/)
(/)
U
>
>
2
(D
TSS (MG/L)
GJ
O o
ro o o
cn o
Z
O <
> c
(Q
>'1•nI
NH3 - N DATA
25.0
20.0
10.0
5.0
0.0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
MONTH
15.0
d S
z
X
TN (MG/L)
I ■&
I
I
I
I
o o
DJ
0)
CD XJ
-I
2
O
>
>
2
O z
£D
&
(Q
XI
CD cr
Z o<
o
CD
O
Repair?Page I
HU
DESIGN CALCULATIONS
Project:CT9901 Influent Pump Station Date:
ITotal2,500,000 gpd
5. Peak Flow:
B. Target Pumping Rate
C.Piping
1
D.Dimensions and Elevations
8.00 ft.80.00 sf
307.78 ft. MSL
897.60 gal.
//REF! min
E.System Works
CLP 705/Exc«1/Dcj Ign/PSDej Ign
Description:
Pump Station Design:
A. Wastewater Flows
Pump On Time =
Pump Off Time =
Pumping Cycle =
2,500,000 gpd
6,250,000 gpd
2.50
1440
6,250,000 gpd
4,340.25 gpm
x
/
Wet Well Dimensions
Pump Station Rim Elevation
Invert of 10M Influent
High Level Alarm
Lag Pump On
Lead Pump On
Pump Off
Low Level Alarm
Bottom Wet Well
x 10.00 ft.
293.95 ft. MSL
285.28 ft. MSL
284.28 ft. MSL
283.28 ft. MSL
282.28 ft. MSL
280.78 ft. MSL
279.78 ft. MSL
277.90 ft. MSL
/’ C. Box 1737
290 S. W. Broad Streeet
Southern Pines. North Carolina 28387
[phone] Fax [phone]
Tcr*m of Clayton Influent Pump Staion
Design Calculations
!
i
i
I
I
»
J
I
Hobbs, Upchurch
& Associates, P.A,
Consulting Engineers
//REF! mm.
//REF! min.
Station Piping
Force Main
Total Force Main Length
Target Pumping Rate
Velocity at Target Pumping Rate
Friction Coefficient
Headloss in FM per 1,000 ft.
Force Main Discharge Elevation
Detention Volume =
10 " D.I.P.
12 " Ductile Iron Pipe
672 ft.
2250 gpm
6.39 ^ps ■
C= 120 ■
13.30 ft.
J
I
Area x (Pump On - Pump Off) x (7.48 gal./cf)
Detention Volume / (Pumping Rate - Q)
Detention Volume / Q =
Pump On + Pump Off =
| Dsej 2250
June 30, 1999
Provide new submersible pumps in dry pit to replace existing
Page 2
1. Static Head:
27.00 ft.Total Static LiftI2. Friction Losses:
Station Lossesa.
67.40 ft.
I b.
I
763.20 ft.Total Equivalent Length
I One Pump runningSystem curve3.
L
I
I
I
I 300025002000150050010000
GPM
12” PVC and Ductile Iron Pipe
12" Gate Valve
12" 90 degree bend
12" 45 degree bend
12" 11 1/4 degree bend
307.78 ft.
280.78 ft.
©
©
©
©
©
3.20 ft/ea.
39.00 ft./ea.
16.00 ft./ea.
430 ft/ea.
13.40 ft./ea.
9.40 ft. / ea.
7.50 ft/ea.
672.00 ft.
430 ft.
26.80 ft.
37.60 ft.
22.50 ft.
6.00 ft.
6.40 ft
39.00 ft.
16,00 ft.
Force Main Max. Elev.
Pump Off Elev.
2 ea.
1 ea.
1 ea.
I
CL9705/Exctl/Dttgn/PSD€aign
Total
Head
(ft.)
36.93
37,90
38,91
39,96
41.05
42.18
4335
Fluid
Hofsepower
(50%cff)
3637
39.24
42.25
45.41
48,72
52.19
55.83
Velocity
Headloss
(ft.)
0.48
0.53
0.58
0.63
0.69
0.75
0.81
Static
Headloss
(ft.)
27.00
27,00
27.00
27.00
27.00
27.00
27.00
Force Main
Headloss
(ft.)
7.79
8.54
933
10.15
11.00
11.88
12.79
Station
Headloss
(ft)
1.67
1.83
■ 2.00
2.18
236
2.55
2.75
1 ea.
2 ea.
4 ea.
3 ea.
10" Ductile Iron Pipe
10" Plug Valve
10" Swing CheckValve
10" 90 degree bend
Total Equivalent Length
Force Main Losses:
44 J
43 --
42 --
g 41 -
W e
r 80
- 70
60
- 50
40 £
- 30
- 20
- 10
- 0
40 -
39
38
37
36
(Q)
Flow
(gpm)
1950
2050
2150
2250
2350
2450
2550
Town of Clayion I fluent Pump Staion Repairs
Calculations
Page 5
I
I
ITwo Pumps running
I
1
I
CL9705/Exc*l/Deflgn/PSDcjlgn
Town of Clayton Influent Pump Staton Repairs
Dejign Calculations
I
J
Ii
I
I
5
I
I
Fluid
orsepowei
(50% eg)
133,80
140,68
147,82
155.21
162,88
170,82
179.03
■ Total
Head
(ft.)
63,08
64,78
66,52
68.29
70,11
71,96
73.85
(Q).
Flow
(gpm)
4200
4300
4400
4500
4600
4700
4800
Velocity
Headloss
(ft.)
2,21
2,31
2,42
2.53
2,65
2,76
2.88
Static
Headloss
(ft.)
27.00
27.00
27.00
27,00
27.00
27,00
27.00
MWW
Force Mai
Headloss
: (ft.)-
32,20
33,63
35,09
36,58
38,10
39,65
41.22
W
Station
Headloss
(ft.)
1.67
1,83
2,00
2,18
2,36
2.55
2.75
Page 3
I
I Pump Selection
Fairbanks Morse 543411.I
HP 85% efficient spec 75 HP71
Phase3
I flTDH39.96
ingRjPumping Rate with One Pu2.
flTDH50gpm @3400.00Pump Capacity:
Pumping Rate with Two Pumps Running• 3.
ft. TDH80.00gpm/ea. @2400Pump Capacity:
I
I
I
I
I
t
mhliinr
10
10
60
1175
240/480
T8D1D
4
2250
Suction Side
Pump Discharge
Motor Horsepower
RPM
Electrical Service
Impeller Diameter
Solids
Target Pumping Rate:
inches
inches
BHP
volt
inches
inches
gpm @
I
CL9705/Exc€l/D€tign/PSDeiign
I
of Clayton Influent Pump Staton Repairs
Calculations
1
COMMENTS
NOTES:
i
f • ** 4* 4
2.5
5.9
1736
4097
1- 40 Hp
2- 60 + 1-40 Hp
2-60 2-40 Hp
TOWN OF CLAYTON
LITTLE CREEK STP - INFLUENT PUMP STATION
PUMP CYCLE TIMES
2000
4370
4495
2.10
0.89
0.89
15.92
14.26
10.06
Good
Good
Okay if pumps alternate lead/lag
Okay if pumps alternate lead/lag
Okay if pumps alternate lead/lag
13.82
13.37
9.17
Flow Regime
Design ADF
Design Peak
GPM
1319
3299
GPM(2)
2000
3750
PUMPING
Pump Regime(l)
1-40 Hp
1-40 + 1-60 Hp
Draw Time
5.36
8.08
Cycle Time
8.12
9.19
Hoped for ADF
Hoped for Peak
INCOMING FLOW
MGD
1.9
4.75
1) Regime is the closest combination of pumps greater than the incoming flow rate.
2) Pumping Rate is from System Curve attached.
3) Fill and Draw times based on a total operating level range of 2.5' for an operating volume of 487.5 Ft3 or 3,647 Gals
Operating range calculated from Influent invert at El. 227.75 minus suction CL at El. 224.50 minus min. submergence of
0.75' leaving a usable range of 227.75 -.224.50 - 0.75 = 2.50'. Operating Vol. 3 2.50' D x10' Wx 19.5' L = 487.5 Ft3
4) General: The cycle time calculations assume constant speed pumps.
PUMP CYCLE TIMES (3 (Minutes)
Fill Time
2.76
1.11
Feet
SUM "K"NO."K" VALUES
1.001
1
Inches
Feet
0.80
9.40
TOWN OF CLAYTON
LCWRF EFFLUENT FORCE MAIN WORKSHEET
MINOR LOSSES IN SEGMENT
FITTING
FLOW
(Gpm)
250
500
750
1000
1250
1500
1750
2000
2250
2500
2750
3000
3250
3500
3750
4000
4250
4500
4750
5000
VELOCITY
(Ft/Sec)
0.40
0.80
1.20
1.60
1.99
2.39
2.79
3.19
3.59
3.99
4.39
4.79
5.19
5.59
5.98
"638
6.78
7.18
7.58
7.98
1
16.00
5476.00'
100.00
80.00
H(m)
(Ft)
0.023
0.093
0.209
0.372
0.581
0.836
1.138
1.487
1.882
2.323
2.811
3.345
3.926
4.553
5.227
5.947
6.714
7.527
8.387
9.293
0.45
1.65
3.50
5.98
9.05
12.70
16.92
21.69
27.01
32.86
39.23
46.13
53.54
61.45
69.87
78.79
88.20
98.10
108.49
119.36
80.45
81.65
83.50
85.98
89.05
92.70
96.92
101.69
Toroi
112.86
119.23
126.13
133.54
141.45
149.87
158.79
168.20
178.10
188.49
199.36
GATE - 4 Inch
GATE - 6 Inch
GATE - 8 Inch
GATE -12 Inch
CHECKVALVE
ELBOW - 90
ELBOW-45
ELBOW-22
ELBOW-11
TEE ______
ENTRANCE
EXIT________
REDUCTION
EXPANSION
TOTAL "K” for SEGMENT
0.14
0.12
0.10
0.07
2.50
0.30
0.20
0.10
0.07
0.50
0.20
1.00
0.04
0.80
1
1
5
10
4
9
1
0.07
2.50
1.50
2.00
0.40
0.63
0.50
H(f)
(Ft)
HEADLOSS
(Ft)
0.43
I. 55
3.29
5.60
8.47
II. 87
15.78
20.21
25.13
30.53
36.42
42.78
49.61
56.90
64.64
72.84
81.49
90.58
100.11
110.07
TDH
(Ft)
PIPE SEGMENT_______
DIAMETER___________
LENGTH
gRICTION FACTOR "C”
wItatichead
1
TOWN OF CLAYTON
LCWRF EFFLUENT FORCE MAIN WORKSHEET
•3
TDH
(Ft)
80.00
80.45
81.65
83.50
85.98
89.05
92.70
96.92
101.69
107.01
112.86
119.23
126.13
133.54
141.45
149.87
158.79
168.20
178.10
188.49
199.36
FLOW
(Gpm)
0
250
500
750
1000
1250
1500
1750
2000
2250
2500
2750
3000
3250
3500
“3750
4000
4250
4500
4750
5000
uTtxn jvrriMflPcv tx xnnno
PROPOSED NEW SEPARATE WAS PIPELINE
Feet
SUM "K"NO."K" VALUES
0.121
6.46
Inches
Feet
TOWN OF CLAYTON
LITTLE CREEK WASTEWATER TREATMENT PLANT
WASTE ACTIVATED SLUDGE FORCE MAIN WORKSHEET
MINOR LOSSES IN SEGMENT
FITTING
TDH
(Ft)
100
125
150
175
200
225
250
275
300
325
350
375
400
425
VELOCITY
(Ft/Sec)
0.41
0.51
0.61
0.71
0.82
0.92
1.02
1.12
1.23
1.33
1.43
1.53
1.63
1.74
0.07
0.10
0.14
0.19
0.24
0.30
0.36
0.43
0.51
0.59
0.68
0.77
0.87
0.97
0.017
0.026
0.038
0.051
0.067
0.085
0.105
0.127
0.151
0.177
0.205
0.235
0.268
0.302
24.33
24.38
24.43
24.49
24.56
24.63
24.72
24.81
24.91
25.02
25.13
25.25 •
25.39
25.52
GATE-4 Inch
GATE - 6 Inch
GATE - 8 Inch
GATE-12 Inch
CHECKVALVE
ELBOW-90
ELBOW-45
ELBOW-22
ELBOW-11
TEE
ENTRANCE
EXIT
REDUCTION
EXPANSION
0.14
0.12
0.10
0.07
2.50
0.30
0.20
0.10
0.07
0.50
0.20
1.00
0.04
0.80
TOTAL "K" for SEGMENT
1
3
1
3
1
1
1
2.50
0.90
0.20
1.50
0.20
1.00
0.04
H(f)
(Ft)
1
10.00
385.00
90.00
24.25
H(m)
(Ft)
HEADLOSS
(Ft)
FLOW
(Gpm)
0.08
0.13
0.18
0.24
0.31
0.38
0.47
0.56
0.66
0.77
0.88
1.00
1.14
1.27
PIPE SEGMENT
DIAMETER
^ENGTH]
FRICTION FACTOR "C”
STATIC HEAD
!
TOWN OF CLAYTON
LITTLE CREEK WASTEWATER TREATMENT PLANT
WASTE ACTIVATED SLUDGE FORCE MAIN WORKSHEET
TDH
(Ft)____
24.25
24.33
/ 24.38
24.431
24.49
24.56
24.63
24.72
24.81
24.91
25.02
25.13
25.25
25.39
25.52
FLOW
(Gpm)
0
100
125
150
175
200
225
250
275
300
325
350
375
400
425
I
of Clayton Total Nitrogen Loadings
I n
I
I
I
i
1 3
I
I
I
I
i
1,157
-5,373
8,280
Permitted
21,400
21,400
21,400
J'own
I Annual
3.9 22556.78
3.9 16027.19
3.9 29679.98
TN
1.9
1.35
2.5
Flow
365
365
365
I
I
VNeeded=
I
I
I
I
!
!
I
!
HUA/CLAYTON/AEROBIC DIGESTERxls
TOWN OF CLAYTON
LITTLE CREEK STP UPRATE STUDY
AEROBIC DIGESTER THEORETICAL DESIGN VARIABLES
12,032 FT3
90,000 Gallons
12,032
90,000
2.5
90000
31600
8324
7327
0.06
0.8
2.85
12,032
90,001
2.5
90000
31600
8324
11785
0.06
0.8
5
12,032
90,001
2.5
90000
31600
8324
19748
0.06
0.8
10
12,032
90,001
2.5
90000
31600
8324
25488
0.06
0.8
15
12,032
90,000
2.5
90000
31600
8324
29823
0.06
0.8
20
2.5 MGD
90000 Gallons
31600 GPD
8324 Mg/1
9393 Mg/1
0.06 d-1 •
0.8
3.8 days
Design Capy=
V Volume^
Q lnfluent=
S lnfluent=
S Digested=
Kd Constant^
Pv Ratio =
OcMCRT=I
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MAY 07 *99 09= 33 FR MUNI MARKETING 801 526 2014 TO 06357 P.01/10
TELEFAX TRANSMITTALI
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Date:Company:Hobbs UpchurchI Total Pages:Fax No:
Copies:
From:Betty-Ann Curtis
Subject:
Michael:
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P.O. Box 300 • 669 Wert 200 South • Salt Lake City, Utah Ml 10-0300 • M*in Mae: <01 -526-2000
• direct lines: Telephone: [phone] U1 • Fax: S01-S26-2014 • betty.wtia^bakethujhoa.oxjm
Clayton, NC
Carrousel System Design Options
Message:
Mick Heavener
Jeff Case
Ihave reviewed the facUity plan information for the Clayton WWTP that you sent to me recently
011 W1UCh 1 fo'USed " l0Oldng 8t the eM'5tine 6day’» capacity tTu«t
2.5 MGD. These three areas are: volume capacity for nitrification (and BOD removal) amtinn
capaetty for BOD removal and nitrification and denitrification capability of the existi^ tankage
and any assorted needs for additional tankage for achieving stringent denitrificatStfts
Carrousel System Volume Capacity
K CUytOn WWTP- fi"t “ 0.75 MQ in volume and
w p Sp^ aeratOrS- Tke a™"! basin « 115 MG in volume and
wes two 50 HP two speed aerators. Presently, the plant is designed to operate at a 24 hour
2 " th® mcr.eased floY rate °f 2-5 MGD, the HDT would have to be reduced to
1 hours This detention time would translate to an operating Solids Retention Time of 25 days
q Mr «°?cent^ti°n on ’.’OO n^1- A 25 day SRT » easily sufficient to folly nitrify
' ?W °f th’ yea!i °nly a 15 SRT is t0 completely nitrifyata
mixed hquor temperature of 12 to IS^C.
?oakCr Pr0Za?wSCrly EIMCO Pr0CCSS E^iPmCnt C™P»*y) “
May?, 1999
The existing Carrousel basin volumes appear to be adequate to treat 2.5 MGD at the BOD
concentrahons given in the report. Calculations are enclosed to support these values.
Carrousel $yyteni Aeration Capacity
LtOta,/,°f ?5° ?P avaiIabIe Can-ousel basins. To treat a BOD of 147 mg/I and a
^°f 4 ,S^b0U? 120 of acquired without the denitrificaticm oxygen
cLmWanov^i0Ut 9\Hp dcnitrification oxygen credit. The existing aeration system is
capable supplying the required oxygen to treat 2.5 MGD. Calculations are enclosed which
support these values.
Wil
p.02/10
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w tivyn in lhl uin iiwiuu-iii hl,
MAY 07 * 99 09:34 RR MUNKMARKETING
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• «Mt « «V/« 4 <_ w A •
801 526 2014 TO
Penhrifiy^tjoti Capacity
The existing treatment facility is achieving outstanding denitrification results. Denitrification k
bSrl/hh blSin dcvd°P^ tn anoxic stretch withKcarr^
the^fc^n a^BtlOn P0^ ControI> <iissolved oxygen (DO)™ be managed sq^
nn t? ad/?uate “?Wc yotome for nitrification and sufficient anoxic volume vriffino rcraainine
efficient dJn?rifi^on. When the plant is underloaded as it is pr^etX
posable to achieve very efficient denitrification because the need for large aerobic volumes^hin
he channels is lesser with the lower loads. More volume can be dedicated to anoxic volume in
achieving the outstanding denitrification that they have seen to date.
t0Td 2 5 MGD dcsign lcVel- d^trification capabilitY
U decrease- More and more aerobic volume will be needed to satisfy the increased non jmH
ammonia 0 ng (both removal reactions requiring aerobic conditions). There will be less and
ess anoxic volume available within the Carrousel channels followins the needed aerobic voXe.
At the future flow of 2.S MGD, the smaller Carrousel basin would treat 1 0 MGD and the larger
Sd T15 M?D-Bo,h biuins “pable <>f SXf
a nn k°n’ ^ow^vcr’ exact amount may be dependent on the ability to control DO levels.Opt!Ti2e2be deoitrifica‘iO“ capability of each basin. It is po^dbte^
r^BU’g fr0” 12 rag/I t0 20 ’"gfl through denitrification within the Carrousel bastns. Hus may not be sufficient to meet future effluent niSte levels
Se ’“r pf.epared for achieving extremely stringcat effluent
down the wall and fanning a smaller aeration zone around that aerator therebv crejitinp
w would remam intact. TTus Carrousel denilZR System is able to achieve high levels SinterL
A budget price for two 40 Hp Carrousel System aerators would be $100,000. Complete new
noXZ re<’Uire<J the iUmp fr0m 25 Hp t0 40 HP' A new motor would
the mCfe“e P Wlth°Ut reSUWng 1,1 *" unaccePtably tow service factor on
MAY 07 *99 09:34 PR MUNI MARKETING 801 526 2014 TO «6357 P.03Z10
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recycle, 6 to 8 times influent flow rate, so the plant would be capable of achieving an effluent
nitrate of 4 to 6 rag/1 using these two stages. Total Nitrogen would be 6 mg/1 to 8 mg/L
Figure 1 also shows an initial anaerobic basin for achieving biolopcal phosphorus removal
Influent flow would enter the two stage anaerobic basin and split between the two treatment trains
following the anaerobic reactions. The facility would be capable of achieving about 5 mg/1 of
phosphorus biologically. The wastewater strength, in terms of BOD is quite low, which Inhibits
the biological phosphorus removal reaction. A higher BOD concentration would allow for the
removal of more influent TP.
Also shown in Figure 1 is a second anoxic basin and a reaeration basin. This would be a complete
five stage Bardenpho Process. The second anoxic basin is there to polish the nitrates that are not
removed in the first anoxic basin down to very low levels {less than 1 mg/1). The reaeration basin
is necessary to re-oxidize or take up any ammonia or phosphorus that was released tn the second
anoxic basin and to strip the nitrogen gas from the mixed liquor prior to the final clarifier. The
five stage Bardenpho would only be necessary if the Affluent limits require Total Nitrogen
values less than 6 mg/1.
Figure 2 shows the Carrousel System layout options that would add the initial anoxic basin
outside of the existing Carrousel basins. No in-basin construction would be needed, however,
internal recycle pumping would be required. This design option (using Just the first anoxic basin)
would be capable of achieving effluent nitrate concentrations of 6 to 8 mg/1. Typically, the
pumped recycle plant produces higher effluent nitrate values because the recycle rate 1$ limited,
economically, to 4 times the influent flow rate. If this design layout option used 600% to 800%
re^dc, as the Carrousel denitZR System does, then it, too, would achieve effluent nitrate values
as low as 4 to 6 mg/1. >
aa- »
The anaerobic barin, second anoxic and reacration basins are also shown on Figure 2. The
complete five stage Bardenpho would only be necessary if the effluent nitrate limits are less than
6 mg/L
Finally, Figure 3 shows the conversion of the existing barins into Carrousel denitZR Systems by
extending the anoxic basin outride the boundary of the Carrousd basin. This would also require
in-basin construction, similar to the option shown in figure I. Again, the anaerobic, second
anoxic and reaeration basins are shown for the full five stage Bardenpho Process, which would be
required If the effluent nitrate limits are less than 4 mg/1 (Total Nitrogen levels of less than
6 mg/I).
It was recommended in your firm’s report, that the clarifiers would be adequate to handle the
2.5 MGD future flows, however, clarifier perfonnance may need to be enhanced to ensure the
treatment of anticipated future flows. Chemical addition and baffles were recommended. Baker
Process (EIMCO) recommends that Stamford baffles and energy dissipating inlets (EDI) be
incorporated into cadi clarifier for enhanced perfonnance during peak flow events. The plant
Wil 1 ll\/«tiv«vu
INS P.04/10
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conditions in one clarifier for a period of time and
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Sincerely,
BAKER PROCESS
Betty- Ann Curtia
Senior Process Marketing Engineer
Ii-.*
may be able to simulate the future peak flow <
monitor the effluent quality. This would help make a final decision on the clarification needs.
w iivii vc_*<_*t lit Lnc » uiviu u-«» 11 iui
MAY 07 ‘99 09:35 FR MUN,801 526 2014 TO 86^^
Michael, I hope this is the type of information you are looking for at this time. Please feel free to
call me if you require any additional information or if you have any questions or comments
regarding this information.
801 526 2014 TO tt6357 P.05/10MAY 07 * 99 09:37 FR MUNI MARKETING
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A. DESIGN CONDITIONS
I B. DESIGN ASSUMPTIONS
»**•«••«•««««« •««*«•<•
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a DESIGN CALCULATIONSI1. AERATION VOLUME
BOD REMOVAL Q x (BODi - BOD«) x 8.34
2^0 X( 147-10) x 8.34
2.856 lbs BOD/day
SLUDGE PRODUCTION YX Q x (BODI - BODe) X 8.34E
0.70 x 2.50 X (147 - 10 ) x 8.34
2.000 IbsTSS/dayE
CONFIDENTIAL page 1
2.50
147
210
34
CARROUSEL® denlt/R® SYSTEM DESIGN CALCULATIONS
for
Clayton, North Carolina
AVERAGE FLOW (MGD)
DESIGN BOD (mg/|) -------------- -
DESI^SN TSS (mg/Q •••*.««•«..•••..«.«•«.
DESIGN TKN (mg/l) —•«••••«•**««• *«•«•«« 9
10
IS
1.0
7.0
EFFLUENT BOD (mgA)-----------------
EFFLUENT TSS (mg/Q .
EFFLUENT NHj
EFFLUENT TN (mg/T)
PROCESS SRT (Nitrification) (days)..
MINIMUM WASTEWATER TEMP, f C)
MAXIMUM WASTEWATER TEMP, f C)....
MLSS CONCENTRATION (mg/1)
NET YIELD (lb TSS / lb BOD)................
OXYGEN COEFFICIENT (lb Oj/lb BOD)
(lb Oj / lb NHs)
ALPHA (a)
BETA(P) •••••«• »•••••.. ... .••«<« ««...• .MM ... .......
ELEVATION (ft.)
- 25.0
-------- 15.0
-------- 28.0
3.100
...... 0.70
......... 1.38
4.G0
0.90
0.87
300
P.08/10
Vision BY O^CKED j * DATE
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. .4Otp FRACTIONAL
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inv. rnA nu. idydxoiHuwo
801 S26 2014 TO
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MAY 07 * 99 09:37 FR MUNI ^pKETING
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801 526 2014 TO «635T H.Uy/10MAY 07 *39 09:38 FR MUNI MARKET I Nj
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•ndli mitfipasitc
lafocnad nAkct to rvttim upon tfomtnd and to not to bowod dlroeify or
hxffrectfy In any way dttflmontd to our ktfWosts.
Xivdx/e. '
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Town of Clayton Effluent Flow Data 1999
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BOD
PPm
TSS
PPm
NH3-N
PPm
__9
13.2
6.78
6.1
4.11
4.14
5.76
5.41
4.21
6.52
0.4
0.41
1.09
1.92
3.13
1.15
1.99
1.05
0.67
1.31
5.5
7.7
12
17.7
5.33
2.27
2.29
2.27
3.52
6.51
3.8
4.45
3.97
2.99
1.43
1.07
0.5
0.75
1.4
2.26
January
February
March
April
May
June
Juty
August
September
Average f
Flow
mgd
1.333
1.245
1.271
1.23
1.13
1.125
1.123
1.197
1.89
1.28
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TN TP
ppm ppm
5.23I
8.98
7.86____
6.29 ____
5.76____
4,39____
______2.8____
3.29 ____
9.74____
6.04
CT9905
EXHIBIT 2: NPDES PERMIT INFORMATION
I 12/13/00Exhibit 2HUA
TOWN OF CLAYTON
WWTP EXPANSION
ENVIRONMENTAL ASSESSMENT
Town of Clayton
Environmental Assessment for wWPr Expansion
I A.
1.
2.
a.
I b.
c.
d.
e.
f.
g-
h.
3.
4.
5.
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Part IM
PART III
OTHER REQUIREMENTS
to include a compliance schedule for the
i as required under Section 402(b)(8) of the
by the requirements of the approved State
Requirements for Control of Pollutants Attribute to Industrial User^
Effluent limitations are listed in Part I of this permit. Other pollutants attributable to inputs
from industries using the municipal system may be present in the permittee s discharge. At
such time as sufficient information becomes available to establish limitations for such
pollutants, this permit may be revised to specify effluent limitations for any or all of such
other pollutants in accordance with best practicable technology or water quality standards.
Under no circumstances shall the permittee allow introduction of the following wastes in the
waste treatment system:
Pollutants which create a fire or explosion hazard in the POTW, including, but not limited to,
wastestreams with a closed cup flashpoint of less than 140 degrees Fahrenheit or 60 degrees
Centigrade using the test methods specified in 40 CFR 261.21;
Pollutants which will cause corrosive structural damage to the POTW, but in no case
Discharges with pH lower than 5.0, unless the works is specifically designed to accommodate
such Discharges;
Solid or viscous pollutants in amounts which will cause obstruction to the flow in the POTW
resulting in Interference;
Any pollutant, including oxygen demanding pollutants (BOD, etc.) released in a Discharge at
a flow rate and/or pollutant concentration which will cause Interference with the POTW;
Heat in amounts which will inhibit biological activity in the POTW resulting in Interference,
but in no case heat in such quantities that the temperature at the POTW Treatment Plant
exceeds 40°C (104°F) unless the Division, upon request of the POTW, approves alternate
temperature limits;
Petroleum oil, nonbiodegradable cutting oil, or products of mineral oil origin in amounts that
will cause interference or pass through;
Pollutants which result in the presence of toxic gases, vapors, or fumes within the POTW in a
quantity that may cause acute worker health and safety problems;
Any trucked or hauled pollutants, except at discharge points designated by the POTW.
With regard to the effluent requirements listed in Part I of this permit, it may be necessary for
the permittee to supplement the requirements of the Federal Pretreatment Standards (40 CFR,
Part 403) to ensure compliance by the permittee with all applicable effluent limitations. Such
actions by the permittee may be necessary regarding some or all of the industries discharging
to the municipal system.
The permittee shall require any industrial discharges into the permitted system to meet Federal
Pretreatment Standards promulgated in response to Section 307(b) of the Act. Prior to
accepting wastewater from any significant industrial user, the permittee shall either develop
and submit to the Division a Pretreatment Program for approval per 15A NCAC 2H .0907(a) or
modify an existing Pretreatment Program per 15A NCAC 2H .0907(b).
This permit shall be modified, or alternatively, revoked and reissued, to incorporate or modify
an approved POTW Pretreatment Program or I ' ’
development of a POTW Pretreatment Program
Clean Water Act and implementing regulations or
pretreatment program, as appropriate.
B. Pretreatment Program Requirements
Under authority of sections 307(b) and (c) and 402(b)(8) of the Clean Water Act and implementing
regulations 40 CFR Part 403, North Carolina General Statute 143-215.3 (14) and implementing
Page 1 of 4
1.
2.
3.
4.
5.
6.
7.
PartlU Page 2 of 4
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Industrial Waste Survey (IWS)
The permittee shall update its Industrial Waste Survey (IWS) of all users of the sewer collection
system at least once every five years;
Industrial User Pretreatment Permits (IUP) & Allocation Tables
In accordance with NCGS 143-215.1, the permittee shall issue to all significant industrial users,
permits for operation of pretreatment equipment and discharge to the permittee's treatment
works. These permits shall contain limitations, sampling protocols, reporting requirements,
appropriate standard and special conditions, and compliance schedules as necessary for the
installation of treatment and control technologies to assure that their wastewater discharge will
meet all applicable pretreatment standards and requirements. The permittee shall maintain a
current Allocation Table (AT) which summarizes the results of the Headworks Analysis (HWA)
and the limits from all Industrial User Pretreatment Permits (IUP). Permitted IUP loadings for
each parameter cannot exceed the treatment capacity of the POTW as determined by the HWA;
Sewer Use Ordinance (SUO)
The permittee shall maintain adequate legal authority to implement its approved pretreatment
program;
regulations 15A NCAC 2H .0900, and in accordance with the approved pretreatment program, all
provisions and regulations contained and referenced in the Pretreatment Program Submittal are an
enforceable part of this permit.
Headworks Analysis (HWA) and Local Limits
The permittee shall obtain Division approval of a Headworks Analysis (HWA) at least once
every five years, and as required by the Division. The permittee shall develop, in accordance
with 40 CFR 403.5(c) and 15A NCAC 2H .0909, specific Local Limits to implement the
prohibitions listed in 40 CFR 403.5(a) and (b) and 15A NCAC 2H .0909;
POTW Inspection & Monitoring of their SIUs
The permittee shall conduct inspection, surveillance, and monitoring activities as described in
its Division approved pretreatment program in order to determine, independent of information
supplied by industrial users, compliance with applicable pretreatment standards. The
permittee must:
Authorization to Construct (A to C)
The permittee shall ensure that an Authorization to Construct (A to C) is issued to all
applicable industrial users for the construction or modification of any pretreatment facility.
Prior to the issuance of an Authorization to Construct (A to C), the proposed pretreatment
facility and treatment process must be evaluated for its capacity to comply with all Industrial
User Pretreatment Permit (IUP) limitations;
Monitoring Plan
The permittee shall implement a Division approved Monitoring Plan for the collection of
facility specific data to be used in a wastewater treatment plant Headworks Analysis (HWA)
for the development of specific pretreatment local limits;
The permittee shall operate its approved pretreatment program in accordance with Section 402(b)(8)
of the Clean Water Act, the Federal Pretreatment Regulations 40 CFR Part 403, the State Pretreatment
Regulations 15A NCAC 2H .0900, and the legal authorities, policies, procedures, and financial
provisions contained in its pretreatment program submission and Division approved modifications
there of. Such operation shall include but is not limited to the implementation of the following
conditions and requirements:
per calendar year;
8.
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9.
10.
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schedule established by the Director and shall
a.)
b.)I
C.)proposed to correct the
d.)
e)
Page 3 of 4Part III
imiai]
7a.
7b.
For all other active pretreatment programs, the permittee shall submit two copies of a
Pretreatment Annual Report (PAR) describing its pretreatment activities over the previous
twelve monthsto the Division at the following address:
NCDWQ Pretreatment Group
P.O. BOX 29535
RALEIGH, NC 27626-0535
These reports shall be submitted according to a
contain the following:
Inspect all S Aicant Industrial Users (SlUs) at least onc^r calendar year; and
Sample all Significant Industrial Users (SlUs) at least tWper calendar year for all
permit-limited pollutants, once during the period from January 1 through June 30
and once during the period from July 1 through December 31, except for organic
compounds which shall be sampled once per calendar year;
SIU Self Monitoring and Reporting
The permittee shall require all industrial users to comply with the applicable monitoring and
reporting requirements outlined in the Division approved pretreatment program, the industry's
pretreatment permit, or in 15A NCAC 2H .0908;
Enforcement Response Plan (ERP)
The permittee shall enforce and obtain appropriate remedies for violations of al1 P^reataient
standards promulgated pursuant to section 307(b) and (c) <
et.seq.), prohibitive discharge standards as set forth in 40 CFR 403.5 and 15A NCAC 2H .0909,
and specific local limitations. All enforcement actions shall be consistent with the Enforcement
Response Plan (ERP) approved by the Division,
Pretreatment Annual Reports (PAR)
The permittee shall report to the Division in accordance with 15 A NCAC 2H .0908. peu.of
submitting annual reports. Modified Pretreatment Programs developed under 15A NCAC 2H
.0904 (b) may be required to meet with Division personnel periodically to discuss enforcement
of pretreatment requirements and other pretreatment implementation issues.
^Abrief discussion of reasons for, status of, and actions taken for all Significant
Industrial Users (SlUs) in Significant Non-Compliance (SNC);
Pretreatment Program Summary (PPS)
A pretreatment program summary (PPS) on specific forms approved by the
Division;
Significant Non-Compliance Report (SNCR)
The nature of the violations and the actions taken or
violations on specific forms approved by the Division;
Industrial Data Summary Forms C ?_ .
Monitoring data from samples collected by both the POTW and the Significant
Industrial User (SIU). These analytical results must be reported on Industrial
Data Summary Forms (IDSF) or other specific format approved by the Division;
Other Information
Copies of the POTW’s allocation table, new or modified enforcement compliance
schedules, public notice of SlUs in SNC, and any other information, upon
request, which in the opinion of the Director is needed to determine compliance
with the pretreatment implementation requirements of this permit;
11.
12.
13.
14.
C. Construction
D. Groundwater Monitoring
E. Publicly Owned Treatment Works
All POTWs must provide adequate notice to the Director of the following:
1.
2.
3.
Part III Page 4 of 4
fen!
The permittee shall, upon written notice from the Director of the Division of Water Quality, conduct
groundwater monitoring as may be required to determine the compliance of this NPDES permitted
facility with the current groundwater standards.
Funding and Financial Report
The permittee shall maintain adequate funding and staffing levels to accomplish the objectives
of its approved pretreatment program;
Public Notice
The permittee shall publish annually a list of Significant Industrial Users (SIUs) that were in
Significant Non-Compliance (SNC) as defined in the permittee's Division approved Sewer Use
Ordinance with applicable pretreatment requirements and standards during the previous
twelve month period. This list shall be published within two months of the applicable twelve
month period;
No construction of wastewater treatment facilities or additions to add to the plant’s treatment
capacity or to change the type of process utilized at the treatment plant shall be begun until Final
Plans and Specifications have been submitted to the Division of Water Quality and written approval
and Authorization to Construct has been issued.
Record Keeping
The permittee shall retain for a minimum of three years records of monitoring activities and
results, along with support information including general records, water quality records, and
records of industrial impact on the POTW;
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The permittee shall continually evaluate all wastewater disposal alternatives and pursue the most
environmentally sound alternative of the reasonably cost effective alternatives. If the facility is in
substantial non-compliance with the terms and conditions of the NPDES permit or governing rules,
regulations or laws, the permittee shall submit a report in such form and detail as required by the
Division evaluating these alternatives and a plan of action within sixty (60) days of notification by the
Division.
Any new introduction of pollutants into the POTW from an indirect discharger which would be
subject to section 301 or 306 of CWA if it were directly discharging those pollutants; and
Any substantial change in the volume or character of pollutants being introduced into that
POTW by a source introducing pollutants into the POTW at the time of issuance of the permit.
For purposes of this paragraph, adequate notice shall include information on (1) the quality and
quantity of effluent introduced into the POTW, and (2) any anticipated impact of the change on
the quantity or quality of effluent to be discharged from the POTW.
Modification to Pretreatment Programs
Modifications to the approved pretreatment program including but not limited to local limits
modifications, POTW monitoring of their Significant Industrial Users (SIUs), and Monitoring
Plan modifications, shall be considered a permit modification and shall be governed by 15
NCAC 2H .0114 and 15A NCAC 2H .0907.
F. Requirement to Continually Evaluate Alternatives to Wastewater Discharges
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A. (3.)
(1)
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(2)
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Town of Clayton
NPDES No. NC0025453
Q
8.34
= the average total nitrogen concentraUon (mg/L) of the composite
samples collected during the month
= the total wastewater flow discharged during the month (MG/month)
= conversion factor, from (mg/L x MG) to pounds
(2) Annual Mass Loading (Ib/yr) = E (Monthly Mass Loadings) for the calendar year
The Permittee shall report the total nitrogen concentration for each sample and the
monSiJmass loading in the appropriate self-monitoring report and the annual mass
loadingof total nitrogen in the December self-monitoring report for the year.
annual limits for total nitrogen
(a) The Neuse Nutrient Management Strategy rule for point sources^ Provides that
1 annual mass limits for total nitrogen shall be included in the permits for all
^harSrs with permitted flows (as defined in the Strategy) greater than or equal to
oTmGD and thafthose nitrogen limits, including the limits in this pennit. shall
become effective with the calendar year beginning on January 1. 2003.
fhl The Neuse rule also provides that members of a group compliance association shall
be subj™t to IndMdual annual mass limits for total nitrogen. At the time of permit
issuance, tire Permittee had expressed interest in joining such an association.
Accordingly.
(1) the total nitrogen limit In Condition A(l) of this permit Is deemed waived
provided that the following conditions are met:
a formal agreement between the association ^d Environ^ntal
Management Commission, as outlined in ISA NCAC 2B. 0234, is
established and is in effect; and
(ii) the Permittee is a party to said agreement; and
(Hl) the association and the Permittee substantially conform with the
agreement.
any subsequent amendments is hereby incorporated as an enforceable part
this permit.
(c) If the Division determines, at any time during the term of this pennlt that these
conditions are not being met. It shall notify the Permittee in writog of tMs
determination and of Its basis. The consequence of such a determination shaU be tna
the Permittee’s annual mass limit for total nitrogen and its effective date shall be
~inSHmm^iately. The Division shall accept and consider written responses
received from the Permittee and/or the association within thirty
original notice before making a final decision and will provide that decision in writing.
A. (2.) TOTAL NITROGEN MONITORING
The Permittee shall calculate the annual massjoading of total nitrogen as the sum of monthly
loadings, according to the following equations:
(1) Monthly Mass Loading (Ib/mo) = TN x Q x 8.34
where:
TN
ANNUAL LIMITS FOR TOTAL NITROGEN (coat’d.)A. (3.)
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A. (4.) CHRONIC TOXICITY PERMIT LIMIT (QRTRLY)
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The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant
mortality to Ceriodaphnia dubia at an effluent concentration of 1.6 %.
The chronic value for multiple concentration tests will be determined using the geometric mean of
the highest concentration having no detectable impairment of reproduction or survival and the
lowest concentration that does have a detectable impairment of reproduction or survival. The
definition of “detectable impairment" collection methods, exposure regimes, and further statistical
methods are specified in the “North Carolina Phase II Chronic Whole Effluent Toxicity Test
Procedure" (Revised-February 1998) or subsequent versions.
The permit holder shall perform at a minimum, quarterlg monitoring using test procedures
outlined in the “North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised
February 1998, or subsequent versions or “North Carolina Phase II Chronic Whole Effluent
Toxicity Test Procedure" (Revised-February 1998) or subsequent versions. The tests will be
performed during the months of March, June, September, and December. Effluent sampling for
this testing shall be performed at the NPDES permitted final effluent discharge below all treatment
processes.
If the test procedure performed as the first test of any single quarter results in a failure or ChV
below the permit limit, then multiple-concentration testing shall be performed at a minimum, in
each of the two following months as described in “North Carolina Phase II Chronic Whole Effluent
Toxicity Test Procedure" (Revised-February 1998) or subsequent versions.
All toxicity testing results required as part of this permit condition will be entered on the Effluent
Discharge Monitoring Form (MR-1) for the months in which tests were performed, using the
parameter code TGP3B for the pass/fail results and THP3B for the Chronic Value. Additionally,
DWQ Form AT-3 (original) is to be sent to the following address:
Town of Clayton
NPDES No. NC0025453
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Footnote:
w Neuse River Basin - Nutrient Sensitive Waters Management Strategy: Wastewater
Discharge Requirements (15A NCAC 2B. 0234).
Completed Aquatic Toxicity Test Forms shall be filed with the Environmental Sciences Branch no
later than 30 days after the end of the reporting period for which the report is made.
(d) The Permittee shall notify the Division in writing within five (5) working days if, at any
time during the term of this permit, the Permittee elects not to join the association, or
if it withdraws or otherwise loses its membership in the association. Notification shall
be sent to:
NC DENR / Division of Water Quality / NPDES Unit
1617 Mall Service Center
Raleigh, NC 27699-1617
Attention: North Carolina Division of Water Quality
Environmental Sciences Branch
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
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Town of Clayton
NPDES No. NC0025453
A. (4.) CHRONIC TOXICITY fl^MIT LIMIT (QRTRLY) (cont’d.^
Test data shall be complete, accurate, include all supporting chemical/physical measurements
and all concentration/response data, and be certified by laboratory supervisor and ORC or
approved designate signature. Total residual chlorine of the effluent toxicity sample must be
measured and reported if chlorine is employed for disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity monitoring
is required, the permittee will complete the information located at the top of the aquatic toxicity
(AT) test form indicaUng the facility name, permit number, pipe number, county, and the
month/year of the report with the notaUon of “No Flow" in the comment area of the form. The
report shall be submitted to the Environmental Sciences Branch at the address cited above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required,
monitoring will be required during the following month.
Should any test data from this monitoring requirement or tests performed by the North Carolina
Division of Water Quality indicate potential impacts to the receiving stream, this permit may be re­
opened and modified to include alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum
control organism survival, minimum control organism reproduction, and appropriate
environmental controls, shall constitute an invalid test and will require immediate fofiow-up
testing to be completed no later than the last day of the month following the month of the initial
monitoring.
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2.
3.
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Permittee shall at all times provide the operation and maintenance necessary to operate the
existing facilities at optimum efficiency.
No later than 14 calendar days following a date identified in the above schedule of compliance,
the permittee shall submit either a report of progress or, in the case of specific actions being
required by identified dates, a written notice of compliance or noncompliance. In the latter case
the notice shall indude the cause of noncompliance, any remedial actions taken, and the
probability of meeting the next schedule requirements.
The permittee shall comply with Final Effluent Limitations specified for discharges in accordance
with the following schedule:
Permittee shall comply with Final Effluent Limitations by the effective date of the permit unless
specified below.
ion B. Schedule of Compliance
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definitionsSECTION A-
1. Permit Issuing Authority
I The Director of the Division of Water Quality.
DEM or wthe Division*2.
Means the Division of Water Quality, Department of Environment, Health and Natural Resources.
3.
Used herein means the North Carolina Environmental Management Commission.
Act or "the Act"4.
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Mass/Pay Measurements5.
reported. The limitation is identified as "Monthly Average" in Part I of the permit
c.
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The Federal Water Pollution Control Act, also known as the Clean Water Act as amended, 33 USC
1251, et seq.
PART II
STANDARD CONDITIONS FOR NPDES PERMITS
b. The "weekly average discharge" is defined as the total mass of all daily discharges sampled
and/or measured during the calendar week (Sunday - Saturday) on which daily discharges are
sampled and measured, divided by the number of daily discharges sampled and/or measured
during such week. It is, therefore, an arithmetic mean found by adding the weights of
pollutants found each day of the week and then dividing this sum by the number of days the
tests were reported. This limitation is identified as "Weekly Average" in Part 1 of the permit
The "maximum daily discharge" is the total mass (weight) of a pollutant discharged during a
calendar day. If only one sample is taken during any calendar day the weight of pollutant
calculated from it is the "maximum daily discharge." This limitation is identified as "Daily
Maximum," in Part I of the permit.
d. The "average annual discharge" is defined as the total mass of all daily discharges sampled
and/or measured during the calendar year on which daily discharges are sampled and
measured, divided by the number of daily discharges sampled and/or measured during such
year. It is, therefore, an arithmetic mean found by adding the weights of pollutants found each
day of the year and then dividing this sum by the number of days the tests were reported. This
limitation is defined as "Annual Average" in Part I of the permit
a. The "monthly average discharge" is defined as the total mass of all daily discharges sampled
and/or measured during a calendar month on which daily discharges are sampled and
measured, divided by the number of daily discharges sampled and/or measured during such
month. It is therefore, an arithmetic mean found by adding the weights of the pollutant found
each day of the month and then dividing this sum by the number of days the tests were
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6. Concentration Measurement
a- The "average monthly concentration,” other than for fecal coliform bacteria, is the sum of the
concentrations of all daily discharges sampled and/or measured during a calendar month on
which daily discharges are sampled and measured, divided by the number of daily discharges
sampled and/or measured during such month (arithmetic mean of the daily concentration
values). The daily concentration value is equal to the concentration of a composite sample or in
the case of grab samples is the arithmetic mean (weighted by flow value) of all the samples
collected during that calendar day. The average monthly count for fecal coliform bacteria is
the geometric mean of the counts for samples collected during a calendar month. This
limitation is identified as "Monthly Average" under "Other Limits" in Part I of the permit.
b. The "average weekly concentration," other than for fecal coliform bacteria, is the sum of the
concentrations of all daily discharges sampled and/or measured during a calendar week
(Sunday/Saturday) on which daily discharges are sampled and measured divided by the
number of dafly discharges sampled and/or measured during such week (arithmetic mean of the
daily concentration values). The daily concentration value is equal to the concentration of a
composite sample or in the case of grab samples is the arithmetic mean (weighted by flow
value) of all the samples collected during that calendar day. The average weekly count for
fecal colifonn bacteria is the geometric mean of the counts for samples collected during a
calendar week This limitation is identified as "Weekly Average" under "Other Limits" in
Part I of the pennit.
The "quarterly average concentration" is the average of all samples taken over a calendar
quarter. It is identified as "Quarterly Average Limitation" in the text of Pan I of thn normit
c. The "maximum daily concentration" is the concentration of a pollutant discharge during a
calendar day. If only one sample is taken during any calendar day the concentration of
pollutant calculated from it is the "Maximum Daily Concentration", it is identified as "Dailv
Maximum" under "Other Limits" in Part 1 of the permit. 7
d. The "average annual concentration," other than for fecal coliform bacteria, is the sum of the
concentrations of all daily discharges sampled and/or measured during a calendar year on
which daily discharges are sampled and measured divided by the number of daily discharges
sampled and/or measured during such year (arithmetic mean of the daily concentration
values). The daily concentration value is equal to the concentration of a composite sample or in
the case of grab samples is the arithmetic mean (weighted by flow value) of all the samples
collected during that calendar day. The average yearly count for fecal coliform bacteria is the
geometric mean of the counts for samples collected during a calendar year. This limitation is
identified as "Annual Average" under "Other Limits" in Part I of the permit
e. The daily average concentration" (for dissolved oxygen) is the minimum allowable amount of
dissolved oxygen required to be available in the effluent prior to discharge averaged over a
calendar day. If only one dissolved oxygen sample is taken over a calendar day, the sample is
considered to be the "daily average concentration" for the discharge. It is identified as "daily
average" in the text of Part I. 3
g. A calendar quarter is defined as one of the following distinct periods: January through March
April through June, July through September, and October through December.
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c.
I 8. Types pf Samples
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b. Grab Sample: Grab samples
9. Calculation pf Means
a
c Weighted by Flow Value Weighted by flow value means the summation of each concentration
times its respective flow divided by the summation of the respective flows.
A "continuous flow measurement" is a measure of discharge flow from the facility which occurs
continually without interruption throughout the operating hours of the facility. Flow shall be
monitored continually except for the infrequent times when there may be no flow or for
infrequent maintenance activities on the flow device.
b. An "instantaneous flow measurement" is a measure of flow taken at the time of sampling, when
both the sample and flow will be representative of the total discharge.
a. Composite Sample: A composite sample shall consist of:
Arithmetic Mean: The arithmetic mean of any set of values is the summation of the individual
values divided by the number of individual values.
b. Geometric Mean: The geometric mean of any set of values is the Nth root of the product of the
individual values where N is equal to the number of individual values. The geometric mean is
equivalent to the antilog of the arithmetic mean of the logarithms of the individual values.
For purposes of calculating the geometric mean, values of zero (0) shall be considered to be one
(1).
“ “ ‘ * ; are individual samples collected over a period of time not
exceeding 15 minutes; the grab sample can be taken manually. Grab samples must be
representative of the discharge or the receiving waters.
(1) a series of grab samples collected at equal time intervals over a 24 hour period of discharge
and combined proportional to the rate of flow measured at the time of individual sample
collection, or
(2) a series of grab samples of equal volume collected over a 24 hour period with the time
intervals between samples determined by a preset number of gallons passing the sampling
point Flow measurement between sample intervals shall be determined by use of a flow
recorder and totalizer, and the present gallon interval between sample collection fixed at
no greater than 1Z24 of the expected total daily flow at the treatment system, or
(3) a single, continuous sample collected over a 24 hour period proportional to the rate of flow.
In accordance with (1) above, the time interval between influent grab samples shall be no
greater than once per hour, and the time interval between effluent grab samples shall be no
greater than once per hour except at wastewater treatment systems having a detention time of
greater than 24 hours. In such cases, effluent grab samples may be collected at time intervals
evenly spaced over the 24 hour period which are equal in number of hours to the detention time
of the system in number of days. However, in no case may the time interval between effluent
grab samples be greater than six (6) hours nor the number of samples less than four (4) during a
24 hour sampling period.
7. Other Measurements
a. Flow, (MGD): The flow limit expressed in this permit is the 24 hours average flow, averaged
monthly. It is determined as the arithmetic mean of the total daily flows recorded during the
calendar month.
10. Calendar Day
11. Hazardous Substance
12. Toxic Pollutant
A toxic pollutant is any pollutant listed as toxic under Section 307(a)G) of the Clean Water Act.
SECTION B. GENERAL CONDITIONS I1. Duty to Comply
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d. Any person may be assessed
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A hazardous substance means any substance designated under 40 CFR Part 116 pursuant to Section
311 of the Clean Water Act
Part II
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The permittee must comply with all conditions of this permit. Any permit noncompliance
constitutes a violation of the Clean Water Act and is grounds for enforcement action; for permit
termination, revocation and reissuance, or modification; or denial of a permit renewal application.
A calendar day is defined as the period from midnight of one day until midnight oi the next day.
However, for purposes of this permit, any consecutive 24-hour period that reasonably represents
the calendar day may be used for sampling.
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Ic. Under state law, a civil penalty of not more than ten thousand dollars ($10,000) per violation
may be assessed against any person who violates or fails to act in accordance with the terms,
conditions, or requirements of a permit. [Ref. North Carolina General Statutes § 143-215.6A]
an administrative penalty by the Administrator for violating
section 301, 302, 306, 307, 308, 318, or 405 of the Act, or any permit condition or limitation
implementing any of such sections in a permit issued under section 402 of the Act.
Administrative penalties for Class I violations are not to exceed $10,000 per viohtion, with
the maximum amount of any Class 1 penalty assessed not to exceed $25,000. Penalties for Class
n violations are not to exceed $10,000 per day for each day during which the violation
continues, with the maximum amount of any Class 11 penalty not to exceed $125,000.
b. The Clean Water Act provides that any person who violates a permit condition is subject to a
dvil penalty not to exceed $25,000 per day for each violation. Any person who negligently
violates any permit condition is subject to criminal penalties of $2,500 to $25,000 per day of
violation, or imprisonment for not more than 1 year, or both. Any person who knowingly
violates permit conditions is subject to criminal penalties of $5,000 to $50/XX) per day of
violation, or imprisonment for not more than 3 years, or both. Also, any person who violates a
permit condition may be assessed an administrative penalty not to exceed $10,000 per violation
with the maximum amount not to exceed $125,000. [Ref: Section 309 of the Federal Act 33
US.C 1319 and 40 CFR 12241 (a)]
a. The permittee shall comply with effluent standards or prohibitions established under section
307(a) of the Clean Water Act for toxic pollutants and with standards for sewage sludge use or
disposal established under section 405(d) of the Clean Water Act within the time provided in
the regulations that establish these standards or prohibitions or standards for sewage sludge
use or disposal, even if the permit has not yet been modified to incorporate the requirement
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2. Duty to Mitigate
3. Civil and Criminal Liability
4. Oil and Hazardous Substance Liability
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5.r Rights
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6. Onshore or Offshore Construction
offshore physical
7. Severability
I ’Duty to Provide Information8.
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The issuance of this permit does not convey any property rights in either real or personal property,
or any exclusive privileges, nor does it authorize any injury to private property or any invasion of
persona] rights, nor any infringement of Federal, State or local laws or regulations.
This permit does not authorize or approve the construction of any onshore or
structures or facilities or the undertaking of any work in any navigable waters.
Nothing in this permit shall be construed to preclude the institution of any legal action or relieve
the permittee from any responsibilities, liabilities, or penalties to which the permittee is or may
be subject to under NCGS 143-21575 et seq. or Section 311 of the Federal Act, 33 USG 1321.
Furthermore, the permittee is responsible for consequential damages, such as fish kills, even
though the responsibility for effective compliance may be temporarily suspended.
The provisions of this permit are severable, and if any provision of this permit, or the application
of any provision of this permit to any circumstances, is held invalid, the application of such
provision to other circumstances, and the remainder of this permit, shall not be affected thereby.
The permittee shall furnish to the Permit Issuing Authority, within a reasonable time, any
information which tiie Pennit Issuing Authority may request to determine whether cause exists for
modifying, revoking and reissuing, or terminating this permit or to determine compliance with this
permit The permittee shall also furnish to the Permit Issuing Authority upon request copies of
records required to be kept by this permit.
9. Duty to Reapply
If the permittee wishes to continue an activity regulated by this permit after the expiration date of
this permit the permittee must apply for and obtain a new permit.
Except as provided in permit conditions on "Bypassing" (Part II, C-4) and "Power Failures" (Part 11,
C-7), nothing in this permit shall be construed to relieve the permittee from any responsibilities,
liabilities, or penalties for noncompliance pursuant to NCGS 143-2153,143-215.6 or Section 309 of
the Federal Act, 33 USC 1319. Furthermore, the permittee is responsible for consequential damages,
such as fish kills, even though the responsibility for effective compliance may be temporarily
suspended.
The permittee shall take all reasonable steps to minimize or prevent any discharge or sludge use or
disposal in violation of this permit which has a reasonable likelihood of adversely affecting
human health or the environment.
10. Expiration of Permit
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The permittee is not authorized to discharge after the expiration date. In order to ‘ receive
automatic authorization to discharge beyond the expiration date, the permittee shall submit such
information, forms, and fees as are required by the agency authorized to issue permits no later than
180 days prior to the expiration date. Any permittee that has not requested renewal at least 180
days prior to expiration, or any permittee that does not have a permit after the expiration and has
not requested renewal at least 180 days prior to expiration, will subject the permittee to enforcement
procedures as provided in NCOS 143-215.6 and 33 USC1251 et. seq.
11. Signatory Requirements
"I certify, under penalty of law, that this document and all attachments were prepared under
my direction or supervision in accordance with a system designed to assure that qualified
personnel properly gather and evaluate the information submitted. Based on my inquiry of the
person or persons who manage the system, or those persons directly responsible for gathering
the information, the information submitted is, to the best of my knowledge and belief, true,
accurate, and complete. I am aware that there are significant penalties for submitting false
information, induding the possibility of fines and imprisonment for knowing violations.”
All applications, reports, or information submitted to the Permit Issuing Authority shall be signed
and certified.
a. All permit applications shall be signed as follows:
(1) For a corporation: by a responsible corporate officer. For the purpose of this Section, a
responsible corporate officer means: (a) a president, secretary, treasurer or vice president
of the corporation in charge of a principal business function, or any other person who
performs similar policy or decision making functions for the corporation, or (b) the manager
of one or more manufacturing production or operating facilities employing more than 250
persons or having gross annual sales or expenditures exceeding 25 million (in second quarter
1980 dollars), if authority to sign documents has been assigned or delegated to the manager
in accordance with corporate procedures.
(2) For a partnership or sole proprietorship: by a general partner or the proprietor,
respectively; or
(3) For a municipality, State, Federal, or other public agency: by either a prindpal executive
officer or ranking elected official.
b. All reports required by the permit and other information requested by the Permit Issuing
Authority shall be signed by a person described above or by a duly authorized representative of
that person. A person is a duly authorized representative only if:
(1) The authorization is made in writing by a person described above;
(2) The authorization specified either an individual or a position having responsibility for the
overall operation of the regulated facility or activity, such as the position of plant
manager, operator of a well or well field, superintendent, a position of equivalent
responsibility, or an individual or position having overall responsibility for environmental
matters for the company. (A duly authorized representative may thus be either a named
individual or any individual occupying a named position.); and
(3) The written authorization is submitted to the Permit Issuing Authority.
c. Certification. Any person signing a
make the following certification:
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1. Certified Operator
Pursuant to Chapter 90A-44 of North Carolina General Statutes, and upon classification of the
facility by the Certification Commission, the permittee shall employ a certified wastewater
treatment plant operator in responsible charge (ORO of the wastewater treatment facilities. Such
operator must hold a certification of the grade equivalent to or greater than the classification
assigned to the wastewater treatment facilities by the Certification Commission. The permittee
must also employ a certified back-up operator of the appropriate type and any grade to comply
with the conditions of Title ISA, Chapter 8A .0202. The ORC of the fadlity must visit each Class 1
fadlity at least weekly and each Class II, ID, and IV facility at least daily, excluding weekends
and holidays, and must properly manage and document daily operation and maintenance of the
facility and must comply with all other conditions of Title ISA, Chapter 8A .0202. Once the
facility is classified, the permittee shall submit a letter to the Certification Commission which
designates the operator in responsible charge within thirty days after the wastewater treatment
facilities are 50% complete.
2. Proper operation and Maintenance
The permittee shall at all times properly operate and maintain all facilities and systems of
treatment and control (and related appurtenances) which are installed or used by the permittee to
achieve compliance with the conditions of this permit. Proper operation and maintenance also
indudes adequate laboratory controls and appropriate quality assurance procedures. This provision
requires the operation of back-up or auxiliary facilities or similar systems which are installed by a
permittee only when the operation is necessary to achieve compliance with the conditions of the
permit
12. Permit Actions
This permit may be modified, revoked and reissued, or terminated for cause. The filing of a request
by the permittee for a permit modification, revocation and reissuance, or termination, or a
notification of planned changes or anticipated noncompliance does not stay any permit condition.
13. permit Modification, Revocation and Reissuance, or Termination
The issuance of this permit does not prohibit the permit issuing authority from reopening and
modifying the permit, revoking and reissuing the permit, or terminating the permit as allowed by
the laws, rules, and regulations contained in Title 40, Code of Federal Regulations, Parts 122 and
173; Title ISA of the North Carolina Administrative Code, Subchapter 2H .0100; and North
Carolina General Statute 143-2151 et. al.
14. Previous Permits
All previous National Pollutant Discharge Elimination System Permits issued to this facility,
whether for operation or discharge, are hereby revoked by issuance of this permit. |Thc exclusive
authority to operate this facility arises under this permit. The authority to operate the facility
under previously issued permits bearing this number is no longer effective. ] The conditions,
requirements, terms, and provisions of this permit authorizing discharge under the National
Pollutant Discharge Elimination System govern discharges from this facility.
SECTION C OPERATION AND MAINTENANCE OF POLLUTION CONTROLS
3. Need to Halt pr Reduce not a Defense
4. Bypassing pfTreatment Facilities
Definitionsa.
b.Bypass not exceeding limitations.
Noticec.
d. Prohibition of Bypass
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It shall not be a defense for a permittee in an enforcement action that it would have been necessary
to halt or reduce the permitted activity in order to maintain compliance with the condition of this
permit.
The permittee may allow any bypass to occur which-does not cause effluent limitations to be
exceeded, but only if it also is for essential maintenance to assure efficient operation. These
bypasses are not subject to the provisions of Paragraphs c. and d. of this section.
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(1) Bypass is prohibited and the Permit Issuing Authority may take enforcement action against
a permittee for bypass, unless:
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(1) "Bypass" means the known diversion of waste streams from any portion of a treatment
facility including the collection system, which is not a designed or established or operating
mode for the facility.
(2) "Severe property damage" means substantial physical damage to property, damage to the
treatment facilities which causes them to become inoperable, or substantial and permanent
loss of natural resources which can reasonably be expected to occur in the absence of a
bypass. Severe property damage does not mean economic loss caused by delays in
production.
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(1) Anticipated bypass. If the permittee knows in advance of the need for a bypass, it shall
submit prior notice, if possible at least ten days before the date of the bypass; induding an
evaluation of the anticipated quality and affect of the bypass.
(2) Unanticipated bypass. The permittee shall submit notice of an unanticipated bypass as
required in Part II, E. 6. of this permit (24 hour notice).
(A) Bypass was unavoidable to. prevent loss of life, personal injury or severe property
damage;
(B) There were no feasible alternatives to the bypass, such as the use of auxiliary treatment
facilities, retention of untreated wastes or maintenance during normal periods of
equipment downtime. This condition is not satisfied if adequate backup equipment should
have been installed in the exercise of reasonable engineering judgment to prevent a bypass
which occurred during normal periods of equipment downtime or preventive maintenance;
and
(O The permittee submitted notices as required under Paragraph c. of this section.
(2) The Permit Issuing Authority may approve an anticipated bypass, after considering its
adverse affects, if the Permit Issuing Authority determines that it will meet the three
conditions listed above in Paragraph d. 0) of this section.
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a.
b.Effect of an upset.
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Conditions necessary for a demonstration of upset.c.I
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6. Removed Substances
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7. Power Failures
The permittee is responsible for maintaining adequate safeguards as required by DEM Regulation,
1106 ISA, North Carolina Administrative Code, Subchapter 2H, .0124 Reliability, to prevent the
discharge of untreated or inadequately treated wastes during electrical power failures either by
means of alternate power sources, standby generators or retention of inadequately treated effluent
In any enforcement proceeding the permittee seeking to establish the occurrence of an upset has
the burden of proof.
A permittee who wishes to establish the affirmative defense of upset shall demonstrate,
through properly signed, contemporaneous operating logs, or other relevant evidence that
An upset constitutes an affirmative defense to an action brought for noncompliance with such
technology based permit effluent limitations if the requirements of paragraph c. of this
condition are met. No determination made during administrative review of claims that
noncompliance was caused by upset, and before an action for noncompliance, is final
administrative action subject to judicial review.
Solids, sludges, filter backwash, or other pollutants removed in the course of treatment or control of
wastewaters shall be utilized/disposed of in accordance with NCOS 143-215J and in a manner such
as to prevent any pollutant from such materials from entering waters of the State or navigable
waters of the United States. The permittee shall comply with all existing federal regulations
governing the disposal of sewage sludge. Upon promulgation of 40 CFR Part 503, any permit issued
by the Permit Issuing Authority for the utilization/disposal of sludge may be reopened and
modified, or revoked and reissued, to incorporate applicable requirements at 40 CFR Part 503. The
permittee shall comply with applicable 40 CFR Part 503 Standards for the Use and Disposal of
Sewage Sludge (when promulgated) within the time provided in the regulation, even if the pennit
is not modified to incorporate the requirement The permittee shall notify the Permit Issuing
Authority of any significant change in its sludge use or disposal practices.
"Upset " means an exceptional incident in which there is unintentional and temporary
noncompliance with technology based permit effluent limitations because of factors beyond the
reasonable control of the permittee. An upset does not include noncompliance to the extent
caused by operational error, improperly designed treatment facilities, inadequate treatment
facilities, lack of preventive maintenance, or careless or improper operation.
(1) An upset occurred and that the permittee can identify the cause(s) of the upset
(2) The permittee facility was at the time being properly operated; and
(3) The permittee submitted notice of the upset as required in Part II, E. 6. (b) (B) of this permit.
(4) The permittee complied with any remedial measures required under Part II, B. 2. of this
permit.
5. Upsets
Definition.
SECTION D, MONITORING AND RECORDS
L Representative Sampling
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3. Flow Measurements
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4. Test Procedures
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Division of Water Quality
Water Quality Section
ATTENTION: Central Files
Post Office Box 29535
Raleigh, North Carolina 27626-0535
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inthi^perndT5 ° e™Se sPecified 40 CFR 503, unless other test procedures have been specified
Appropriate flow measurement devices and methods consistent with accepted scientific practices
shall be selected and used to ensure the accuracy and reliability of measurements of the volume of
monitored discharges. The devices shall be installed, calibrated and maintained to ensure that the
accuracy of the measurements are consistent with the accepted capability of that type of device.
Devices selected shall be capable of measuring flows with a maximum deviation of less than + 10%
from the. true discharge rates throughout the range of expected discharge volumes. Once-through
condenser cooling water flow which is monitored by pump logs, or pump hour meters as specified in
Part 1 of this permit and based on the manufacturer’s pump curves shall not be subject to this
e monitonng required by this permit, all test procedures must produce
minimum detection and reporting levels that are below the permit discharge requirements and all
data generated must be reported down to the minimum detection or lower reporting level of the
procedure. If no approved methods are determined capable of achieving minimum detection and
Samples collected and measurements taken, as required herein, shall be characteristic of the
volume and nature of the permitted discharge. Samples collected at a frequency less than daily
shall be taken on a day and time that is characteristic of the discharge over the entire period
which the sample represents. All samples shall be taken at the monitoring points specified in this
permit and, unless otherwise specified, before the effluent joins or is diluted by any other
wastestream, body of water, or substance. Monitoring points shall not be changed without
notification to and the approval of the Permit Issuing Authority.
2. Reporting
Monitoring results obtained during the previous month(s) shall be summarized for each month and
reported on a monthly Discharge Monitoring Report (DMR) Form (DEM No. MR 1, 1.1, 2, 3) or
alternative forms approved by the Director, DEM, postmarked no later than the 30th dav
following the completed reporting period.
The first DMR is due on the last day of the month following the issuance of the permit or in the case
of a new facility, on the last day of the month following the commencement of discharge.
Duplicate signed copies of these, and all other reports required herein, shall be submitted to the
following address:
Page 11 of 14
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ion and Entry
The permittee shall allow the Director/
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otherwise authorized by the Clean Water Act, any substances or parameters at any location. ■
7. Recording Results
For each measurement or sample taken pursuant to the requirements of this permit, the permittee
shall record the following information:
5. Penalties fpr Tampering
The Clean Water Act provides that any person who falsifies, tampers with, or knowingly renders
inaccurate, any monitoring device or method required to be maintained under this permit shall,
upon conviction, be punished by a fine of not more than $10,000 per violation, or by imprisonment for
not more than two years per violation, or by both. If a conviction of a person is for a violation
committed after a first conviction of such person under this paragraph, punishment is a fine of not
more than $20,000 per day of violation, or by imprisonment of not more than 4 years, or both.
6. Records Retention
Except for records of monitoring information required by this permit related to the permittee's
sewage sludge use and disposal activities, which shall be retained for a period of at least five
years (or longer as required by 40 CFR 503), the permittee shall retain records of all monitoring
information, including all calibration and maintenance records and all original strip chart
recordings for continuous monitoring instrumentation, copies of all reports required by this permit,
for a period of at least 3 years from the date of the sample, measurement, report or application.
This period may be extended by request of the Director at any time.
reporting levels below permit discharge requirements, then the most sensitive (method with the
lowest possible detection and reporting level) approved method must be used.
* or an authorized representative (including an authorized
contractor acting as a representative of the Director), upon the presentation of credentials and other
documents as may be required by law, to;
a. Enter upon the permittee's premises where a regulated facility or activity is located or
conducted, or where records must be kept under the conditions of this permit;
b. Have access to and copy, at reasonable times, any records that must be kept under the conditions
of this permit;
Inspect at reasonable times any facilities, equipment (including monitoring and control
equipment), practices, or operations regulated or required under this permit; and
d. Sample or monitor at reasonable times, for the purposes of assuring permit compliance
a. The date, exact place, and time of sampling or measurements;
b. The individual(s) who performed the sampling or measurements;
c. The date(s) analyses were performed;
d. The individual(s) who performed the analyses;
e. The analytical techniques or methods used; and
f. The results of such analyses.
SECTION E. REPORTING REQUTREMENTS
1.Change in Discharge
2.Planned Changes
a.
b.
c.
I3.
ITransfers4.
Monitoring Reports5.
Monitoring results shall be reported at the intervals specified elsewhere in this permit.
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This permit is not transferable to any person except after notice to the Director. The Director may
require modification or revocation and reissuance of the permittee and incorporate such other
xequirements as may be necessary under the Clean Water Act.
All discharges authorized herein shall be consistent with the terms and conditions of this permit.
The discharge of any pollutant identified in this permit more frequently than or at a level in excess
of that authorized shall constitute a violation of the permit.
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Page 12 of 14
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The alteration or addition results in a significant change in the permittee's sludge use or
disposal practices, and such alternation, addition or change may justify the application of
permit conditions that are different from or absent in the existing permit, including notification
of additional use or disposal sites not reported during the permit application process or not
reported pursuant to an approved land application plan.
Anticipated Noncompliance
Calculations for all limitations which require averaging of measurements shall utilize an
arithmetic mean unless otherwise specified by the Director in the permit
The permittee shall give notice to the Director as soon as possible of any planned physical
alterations or additions to the permitted facility. Notice is required only when:
The permittee shall give advance notice to the Director of any planned changes in the permitted
facility or activity which may result in noncompliance with permit requirements.
The alteration or addition could significantly change the nature or increase the quantity of
pollutants discharged. This notification applies to pollutants which are subject neither to
effluent limitations in the permit, nor to notification requirements under 40 CFR Part 122.42 (a)
(1).
The alteration or addition to a permitted facility may meet one of the criteria for determining
whether a facility is a new source in 40 CFR Part 122.29 (b); or
b. If the permittee monitors any pollutant more frequently than required by the permit, using test
procedures specified in Part II, D. 4. of this permit or in the case of sludge use or disposal,
approved under 40 CFR 503, or as specified in this permit, the results of this monitoring shall be
induded in the calculation and reporting of the data submitted in the DMR.
a. Monitoring results must be reported on a Discharge Monitoring Report (DMR) (Sec Part 11. D. 2
of this permit) or forms provided by the Director for rqxjrting results of monitoring of sludge use
or disposal practices.
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information which must be reported within 24 hours underb.
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The following shall be included as
this paragraph:
(1) Any unanticipated bypass which exceeds any effluent limitation in the permit.
(2) Any upset which exceeds any effluent limitation in the permit.
(3) Violation of a maximum daily discharge limitation for any of the pollutants listed by the
Director in the permit to be reported within 24 hours.
The Director may waive the written report on a case-by-case basis for reports under paragraph
b. above of this condition if the oral report has been received within 24 hours.
7. Other Noncompliance
The permittee shall report all instances of noncompliance not reported under Part II. E. 5 and 6. of
this permit at the time monitoring reports are submitted. The reports shall contain the information
listed in Part IL E. 6. of this permit
6. Twenty-four Hour Reporting •
The permittee shall report to the central office or the appropriate regional office any
noncompliance which may endanger health or the environment. Any information shall be
provided orally within 24 hours from the time the permittee became aware of the
circumstances. A written submission shall also be provided within 5 days of the time the
permittee becomes aware of the circumstances. The written submission shall contain a
description of the noncompliance, and its cause; the period of noncompliance, including exact
dates and times, and if the noncompliance has not been corrected, the anticipated time it is
expected to continue; and steps taken or planned to reduce, eliminate, and prevent reoccurrence
of the noncompliance.
Where the permittee becomes aware that it failed to submit any relevant facts in a permit
application, or submitted incorrect information in a permit application or in any report to the
Director, it shall promptly submit such facts or information.
8. Other Information
9. Noncompliance Notification
The permittee shall report by telephone to either the central office or the appropriate regional
office of the Division as soon as possible, but in no case more than 24 hours or on the next working
day following the occurrence or first knowledge of the occurrence of any of the following:
a. Any occurrence at the water pollution control facility which results in the discharge of
significant amounts of wastes which are abnormal in quantity or characteristic, such as the
dumping of the contents of a sludge digester; the known passage of a slug of hazardous substance
through the facility; or any other unusual circumstances.
b. Any process unit failure, due to known or unknown reasons, that render the facility incapable of
adequate wastewater treatment such as mechanical or electrical failures of pumps, aerators,
compressors, etc
Any failure of a pumping station, sewer line, or treatment facility resulting in a by-pass
directly to receiving waters without treatment of all or any portion of the influent to such
station or facility.
I10. Availability of Reports
11. Penalties for Falsification of Reports
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Persons reporting such occurrences by telephone shall also file a written report in letter form within
5 days following first knowledge of the occurrence.
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Page 14 of 14
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The Clean Water Act provides that any person who knowingly makes any false statement,
representation, or certification in any record or other .document submitted or required to be
maintained under this permit, including monitoring reports or reports of compliance or
noncompliance shall, upon conviction, be punished by a fine of not more than $10,000 per violation,
or by imprisonment for not more than two years per violation, or by both.
Except for data determined to be confidential under NCGS 143-215.3(a)(2) or Section 308 of the
Federal Act, 33 USC 1318, all reports prepared in accordance with the terms shall be available for
public inspection at the offices of the Division of Water Quality. As required by the Act, effluent
data shall not be considered confidential. Knowingly making any false statement on any such
report may result in the imposition of criminal penalties as provided for in NCGS 143-215-1(b)(2) or
in Section 309 of the Federal Act
CT9905
P Expansion
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EXHIBIT 3: NPDES SPECULATIVE LIMITS
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12/13/00Exhibit 3HUA
Town of Clayton
Environmental Assessment for
TOWN OF CLAYTON
WWTP EXPANSION
ENVIRONMENTAL ASSESSMENT
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I July 10. 2000
JUL 17 2000
1
Subject:
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I Dear Mr. Biggs:
Environmental Assessments of New Projects and Expansions
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1617 Mail Service Center, Raleigh, North Carolina 27699-1617
An Equal Opportunity Affirmative Action Employer
State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Bill Holman, Secretary
Kerr T. Stevens, Director
Mr. R. Steven Biggs, Town Manager
Town of Clayton
P.O. Box 879
Clayton. North Carolina 27520
Speculative Limits for Little River Water Reclamation Facility/ Clayton WWTP
NPDES Permit NC0025453
Town of Clayton
Johnston County
919 733-5083, extension 510 (fax) 919 733-0719
Susan A Wilson Q ncmail.net
NCDENR
North Carolina Department of
Environment ano Natural Resources
As you are aware, the Town will have to evaluate this project for environmental impacts before
applying for a permit modification. Any entity proposing to construct new or expanded waste
This letter Is in response to your request for speculative effluent limits for the proposed expansion
(hydraulic re-rating to 2.5 MGD) at the Clayton wastewater treatment plant. This letter will also
address Clayton’s request to perform minor modifications at the plant in order to obtain better
operational flexibility.
The Clayton plant currently has a permit to discharge 1.9 MGD of treated municipal wastewater to the
Neuse River In the Neuse River Basin. Michael Wicker. Hobbs. Upchurch & Associates, requested
updated speculative limits on the Town’s proposed re-rating to 2.5 MGD. The NPDES Unit is currently
processing the renewal of the Town’s permit for 1.9 MGD.
We have reviewed the request and provide the following response with the enclosed speculative limits.
The speculative limits presented here are based on our understanding of the proposal and of present
environmental condiUons. The Division of Water Quality (DWQ) cannot guarantee that It will issue the
Town an NPDES permit to expand its discharge of treated wastewater into waters of the State. Nor can
we guarantee that the effluent limitations and other requirements included in any permit will be
exactly as presented here. Final decisions on these matters will be made only after the Division
evaluates a formal permit application for the Town’s discharge and notices the proposal for public
comment.
Speculative Effluent Limits
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The NMS rule establishes additional requirements for facilities planning to expand beyond their 1995
permitted flows. An expanding facility must acquire any nitrogen allocation it needs for the added
discharge before it can apply for the necessary NPDES permit modification. The facility can (1) provide
additional treatment in order to meet its original allocation, (2) acquire additional allocation from
existing point sources, or (3) acquire additional allocation from nonpoint sources through the
Wetlands Restoration Fund. In the last case, the facility must obtain 30 years’ allocation prior to
permit application. In any event, the facility’s total allocation cannot be greater than the annual mass
limit equivalent to 3.5 mg/LTN at the expanded flow.
Total Nitrogen. The Nutrient Management Strategy (NMS) rule (adopted December 1997 and revised
February 2000) requires that point sources in the Neuse River Basin, including the Little River WRF/
Clayton WWTP, meet annual mass limits for total nitrogen (TN) beginning with calendar year 2003.
Clayton’s initial allocation is approximately 21, 400 Ib/yr TN.
Based on the available information, speculative limits for the proposed discharge of 2.5 MGD flow to
the Neuse River are presented in the attached table and are explained below.
Facilities joining a group compliance association are not subject to individual limits but will be
responsible as a group for meeting their collective allocation. Clayton has expressed its intent to join
such an association, so much of this explanation does not apply directly to its discharge requirements.
However, the discussion is still relevant to the Town’s nitrogen allocation and the limit the association
must meet.
Note that the Division expects to complete a more comprehensive modeling effort in early 2001 and will
use those results to better define the nitrogen reduction target for the Neuse River estuary. It is not
clear from preliminary results whether the target will need to be changed. Be aware that if the target
level is lowered, it could lead to further reductions in the point source allocations.
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To reiterate, design considerations must include the ability to achieve an annual load based on a
concentration of 3.5 mg/1 at 2.5 MGD, regardless of the Town's chosen route of compliance.
[Please refer to ISA NCAC 2B .02341
l Town of Clayton
Speculative Limits for 2.5 MGD
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Flow Limits. The flow limit will be increased to 2.5 MGD as requested by the Town. This limit will be
applied as a monthly average.
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treatment facilities using public funds or public (state) lands must first prepare an environmental
assessment (EA) when wastewater flows (1) equal or exceed 0.5 MGD or (2) exceed one-third of the
7Q10 flow of the receiving stream. DWQ will not accept a permit application for a project requiring an
environmental assessment until the Division has approved the EA and sent a Finding of No Significant
Impact (FONSI) to the state Clearinghouse for review and comment. The Division is aware that
Clayton has submitted a draft EA for review.
An Environmental Assessment should contain a clear justification for the proposed project. It should
provide an analysis of potential alternatives, including a thorough evaluation of non-discharge
alternatives. Nondischarge alternatives or alternatives to expansion, such as spray irrigation, water
conservation, or inflow and infiltration reduction, are considered to be environmentally preferable to a
surface water discharge. In accordance with the North Carolina General Statutes, the preferred
alternative must be the practicable waste treatment and disposal alternative with the least adverse
impact on the environment. If the EA demonstrates that the project may result in a significant
adverse ^effect on the quality of the environment, you must then prepare an Environmental Impact
Statement. Mr. Steve Zoufaly of the Water Quality Planning Branch can provide further information
regarding the requirements of the N.C. Environmental Policy Act. You can contact Mr. Zoufaly directly
at [phone], ext. 566.
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Please note that Item (0 will not. and cannot, be approved without an AuthorizaUon to Construct
permit.
Chronic Toxicity Testing: The Town’s effluent must not exhibit chronic toxicity at the 2.5 MGD flow
based on a Ceriodaphnia Pass/Fail test at 2.0 %.
Toxicant Parameters: EsUmation of toxicant parameters will not be given with this speculative letter,
but will be submitted as appropriate with the draft NPDES permit.
Town of Clayton
^j^ulative Limits for 2.5 MGD
Fecal Coliform, pH. The limits for fecal coliform bacteria and pH are derived to protect water quality in
the receiving stream and remain the same as in the current permit.
Chlorine. The Division requires chlorine limits and dechlorination for all new or expanding
dischargers using chlorine for disinfection. The process of chlorination/ dechlorination, or an alternate
form of disinfection such as ultraviolet radiation, should allow the facility to comply with the total
residual chlorine limit.
Minor Treatment Plant Modifications
The letter dated February 21. 2000 also requested approval of minor modifications to the treatment
plant in order to improve flexibility and improve operaUons. By this letter the Division of Water
Quality will approve Items (a), (b). (c). (d). (e). (g). (h). (i). (j) listed in the aforementioned letter
(attached). Technically, under normal circumstances, the Division would likely require an
Authorization to Construct permit at least for Items (g) and (j). However, due to resource constraints
and the acknowledgement that such improvements will provide Increased operational flexibility at the
plant, the Division will not require a permit for this project. AddiUonafly. as stated in the letter from
Mr. Wicker, the process units will not change and no treatment units will be added with this
modification. The Town of Clayton assumes all risk with implementation of these improvements and
no permit for 2.5 MGD may be issued until a FONSI is received and after a draft permit is submitted
for public notice. All calculations documenting the ability of the treatment units to accommodate a
design flow of 2.5 MGD, along with plans and specifications for any treatment unit modifications or
additions, must be submitted at that time.
BOPs, NHb-N, P.O. The summer limits are 5 mg/1 (BOPS) and 1 mg/1 (NH3-N) based on the waste
assimilative capacity of the receiving stream at low flow conditions for this size facility (2.5 MGP).
This is a reduction from the previous summer limits of 5 & 2 at the 1.9 MGP permitted flow. The
winter limits of 10 mg/1 (BOPS) and 2 mg/1 (NH3-N) are reduced from the previous winter limits of 10
& 4 at the 1.9 MGP permitted flow. The effluent dissolved oxygen will be limited at a minimum of 6.0
mg/1.
TSS. The limits for total suspended solids are standard for secondary treatment of municipal
wastewater and are the same as in the current permit.
Total Phosphorus. The NMS rule sets the following phosphorus limits for point source discharges:
Existing facilities: 2 mg/L. quarterly average
New or expanding: 1 mg/L. monthly average (this if not part of an associaUon, see below)
If a discharger is part of a group compliance association, as in Raleigh’s case, then it may retain the
quarterly limit of 2 mg/L upon expansion. The Pivision may also establish more stringent limits if
necessaiy to protect water quality standards in localized areas.
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Again, as stated previously, this approval is allowed specifically for this case, only, and only for the
Town of Clayton. Please inform your consultants that although similar situations may occur at other
facilities in the future, the Division may not provide approval in this manner.
This written response is offered following the verbal transmission of the speculative limits to Michael
Wicker on Friday, June 9, 2000. If you have any additional questions about these limits, feel free to
contact Susan Wilson at [phone], extension 510.
Raleigh Regional Office/ Water Quality
Central Files
NPDES Unit Files
Michael Wicker, P.E., Hobbs, Upchurch & Associates
P.O. Box 1737
Southern Pines, NC 28388
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Sincerely,
David A. Goodrich, Supervisor
NPDES Unit
Water Quality Section
|| Town of Clayton
Speculative Limits for 2.5 MGD
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Effiueiit 063 racterislics
r'"
Continuous Recording2.5 MOD
Daily Composite7.5 mg/l5.0 mg/l
CompositeDaily15.0 mg/l10.0 mg/l
1 CompositeDaily45.0 mg/l30.0 mg/l
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400/100 ml200/100 ml
GrabTotal Residual Chlorine4
I 6
I 6-9
(Footnotes on next page)
S'
1.0 mg/l
2.0 mg/l
Daily
3/Week
Grab
Grab
Fecal Coliform (geometric mean)
Fecal Coliform (geometric mean)
NHa as N (April 1 - October 31]
NHa as N (November 1 - March 31]
Dissolved Oxygen3_________
Dissolved Oxygen
Conductivity
Conductivity
21,400 Ib/year (Annual Mass Loading
2.0 mg/L (Quarterly Average)
No
No Effluent Limit (Ib/month)
Daily
Weekly
Monthly
Annually
Weekly
Daily
3/Week
Quarterly
Daily
Daily
Daily
Daily
3/Week
Daily
3/Week
Composite
Composite
Grab
Grab
Composite
Grab
Grab
Grab
Influent or
Effluent
Influent &
Effluent
Influent &
Effluent
Influent &
Effluent
Effluent
Effluent
Effluent
Upstream &
Downstream
Effluent
Upstream &
Downstream
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
Upstream &
Downstream
Effluent
Upstream &
Downstream
Effluent
Effluent
Chronic Toxicity8
pH™
Composite
Calculated
Calculated
Composite
Grab
Grab
Town of Clayton
Si^culative Limits for 2.5 MGD w
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
SPECULATIVE ONLY
BOO, 5 day (20^)2
[April 1-October 31]
BOO, 5 day (208C)2
(November 1 - March 31]
Total Suspended Residue2
28jig/l
Effluent Limit (mg/l)
Tiow
Total Nitrogen
(NO2-N + NO3-N + TKN)5
Total Phosphorus 7
Temperature fC)
Temperature (9C)
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Footnotes:
3. The daily average dissolved oxygen effluent concentration shall not be less than 6.0 mg/1.
5. See Special Condition A.(2.), Total Nitrogen Monitoring.
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There shall be no discharge of floating solids or visible foam in other than trace amounts.
2. The monthly average effluent BODS and Total Suspended Residue concentrations shall not exceed
15% of the respective influent value (85% removal).
4. Total residual chlorine is required only if chlorine is used as a disinfectant (or elsewhere in the
process).
6. The annual mass loading limit for total nitrogen shall become effective with the calendar year
beginning on January 1, 2003 unless it is provisionally waived per Special Condition A.(3.J, Annual
Limits for Total Nitrogen.
7. The quarterly average for total phosphorus shall be the average of composite samples collected
weekly during the calendar quarter (January-March, April-June, July-September, October-
December).
8. Chronic Toxicity (Ceriodaphnia dubia) P/F at 2.0 %: March, June, September, and December Isee
Special Condition A.(4)]. Toxicity monitoring shall coincide with any metals monitoring.
9. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units and shall be
monitored daily at the effluent by grab sample.
1. Sample locations: E - Effluent, I - Influent, U - Upstream at NCSR 1700, D - Downstream at (1)
NC Highway 42 and (2) NCSR 1908. Stream samples shall be grab samples and shall be collected
3/Week during June - September and 1/Week during the remaining months of the year.
Instream monitoring is provisionally waived in light of the permittee’s participation in the
Lower Neuse Basin Association. Instream monitoring shall be conducted as stated in this
permit should the permittee end its participation in the Association.
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
SPECULATIVE ONLY
(Continued)
| Town of Clayton
Speculative Limits for 2.5 MGD
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(2) Annual Mass Loading (Ib/yr) = (Monthly Mass Loadings) for the calendar year
I A. (3.)
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(2)
A. (2.) TOTAL NITROGEN MONITORING
The Permittee shall calculate the annual mass loading of total nitrogen as the sum of monthly
loadings, according to the following equations:
= the average total nitrogen concentration (mg/L) of the composite
samples collected during the month
= the total wastewater flow discharged during the month (MG/month)
= conversion factor, from (mg/L x MG) to pounds
Q
8.34
The Permittee shall report the total nitrogen concentration for each sample and the monthly
mass loading in the appropriate self-monitoring report and the annual mass loading of total
nitrogen in the December self-monitoring report for the year.
Town of Clayton
ii^ulative Limits for 2.5 MGD
(1) Monthly Mass Loading (Ib/mo) = TN x Q x 8.34
where:
TN
ANNUAL LIMITS FOR TOTAL NITROGEN
(a) The Neuse Nutrient Management Strategy rule for point sources w provides that annual
mass limits for total nitrogen shall be included in the permits for all dischargers with
permitted flows (as defined in the Strategy) greater than or equal to 0.5 MGD and that
those nitrogen limits, including the limits in this permit, shall become effective with the
calendar year beginning on January 1, 2003.
(b) The Neuse rule also provides that members of a group compliance association shall not be
subject to individual annual mass limits for total nitrogen. At the time of permit issuance,
the Permittee had expressed interest in Joining such an associaUon. Accordingly,
(1) the total nitrogen limit in Condition All) of this permit is deemed waived provided
that the following conditions are met:
(I) a formal agreement between the association and Environmental Management
Commission, as outlined In 15A NCAC 2B. 0234, is established and is in effect;
and
(II) the Permittee is a party to said agreement; and
(ill) the association and the Permittee substantially conform with the agreement.
So long as the total nitrogen limit in Condition A.(l.) is waived, the group nitrogen
allocation established pursuant to the agreement referenced above and any
subsequent amendments is hereby incorporated as an enforceable part of this
permit.
(c) If the Division determines, at any time during the term of this permit, that these
conditions are not being met. it shall notify the Permittee in writing of this determination
and of its basis. The consequence of such a determination shall be that the Permittee’s
annual mass limit for total nitrogen and its effective date shall be reinstated immediately.
The Division shall accept and consider written responses received from the Permittee
and/or the association within thirty (30) days of the original notice before making a final
decision and will provide that decision in writing.
ANNUAL LIMITS FOR TOTAL NITROGEN (cont'd.)A. (3.)
(d) The Permittee shall notify the Division in writing within five (5) working days if, at any time
. 1
A. (4.) CHRONIC TOXICITY PERMIT LIMIT (QRTRLY)
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The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant
mortality to Ceriodaphnia dubia at an effluent concentration of 2 %.
If the test procedure performed as the first test of any single quarter results in a failure or ChV below
the permit limit, then multiple-concentration testing shall be performed at a minimum, in each of the
two following months as described in “North Carolina Phase II Chronic Whole Effluent Toxicity Test
Procedure" (Revised-February 1998) or subsequent versions.
Completed Aquatic Toxicity Test Forms shall be filed with the Environmental Sciences Branch no later
than 30 days after the end of the reporting period for which the report is made.
Town of Clayton
Speculative Limits for 2.5 MGD
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The chronic value for multiple concentration tests will be determined using the geometric mean of the
highest concentration having no detectable impairment of reproduction or survival and the lowest
concentration that does have a detectable impairment of reproduction or survival. The definition of
“detectable impairment," collection methods, exposure regimes, and further statistical methods are
specified in the “North Carolina Phase II Chronic Whole Effluent Toxicity Test Procedure" (Revised-
February 1998) or subsequent versions.
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The permit holder shall perform at a minimum, quarterlii monitoring using test procedures outlined in
the “North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised Februaiy 1998, or
subsequent versions or “North Carolina Phase II Chronic Whole Effluent Toxicity Test Procedure"
(Revised-February 1998) or subsequent versions. The tests will be performed during the months of
March, June, September, and December. Effluent sampling for this testing shall be performed at the
NPDES permitted final effluent discharge below all treatment processes.
during the term of this permit, the Permittee elects not to join the association, or if it
withdraws or otherwise loses its membership in the association. Notification shall be sent
to:
Footnote:
n) Neuse River Basin - Nutrient Sensitive Waters Management Strategy: Wastewater
Discharge Requirements (15A NCAC 2B. 0234).
NC DENR / Division of Water Quality / NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
All toxicity testing results required as part of this permit condiUon will be entered on the Effluent
Discharge Monitoring Form (MR-1) for the months in which tests were performed, using the parameter
code TGP3B for the pass/fail results and THP3B for the Chronic Value. Additionally, DWQ Form AT-3
(original) is to be sent to the following address:
Attention: North Carolina Division of Water Quality
Environmental Sciences Branch
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
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A. (4.) CHRONIC TOXICITY PERMIT LIMIT (QRTRLY) (cont d.)
Test data shall be complete, accurate, include all supporting chemical/ physical measurements and all
concentration/response data, and be certified by laboratory supervisor and ORC or approved designate
signature. Total residual chlorine of the effluent toxicity sample must be measured and reported if
chlorine is employed for disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity monitoring is
required, the permittee will complete the information located at the top of the aquatic toxicity (ATI test
form indicating the facility name, permit number, pipe number, county, and the month/year of the
report with the notaUon of “No Flow" in the comment area of the form. The report shall be submitted to
the Environmental Sciences Branch at the address cited above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required,
monitoring will be required during the following month.
Should any test data from this monitoring requirement or tests performed by the North CaroUna
Division of Water Quality Indicate potential impacts to the receiving stream, this permit may be re­
opened and modified to include alternate monitoring requirements or limits.
NQTE: Failure to achieve test conditions as specified in the cited document, such as minimum control organism survival,
minimum control organism reproduction, and appropriate environmental controls, shall constitute an invalid test and will
require immediate follow-up testing to be completed no later than the last day of the month following the month of the initial
monitoring.
Town of Clayton
Si^^ilative Limits for 2.5 MGD
RE:
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Dear Mr. Goodrich:
I
The minor changes we are making to the WWTP to improve flexibility are as follows:
a.
b.
7
Southern Pines, NC • Telephone ||0^92-5616
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The Town of Clayton intends to expand its existing 1.9 mgd wastewater treatment plant,
including an Environmental Assessment The purpose of this letter is to request speculative
limits for expanded NPDES permit flows of 2.5 mgd. It is assumed that the existing Neuse
River Basin Policy, the Neuse River Basin Rules, etc. will result in limits similar to the 5
BOD, 2 Ammonia, 30 TSS limits currently proposed for the 1.9 mgd facility. We are also
assuming that the TP will be lowered from 2 ppm to 1 ppm and that the Nitrogen limit of
21,400 lbs . per Annum will stay the same. The discharge point to the Neuse River will
remain the same as in the current permit
The Town of Clayton wastewater treatment plant discharges to the Neuse River WS-IV,
NSW, CA. The wastewater treatment plant operates under NPDES permit No. NC0025453.
The attached Quadrangle map shows the location of the treatment facility.
A DRAFT EA has been submitted to DWQ for review. The WWTP is approaching 80%
capacity at this time and the Town wishes to be proactive in expanding the NPDES permit. A
recent re-rating study indicates that the existing WWTP can be re-rated to 2.5 mgd as
currently designed. Minor piping and flow control improvements will be added for increased
flexibility as a factor of safety. A full 201 study for a 20 year plan will be initiated at a later
date to consider further permit increases or other options which will involve additional
construction of facilities.
Mr. David Goodrich, Supervisor
NPDES Unit, Division of Water Quality
Post OfiSce Box 29535
Raleigh, North Carolina 27626-0535
Speculative Limits for WWTP Expansion
Town of Clayton Wastewater Treatment Plant
.- NPDES Permit No. NC0025453
HUA No. CT9905
Hobbs, Upchurch & Associates, P.A.
Consulting Engineers
29Q S.W. Broad Street • Post Office Box 1737 • Southern Pines, NC 28388
February 21,2000
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Design modifications to the following:
Replace existing extended shaft centrifugal pumps with submersible
centrifugal pumps in the dry pit and add variable frequency drives to control
pumps in relation to influent flows.
Improvement to the existing hydraulic split at influent pump station by the
addition of a slide gate for diversion to the existing intermediate pump station,
which pumps to trickling filter system.
} • Fax [phone] • e-maB:huanuin©pinehurstnet
MyrtieBeach • KI Devi Bins • Raleigh . i
c.
d.
e.
g-I
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I Michael C. Wicker J3.E.
Cc:
Sincerely,
Hobbs, Upchurch & Associates, P.A.
to the influent headworks to lesson surge on clarifiers. Additional backwash
manhole to increase storage capacity.
If you have any questions about this matter or if you require additional information, please
contact me at [phone].
Mr. Dave Goodrich
February 21, 2000
Page 2
Enclosure
Mr. Steve Biggs, Town of Clayton
Mr. Tim Simpson, Town of Clayton
Mr. Randy Jones, Raleigh Regional Office
Mr. Mike Templeton, DWQ NPDES Group
and WAS to operate concurrently. Replacement of the existing RAS pumps with
new pumps.
i. Replacement of the existing air diaphragm sludge transfer pumps with positive
. displacement or rotary lobe pumps.
j. Rerouting of the existing backwash return piping from oxidation ditch splitter box
Improvements to existing oxidation splitter box by adding slide gates to allow
control of flow split to each oxidation ditch.
Improvements to existing clarifier splitter box by adding slide gates to allow
control of flow split to each clarifier.
Improvements to existing clarifier hydraulics by installation of Stamford Baffles.
f. Improvements to oxidation ditch aeration efficiency by replacing existing Carousel
aerators or conversion to fine or course bubble aeration system with blowers.
Duplication of existing WWTP polymer feed system through additional polymer
feed piping to the clarifiers and additional polymer pumps for redundancy.
h. Separation of RAS/WAS pump piping by additional WAS piping to allow RAS
The above changes will aid the operator to control flow and air and therefore run the WWTP
more efficiently. The process units will not change nor are we adding additional units. We
do not see that this requires an ATC; however the Town has requested that DWQ confirm this
prior to our beginning construction. The Raleigh Regional Office will be contacted in
advance of any construction. Design of these improvements has just begun with a start
construction date of September 2000 projected.
I
August 7. 2000
I
Subject:
Mr. R. Steven Biggs. Town Manager
Town of Clayton
P.O. Box 879
Clayton. North Carolina 27520
State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Bill Holman, Secretary
Kerr T. Stevens, Director
Final Permit
Clayton/ Little Creek WRF
NPDES Permit NC0025453
Johnston County
NCDENR
North Carolina Department of
Environment and Natural Resources
1617 Mail StRv»a Center, Raieich, North Caroona 27699-1617 - Telephone [phone]O83/FAX [phone]
An Equal Opportuntty Aeeirmattve action Employer - 50% recyclecV 10% post-consumer paper
VtSJT us ON THE WEB AT http://h2o.enr jUte.naus/NPDES
Dear Mr. Biggs:
In accordance with the Town of Clayton’s application for renewal of its municipal discharge
permit the Division of Water Quality is forwarding herewith the Town’s NPDES permit renewal. This
■ permit is issued pursuant to the requirements of North Carolina General Statute 143-215.1 and the
| Memorandum of Agreement between North Carolina and the U.S. Environmental Protection Agency
dated May 9. 1994.
| The Little Creek Water Reclamation FaciUty discharges in the Neuse River Basin (NRB). All
■ streams In the NRB have been designated as nutrient sensitive waters (NSW) as a result of algal bloom
problems In the estuary. The North Carolina Environmental Management Commission recently
■ adopted rules establishing the Neuse River Basin Nutrient Sensitive Waters Management Strategy for
■ the reduction of phosphorus and nitrogen inputs. The point source rule (15A NCAC 2B.0234) is
intended to reduce total nitrogen (TN) discharges by 30% by 2003. All faculties with permitted flow
« greater than or equal to 0.5 MGD are receiving a TN limit in this permit cycle. This final permit
I contains the previous total phosphorus limit, as well as a total nitrogen limit to comply with the point
■ source rule for the Neuse River Basin.
■ Based on further review of the existing data and Mr. James Warren s comments regarding the
| Town’s potential lead limit, the Division has agreed to phase the lead limit into the permit. The permit
requires the Town to conduct lead monitoring 2/month for the first year, then comply with the acute
limit of 33.8 pg/1 as a daily maximum value. The Town may request that the lead data be reviewed
■ again prior to implementation of the limit, should lead values be consistently (at least one year)
® reported below 33.8 pg/1.
Sincerely.
I
Enclosures: NPDES Permit No. NC0025453
cc:
Mr. Steven Biggs
Town of Clayton
Page 2 of 2
Please take notice that this permit is not transferable except after notice to the Division of
Water Quality. The Division of Water Quality may require modification or revocation and reissuance of
the permit.
If you have any questions concerning this permit, please contact Susan Wilson at telephone
number [phone], ext. 510.
Mr. Roosevelt Childress, EPA
Raleigh Regional Office, Water Quality
Point Source Compliance/ Enforcement Unit
Aquatic Toxicology Unit
Training and Technical Assistance Unit
Central Files
NPDES Files
^rr T. Stevens
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This permit does not affect the legal requirements to obtain other permits which may be required
by the Division of Water Quality, the Division of Land Resources, the Coastal Area Management Act, or
any other federal or local governmental permit.
If any parts, measurement frequencies, or sampling requirements contained in this permit are
unacceptable to you. you have the right to an adjudicatory hearing upon written request within thirty
(30) days following receipt of this letter. This request must be in the form of a written petition,
conforming to Chapter 150B of the North Carolina General Statutes, and filed with the Office of
Administrative Hearings. Mail Service Center 6714. Raleigh. North Carolina 27699-6714. Unless such
a demand is made, this permit shall be final and binding.
I
I PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
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Signed this day August 7, 2000.
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES -
DIVISION OF WATER QUALITY
Town of Clayton
JAftle Creek Water Reclamation Facility
Clavton WWTP
NPDESNo. NC0025453
No. NC0025453
to receiving waters designated as the Neuse River in the Neuse River Basin
in accordance with the discharge limitaUons, monitoring requirements, and other conditions set forth in
Parts I, II, III, and IV hereof.
In compliance with the provisions of North Carolina General Statute 143-215.1, other lawful standards
and regulations promulgated and adopted by the North CaroUna Water Quality Commission, and the
Federal Water Pollution Control Act, as amended.
This permit shall become effective September 1, 2000.
This permit and the authorizaUon to discharge shall expire at midnight on March 31. 2003.
------------
—T. Stevens, Director
fy Division of Water Quality
U By the Authority of the Environmental Management Commission
is hereby authorized to discharge wastewater from a facility located at
Little Creek Water Reclamation Facility
On Durham Street Extension
Clayton
Johnston County
I
Permit No. NC0025453
SUPPLEMENT TO PERMIT COVER SHEET
I
is hereby authorized to:
1.
2.
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1
•..s’
Discharge wastewater from said treatment works at the location specified on the
attached map Into the Neuse River which is classified WS-FV NSW CA waters in Neuse
River Basin.
Town of Clayton
Little Creek Water Reclamation Facility
Town of Clayton
NPDES No. NCOO25453
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Continue to operate an existing 1.9 MGD wastewater treatment facility consisting of
a mechanical bar screen, grit removal, parshall flume with flow measurement,
primary clarifier/digester. trickling filter, dual oxidation ditches, dual secondary
clarifiers, tertiary filters, ultraviolet disinfection, chlorine contact chamber, sulfur
dioxide dechlorination, sludge thickener tank, aerobic sludge digester, and sludge
drying beds located at the Little Creek Water Reclamation Facility, Durham Street
Extension. Clayton, Johnston County, and
J2'
0 A-
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a
N V.n
£
I UNIMPROVED ROAD
~ify ~
CONTOUR INTERVAL 10 FEET
QUAD LOCATION
■
Neuse River
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0
T
SECONDARY HIGHWAY
HARD SURFACE C
PRIMARY HIGHWAY
HARD SURFACE
Map #E25NW
Stream Class____
Discharge Class__
Receiving Stream
Design Q 1.9 MGD
Town of Clayton
NC0025453
Johnston County
WWTP
WS-V NSW
01
o
o________
1
MEg
ROAD CLASSIFICATION
LIGHT-DUTY ROAD. HARD OR
IMPROVED SURFACE —
Latitude 35O39,5Q,< Longitude 78°25,26M
Sub-basin 3-04-02
:<<<<
:^sasaei
M!
SCALE 1:24 000
____ 1 MILE
7000 FEET
1 KILOMETER
z-V .' / •
...................1 fe#
IO?®
® i
X\x
REMENTS - FINAL
Effluent Characteristics Monitoring RequirementsLimits
Sample Type
Flow Recording
Daily5.0 mg/l 7.5 mg/l Composite
10.0 mg/l 15.0 mg/l Daily Composite
30.0 mg/l 45.0 mg/l Daily Composite
200/100 ml 400/100 ml
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Total Residual Chlorine4 Grab
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I33.8 ptg/l
6-9
(Footnotes on next page)
Grab
Grab
During the period beginning on the effective date of the permit and lasting until expiration, the
Permittee is authorized to discharge 1.9 MGD of municipal wastewater from outfall 001. Such
discharges shall be limited and monitored by the Permittee as specified below:
Daily
Maximum
Total Nitrogen
(NO2-N + NO3-N + TKN)5
Weekly
Average
Town of Clayton
NPDES No. NC0025453
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Daily
3/Week
Conductivity
Conductivity
Fecal Coliform (geometric mean)
Fecal Coliform (geometric mean)
BOD, 5 day (205C)2
[April 1 - October 31]
BOD, 5 day (209C)2
[November 1 - March 31]
Total Suspended Residue2
NH3 as N [April 1 - October 31]
NH3 as N [November 1 - March 31]
Dissolved Oxygen3_________
Dissolved Oxygen
2.0 mg/l
4,0 mg/l
Quarterly
2/Month
Weekly
Daily
Weekly
Monthly
Annually
Weekly
Daily
3/Week
Daily
3/Week
Daily
Daily
Daily
3/Week
Composite
Composite
Composite
Grab
Composite
Composite
Composite
Composite
Composite
Grab
Grab
Grab
Grab
Effluent
Effluent
Effluent
Effluent
Chronic Toxicity8__________
Lead [Through July 31,2001]9
Lead
[Beginning August 1,2001]9
Copper_________________
Zinc___________________
Silver__________________
PH1O
Total Phosphorus 7
Temperature (*£)
Temperature fC)
Monthly
Average
1.9 MGD
Monthly
Monthly
2/Month
Daily
Composite
Calculated
Calculated
Composite
Grab
Grab
Effluent
Effluent
Effluent
Effluent
Effluent
Upstream &
Downstream
Effluent
Upstream &
Downstream
Effluent
Effluent
Effluent
Measurement
Frequency
Continuous
Sample
Locato
Influent or
Effluent
Influent &
Effluent
Iinfluent &
Effluent
Influent &
Effluent
Effluent
Effluent
Effluent
Upstream &
Downstream
Effluent
Upstream &
Downstream
Effluent
A. (1.) EFFLUENT LINmwriONS AND MONITORING REQ^i
___________________28 pg/1
No Effluent Limit (mg/l)
No Effluent Limit (Ib/month)
21,400 Ib/year (Annual Mass Loading)8
2.0 mg/L (Quarterly Average)
-Ci'J-J’
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II•' < A?vrxnJAT-.-A^?vf^^^TFR-T-?s3{
.-..' ;^->. ^;->?££ -Z\.- •. ’
• •• • •;-: • ' • ••" •• -. > -■•. -% .• . .. ‘•,<4<-
The permittee must pay the annual administering and compliance monitoring fee
within 30 (tiurty). days after beingidllediiy Hie Diwisioiu Failure^ to pay the fee in
< «««*» w -- «*
■ •• • ■■“•■ .• •-■.<; 5.-1 -i £- - ... .•••?.'1. ' »- •• - . .: •
:^«.W<;gKry..gi.jQ.:
CT9905
I
EXHIBIT 4: ALTERNATIVES ANALYSIS FIGURES
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12/13/00Exhibit 4HUA
Town of Clayton
Environmental Assessment for WWTP Expansion
TOWN OF CLAYTON
WWTP EXPANSION
ENVIRONMENTAL ASSESSMENT
Sheetl
Upgrade to 2.5 MGD]Town of C ayton Alternative Cost Analysis
Annual O&M Present WorthlAKemativeCaptlal Cost
$$9,489,630733,000$730,000
$ $
500,000 23,475,191$17,500,000New Land Application WWTP
$ $
15,506,756670,0007,500,000Convey to City of Raleigh $
$1,055,000 $18,347,654$5,740,000Convey to Johnston County
)/((i)*(Hi)An)
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Hobbs, Upchurch and Associates, P.A.
Southern Pines, NC
i=interest rate
n=design life
PV=Co + Ct‘((1+i)An)-1
I
Co= construction cost
Ct= O&M cost
A/P factor I 11.95038
5.5 %.
20 yrs ~
| Modifications to existing
WWTP T
I Modify Existing WWTP to 2.5 mgd
I $150,000Influent Pump Station 3 new 75 Hp 2400 gpm submersible w/VFD
Aeration Basins
Clarifiers
I Sludge Pumping
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$15,000Install 600 If of 8inch DIP
$590,000Total Estimate of Construction Costs
Engineering Design & Construction 12%$71,000
I $60,000
$721,000Total Estimated Project Costs
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ReRoute Backwash
Line
Conduct Field Oxygen Transfer Rate Test
Upgrade Aerator Motors
Comprehensive Field Test of New Train
$ 5,000
$25,000
$25,000
$50,000
$15,000
$10,000
$10,000
$ 7,500
Contingencies 10% .
Conduct Field Test of Chemical Enhancement
Install Polymer Addition to Clarifiers
Install Baffling
Install Energy Dissipating Inlet
Improve Inlet flow Split Hydraulics
Replace Sludge Transfer Pumps
Upsize Two Smaller Pumps to 1000 GPM
Install 315 feet of 8 Inch DIP with Valving
♦Recommendation at this stage would be to add blower and diffused aeration. Costs would be less than $100,000 to
aerate both basins.
$ 2,500
$250,000 *
$25,000
Convey to City of Raleigh WWTP
ExtensionUnitQuantityDescriptionUnit
&I
and
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01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
8
35,200
14___
3
280
8.4
300
500
LF
LF
LF
EA
LB
EA
EA
CY
CY
LF
SY
LS
LS
LS
45.00
100.00
2.50
20.00
1,475.00
1.75
1,200.00
1300.00
12.00
5300.00
30.00
8.00
11300.00
61,600.00
16300.00
3,900.00
22300.00
20,000.00
2300.00
5,600.00
44,500
340
340
TONS
MILE
SY
CY
4300.00
48,720.00
9,000.00
4,000.00
500
200
1,000
280
Cost/
Unit
26.00
30.00
100.00
$1,157,000.00
10,200.00
34,000.00
90,000.00
150,000.00
75,000.00
1,727,000.00
173,000.00
259,000.00
2,159,000.00
5303,000.00
$7,462,000.00
16wq>ss 150 D.l. Force Main
16” Class 150 D.L Carrier Pipe
24” Steel Encasement Bored
Jacked_____________________
16” Divisional Valves
Ductile Iron Fittings
Air Release Valve in Manhole
Air & Vacuum Release Valve in
Manhole_________________
Trench Rock Excavation
Protection Concrete
Stabilization Stone in Trench
Asphalt Pavement Cutting
Replacement______________
Stone Driveway Replacement
Erosion Control
Concrete D/W Replacement
Remove & Replace Unsuitable
Material_______________________
Meter Station (In Place)
Influent Works__________________
Plant Pumping Improvements
Total Construction
Contingency_________________________
Admin. Eng. Legal____________________
Total Project Cost____________________
Raleigh Capital Charge
TOTAL CAPITAL COST
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Convey from Town of Clayton to Johnston County WWTP
Quantity Unit ExtensionUnitDescription
I
“CrossMain
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01
02
03
04
05
4,440
11
LF
EA
310,800
22,000
87,200
1,884,000
108,000
90,000
150,000
75,000
2,727,000
1,865,000
4,592,000
459,000
689,000
$5,740,000
LF
LF
06
07
08
SUBTOTAL CONVEYANCE_________________
CJCRWWTP Expansion and Upgrade Construction
TOTAL CONSTRUCTION_____________________
Contingency__________________________________
Admin. Eng. Legal_____________________________
TOTAL CAPITAL COST
Cost/
Unit
70.00
2,000.00
62,800
3,000
30.00
36.00
30” Gravity Interceptor Pipe
Manholes_____
River Crossing
16** Force Main
16” Force
Country”
Meter Station
Influent Works
Pump Station
Sheetl
RESIGN CRITERIA
CLAY
FT
Qty
ea
lump sumI
Is
20%I
Page 1
Unit
Is
acres
acres
acres
ea
ea
ea
ea
ea
ea
ea
10%
10%
nozzles
valves
16"
SOhp
1
_______54621141 SOFT
SPRAY PIPE____________
12000 FORCE M
2,500,000 GPP
750 AC______
60 DAYS
_______30 DAYS
227505277 GALLONS
118 AC
£
£
£
£
$
£
£
£
£
£
£
$
£
£
£
£
£
$
£
$
£
$
£
£
£
$
£
£ £
£
£
£
£
$
|HOBBS , UPCHURCH AND ASSOCIATES, PA.
ISOUTHERN PINES. NC
, I I
[Town of Clayton
[LAND APPLICATION COST ANALYSIS
HUA NO. CT9905
1
975
_______750
750
232631 If
4656961 If
6468
210
1126486.814 Icy
202300.5185|cy
__________1
100 ft
94001ft
1
2500 ft
__________1
_______25001 ft
__________2
2
2
2
8
3"pvc
16" DIP
2790 FT______
1860 FT______
9.5 FT______
202300.5
_______465696
2500
$/unit________
$ 200,000.00
2,000.00
2,000.00
1,000.00
1.50
5.00
100.00
175.00
2.50
5.00
20,000.00
30.00
_ 3.00
$ 200,000.00
$ 30.00
$ 400,000.00
30.00
15,000.00
10,000.00
4,000.00
7,000.00
1,500.00
COST ESTIMATES
Item |
[General-Bonds, Ins.
[Land acquistion
[Land clearing,gradin"
[Crop planting, coasta
[barbed wire fencing
spraypipe |3"pvc
1/4"
3" pvc
lagoon excavation
lagoon liner_______
lagoon effluent box
influent |l6"dip
woven wire fence
pump stat 12000gp
forcemain 116" DIP
irrigation pump sta
header
tractor
mower
rake
baler
monitoring wells
subtotal |
contractor's O&P
Total estimated construction cost
Engineering costs_________
Contingencies____________
Total estimated project costs
I l~'~
FLOW
WETTED ACRES
LAGOON STORAGE
TREATMENT
TOTAL LAGOON VOLUME
TOTAL LAGOON AREA
TYPE OF UNER_____________
THICKNESS OF UNER _____
AREA OF LINER____________
NOZZLE | 6468_____
IRRIGATION PUMP STATION
Total
$ 200,000.00
$ 1,950,000.00
$ 1,500,000.00
750,000.00
34,894.50
$ 2,328,480.00
646,800.00
36,750.00
$ 2,816,217.04
$ 1,011.502.59
20,000.00
3,000.00
28,200.00
200,000.00
75,000.00
400,000.00
75,000.00
30,000.00
20,000.00
8,000.00
14,000.00
12,000.00
$12,159,844.13
$ 2,431,968.83
$ 14,591.812.95
$ 1.459.181.30
$ 1.459.181.30
$17,510,175.54
30415144 CF_____
LENGTH
WIDTH___________
DEPTH
VOLUME OF UNER
IN LF
IN LF
Sheetl
Annual Operation and Maintenance Costs
$496,361.95Total
Annual $Personnel #Annual $Direct Overhead
$Total $230,000.00 312,800.008
Annual $efficiency kwhr/yrkwd/yr ratehr/d
$10,000.00Analytical
Page 2
ORC I
Labor II
Electrical
motor HP
600
3
0.8
0.5
2
6
$ 40,000.00
$ 25,000.00
559.5
4.476
6
11.28
1.36
1.36
305
365
1023885
18428.5872
1
$
1
1
$
1
$
1
$
312,800.00
72,961.95
10,000.00
100,000.00
600.00
108,800.00
204,000.00
71,671.95
1,290.00
72,961.95
Personnel
Electrical
Analytical
Maintenance
Permit Fees
0.07
0.07
total
Preliminary Design
WATER STORAGEWATER BALANCE
D>.5" PRCHANGEFLOWHYDRLDPERCD<32DEGPERMET-PRETPRECIPDAYSMONTH
31-642.568643.57143686.14698.8812-12.7434.647.34365Annual
2.5833333.630952 -53.5473857.1783358.240.0833333332-1.0616672.8833333.945Average
OR STORAGE = NONSPRAY DAYS
60 days
Page 1
L
ET-PR+PERC=MAX HYDRAULIC LOADING___________________
PERC=.O4 ( PERMEABILITY ) X 24 HRS X DAYS - FREEZING DAYS)
STORAGE = AVAILABLE WASTEWATER - HYDRAULIC LOADING
selected storage
Town of Clayton Land Application
HUA No. CT 9905
21
28
31
30
21
30
31
31
30
31
30
31
3.74
3.85
4.74
3.53
4.07
4.12
4.96
4.56
4.36
3.06
2.86
3.49
0.2
0.5
1.5
2.7
3.3
5.9
6.7
5.4
4,6
2.3
1.2
0.3
-3.54
-3.35
-3.24
-0.83
-0.77
1.78
1.74
0.84
0.24
-0.76
-1.66
-3.19
2
2
2
2
2
2
2
2
2^
2
2
2
57.6
53.76
59.52
57.6
59.52
57.6
59.52
59.52
57.6
59.52
57.6
59.52
54.06
50.41
56.28
56.77
58.75
59.38
61.26
60.36
57.84
58.76
55.94
56.33
3.700587
3.342466
3.700587
3.581213
3.700587
3.581213
3.700587
3.700587
3.581213
3.700587
3.581213
3.700587
-50.35941
-47.06753
-52.57941
-53.18879
-55.04941
-55.79879
-57.55941
-56.65941
-54.25879
-55.05941
-52.35879
-52.62941
CUMULT
STORAGE
-50.35941
-97.42695
-150.0064
-203.1951
-258.2446
-314.0433
-371.6028
-428.2622
-482.521
-537.5804
-589.9392
-642.5686
3
3
3
2
3
3
3
3
2
2
2
2
Jan
Feb
March
April
May
June
July
August
Sept
Oct
Nov
Dec
1
0
0
0
0
0
0
0
0
0
0
0
II?
IN/WK
0.240740741 ln/hr
diameter x % overlap
6468total nozzles site
465696 fttotal field p pe
750select acres749acres
Page 2
L
4658582 sq.ft.
107 acres/zone
flow/(hrs o operation x 60)
2991803|gpd
length force main
force main selected
OPERATION CYCLE 7 ZONES ONCE PER WEEK EA.
'll I ..
365 days minus nonspray days x days/wk/7_________
209426231GAL/WK | |
ACRES=FLOWZ (27154 X APPLICATION RATE)
DESIGN FLOW
APPLICATION RATE
DAYS /WEEK __
NONSPRAY DAYS
APPL PERIORD
APPL FLOW______
ACRES REQD
Sprinkler selected
pressure_______
nozzle size_____
flow__________
diameter
overlap selected
spacing |
selected spacing
actual overlap
number zones
nozzles per zone
number of rows
number nozzles per row
length of pipe per row |
total length of pipe per zone
selected diameter
wetted area=2xradius + no. rows-1 x spacing x 2xradius+nozzles per row-1 minus
| diameter squared- pi(radius)A2/4) x 4 » nozzles per row-1 x rows-1 Z2
Pump station calculations
flow applied per day
hrs/day applied
pump size
pump selected
Sennlger_____
50 Psl
0.25 in
______13 gpm
125
50 %
62.5 ft__
______72 ft__
57.6 %
2,500,000 GPP
1
______7
60
305
2991803IGPD
771.2537
4.153846___
12004.15 gpm
12000 gpm
2500___
16 inch
____7___
924
30___
30.8___
2217.6 ft
66528 ft__
3 inch
application rate=96xflowZspac ng x spacing
application rate_______
time of operation = daily app rate/hourly
| 4.153846154|hrsZd
# nozzles = flow/flow per nozzle______
923.3960737
required.agoon requirements
days
gallons227,505,277
5185681 sqft
359,138,336 gallons
clay
202300.5 cy
buffer area
9785228 sq ft
Page 3
water surface
water surface
2732
1821
volume
(gals)
acres
30415144 Icf
__depth
30 depth
60 depth
volume
«*)
1 vertical
1 width
9356.667 If
23263.07 If
225 acre
975 acre
1 ft
5462114 sqft
5462114 cf
400 If outside wetted area________________
(c100)A2x4 ■Mxc100)x wetted area sq.ft.)A.5)
75,000,000
150,000,000
225,000,000
3 horizontal
1.5 length
___6ft______
2780 ft______
1853|ft
118
bottom of berm length
bottom of berm width
sludge zone
treatment [days
storage
25 yr/24hr storm
freeboard
total
total area
total volume to top of berm
estimated excavation
type of liner_____
thickness required
area of liner
volume
woven wire fence
barbed wire
buffer ______
total=buffer+wetted
2789
1859
2ft
3ft
3ft
0.5 ft
_[ft
9.5 ft
treatment
storage
trt + strge
10026738
20053476
30080214
119 acres
48013146 cf
1778265 cy
berm side slope
length to width
trt+storage depth
selected length
width |
water surface area
trt + strge volume ck
I
top of berm length
top of berm width
CT9905
EXHIBIT 5: TOWN LIMITS MAP
I
I
12/13/00Exhibit 5HUA
I
I
Town of Clayton
Environmental Assessment for WWTP Expansion
TOWN OF CLAYTON
WWTP EXPANSION
ENVIRONMENTAL ASSESSMENT
N
4000 Feet2000
Town of Clayton
December 2000
o
o
K Z □ Clayton WWTP
o Discharge Point
Water Bodies
Roads
__ _ City Limits
County
CT9905
I
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I
12/13/00Exhibit 6HUA
Town of Clayton
Environmental Assessment for WWTP Expansion
EXHIBIT 6: TOWN EXTRATERRITORIAL LIMITS
AND UTILITY SERVICE AREA MAP
TOWN OF CLAYTON
WWTP EXPANSION
ENVIRONMENTAL ASSESSMENT
Exhibit A
Legend
Clayton Strategic Growth Plan
Current and Proposed Planning Boundaries
Created By: DSAtlantic Corporation
October 1, 2000
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/ County boundaries
g'Tl Municipal Boundaries
ES3 etj
Utility Service Area
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CT9905
I
EXHIBIT 7: COMPOSITE TOPOGRAPHIC MAPI
I
I
I
12/13/00Exhibit 7HUA
Town of Clayton
Environmental Assessment for WWTP Expansion
TOWN OF CLAYTON
WWTP EXPANSION
ENVIRONMENTAL ASSESSMENT
Town of Clayton Topo Map
December 2000
Topology
140
150
160
170
180
190
200
210
220
225
230
235
240
250
260
270
280
285
290
300
310
320
330
340
350
360
City Limits
County
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CT9905
EXHIBIT 8: SOIL MAPS
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12/13/00Exhibit 8HUA
Town of Clayton
Environmental Assessment for WWTP Expansion
TOWN OF CLAYTON
WWTP EXPANSION
ENVIRONMENTAL ASSESSMENT
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CT9905
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I EXHIBIT 9: ZONING ORDINANCES
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12/13/00Exhibit 9HUA
Town of Clayton
Environmental Assessment for WWTP Expansion
TOWN OF CLAYTON
WWTP EXPANSION
environmental ASSESSMENT
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ARTICLE VII
DEVELOPMENT REQUIRING A SITE PLAN
701.1.2
701.2
701.2.1
I
I 701.3
i
The following uses may701.3.1
67
|701.1.1
|701.1
Any use or development of property for purposes other than
resident^ al purposes located in AR/R-40/20, R-10, R-8, or R-
6 zoning districts and multifamily development in any
district.
| 701.1.3
In order to secure a vested right for a site plan, the
appl irant must submit a site specific development plan in
accordance with the town's ordinance implementing the
statutory vested right provisions of G.S. 160A-385.1 and
Article VTII of this ordinance. (Amended 11/18/91)
None of the following uses, except temporary public uses
when such uses do not exceed thirty (30) days in duration,
shall be permitted until a site plan showing the proposed
development of the area has been approved by the Technical
Review Committee or the Planning Board, as set forth herein.
(Amended 7/21/97)
Any use requiring a special use permit or a conditional use
permit. Such special use permit applications projects shall
also require approval by the Town Council after a
recommendation has been made by the Planning and Zoning
Board in accordance with Section 808 of this ordinance.
(Amended -5/7/90)
[section 701 Development Requiring A Site Plan
Any non-residential use or development of property located
in any zoning district other than AR/R-40/20, R-10, R-8, or
R-6.
be established in the appropriate
zoning district only upon approval by the Planning Board of
a site plan meeting the standards of this section. It is
The town may refuse to approve a site plan on the grounds
that it fails to fully comply with any specific requirement
of this article or that it fails to adequately protect the
residentially zoned property, or property in residential
use, from the adverse effects of a business operation; or
that it fails to provide safe conditions for pedestrians and
motorists.
No building permit-or certificate of occupancy shall be
issued until the required site plan of the proposed use or
development has been approved by the appropriate town
officials.
I
a.
701.4 Dedication and Improvements
I
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1995,
68
of all
required by this ordinance including provision
Any owner
U
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*
!
!
■
Outdoor storage - all outdoor storage shall be
screened in an appropriate manner from adjacent
property or right-of-way. Buffers, as set forth in
Section 207, may be required. (Amended 7/21/9?)
The owner or developer shall bear the costs of the installation
oh-sipe improvements as : • - -
for surface drainage, pavement, landscaping, and utilities.
or developer required to install or construct off-site improvements
pursuant to this section may, with the approval of the Planning
Director or designee as a condition of site approval, and upon a
determination by the Planning Director or designee that such
in^rovements are not necessary or desirable at the time but will be
needed in the future, make a payment in lieu of such improvements or
part thereof. The amount of any such payment shall be an amount
estimated by the town to be the actual and total installation and
construction costs of such improvements. The amount paid for a given
improvement shall be considered total and complete payment for the
improvements considered, and will preclude any further assessment of
said property in the event that the town elects to install such
improvements at a later date. Full payment shall be made before any
building permit or certificate of occupancy is issued for any use
shown on the site plan.
recognized that particular problems may be created by
particular developments in particular locations. Therefore
the Planning Board may impose reasonable conditions for pla^
approval such as increased setbacks, buffering, and other
development standard adjustments when it is determined to be
in the best interest of surrounding properties and the
general public.
In the development of any property for which a site plan is required
in this section, the owner or developer shall be required to dedicate
any additional right-of-way necessary to the width required by the
town for streets adjoining the property, to install curbs and gutters
and pave all streets adjoining the property to town standards, and to
install sidewalks in accordance with the policies and requirements of
Article XT, Section E.2 of the Subdivision Regulations. (Amended-
6/6/94)
For all residential developments approved after July 3,
recreation and open space dedication, or payment of fee-in-lieu
thereof in accordance with Article IX, Section F. of the Subdivision
Ordinance shall be required. For purposes of calculating maximum
permitted units on a tract, gross land area prior to recreation/open
space dedication shall be used and so noted on any approved plan or
recorded plat. (Amended 7/3/95)
1
Procedure701.5
I
Required' Fees (Amended 7/17/89)701.6
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68a
The fol 1 owl ng fees shall be paid when a site plan is submitted to the
town for review:
The Planning Director shall review all site plans which are submitted
to the town. The Planning Director shall consult with the Technical
Review Committee and may consult with any town, county, or state
official if the need arises.
Type of Development Fee
Commercial $100 + $1.00 per 1000 square feet
of gross floor area (Amended 7/17/89)
The owner or developer shall submit to the Planning Director or
designee for consideration a site plan prepared and certified by a
registered engineer, architect or land surveyor. Five (5) prints of
the site plan at a scale of not less than one inch equals fifty feet
(l"=50’), together with all information required by this section shall
be submitted. All plans shall be no larger than 24"x 36".
F
Type of Development Fee
Industrial
Mobile Home Parks
$25.00 + $.50 per unit
701.6 Information Required
Location .and dimensions of all building701.6.1
showing distance to all lot lines.
701.6.2
701.6.3
701.6.4
701.6.5 Area in square feet of parcel.
701.6.6
701.6.7
701.6.8 Frontt side, and rear yard setbacks.
701.6.9
701.6.10
701.6.11
701.6.12
showing existing and proposed
69
at a scale of
inch equals two thousand feet
$500 per acre for water
$500 per acre for sewer
Multi-family
(more than four units)
Acreage Fees
I
4:3
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f
I
$50.00 + $.50
square feet of
area (Amended 7
Boundary of the entire tract fully dimensioned by
lengths and bearings.
Name and address of the present
purchaser, if any.
Location and general design of proposed sidewalks
curbs and gutters, and proposed landscaping.
Location, dimensions, and area of proposed and existing
parking and loading areas with the number of parking
spaces to be provided.
Proposed widths of any streets and sidewalks adjoining
the tract, showing right-of-way and pavement widths in
accordance with the town specifications as defined i n
Article X, Section A of the Subdivision Regulations of
the Town of Clayton and showing curbs and gutters to be
constructed.
Topographic map of parcel at a minimum two foot (2*)
contour interval, s’ * ...
contours. ’
owner or contract
per looo
gross floor
/17/89)
$50.00 + $1.00 per lot
(Amended 7/17/89)
Owners of ail contiguous property.
Vicinity map showing location of tract
not less than one
(l"=2000*).-
Location and dimensions of proposed and existing
driveways and curb cuts on site.
s on site
701.6.17
701.6.18
Landscaping
702.1
702.1.3
70
I
Provisions
storm
grades
1701.6.16
B701.6.14
I Section 702.
^701.6.15
^701.6.13 for the adequate disposition of natural and
water indicating locationr sizes, types, and
of ditches, catch basins, and pipes, with
connections to existing drainage.
l accordance with
landscape plan designed to
the following manner. -1-- -
from the public view and adjacent properties.
3/5/90)
A completed sign permit application or common signage
plan 1n conformance with Section 503.2 of this ordinance.
(Amended 5/7/90)
Location of all existing underground utilities such as
water, sewer, electric, and telephone cables on the tract
and proposed changes and extensions, if any.
Provisions for adequate screened or planted buffer areas
as required in Section 207 of this ordinance.
A plan of regni red landscaping in accordance with Section
207 of this ordinance.
All refuse storage facilities shall be screened by a
solid wall, fence, tight evergreen hedge, earthen berm,
or combination of the above. Such screening shall be of
sufficient height and design to obstruct the facility
from the public view and adjacent properties. (Amended
702.1.1
All site plans requiring landscaping in
this section shall have a 1 1
provide landscaping in the following manner. These
standards shall not apply to properties zoned B-l Central
Business District. (Amended 4/3/95)
Of the first 40,000 square feet or part thereof, twenty-
five percent (25%) shall be landscaped.
Of the second 40,000 square feet or part thereof, twenty
percent (20%) shall be landscaped.
No less than one canopy tree, one understory tree, and
two shrubs shall be planted for each one thousand (1,000)
square feet of landscape area required. Such trees need
to be evenly planted throughout the landscaped area, but
may be staggered or clustered as necessary to maximize
visual and screening objectives and to meet the needs of
the particular species of plants for root space, water
light, and air circulation. At the time of planting all
c^anopy trees shall be at least six (6) feet in height,
all understory trees shall be at least four (4) feet in
height, and all shrubs shall be at least one foot in
height.
702.1.2
I
r
i
702.1.4
a
requirement set
702.1.5
of this
breast height (DBH) of the tree as follows and with
Trunk diameter (DBH)Area Required
702.1.6 shall provide the following
702.1.6.1 Proposed locations of all landscaping materials to be
placed on the site.
702.1.6.2 size
702.1.6.3
702.2
71
4"
11"
17"
21"
I
!
f
JJ
80 sq. ft.
180 sq. ft.
320 sq. ft.
340 sq. ft.
- 10"
- 16"
- 20"
- plus
All landscape plans
general information:
Where a buffer is required by Section 207 of this
ordinance, that buffer area may be applied toward
satisfying requirements of this section. Existing trees
specified on the landscape plan to remain on the site as
a function of fulfilling purpose of this section shall
be protected from vehicular movement and material
storage over their root spaces during the followinc
construction. An undisturbed area with a porous surface
shall be reserved around a tree, based on diameter
---1 no
four (4) feet from the
A planting list that shall include the quantity, size,
height, caliper, and botanical and common names of all
plant materials to be planted on the site.
The calculations i _Z_
landscape plan to determine
Streams, creeks, rivers, lakes, or other similar
watercourses located on a site plan shall be left in
their natural state and shall be bordered on each sid
by a natural buffer twenty (20) feet in width al
measured perpendicular to the bank of the water course
Such natural buffers may be used to satisfy a maximum of
forty percent (40%) of the total landscaped area
.--'• forth in Section 702.1.1.
made by the preparers of the
. - - -----------------‘ that the landscaping
requirement of this section has been met.
Maintenance of Landscaped Areas
The owners and their agents shall be responsible for protectina
and maintaining ail landscaping in a healthy, growing condition,
9 it When necessary« and keeping it free of refuse and
An undisturbed
a tree.
protective distance less than
base of the tree.
ARTICLE XIII
•5;
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■ -'■ • ■ '' .?• -•- ^y*
■ .' • - • .V ■ v - v.
■■ ■-•i?? ■'•.•■■<•,
, . v r» .■'; z.^.,., ... ,y. ». ,t--
• • ••••• ■ - -•’•?•• • ••& '
- '■" • «:. ‘yr--. .
Bou.A ^iux.■ • - —JK.S--& <
■' ■'''v y'•’iWRSfP
’-‘ ; ‘ ’ •■-■■ ■ •■ - ■■• -’ - ■* -• ' ■■
fl* Aywr.: < 5 ; •'■• ., ‘
’ A •., ....
■• ■ .->••- •?.•;>A
■.... - = - >< -4 . - -;■< <"
‘KX-4 :t».i. fte r^f
iB< A>_. ■ S-'i-'-’4~ • V. ” . v . . < -s-
‘T.?A" i• ‘ - -■
^■*nV.*. •* Ajjj.-■ w . -•,’ -»■- ■•. t ■••.-' •.' ■•;•''•-??;-"•< •i“1-> -. . • *: : ' ’.^ .'^
fl^c y. -’ A •••■/'-Afv--’’; A"’ ‘^ A - -•• ■■'• -?■ '-■' -•-•■• • -■^
-*;A> 'AS^y->.::-
B- ■ x--
.•• '.’ <>• ??\*‘ A-’'.:
•-• ^*«.-■ ->XC*<:
ARTICLE XIII
Section 1301.Definition and Purpose
as determined in Section 1302.1 shall not be exceeded.
Section 1302. Development Standards
1302.1
a
1302.2 Site and Lot Area; Minjmum Yard Requirements
1
108 J
within
area.
CLUSTER DEVELOPMENT
(Adopted 5/6/96)
[P
than thirty (30) feet in width,
be constructed as
periphery yard around the entire
• no less
to provide
recreational
by allowing
1.1 exchange
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11
1
(a) The minimum size of a < '
be no less than ten (10) contiguous
(b) There shall be a [ a a _
perimeter of a cluster development which shall be
. If a use or structure to
part of the cluster which adjoins the
cluster development site shall
> acres.
Purpose: The propose of cluster development is
desirable and usable open spaces, scenic vistasr
ecreaiSf and preserve environmentally sensitive areas
flexible development standards and lot size reductions in <__1__^2
for their provision; provided that the overall permitted density^
Cluster Development - a planned residential development of at least
ten (10) contiguous acres served by public utilities, which mav
include a variety of housing types such as single-family, duplex
and multi-family units (apartmentsf town houses, condominiums
etc.), recreational/open spaces, and other uses related to
residential communities as permitted within the applicable zoning
district. However, duplex or multi-family units may comprise no
more than 50% of the total dwelling units. The minimum lot size
and development standards may be reduced in these developments as
set forth herein, when common areas are provided which comprise at
least twelve and one-half percent (12.5%) of the gross acreage of
the tract to be developed.
Permitted Density: The maximum number of dwelling units
permitted in a cluster development shall be determined by
dividing the gross acreage of the tract to be developed
by 20,000 square feet in AR/R-40/20 districts; 10,000
square feet in R-10 districts; 8,000 square feet in R-8
districts; and 6,000 square feet in R-6 districts. In
no case shall the permitted density exceed those
permitted in Article XII of this ordinance if the site is
designated Water Supply Watershed Protection
part of the plan by the Town
Mi niimim Lot Size and Width in a Cluster Development(c)
Lot Size Lot WidthZone
I
(d) Mi niTmun Setback Requirements in a Cluster Development
(single-family dwellings)
Side RearDistrictFront
For duplex development, the minimum front and street
I
(f)
I
109
21
18
18
12
12,000
6,000
4,800
3,600
Street
Side
15
12
12
10
9
6
6
4 ’
48'
42*
36*
30'
18
15.
15
12
AR/R-40/20
R-10
R-8
R-6
(g)
more
duplex developments.
AR/R-40/20
R-10
R-8
R-6
Off-street parking and/or driveways may cover no
than 75% of a required yard in single-family and
For all Tonlti-family and other permitted uses, the
required lot size and setbacks shall be the same as
required in the respective zoning district unless located
on the periphery of the cluster development [Ref.
1302.2(b)].
periphery is proposed as any use other than a single­
family dwelling, and the adjoining property is zoned in
an R classification, the mi nimum periphery setback shall
be one hundred (100) feet, or fifty feet if a solid fence
and/or evergreen hedge at least six (6) feet in height is
installed. This periphery yard may contain only
landscaping, natural vegetation or lawn, fence or
decorative wall, utilities, sidewalk or pedestrian
facility, or required driveway, unless such other use is
specifically approved as part of the plan by the Town
Council•
(e) For duplex development, the minimum front and street
side setbacks are the same as single-family uses. The
lot size, lot width, and side and rear yards for exterior
walls shall be one and one-half times the mi nimum
requirement in 1302.2 (c) and (d).
CT9905
I
EXHIBIT 10: STRATEGIC GROWTH PLAN
I
12/13/00Exhibit 10HUA
TOWN OF CLAYTON
WWTP EXPANSION
ENVIRONMENTAL ASSESSMENT
Town of Clayton
Environmental Assessment for WW o’Expansion
; Clayton Strategic Growth Plan*
Clayton Strategic Growth Plan
I
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Strategic Planning Committee:
Special thanks to:
Robert E. Reiman, PhD.
1
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James H. Upscomb
Robert N. Satterfield
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Town Council:
Mayor Douglaa McCormic
Mayor Pro Tern Ronald Gurganua
Robert J. Ahlert
R. S. "Butch" Lawler
Ronald Johnson
Edwina Oliver
J. D. Solomon
Donna White
Alien Mimi
David Pittman
JD. Solomon
George Waterman, Chair
Town of Clayton Planning Department
Mark Freeman, PIE., DSAtlanfic Corporation - Consultant
BSR
Clayton Planning Board:
Allen Mimi, Chairman
Frank Price, Vice Chairman
Bob Barbour
David Pittman
Randolph Reid
David Teem
George Waterman •
Clayton Strategic Growth Plan
2. ISSUES/GOALS/VISION
As a result of the Town Council’s initiative, a well rounded, balanced, and diverse community that
orovides a healthy and functional environment for its citizens will be the pnmary focus of
local economy is growing more slowly. It became apparent that policies aimed at promotmg
development of local business were necessary. Also, the supportive activities of this expandi g
residential population. I.e. government, public safety, recreation, will be g.ven attention.
Provision of adequate infrastructure to support continuing growth is a major challenge as
Planning, with recognition of the increasing complexity of State-level regutatory standards 'ntM
Neuse River basin, will require major attention by Town leaders dunng the coming months
development projects must be thoroughly analyzed relative to their .mpact or> the
treatment program. Close coordination with Johnston County and o h«f c‘®8'®XX
to assure adequate quantity and quality of potable water. Deregulation of the electrical ndustry
and potential Impacts on the Town must be monitored. Finally. « !°df“n?ft“"Xate the
htah priority thoroughfares on the Thoroughfare Plan must be created in order to accelera e the
plansof NCDOTsTransportation Improvement Program (TIP). The Town Councils ad p
goals for Clayton are as follows:
• Safest, healthiest city In the Triangle area
• Downtown: The community hub
• Regional service center
• A place for fun and leisure
. Business community: diverse and profitable
. Value for taxes and public fees
The Town Council’s adopted Vision: "Clayton ■ Premier Community for Active Families"
1. INTRODUCTION
!n 1998. the Clayton Town Council held a retreat, during which issues ^P^n’ihlt^^o^mal
growing community were discussed. There was a “nsensu^^ng me^up that a formal
planning document was needed to assist them in guiding the X ^co^s’de ration aJd
Clayton Planning Board was directed to prepare and present a growth plan for consideration
adoption by the Council.
Poling that tntttal treat, a joint ptanning ..aslon, .ttentM by To»"
Board mambor.. «aa conductM for the purpos. of ealabllahlng goa^s £ ateolc Wan
growth plan. Th. raaolt. of that planning ....ton war. eompfed “ 'hXan In
8;.X“ rirX’ K X 2 p" Hfia. <0, th. character and intaga of our
community.
review and decision making processes.
plan.
CLAYTON: YESTERDAY, TODAY AND TOMORROW
POPULATION3.1
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3.2 EMPLOYMENT
as®
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One of the best indicators of the growth of an area is the increase in population.
From 1990 to 1998, the Town population grew at an average annual rate of 6.3
%. That was well above the 1.6 % average annual growth for the State.
Johnston County’s population increased at 3.6 % annually over the same period
of time.
Studying the trends of areas such as population and employment gives clues to
the needs of a growing area. By researching data from various topics, we are
better able to understand the direction we are headed. There are things that must
be done to allow us to continue to grow, and things that must be done as a
consequence of our actions. This section looks at the quantifiable portion of the
information used in the development of the plan.
Table 3.1.1
Population
I
ci
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61,737
70,599
81,306
95,300
99,096
103,255
107,701
5,084,411
5,880,095
6,632,448
7,185,327
7,307,565
7,428,579
7,545,735
N/A '
1.3
1.4
3.2
3.9
2.1
4.3
Bnc^ase;*
N/A
2.8
1.5
6.3
5.4
~ 7.8
5.4
6.3
N/A
1.5
1.2
1.6
0.8
0.8
0.8
MB
3,103 __
4,091 __
4,756 __
6,458 __
6,810 __
7,346 '
7,743 __
11,171
II
1970
1980
1990
1995
1996
1997
1998
2004*__________________
Source: Office of State Planning
•Planning Department estimate.
Johnston County’s employment is also growing. From 1993 to 1997 employment
grew at an average annual rate of 5.4%, outpacing the overall State employment
growth of 3.5 % over the same period. As Clayton and the rest of the County
continue to grow, it will develop into more of a destination, than a bedroom
community for Raleigh. This trend is evidenced by the new services that are
available in the area. Shopping centers and service retail uses are becoming
conveniently located in and around Clayton. Table 3.2.1 shows the growth in
employment over the past few years.
MBS
SCHOOL ENROLLMENT
SI
4,818
7,952
Table 3.2.1
Employment
7,826
8,388
9,001
10,353
10,829
25,838
(0.08 %)
3,059,041
3,551
3,757
4,063
4,401
4,713
25,392
(0.08 %)
2,992,175
3,879
3,864
4,377
4,256
4,578
HK* . - ~___________________________________________________________
i: Johnston County Schools Membership Report, Johnston County Board of Education.
22,670
(0.08 %)
2,759,391
23,969
(0.08 %)
2,854,742
27,938
(0.08 %)
3,167,303
Table 3.3.1
Johnston County School Enrollment
157121
16,475
17,441
19,010
20,120
26,235
Bl994-95
I 1995-96^
L 1996-97
1 1998-99~
| 1999-00^
fa 2004-05*
■Source: ~
* 2004-2005 projected total.
■as student enrollment continues to increase, so too does the need for additional space. This must
be addressed by expanding current facilities, constructing new facilities, or-a combination o
■Current enrollment projections estimate all Clayton area schools will exceed designed student
■populations by 2004-2005.
■ Johnston
Ji County
I (%ofNC)
■ North
* Carolina
Source: U.S. Census Bureau
i3
R\s the area continues to grow, so will the need to provide services to the residents of the area.
_The educational environment is identified as a goal in the plan. This involves not only the public
ftchool system, but also should address the needs of the adult population, and those with special
Educational needs. Johnston County has seen an increase in the number of students in its school
-svstem over the last few years. In fact, there has been an average annual increase in school
Enrollment of 5 % from 1995 to 2000. Table 3.3.1 shows the actual growth in enrollment.
3.4 CONSTRUCTION / DEVELOPMENT IN THE CLAYTON AREA
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Table 3.4.3
Permits for New Construction
Table 3.4.2
New Construction Activity
Table 3.4.1
Site Plans and Rezonings
234
246
275
281
576
$ 19,704,275
$ 20,820,088
$26,905,414
$ 23,822,044
$35,476,112
263
228
312
281
432
1,516
18
22
17
25
46
128
39
31
37
20
79
13-192 acres
10 -394 acres
12 - 67 acres
16-174 acres
16 - 939 acres
67 -1,766 acres
24,845,239
24,528,800
62,660,441*
30,882,113
47,954,032
$ 190,870,625
$ 5,140,964
$ 3,708,662
$ 35,755,027
$ 7,060,069
$ 12,477,920
1995 _______
1996 _______
1997 _______
1998 _______
1999 _______
Total_______
* Winn-Dixie Warehouse included.
1995
1996
1997
1998
1999
Total __
Source: Town of Clayton Planning Department
1995
1996
1997
1998
1999_________
Source: Town of Clayton Planning & Inspections Department
There has been a steady increase in new construction in the area. This is evident when observi
the number of site plan submittals. Table 3.4.1 shows the number of site plans submitted and '
- rezonings filed. In addition to the site plans listed in the table, there have already been 26 site
plans submitted from January through September of 2000. New Construction activity is reflected
in Tables 3.4.2 and 3.4.3. <'
VEHICLE REGISTRATION
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Table 3.6.1
Vehicle Registration
80,778
(1.43 %)
5,629,954
72,247
(1.37%)
5,264,350
68,484
(1.34 %)
______ _______5,093,786 "T
Source: NC Office of State Planning
^^994^
75,886
(1.39%)
5,449,792
^995^
78,328
(1.42%)
5,525,067
Johnston County
(% of NC)
North Carolina
3.5 PROJECTED TRAFFIC
^Traffic projections have been made on the thoroughfares identified in the 1990 Clayton
Thoroughfare Plan. The 1990 plan only projected traffic out to 2010. That plan is currently under
■revision, and will extend projections to 2025. The actual 1998 traffic counts on US 70 show an
■average daily traffic of approximately 40,000 vehicles per day (vpd). The 2010 projected ADT
ranges from 17,4000 vpd to 20,700 vpd. Projected volumes are lower than current volumes due
■to the anticipated construction of the US 70 Bypass. This proposed facility should remove some
■of the traffic from US 70.
InC 42 volumes currently range from 8,900 vpd to 15,000 vpd. The current TIP includes
■construction of the US 70 By-Pass to begin construction in 2004 and widening of NC 42 East to a
multi-lane facility in 2004.
I several other roads in the plan are identified as requiring widening to a multi-lane cross-section.
For more information see the 1990 Clayton Thoroughfare Plan, or the updated version when it is
| completed.
13.6
M One indicator of the increase in vehicle miles of travel (VMT) in an area is the number of vehicles
I reqistered. Table 3.6.1 shows the number of vehicles registered in Johnston County, as well as in
* North Carolina. Form 1992 to 1996 vehicle registration in Johnston County rose at an average
annual rate of 4.2 %, almost twice the State rate of 2.5 % over the same period of time.
3.7 PUBLIC SAFETY
The following table gives employee totals for the Fire. Rescue, and Police Departments. Although
population has continued to increase, emergency staffing levels have remained constant. E^c,l
department should be reviewed on a regular basis to assure manpower needs are being met. For
instance, the national average of police officers per 1,000 population for cities under 10,000 is 4. .
Currently, Clayton’s ratio of sworn officer to 1,000 population is 3.2. In order to maintain the
national average, 6 additional officers would currently be needed.
I
Year^
TRAVEL AND TOURISM3.8
10130J
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Table 3.7.1
Police, Fire, Rescue Department Employee Totals
(Including Volunteers)
Table 3.8.1
Economic Impact of Travel and Tourism
gguja
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1995
1996
1997
1998
1999
Source: NC Department of Commerce
$54.65
$57.19
$6123
$59.58
$61.89
1995
1996
1997
1998
1999
2000
2004
$9.77
$9.91
$11.26
$11.61
$11.59
830
820
900
820
800
43
43
43
43
45
36
161,860
166,130
170,630
186,440
189,270
SQ'i-z- ■•••• FinpRp<;cii
Pepa rtment^}^ Depa^efif
32
32
32
33
34
33
^argliQ
$2,601.20
$2,707.08
$2,812.51
$3,486.16
$3,625.68
33
28
29______
33
37______
27*
____________ 44**
* Sworn Officers Only
‘•Estimate based on four officers per 1,000 population
Source: Town of Clayton Police and Fire Departments & Clayton Area Rescue
—
With its cultural and historical places and festivals, it is easy to see why people would want to virB
Clayton and Johnston County. In addition to the cultural value of these places and activities, the ■
I
$9,233.40
$9,767.82
$10,117.43
$10,768.08
$11,493.09
why people would want to virB
ipcp nlarAC and arfivifioc fhr ®
is also a monetary value. Table 3.8.1 shows the economic impact of travel and tourism in
Johnston County, and how it compares with the rest of the State.
PUBLIC LANDS
I
IL®|anrn§
I 49.40651.85459.284
9.122,3798.936.0519.447.705
Table 3.10.1
Farms and Farmland
230.402
(2.58 %)
1,216
(2.46 %)
211.011
(2.31 %)
1,406
(2.71 %)Number
of Farms
(%ofNC)
Total
Land (Ac)
le^gdl
1.713
(2.89 %)
234,394
____________________ (2.48 %)
Source: North Carolina Department of Agriculture
" Based upon information provided by the Johnston County Tax Office, there are currently 5,000
. acres of land in the Clayton ETJ that are taxed as bona fide farmland. These lands represent a
I relatively small amount of the total in the County (about 2.5%), but development policies should
" encourage their preservation.
I
13.10 FARMLAND
Table 3.10.1 shows the decline of farms in the area. The Town should work with Johnston County
|and the NC Department of Agriculture to preserve farmland to the fullest extent possible.
presently 282 acres of land owned by the Town of Clayton. The areas are shown in
23 acres
54 acres
98 acres
169 acres
26 acres
81 acres
|3.9
There are |
■Exhibit E and are categorized in the following manner
I A. Operations / Administration =
B. Utilities (does not include easements =
I C. Recreation / Parks (including greenway) =
I D. Schools (Johnston County Board of Ed.) =
E. Cemeteries
I F. Unprogrammed
It should also be mentioned that the State of North Carolina has significant acreage between the
■town limits and Wake County in the form of Clemmons State Forest (248 ac.) and Department of
■Agriculture (449 ac.) lands.
■Top priorities in public facilities needs during the next few years will be - development of the
•Clayton Elementary school site as a cultural center and town adnninistratiye offices, a new park
site and greenway development, expanding police facilities and site location for fire station No. 3
■on the western side of the fire district. The prospect of a public safety substation in the Riverwood
"Athletic Club area and a new site for the Clayton Area Rescue Squad must also be considered.
: i
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Year I
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1995
1996
1997
1998
1999
2000
Daily Flow Percentage
Of Capacity
81% ’
70%
_______55%_______
_______75%_______
________69%________
69%
T reatment
Capacity
(mgd)
1.6
1.6
1.9
1.9
1.9
1.9
Average Daily Flow
(mgd)
tai
_____1J2
_____ro4
V42
T32
1.31
Table 4.1.1
Plant Capacity vs. Measured Daily Flow Average
Clayton WWTP
4.0 UTILITIES
The two major issues facing the Town in providing utility services are 1) expanded
capacity of the wastewater treatment plant to keep pace with the demands of the
growing community and 2) deregulation of the electric industry.
Expansion of the wastewater treatment plant is anticipated in the very near future.
During the interim, the Town staff and consultant engineers will be working with
the State to resolve administrative program issues related to capacity allocations
for new development. Also, the Town Council will be considering a standard
policy on reservation of remaining allocation by perspective developments and
reclamation of outstanding unused allocation to dormant projects. An application
has been filed with the State of North Carolina that would increase the treatment
capacity from 1.9 million gallons per day (gpd) to 2.5 million gpd. Also, the Town
reached agreement with Johnston County to purchase 75,000 gpd capacity at
their treatment plant in Smithfield, which should become effective before January
2001. An additional 125,000 gpd of capacity will be purchased when planned
expansion of the County plant is completed, sometime during 2002. The Town
will begin preparing long range expansion and improvement plans for the
wastewater treatment system, including regional possibilities and other
alternatives, as soon as the present application is approved. The Town will
continue to develop the current relationship with Johnston County as its source of
potable water.
Maintenance and strengthening of the present electrical system will be
emphasized during the next few years. The Town recently Purc
adjacent to the substation on US 70 that will allow for expanded faci ities a that
location. As statewide deregulation of the industry is deliberated V
legislature, the Town will monitor related activities and continue o imp
service to its customer base.
LAND USE PLAN
Table 4.1.2
Clayton Public Power Sales Analysis
Residential
Commercial
ndustrial
3ublic_____
Dther______
Total
3,711
933
930
75
348
5,997
3,823
925
881
227
265
6,121
34,989
8,110
10,710
3,166
2,621
59,596
30,666
7,995
11,178
6,344
2,762
58,945
35,171
8,428
11,297
702
4,415
60,013
|
s ^et^^nS^QOO^FMw^
2,968
486
21
74
44
3,593
3,199
540
27
173
90
4,029
1.0
2,760
469
20
67
46
3,362
a
■As shown in Section 3.4, there has been considerable development activity in the Clayton area
■during the past five years. Residential building activity has been the predominant form of new
development. Commercial development activity has increased as well, particularly in the past two
■years. While more recent indicators reflect a minor slowdown in new construction, the established
■trend should continue.
■Currently, the Town exercises zoning and subdivision ordinance enforcement in its extraterritorial
■zoning jurisdiction approximately one mile, more or less, outside the contiguous town limits.
Preliminary talks with Johnston County Commissioners have been held concerning a possible
■expansion of the ETJ to perhaps two miles. In addition, a utility service area, which defines future
■growth of the Town's water and sewer systems, has been identified and submitted for approval by
the Johnston County Board of Commissioners. Further, an area of future impact, or longer range
■anticipated development, has been studied, using the proposed Municipal Transition Zones
■mentioned in Johnston County's strategic plan as a basis for consideration. These limits are
reflected in Exhibit A.
®For tax purposes, the Johnston County CIS office has created a current land use inventory, as
shown in Exhibits B & C. While this information will need refinement and adaptation for local use.
|it presents a useful picture of general land use in the Clayton area.
In terms of future land use. several categories related to present zoning classifications or other
■specific functions have been used to establish future development patterns and policies,
■proposed use classifications have been applied using existing uses, proposed roadway an(lu’li'ty
improvements and topography as the principal criteria. These classifications are shown on Exhibit
1°
^ForrtKe'^e
^Decem6eE31;: 1999J feSWmlejf.jQWa
3,445
814
954
191
280
5,684
1
General development policies for each classification follows:
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6. Office and Institutional - office uses and related support uses are very flexible in their
locational needs and are indicated in a variety of areas. A valuable function for these uses is
that of a transition between commercial or industrial uses and residential uses. Office parks,
which are sources of employment and require minimal utility capacity, should be encouraged.
5. Major Arterial Interchange - these properties are situated at the interchanges on the US 70
Bypass. Standards for minimum lot size, setback and building intensity, signage, landscaping
and buffering, as well as permitted uses should be developed and applied prior to construction
of the facility.
-9. Residential - most of the properties remaining in the planning area are designated for
residential development. Overall target densities should be 4-5 units per acre, with higher
densities nearer thoroughfares and major collector streets. Cluster development should be
4. Industrial - prime industrial properties have been identified and should be preserved for job­
creating uses and buffered from residential uses. Thoroughfare and utility improvements are
available or planned to serve these areas.
1. CBD Central Business District - a specific plan will be developed for facility and appearance
improvements, marketing and economic stabilization and organizational structure. The
Downtown Development Association (DDA) should continue to be the lead organization in this
effort, with support and assistance by the Town government and area property owners.
8. Public - these areas are locations of publicly-owned lands, including schools, town properties,
parks, cemeteries (public only), utility facilities, and other such properties. State-owned
properties are also-included. Public facilities are subject to specified processes, i.e. public
hearings or special/conditional use procedures, in establishing their location.
2. Commercial - these uses should be located in well-planned nodes and not randomly stripped
along thoroughfares. Shopping centers and retail villages should be located to serve
surrounding residences and reduce reliance on automobiles.
7. Open Space / Conservation - these areas are indicated where documented wetlands, flood
hazard areas, riparian buffers, or other environmentally sensitive lands are situated. Also
included are properties intended as greenways along Neuse River and Little Creek. Their
preservation and consideration in development of nearby properties should be required. An
inventory of significant resources in Johnston County is presently being compiled by Triangle
Land Conservancy and protective measures for them should be developed.
3. Future Commercial - these locations were identified as probable major commercial
developments at the intersections of major thoroughfares or in proximity to other major
developments.
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B promoted to facilitate open space preservation, particularly when water bodies, wetlands, or
I significant natural features are involved. Neighborhoods served by public utility systems and
" pedestrian amenities should be located in proximity to necessary support services, i.e.
■ shopping, recreation, public safety. Densities of residential developments in more remote
| locations or without access to public utilities should be a maximum of 1 unit per acre or less.
0. Residential Infill - this classification involves older, established residential areas that should
be conserved and maintained in their original character. Redevelopment should be kept in
scale with established uses and should be pedestrian oriented. Programs which provide
favorable terms, both financial and regulatory, for projects aimed at rehabilitation and/or
appropriate redevelopment should be encouraged.
5.1 ANNEXATION / ETJ EXPANSION
Demand for the Town's services has been the key factor in expansion of the
corporate boundaries. Presently, there is a total of 4,836 acres in the entire town
limits 1,674 of which are non-contiguous. During the coming months, the staff
will be preparing an analysis of surrounding areas and their potential for
annexation into the corporate limits. There has been no involuntary annexation
by the Town of Clayton since 1992.
Also as the Town’s corporate limits have expanded, the area within its
extraterritorial jurisdiction (ETJ) has been reduced. In 1992, the Johnston County
Board of Commissioners approved an adjustment to the Town s ETJ to coincide
with physical features and property lines. Currently, the Town of Clayton s ETJ
extends roughly one mile from the town limits and much less in some areas.
Based upon the anticipated growth of the Town’s services and utility service area,
the County Commissioners will be requested to consider another ETJ expansion
to accommodate this future development.
Approval Checklist
Approval Checklist
B. Request printout of applicable section of the Strategic Growth Plan.
1. Does the proposed development meet the zoning requirements?
2. Is it in conflict with the Clayton Thoroughfare Plan?
D. Obtain the necessary application forms from the Town office.
E. Submit request along with appropriate documentation and fee.
F. Request dates for Planning Board Review and Town Council Review.
The checklist serves a dual purpose. First, the list is to advise potential developers of the issues
that will be considered during the development review process. This allows potential problems to
• be avoided or minimized before submittal for approval. The list is also meant to guide local
officials when reviewing requests. By providing a clear set of expectations, this checklist should
simplify the development review process.
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C. Check all layers of the Clayton Strategic Plan to determine if the proposed development is
in conflict with the plan. Sample questions to ask could include:
f
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5. Does the proposed development impact natural resources (streams, high quality water
zones, threatened and endangered species, wetlands, greenways, parks, etc.)?
4. Is the area a zone identified as a future park, or other public facility (fire station, police
department, etc.) - refer to appropriate document.
3. Is it located in an area planned for future industrial growth, if so, does it conflict with
planned growth?
A. Contact Town Planning Department to inform of intent of to request. Obtain applicable
forms.
6. Does the proposed development significantly impact Town infrastructure based on
traffic production, water use, power use, emergency services?
C. If any conflicts or impacts exist, contact the Planning Department to discuss issues prior to
submittal. Determine if impacts can be avoided or mitigated. Determine if the impact is
based on regulatory issues or planning issue. If the impact is based on planning issues,
can the Strategic Growth Plan be altered or amended without impacting its intent?
3
7.
Legend
=5
Downtown Enlargement
/
z
4 Clayton Strategic Growth Plan
Proposed Land Use
y.'\
Created By: DSAtlantic Corporation0
October 1. 2000I
>'''•!!!!•
if
lllli 5-y
' / /
Exhibit D*I
J
H
Thoroughfare plan
Major Thoroughfare
/\/ Minor Thoroughfare
Proposed Maj
‘/\/ Proposed Min
| l Property Lines
/\/ Major Hydro -arc
Development zones
S2S C8D
■■I Commercial
HI Future Commercial
■I Industrial
BU Maj Arterial Interchange
Office/lnstitutional
MB Open Space/Conservauon
| | Public
Residential
| I Residential-Infill
/\/ US 70 Bypass
Roads (Tiger File)
/\/NC Railroads
is
KBSaWK-vibUyi
Exhibit ®
Downtown Enlargement
I
Clayton Strategic Growth Plan
Public Lands and Facilities
Created By: DSAtlantic Corporation
October 1, 2000
R
Legend
Property
PuStc L»nd» and FacdltlM
[rWfl 1. NC CM*. O< Aorta*»Jr«
fea 2. NC CM*. <* Aflrtcu<tur«
fiSj 3. Clayion MkMa School
[jM 4. Oparattona Cantar
ffR 5 W. Oayton Elam
pjgj 8. WWTPrOurham St
fjH 7. Community Park
(kt*) 8. Elac. SubataUon
j^j 8. EJac. Subataeon
Patil JO. Qeyton H.S.
U QtyCamatary
fflB 12. Municipal Park
FKa 13. Mapltwood Camatary
f|g9 14. Foraat HMa Camatery
PHI IS. Ara Station «2
18. Qeyton Elementary
fSffl 17. Town Hal
risg 18. PoHca/Ara/Reecue
[a3 IB. Town Square
(foal 20 Lepend Park
[Wfl 21. Alt Star Park
22. E. Qeyton Elam
[jW 23. Unprosrammed Novae Rrvor
pyj 24. Cooper School
fat] 25. Qemmona State Forest
rag} 28. Riverwood Middle & Elam Sen
Thofoghfaro plan
Thoroughfare
/\/ Minor Thoroughfare
«•_»*Propoaed Maj
Exhibit F
Legend
r
V4
>
z
a
1
Clayton Strategic Growth Plan
A Environmental Concerns
r
Created By: DSAtlantic Corporation
I
i October 1, 2000
/ J
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.1 . • '
'v.r ■■■ .........
WifeMl
. "/ J
i ■ r:,.'..
1
Li
Thoroughfare plan
Major Thoroughfare
/\y Minor Thoroughfare
Proposed Maj
Proposed Min
j Npdes
/\/ US 70 Bypass
/ v County boundanes
Has Waste Facilities
4 HSDS (Superfund) point da la
x> Solid Waste Facilities
____Hydro (line)
| ■-'.■I Maj. Hydro- poly
H National Wetians Inventory • poty
Nationa Wetland Inventory-arcs
© Wwells
I Wtreat
Water Supply Watershed
EB3 Critical
F Protected
/\7 Wpipes
® Surface Water Intakem Flood Plains
SpijS Land and Water Cons Fund
fl Ground water inddents
Bl Municipal Boundanes
Egg etj
\ 'z
TKbHW*- ’
\ F' F4'- L.'.
ACTION PLAN
ISSUE A - PUBLIC INFRASTRUCTURE
Goal - Provijlon of adequate and eojt-effeetlve utility aervlee*.
14.3.4.5.6Budget
1.6N/A2000BudgetTown StiffComplete turvey A input dm into CIS.
U4.62001BudgetStiff, Coniultint
6To be determined• On going BudgetTown Council. StiffContinue ictive involvement in Electricitier orginintion.
A
Utility Extension Policy2001Budget
14.5
To be determined N/A2001
134.6
Budget N/A2001
1.6
3.5.6• On going BudgetTown Council, StiffReview impact fee policy
. • Denotes “In progress"
N/A
Town of Clayton, North Carolina
Strategic Growth Plan 2000
I. Develop the Strategic
Growth Pile.
5. Seek cooperative efforts with
Jobnatou County, establish
utility service areas and policies. •
7. Rapfrs detailed impect study
of proposed wbdivWoee, site
plsm, and mnninga. *
Review subdivision regulations, toning ordinances. Adopt
appropriate ame nd. ueuti.
Council, Staff; County Staff;
Legal Counsel, (County
CommiMionen)
Town Council, Planning
Board, Staff; Consultant
Kay to "Supports Council Goals" oohmn:
1 • Safest, Healthiest Town in Triangle Area
2 • Downtown: The Community Hub
J - RegioniI Service Center
4. Monitor the Legislative
actiom regarding electric
deregulation. •
6. Investigate the possibility of a
local (or countywide) bond issue
to flnanee knprovssstntt.
Shared representatives on Town ind County Planning
Boards, Staff Coordination, Utility Service Agreement
Coordinate with area development
Determine what spedflc projects are to be funded. Oct
cost estimates fbr each. Determine type ofbond and
method of Implementing program.
Town Council, Staff
County Commiss loners.
County Staff
Existing (1991) Water and
Sewer Needs Study, Utility
Extension Policy. 201 Facilitiea
Plan
Utility Extension Policy,
Comprehensive Fee Schedule
J. Update the Water and Sewer
Needs Study and 201 Facilities
Plan to stoy responsive to
growth. •
S. Review utility impact fee
schedules every two years.
1 Complete inventory A
Mapping of the Town’s Water A
Sewer System
Hire consultant and establish dates for completion of
review.
Potential
Funding.
Sonrctt
Draff refine, and present plan to Planning Board and
TownCouneD
Create utility layer for Land Um Plan
Strategies for Attaining ■ l.r Specific Actlona to be Taken » . <
Planning Board, Sub­
committee, Town Council,
Staff
Ta focua resources toward
support of iaftastnscture
improvements
(njafatenance and
erpereioo).
4 • A place for Family Fun and Leisure
3 • Business Community: Diverse and Profitable
6 • Value for Taxes and Public Fees
policies that will Need to.,
belPlti^Chj^ed.or,
-fteyoke^ 6.-r
Supports Council
; Goals te - •
Timeframe For
Implementation
Jan 2001
ACTION PLAN
iployment In the Immediate area, and a quality of life which li attractive
Create layer for Land Um Flan.
13,5.6Budget2001
33.6N/ABudget2001Identify Coordinator reapotuible for facilitation
2J3.6To be detomfoed2001BudgetDevelop coordinated plan for “marketing" Clayton.
3.5.6Budget2001future needs. Compare
133.6Budget2001
■
b
Town of Clayton, North Carolina
Strategic Growth Plan 2000
Town Council, Planning
Board, Staff, NCDOT,
CAMPO
Tranaportation Plan, Utility Extension
Policy and Plana
Utility Extenaion Policy, Cotnprebenaive
Feet and Charges
Land Use Plan and Regulations, Zoning
Ordinance
J, Develop an effective method
of comrnunieation between the
Johnston County Economic
Development Office and Town
of Clayton administration.
Town Council, Johnston
County Economic
Development Office
Town Council, Staff;
Chamber of Commerce
1 Ta toertnaa the Town’s
property tax-baaed
revenues through the
expensioaand
ianprovement of higber-
vsteed commercial and
todestrial land uses.
Town Council, Staff;
Johnston County Economic
Development Office
Town Council, Planning
Board, StafL NCDOT,
property Ownen
Timeframe For
Implementation
* Ongoing
Monitor revenue produced veraus
fees with surrounding areas.
Supports
Council Goals
2333
Potendal-
Funding Sources
BudgetStaff, Johnston County
Economic Development
Commission, County Staff
Policies that will Need to hq
1 n Itl a ted. Changed^ or itevcfcfad
Initiate Land Um Plan, Land Use Plan
and Regulations
4. Promote local economic
growth through support of the
Clayton Area Chairiber of
Comrnerea and their related
programs and projects which
benefit local business. •
4. A place foe Family Fun and Leisure
5. Business Community: Diverse and Profitable
6 - Value for Taxes and Public Fees
Key m "Supports Council Goals" column:
1 • Safest, Healthiest Town in Triangle Area
2 • Downtown: The Community Hub
J . Regional Service Center
J. Review the local
development fee program to
nwintain its effectiveness and
competitfveneM in support of
economic development
opportunities and institute an
equitable program of incentives.
Establish Transportation Advisory Group. Develop
toning districts for controllod access roadway interchanges
(US 70 Bypass, others that become applicable).
Identify Resources, Select Participants, Define
Responsibilities, Establish Work Program and Boundaries
Strategic
frfoM_____
I. In accordance with the
Comprehensive Land Um
Plan, identify prime sites for
economic development and
protect theM properties from
incompatible soes through
effective land nM controls
w,thin the Clayton ETJ and
recognized fiiture growth areas.•
2. Cooediaatt the transportation
and infrastructure plana for the
Town with economic
development efforts and aasura
adequate wxeoa and support
facilities for identified prime
sites and fature growth areas.
6 Establish a task force to
promote redevelopment of
targeted areas along US 70
• Denotes “In progress’’
C.T!. or. >00.1 eoonomy. Inere..rf opportooKI- for «m|
______to bnglness development
‘I Tartetc
■ - Objectf^>. ■■
• I. To strengthen the
relatioeBhip with Johnston
County Economic
Development
AdraMstretion and foster a
ftverabk position in
countywida efforts.
Coordinate efforts with Johnston County. Review current
land use, toning end development regulations
ACTION PLAN
ISSUE C- DOWNTOWN DEVELOPMENT
Goal - Reeotnltlon of the downtown area at the historical and cultural center of Clayton
Tarttf<
•2000
Town Council, Stift DDA 2001 Budtet, DDA Land Um Plan and regulatiom 2.4.5,6
2001 Budget, DDA Land Um Plan and regulabotM 2.44.6Involve DDA and review reguhtioni
• On going N/ATo be determined 2.4.6
•Ongoing Budget Land Um Plan and regulations U.44.6Create layer for Land Um Plan.
* Denotes "In progrest"
Town of Clayton, North Carolina
Strategic Growth Plan 2000
Support the steering coomittM for planning and hind
raising and actively involve the DDA in the effort.*
Town Council, Planning
Board, DDA, Stiff;
Consultant
Town Council, Steering
Committee, DDA, Staff
Town Council. Planning
Board, Stiff
Preaenre and promose the
downtown area m a unique
and desirable place to live,
shop, and conduct business.
Key io “Supporti Council Goals" column:
1 • Safest, Healthiest Town fa Triangle Area
2 • Downtown: The Community Hub
J - Regional Service Center
3 Explore a "Fanner’s
MiAet/Fka Marta" concept fbr
Downtown
4. Cootiaue efforts to renovate
Clayton School*
5. Develop Strategic Growth
Plan with a Downtown
Development strategy.
Create DDA Charter
Review zoning regulations
4 . A place for Family Fun and Leisure
5 - Business Community: Divene and Profitible
6 - Value for Taxes and Public Fees
Town Council Planning
Board, DDA, Staff
Consultant
2. Expand the involvement of
the DDA. in matters related to
downtown — Ln, site plan
review, marleting'promotioa,
etc.________________________
I. Develop a comprehensive
plan for aesthetic, architectural
and economic improvements ia
doWTtfOWIL* ___ ____
Policies that w|l) ^ced tp
Budgetary (tax District), Land
Um Plan and regulations
Potential
Funding' .
Sources
Budget, DDA 2.44.6Empower Downtown Drvelopment Associition (DDA) to ' *
engage services of a consultant to assist to developing the
plan. Conduct a parting study fbr the downtown area.
ACTION PLAN
ISSUE F - TRANSPORTATION
* On going Budget I jnd Um Phn end regulttiom 1.6
Create layer for Land Ute Plan.• On going Budget Land Um Plan and regulations 1 J.5.6
• Denote* “In projreji”
Town of Cliyton, North Carolina
Strategic Growth Plan 2000
Town Council, Planning
Board, Consultant, NCDOT,
Staff
Budget, Potential
Ortffl
Kay to "Supports Council Ooalt* cohstnn:
1 - Safest, Healthiest Town in Triangle Area
2 • Downtown: The Community Hub
J • Regional Service Center
J. Add Thoroughfare Plan and
other transportation related plana
to the Strategic Growth Plan. •
4 * A place for Family Fun and Leisure
$ • Business Community: OiverM and Profitable
6 • Value for Taxes and Public Fees
Town Council, Planning
Board, Consultant, NCDOT,
Staff
2. Evaluate the Town’s
development regulations to
determine efTectiveneM in
provision of adequate
transportatioo-relatod facilities.•
Town Council, Planning
Board, NCDOT, NCRR,
CAMPO, Targeted citizens.
Staff
Review existing regulations and propose changes where
necessary.
Require Traffic Impact AnalyMt where applicable as part
of site approval process.
Identity Resources, Select Participants, Define
Responsibilities, and Establish Work Program.
Explore ahemate means of transportation (l.e. Rail,
Bicycles)
Explore ahemativs means of financing transportation
improvements, including land issues, public/private sector
partnership*, rtc.
Continue DOT involvement in the bi-monthly Technical
Review CommitteefTRC) process.*
—as-,
Town Charter2001 I - - -13.5.6I. establish an oo-gotng
Transportation Advisory Group
including members of the Town
Council io deal with related
matters and promote good
working relations with NCDOT.
t Goal - Implementation of (be updated Thoroughfare Plan and exploration of opportunities for multi-modal transportation facilities which will enhance public mobility and safety.
Prioritize needed
traneportadoo
igprovamauts and
investigate shtmatives for
financing Mlected projects
and fecilities.
ACTION PLAN
io®
1J.6tanH U»e Phn and retuUDom
)J.6N/A2000
13.6N/AN/A2001Town StafT. Town Council
13.6Land Um PhnN/A2000Town Staff. Town Council
13.6N/ABudget2001Town Staff; Town Council
13.6N/ABudget2000Town StafT Town CouncilPrepare reaohirion. Council contidcretion
• Denote “in pro£resi”
Town of Clayton, North Carolina
Strategic Growth Plan 2000
Town Council, Johnaton
County Board of Education,
County Commiaaionere,
Staff
Budget, To be
determined
N/A
Study featibility and need of a aalellite facility for JCC to
be located in Clayton
•r " >x>;.
Key to “Supporta Council Ooala* column:
1 .Safeat, Healthieet Town ta Triangle Area
2 • Downtown: The Community Hub
3 • Regional Service Center
I. Effect coordination of local
activities that impact the
educational ayatem with the
Johnaton County Board of
Education, County
Commiiaionen, and other
imereated agencies
A
EatabHeh and support
educational facilities.
education.! environment to aerve all aegmenti of Clayton’, population._____________
2001
■
4 . A place for Family Fun and Leisure
5 . Business Community: Dtverae and Profitable
6 - Value for Taxes and Public Fees
2. Analysis A adopt resohition
of poaitioo on pending related
bond referenda.
Deftna responsible parties
Inchsda forecasts of school student population in proposed
residential developments and seek Johnston County Board
of Education (JCBOE) input in the review process
Provide regular reports or create other methods of
Information sharing between the Town of Clayton and
JCBOE
Integrate future school locations Into the Comprehensive
Land Use Plan in order to facilitate site reservations.
ISSUE G - EDUCATION
Goal- Establishment of »n exceptional community
ACTION PLAN
ISSUE H - PUBLIC SAFETY
Coal — Provision of an effective, well-equipped comprehensive public safety service for the entire Clayton community.
2001 Budget Land Um Plan and rtgulatkru 1.6
• Denotes “in progress"
*1
Determine need and logistics in establishing satellite
facilities. Add as layer to Land Use Plan
Town of Clayton, Nonh Carolina
Strategic Growth Plan 2000
Determine feasibility of combining departments to
maximize resources.
Establish criteria for needed manpower of each service
relative to population of service area.
4 - A place for Family Fun and Leisure
5 - Business Community. Diverse and Profitable
6 • Value for Taxes and Public Fees
Land Um Plan and regulaoons.
Fire Districts, Rescue Service
Area, Town Charter
Key to “Supports Council Goals" column:
1 • Safest, Healthiest Town in Triangle Area
2 - Downtown: The Community Hub
J - Regional Service Center
2. Integrate future public safety
facility needs into the Strategic
Growth Plan with an emphasis
on shared facilities where
passible.
Town Council, StafL
Clayton Area Rescue Squad.
1.620011. Create a Council-appointed
Public Safety Committee, which
includes the Police, Fire and
Rescue-, Chieft appointed
officials and citizens to assist in
coordinating planning efforts,
exploring funding alternatives,
and advising the Town Council
and other government agencies
on related issues.
■■■
Budget, Potential
grants
Town Council, Police Dept,
Fire Dept, Clayton Area
Rescue Squad, Staff
bgTtkeifcJ;:;Mt
Develop short and long
tern plans for program,
fkcOhy needs and
manpower for the Police
and Hre Departments and
the Claytoe Area Rescue
Squad.
CT9905
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EXHIBIT 11: SUBBASIN MAP
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12/13/00Exhibit 11HUA
Town of Clayton
Environmental Assessment for WWTP Expansion
TOWN OF CLAYTON
WWTP EXPANSION
ENVIRONMENTAL ASSESSMENT
lieYj
■it
ille
2
o
A°
A
Vicinity Map
Api
o"S'
0
Q
LEGEND
I
■S1
A
©
I
MOm
I
I
%
H
SCALE
1:350,000
oo
k5
Water Quality Monitoring
Stations in the Upper Neuse
River Basin (Subbasin 02)
& J
.AS.
NCDENR
March 1998
c.
5.
Ux
I7T218S
5
I
g
I
T
CTio
S-.
i
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i
NC-*3>
2087500'K
ro
/.RiA
Anst
iBS
Rolei
o NPDES Wastewater Discharges
(?) Lake Monitoring Sites
a Benthic Macroinvertibrate Sites
Ambient Monitoring Sites
- A Fish Community Sites
-H Fish Tissue Sites
*-*0 Comprehensive Sites
(all 4 monitoring methods performed)
^\y Major Roads
/\/ County Boundaries
'/\/ Hydrography
ggS Municipalities
iQ
CT9905
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EXHIBIT 12: WATERSHED MANAGEMENT PLAN
I
12/13/00Exhibit 12HUA
Town of Clayton I
Environmental Assessment for W
TOWN OF CLAYTON
WWTP EXPANSION
ENVIRONMENTAL ASSESSMENT
Expansion
Authority
IntentSection 2«
ApplicabilitySection 3.
Section 4•
an accessory
95
These watershed
development t
ARTICLE XII
WATER SUPPLY WATERSHED PROTECTION
The Legislature of the State of North Carolina has, in 143-214.5,
160A-371 and 160A-381 of the North Carolina General Statutes,
delegated the responsibility and authority to local governmental
units to establish water supply watershed protection programs, to
regulate land use and development within water supply watersheds
and to adopt regulations designed to promote the public health,
safety and general welfare of its citizenry.
The intent of this amendment. Water Supply Watershed Protection, is
to provide in the designated watershed area a higher level of
control from activities and situations that could degrade the
quality of the water entering the Neuse River as identified m the
Watershed Protection Management Policy and Plan for the Town of
Clayton.
protection requirements shall not apply to existing
z as defined in this Ordinance, except as provided in
Section 7 of this Article. Furthermore, these requirements shall
not apply to a single-family detached dwelling unit or
dwelling unit developed on an existing lot.
Section 1.
■ - The provisions of this • article shall apply within the area
I designated as a Public Water Supply Watershed by the NC
Environmental Management Commission and shall be defined and
established on the map entitled, "Watershed Protection Map of
Clayton, North Carolina", which is adopted simultaneously
The Watershed Protection Map and all explanatory matter containe
thereon accompanies and is hereby made a part of this Ordinance.
This Ordinance shall be permanently kept on file in the °fs ot
the Town Clerk and a copy shall be on file m the Clayr
Departments of Planning and Code Enforcement.
Exceptions to Applicability
The use of waters for stock watering, irrigation
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I96
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nonstructural
to
to
Agricultural Use:
and other farm purposes.
discharging Eandfj.ll: A facility with liners, monitoring equipment
and other measures to detect and/or prevent leachate from entering
the environment and in which the leachate is treated on site and
discharged to a receiving stream.
Best Management Practices A structural or i
management-based practice used singularly or in combination
reduce nonpoint source inputs to receiving waters in order
achieve water quality protection goals.
BMffgg: An area of natural or planted vegetation through which
stormwater runoff flows in a diffuse manner so that the runoff does
not become channelized and which provides for infiltration of the
runoff and filtering of pollutants. The buffer is measured landward
from the normal pool elevation of impounded structures and from the
bank of each side of streams or rivers.
Section 5. Definitions
Hixectcr: The Director of Planning and Code Enforcement, or this
officials assigned agent, is for the purposes of this Ordinance the
Watershed Administrator.
B.uilt-Upon Area.: Built-upon area shall include that portion of a
development project that is covered by impervious or partially
impervious cover including buildings,, .pavement, gravel roads2
recreation facilities (e.g. tennis courts), etc. (Note: Wooden
slated decks and the water area of a swimmi ng pool are considered
pervious.)
Cluster ' Development: The grouping .of- buildings, including
residential and non-residential development, in order to conserve
land resources and provide for innovation in the design of a
project.
C-Pinppsting Facility: A facility in which only stumps, 1 i mbs,
leaves, grass and untreated wood collected from land clearing or
landscaping operations is deposited.
Pev^lQpmgnt: Any land disturbing activity which adds to or changes
the amount of impervious or partially impervious cover on a land
area or which otherwise decreases the infiltration of precipitation
xnto the soil.
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97
mi nlrnmn lot size or other development requirements of the statewide
watershed protection rules.
Plat: A map or plan of
subdivided.
Hazardous Material: An substance listed as such in: SARA Section
302, Extremely Hazardous Substances, CERCLA Hazardous Substances,
or Section 311 of CWA (oil and hazardous substances).
a parcel of land which is to be, or has been
Existing Development: Those developments as of the effective date
of this ordinance that are built or those developments having an
outstanding valid building permit or a site specific development
plan as authorized by G.S. 160A-385.1, or having an approved site­
specific or phased development plan in compliance with G.S. 153A-
344 or G.S. 160A-385 and having expended substantial resources
(time, labor, money), or meeting the court-created common law or
constitutional standards of a substantial expenditure of resources
(time, labor, or money) based on a good faith reliance upon having
received a valid local government approval to proceed with the
project.
Landfill: A disposal facility or part of a disposal facility where
solid waste is placed in or on land in accordance with Chapter
130A, Article 9 of the N.C. General Statutes. For the purpose of
this Ordinance, this term does not include composting facilities.
IiOtr Existing: A lot which is part of a platted subdivision of
which has been recorded in the Office of the Register of Deeds in
Johnston County prior to the effective date of this Ordinance, or
a lot described by metes and bounds, the description of which has
been so recorded prior to the effective date of this Ordinance.
Noncohforming Lot of Record: A lot described by a plat or a deed
that was recorded prior to the effective date of these watershed
| protection regulations (or their amendments) that does not meet the
Protected Area: The area adjoining and upstream of the critical
area in which protection measures are required. The boundaries of
the protected area are defined as extending ten (10) miles upstream
and drai ns ng to water supply or to the ridge line of the watershed
whichever comes first.
Structure: Anything constructed or erected which requires location
on or attachment to the land or attachment to something having
permanent location on the land.
I
A variance that results in any one of the
(1)The complete waiver of a management requirement;
(2)
Minor?
Section permits
Watershed Protection PermitA.
1.
I2.
documentation deemed necessary by the Director.
3.
J
I4 .
98
applications shall
The
IVariance
variance.
Watershed: r"
a specific point (i.e
be
application shall
The relacation of, by a factor more than 10%,
of any management requirement.
Variance< Major?
following ?
Prior to
Permit,
The entire land area contributing surface drainage to
-J-J- the water supply intake).
Except where provided for elsewhere in this Article,
no building or built-upon area shall be erected,
moved, enlarged or structurally altered, nor shall
any building permit be issued nor shall any change in...
the use of
Watershed Protection Permit has been issued by
Director. No Watershed Protection Permit shall
issued except in conformity with the provisions
this Article.
a Watershed Protection
consult with qualified
to determine if the
the issuance of
the Director may
personnel for assistance
application meets the requirements of this Ordinance.
A Watershed Protection Permit shall expire if a
Building Permit is not obtained by the applicant
within twelve (12) months from the date of issuance.
a major
Watershed Protection Permit
filed with the Director,
include a completed application form and supporting
any building or land be made until a
the
be
of
not qualify as
Toxic Substance: Any substance or combination of substances
(including disease causing agents), which after discharge and upon
exposure, ingestion, inhalation, or assimilation into any organism
either directly from the environment or indirectly by ingestion
through food chains, has the potential to cause death, disease
behavioral abnormalities, cancer, genetic mutations, physiological
malfunctions (including malfunctions of suppression in reproduction
or growth) or physical deformities in such organisms or their
offspring or other adverse health effects.
A variance that does
B.
C
1.
2.I Watershed
change in3. When only
4.
5.
as
A. Vacant Lots
Permit
Ordinance
all
met
or
of
«
I
l^^uired
existing development must
.o yjj. —i however, the built-upon
development is not required to be included in
Any existing development
Expansions to structures classified as
meet the requirements of~ this Ordinance^,
area of the existing <" .
| the density calculations.
Any exiBtiug as defined in this Ordinance, may be
continued and maintained subject to the provisions provided herein.
bui1 ding, shall be applied for
for a
I
Section 7 *
. If the
This category consists of vacant lots for which plats
deeds have been recorded in the office of the Register
Deeds of Johnston County. Lots may be used for any of the
uses allowed in the watershed area in which it is located,
provided the following:
99
1 ■ a change in use of land or existing
building occurs, the Director shall issue a Watershed
Protection Occupancy Permit certifying that 1
requirements of the Ordinance have been
coincident with the Watershed Protection Permit.
If the Watershed Protection Occupancy Permit is
denied/ the Director shall notify the applicant m
writing stating the reasons for denial.
No building or structure which has been erected,
moved, or structurally altered may be occupied until
the Director has approved and issued a Watershed
Protection Occupancy Permit.
Existing Development; Non-Conformities
defined in this Ordinance,
Building Permit
Except for where provided elsewhere in this Article, no
building permit required under the North Carolina State
Building Code shall be issued for any activity for which
a Watershed Permit is required until that permit has been
issued.
. Watershed Occupancy Permit (Zoning Compliance)
Prior to the occupancy or use of a building hereafter
erected, altered or moved and/or prior to building
hereafter erected, altered or moved and/or prior to
the change of use of any building or land, the
Director shall issue a Watershed Protection Occupancy
Permit certifying that all requirements of this
Ordinance have been met.
A Watershed Protection Occupancy Permit, either for
the whole or part of al
coincident with the application
Protection Permit.
Watershed Protection Occupancy
for denial.
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I1.
2.
B. Occupied Lots i
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C. Buildings and Built-Upon Area
Reconstruction of Damaged Buildings or Built-Upon AreaD.
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100
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This category consists of lots, occupied for residential
purposes at the time of the adoption of this Ordinance.
These lots may continue to be used provided that whenever
two or more adjoining lots of record, one of which is
occupied, are in single ownership at any time after the
adoption of this Ordinance, and such lots individually or
together have less area than the mi ni miiTn requirements for
residential purposes specified, in this Article, such lots
shall be combined to create lots which meet the minimum
size requirements or which mini mize the degree of non­
conformity.
This category includes any buildings or built-upon area
existing at the time of adoption of this ordinance not in
conformance with the restrictions of this Ordinance. Such
buildings shall be allowed to remain except as provided
for in Article IX of this Ordinance.
Where the lot area is below the minimum specified in
this Ordinance and no other standard needs to be
modified to use the lot for residential purposes, the
Director is authorized to issue a Watershed
Protection Permit.
Any existing building or built-upon area, not in
conformance with the restriction of this Ordinance that
has been damaged by fire, wind, flood or other causes, may
be repaired and used as before as provided in Article II
of the Zoning Ordinance. The total amonnt of space
devoted to built-upon area may not be increased unless
storm water controls that equals or exceeds the previous
development is provided.
Notwithstanding the foregoing, whenever two or more
adjoining residential vacant lots of record are in
single ownership at any time after the adoption of
this Ordinance and such lots individually have less
area than the minimum requirements for residential
purposes for the watershed area in which such lots
are located, the Director may require such lots to be
combined to create a single lot or lots which meet or
minimize the degree of nonconformity.
otectjonSection 8-
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overlay sub-district.
I Watershed Protected Area (WSP)Section 9.
A. Intent
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I B. Permitted Uses
2.
101
by
a
Establishmei
Overlay Dist
nMfcbf Water Supply Watershe^^E-3Kt~ W
I
m ann oevexopmen'c witnxii uxks no unoc wxuh
■ of both the underlying zoning district and the applicable watershed
: acre or 36% built-
--i if no' curb and gutter street system is used) .
new development activities that . require an
state law or
required to meet the
The Water Supply Watershed Protection Overlay District (WS) is
hereby established as a district that overlays the designated water
supply watershed. The designated water supply watershed under this
district is defined and established by the overlay district "WSP
Water Supply Watershed Protection District" on the Official Zoning
Map and delineated on the map entitled "Watershed Protection Area
of Clayton" which is adopted as a part of this division and
permanently kept on file in the office of the Town Clerk. Land use
and development within the WS must comply with all the requirements
The following uses and activities are permitted in the WSP
provided such uses are also permitted in the underlying
zoning district and providing that the restrictions stated
herein are met.
1. Agriculture, subject to . the provisions of the Food
Security Act of 1985 and the Food, Agricultural,
Conservation and Trade Act of 1990.
Silviculture, using BMP’s required to implement the
provisions of the Forest Practices Guidelines Related
to Water Quality (15 NCAC II.6101-.0209).
The Watershed Protected Area (WSP) within the Town of
Clayton is designated by the State Environmental
Management Commission as a Class IV watershed protected
area (WS-IV PA) and is referred to as the • Neuse River
(Smithfield) watershed within the Neuse River basin. In
order to accommodate a moderate to high land use intensity
pattern, single family detached use shall develop at. a
maxi innin. of two (2) dwelling units per acre. All other
residential and ‘non-residential development- shall be
allowed a maximum of twenty-four percent (24%) built-upon
• area (or three (3) dwelling units per t-—-
' upon area f" '
Only new . development activities that
erosion/sedimentation control plan under
approved local government program are
provisions of this program.
3.Residential Development I4 .
Density and Built-Upon AreasD.
Residential Development1.
I
established
2.
I
3.
102 II
All other Residential and Nonresidential
Development
I
Nonresidential uses excluding discharging landfills
and, sludge application sites, mining and quarryinc
activities, and the storage of toxic and hazardous
materials unless a spill containment plan j <=
implemented.
, , . acre,
approved cluster ■ development which
---» established elsewhere in
All other residential and non-residential development
shall not exceed twenty-four percent (24%).built-upon
area on a project by project basis (or three (3)
dwelling units per acre or 36% built-upon area if no
curb and gutter street system is . used). For the
purpose of calculating built-upon area, total project
area shall include total acreage in the tract on
which the project is to be developed.
Development in Industrial (1-1,
(B-l, B-2, B-3) Districts
The Watershed Administrator is
consistent with the
Projects must, to the
- . minimize built-upon
direct stormwater away from surface
Best Management Practices to
i *.• ■' lmPacts* For the purpose of
calculating built-upon area, total project area shall
include total acreage in the tract on which the
project is to be developed.
Single family residential development shall not
exceed two (2) dwelling units per acre (or three (3)
dwelling units per acre or 36% built-upon area if no
curb and gutter street system is used), and defined
on a project by project basis. No residential lot
shall be less than one-third (1/3) acre, except
within an approved cluster development which meets
the standards established elsewhere in thi c?
Ordinance.
In addition to the development allowed under
paragraphs (1) and (2) above, new non-residential
development and expansions to existing non-
residential development may occupy up to ten percent
(10%) of the protected area with up to seventy
percent (70%) built-upon area on a project-by-project
basis, when approved as a special intensity
allocation (SIA) . ‘ .j
authorized to approve SIAs
Provisions of this ordinance,
maximum extent practicable,
surface area,
waters and incorporate
minimize water quality
1-2) or Business
Supplemental Development Requirements
A. Cluster Development
the
1.
2.
3.
I
Buffer Areas Required
Vegetative Buffer RequiredA.
vegetativethirty(30)A
I
B.
I 103
I
Clustering of development is allowed in the watershed with
following requirements:
minute)
local
stream bank
Mi niimim lot sizes are not applicable to single family
cluster development projects; howevert the total
number of lots shall not exceed the number of lots
allowed for single family detached developments
established elsewhere in this Article. Density or
built-upon area of the project shall not exceed that
allowed for the WSP.
Section 10.
I
J. minimum thirty (30) foot vegetative buffer for
development activities is required along all perennial
waters indicated on the most recent versions of U.S.G.S.
1:24,000 (7.5 minute) scale topographic maps or as
detArmined by local government studies. Desirable
artificial stream bank or shoreline stabilization is
permitted.
No Development in Buffer; Exceptions
No new development is allowed in the required buffer
except for water dependent structures (e.g.z boat docks,
piers, ramps, etc.) and public projects such as road
crossings and greenways where no practical alternative
exists. These activities should minimize built-upon
surface area, direct runoff away from the surface waters,
and maximize the utilization of stormwater BMP’s.
I
" Section 11»
The rema inder of the tract shall remain in a
vegetated or natural state. Title to the open space
area shall be conveyed to an incorporated, homeowners
association for management or to a local government
for preservation as a park or open space or to a
conservation organization for preservation as a
permanent easement.' Where a property association is
• not incorporated, a maintenance agreement shall be
filed with the property deeds.
All built-upon area shall be designed and located to
minimize stormwater runoff impact to the receiving
waters and minimize concentrated stormwater flow.
ISectiQn 12.Public Healt-h Requirements
GeneralA.
IB. Abatement
I1.
I2.to
3.
ISection 13
I
A.
be said boundaries .
B.approximately
I104
Rules Governing the Interpretation of Watershed Area
Boundaries
report
agency
accordance with the provisions of Section 1.8 of the
Town of Clayton Code of Ordinances.
a surveyed plat prepared by
may be submitted to the
or more properties along
--------1 area.
Where uncertainty exists
areas,
apply:
as to the boundaries of the watershed
as shown on the Watershed Map, the following rules shall
No activity, situation, structure or land use shall be
allowed within the watershed which poses a threat to water
quality and the public health, safety, and welfare. Such
conditions may arise from inadequate on-site sewaqe
systems which utilize ground absorption; inadequate
sedimentation and erosion control measures; the improper
storage or disposal of junk, trash or other refuse within
a buffer area; the absence or improper implementation of
a spill containment plan for toxic and hazardous
materials; the improper management of stormwater runoff*
or any other situation found to pose a threat to water
quality.
as approximately
or highway lines
The Director shall monitor land use activities within
the watershed areas to identify situations that may
pose a threat to water quality.
The Director shall report all findings to any
appropriate public agency or official and request
recommendations and assistance.
Where area boundaries are indicated
following either street, alley, railroad _ 3
or center lines thereof, such lines shall be construed to
Where the Director finds a threat, to water quality
and the public health, safety, and welfare, the
Director shall institute any appropriate action in
Where area boundaries are indicated as
following lot lines, such lot lines shall be construed to
be said boundaries. However,
a registered land surveyor
Director as evidence that one
these boundaries do not lie within the watershed
c.I
aD.
E.
Administration Enforcement and AppealsSection 14.I Watershed Administrator and Duties thereof.A.
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I 1.
2.
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3.
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105I
shall
such
any
area
Where other
interpret the
watershed area
twenty-five
For the purposes of this Article,. the Director of Planning
and Code Enforcement of the Town of Clayton, hereinafter
referred to as the Director, shall be appointed to serve
as the Watershed Administrator. It shall be the duty of
the Director to administer and enforce the provisions of
this Ordinance as follows:
Where the watershed area boundaries lie at a scaled
distance more than twenty-five (25) feet from any parallel
lot line, the location of watershed area boundaries shall
be determined by; use of the scale appearing on the
watershed map.
inspection
Director.
The Di rector shall keep records of the jurisdiction's
use of the provision which allows a maxi mum of 70% of
the regulated area to be developed at a maximum of
70% bni1t—upon area. Records shall include the total
areas of non-critical watershed area, total acres
eligible to be developed at this option and total
acres approved for this development option.
Individual records which include location, type of
use, number of developed acres and stormwater
management plans shall be kept for each project.
The Director shall keep records of all amendments to
the local Water Supply Watershed Protection Ordinance
and shall provide copies of all amendments upon
adoption to the Water Quality Section of the Division
of Environmental Management.
The Director shall issue Zoning Compliance Permits
and Watershed Protection Occupancy Permits as
described herein. A record of all permits shall be
kept ■ on file and shall be available for public
inspection during regular office hours of the
uncertainty exists, the Director
_________ __ Watershed Map as to location of
boundaries. This decision may be appealed to the Clayton
Board of Adjustment.
Where the watershed area boundaries lie at a scaled
distance of twenty-five (25) feet or less from
parallel lot line, the location of watershed
boundaries shall be construed to be the lot line.
4 .
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5.
..A
1
variance.
Section 15.
Section 16.
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IAppeals and Variances
A.I
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106
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■
.to the
Ordinance.
Quality
I
responsibility
The
may
as
or modify the order, decision,
interpretation of the Director, shall
. 7 — - --— of ARTICLE VIII
of these regulations.
The Director shall keep a : __2
local Water Supply Watershed Protection
s Water r - - ”
Management
The.Town Council of the Town of Clayton may, on its own motion or
on petition, after public notice and hearing, amend, supplement,
change^ or modify the watershed regulations and restrictions . as
described herein. All applications for changes, supplements,
amendments, or modifications of this Article shall follow the
< in Article IX of this Zoning Ordinance. Under
no circumstances shall the Town Council adopt such amendments,
supplements, or changes that would cause this ordinance to violate
_SuPP1y- Watershed Protection Rules as adopted by the
NCEMC. All amendments must be filed with the NC Division of
“v^o^ental Management, NC Division of Environmental Health, and
NC Division of Community Assistance.
Section 17.
record of variances
This record shall 'be submitted to the ^l
Section of the Division of Environmental
on an annual basis on or before January 1, and^shall
provide a description of each project receiving a
variance and the reasons for granting the variance.
Appeal from the Watershed Administrator
Any order, requirement, decision, or determination made by the
Director may be appealed to and decided by the Board of Adjustment.
All appeals will follow the procedures outlined in Article VIII of
this Zoning Ordinance. ” r
The Director is granted the authority to administer
and enforce the provisions of this Ordinance
exercising in the fulfillment of his rrrp'
the full police power of the Town of Clayton."
Director, or his duly authorized representative*,
enter any building, structure, or premises^
provided by law, to perform any duty imposed upon
by this Ordinance.
Changes and Amendments to the Watershed Protection
Ordinance .
An appeal to reverse
determination, or f
comply with the procedures and standards
modify the order.
I B.
differentiatedVariances byMinorare1.
Minor variances(a)
residential density or built upon percentage.
I shall include:Major variances(b)
(1)
(2)I
2.
Minor(a)
I
(b)
(1)
I
(2)
I
107
of
and
Carolina
Commission
the
VIII
variance.shall be
The .
within
the
findings,
North <--
variance to the standards of the Watershed
shall comply with the procedures
A decision by the Board of Adjustment
to approve a major variance shall be
only. The. Watershed
shall within 30 days
record of the Board
hearing,
to the
Management
advisory
Administrator
forward a
Adjustment
conclusions
Environmental
for final decision.
comply • with • the
of ARTICLE VIII of
1 ; shall include petitions for
the reduction of any standard of the overlay
district by a factor of less than 10%, except
Major and Minor Variances are
procedures and standards.
: variances shall
procedures and standards
these regulations.
major
final. Appeal shall be to
competent jurisdiction as
ARTICLE VIII.
Petitions to increase residential density
. or built upon percentage.
Major and
definition.
differentiated as to
Petitions for the reduction of any
standard of the overlay district by a
factor of 10% or more; and
A petition for . , .,
Overlay District shall comply with the procedures and
standards of ARTICLE VIII of these regulations, with the
following exceptions:
comply with
of ARTICLE
Major variances, shall
procedures and standards
except that:
A decision by the Board of Adjustment
to deny a major variance shall be
a court of
provided in
I(3)
I
3.
become
I
Part II.
I
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I107A
I
the Director
i Johnston
--> being
Adopted on
Prior to the Board of Adjustment meeting,
shall notify in writing the Town of Smithfield, r •
County, and the Town of Selma of the variance L *'
requested. Written responses from any of these loca?
governments using the Neuse River as a water supply shall
-----• a permanent part of the records.
Section 18. Severability
Should any section or provision of this Article be declared invalid
or unconstitutional by any court of competent jurisdiction, the
declaration shall, not affect the validity of this Article as a
whole or any part thereof that is not specifically declared to be
invalid or unconstitutional.
The Board of Adjustment may advise
approval of a Major Variance petition
upon satisfying the findings Of
Article VIII, Section 805.3.2, or upon
the finding that significant community
economic or social benefit would be
derived from the granting of the
variance.
^wiSm°rdX2a;iCe • ®ha11 take effect and be in force upon adoption by
the Town Council of the Town of Clayton, North Carolina. 7
September 27, 1993 and amended on June 4, 1996.
CT9905
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EXHIBIT 13: NUTRIENT REMOVAL STUDY
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12/13/00Exhibit 13HUA
Town of Clayton
Environmental Assessment for WWTP Expansion
TOWN OF CLAYTON
WWTP EXPANSION
ENVIRONMENTAL ASSESSMENT
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October 2000
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NUTRIENT REMOVAL STUDY
LITTLE CREEK WATER RECLAMATION FACILITY
TOWN OF CLAYTON, NORTH CAROLINA
The Wooten Company
Engineering • Architecture • Planning
120 North Boylan Avenue
Raleigh, North Carolina 27603
Raleigh / Hickory/ Greenville / Asheboro, North Carolina
ELL
8089
R.
R..
Shankar R. Mistry, Ph.D., P.E.
October 27, 2000
Dear Mr. Simpson:
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1 Sincerely,
THE WOOTEN COMPANY
u le-*« V
I Attachments
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Since 1936
919-828-0531
Fax: [phone]
Engineering
Planning
Architecture
Mr. Tim Simpson
Director of Public Works
P.O. Box 879
Clayton, North Carolina 27520-0879
120 N. Boylan Avenue
Raleigh. NC
27603
Re: Nitrogen Removal Study
Little Creek Water Reclamation Facility
Town of Clayton, North Carolina
TWC No. 2756
Shankar R. Mistry, Ph.D., P.E.
c: Mr. James Warren, Superintendent LCWRF
Again, we would like to express our sincere thanks to all the Town officials for the
opportunity given to us in providing this service to the Town.
Attached please find three (3) draft copies of the “Nitrogen Removal Study” for
your review. We appreciate the assistance provided by you and Mr. James Warren
in preparation of this study.
After your review, we will be glad to meet with you and your staff to go over the
findings of the study and address any questions you or your staff may have.
-WootenCompany
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NUTRIENT REMOVAL STUDY
LITTLE CREEK WATER RECLAMATION FACILITY 1TOWN OF CLAYTON, NORTH CAROLINA
October 2000
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The Wooten Company
Engineering • Architecture • Planning
120 North Boylan Avenue
Raleigh, North Carolina 27603
Raleigh / Hickory/ Greenville / Asheboro, North Carolina
/a? SEAL x
’ ' z co \ 8089 f
'y.............• . C-,
R.
Shankar R. Mistry, Ph.D., P.E.
I The Wooten Company
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ACKNOWLEDGEMENT
The successful completion of this study would not have been possible without the
valuable assistance, support and cooperation of the municipal officials of the
Town of Clayton.
The assistance, active participation and cooperation of Mr. Tim Simpson,
Director of Public Works, and Mr. James Warren, Superintendent of LCWRF, is
gratefully appreciated.
ITABLE OF CONTENTS
SUMMARY, CONCLUSIONS AND RECOMMENDATIONS 11.0
7INTRODUCTION2.0
EFFLUENT LIMITATIONS/NUTRIENT REMOVAL REQUIREMENTS 83.0
4.0
5.0
6.0
1
97EVALUATION OF EFFLUENT (RECLAIMED WATER) REUSE7.0
»
1
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-1-
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4
5
6
7
8
9
24
49
50
51
58
59
66
. 73
. 81
. 86
. 88
. 89
103
104
40
40
40
14
14
14
25
41
43
52
60
67
74
82
90
95
16
33
34
94
EVALUATION OF THE EXISTING FACELITIES FOR NUTRIENT REMOVAL . .
4.1 Description of the Existing Facilities .................................................................
4.2 Description of the Proposed Improvements ........................................................
4.3 Evaluation of the Existing Facilities for Nutrient Removal ................................
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DESIGN BASIS ..................................................................
5.1 Wastewater Flows and Characteristics ........................
5.2 Effluent Limitation and Nutrient Removal Requirements
LIST OF TABLES:
1 - Design Data Of The Existing Clayton LCWRF .........
2 - LCWRF Performance Data..........................................
3 - LCWRF Performance Data - Nitrogen and Phosphorus
4 - Summary Of Alternative Evaluation............................
LIST OF EXHIBITS:
1 Schematic Flow Diagram of Clayton LCWRF...............................................
2 Schematic Flow Diagram of Alternative No. 1...............................................
2a Schematic Flow Diagram of Alternative No. 1...............................................
2b Schematic Flow Diagram of Alternative No. 1 -Sludge Handling Facilities . .
3 Schematic Flow Diagram of Alternative No. 2...............................................
3a Schematic Flow Diagram of Alternative No. 2...............................................
Schematic Flow Diagram of Alternative No. 3...............................................
Schematic Flow Diagram of Alternative No. 4...............................................
Schematic Flow Diagram of Alternative No. 5...............................................
Schematic Flow Diagram of Alternative No. 6...............................................
Schematic Flow Diagram of Alternative No. 7...............................................
Effluent Transport from Clayton LCWRF to Proposed Land Application Site
10 Proposed Force Main Route to Pine Hollow Golf Course............................
11 Soil Map of Pine Hollow Golf Course..........................................................
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NUTRIENT REMOVAL ALTERNATIVES
6.1 Alternative No. 1 ............................
6.2 Alternative No. 2 ............................
6.3 Alternative No. 3 ............................
6.4 Alternative No. 4 ............................
6.5 Alternative No. 5 ............................
6.6 Alternative No. 6 ............................
6.7 Alternative No. 7 ............................
6.8 Summary of Alternative Evaluation .
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-ii-
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APPENDIX 1
1.
2.
Copy of the July 10, 2000 Speculative Limits letter.
.0234 Neuse River Basin - Nutrient Sensitive Waters Management Study: Wastewater
Discharge Requirements.
APPENDIX 3
1. Preliminary Design Calculations for Upgrading and Expansion of LCWRF for Nutrient
Removal r
2. Evaluation of Sludge Handling Facilities for Upgrading and Expansion of LCWKr tor
Nutrient Removal
APPENDIX 4
1. Administrative Code Section: ISA NCAC 2H .0200 - Waste Not Discharged to Surface
Waters, March 1,2000
APPENDIX 2
1. Nitrogen Study Test Data
2. Evaluation of the Existing Carrousel System for Nitrogen Removal
3. A copy of letter from the City of Raleigh Public Utility Department
1.0
1
Page 1Town of Clayton
Total Nitrogen and Total Phosphorus.
This study includes: (1) evaluation of the influent wastewater characteristics and overall
plant performance in terms of compliance with the effluent limitations and nutrient removal
SUMMARY, CONCLUSIONS AND RECOMMENDATIONS
The Town of Clayton operates a 1.9 mgd Little Creek Water Reclamation Facility
(LCWRF) which discharges its effluent into the nutrient sensitive Neuse River. As per the Neuse
River Basin Nutrient Sensitive Water Management Strategy/NCAS Temporary Rule .0214, the
Clayton LCWRF (based upon its permitted flow of 1.9 mgd) will be required to comply with the
annual Total Nitrogen Permit limit of 21,400 Ib/year and quarterly average Total Phosphorus limit
of 2.0 mg/L, beginning with calendar year 2003.
In order to deal with its recent growth trend, the Town of Clayton has already initiated the
process for increasing its LCWRF permitted wastewater discharge flow to 2.5 mgd. The process
for increasing (rerating) the LCWRF capacity to 2.5 mgd included preparation and submittal of
environmental assessment, filing an application for the NPDES permit modification, preparation
and submittal of plans and specifications of the LCWRF improvements and obtaining an
authorization to construct. The NSWMS rule also requires that the expanding facilities shall
comply with the annual Total Nitrogen permit limit of 21,400 Ib/year and a monthly average Total
Phosphorus limit of 1.0 mg/L, beginning with calendar year 2003. Facilities joining a group
compliance association will be required to meet a quarterly average total phosphorus limit of 2.0
mg/L. The Town has expressed its intent to join the Lower Neuse Basin Association (LNBA) and
accordingly the Town will not be subject to individual nitrogen allocation limits and will be
required to meet a quarterly average total phosphorus limit of 2.0 mg/L. The LCWRF
improvements proposed at the present time are designed for the purpose of rerating the LCWRF to
2.5 mgd and compliance with all the speculative effluent parameter limits, with the exception of
Total Nitrogen and Total Phosphorus, as required by the rule and the speculative limits.
Accordingly, the purpose of this study is to develop a nutrient management plan that will allow the
LCWRF to operate at 2.5 mgd and staying in compliance with the effluent discharge limitations on
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1.
2.
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4.
Page 2Town of Clayton
requirements; (2) evaluation of existing facilities for biological and chemical phosphorus removal
and biological nitrogen removal; (3) establishing design influent wastewater characteristics; (4)
evaluation of nutrient removal alternatives, and (5) evaluation of effluent reuse. The conclusions
purchase of additional allocation.
Based upon the review of the plant monitoring data, the influent wastewater at the plant is
characterized as follows: pH = 6.93; Temperature = 21.10° C; BODs = 228 mg/L; NHa-N
= 17.84 mg/L; Total P = 6.58 mg/L; Total Alkalinity = 136 mg/L; COD/BODs Ratio =
drawn from the study are summarized as follows:
The Clayton LCWRF will be required to comply with the annual Total Nitrogen permit
limit of 21,400 Ib/year (2.811 mg/L = ADF of 2.5 mgd) and monthly average Total
Phosphorus limit of 1.0 mg/L, beginning January 1, 2003. The Town of Clayton has
expressed its intent to join the Lower Neuse Basin Association for group comphance and
in this situation the Clayton LCWRF will not be subject to individual limit on Total
Nitrogen discharge, but will be responsible as a group, for meeting their collective
nitrogen discharge allocation. Also, in this situation, the Clayton LCWRF will be required
to meet a quarterly average Total Phosphorus limit of 2.0 mg/L.
The expanded Clayton LCWRF will be required to meet a total nitrogen annual mass
permit limit (26635.87 lb TN/yr) calculated using a total nitrogen concentration of 3.5
mg/L and maximum average flow of 2.5 mgd.
3. The Town has the following options for complying with the total nitrogen discharge
requirements: (1) purchasing additional allocation of 26635.87 - 21,400 = 5235.87 lb/TN/
year and constructing and operating the LCWRF improvements to limit its total nitrogen
discharge to 26635.87 Ib/year, (2) constructing and operating the LCWRF improvements
to limit its nitrogen discharge to its unexpanded allocation of 21,400 Ib/year (2.811 mg/L),
and (3) combination of reduced concentration (3.0 mg/L) of total nitrogen discharge,
effluent reuse program, use of decentralized altemative/innovative wastewater collection
and treatment system, using on-site disposal, for new developments and industries, and
5.
6.
7.
1
I8.
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9.
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Page 3Town of Clayton
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1.917; BODs/TP Ratio = 35.57; COD/TP Ratio = 56.58 and BODs/TKN ratio = 8.62. The
influent wastewater characteristics are conducive of achieving biological nutrient removal
Ib/year.
The plant is capable of complying with the quarterly average Total Phosphorus limit of 2.0
mg/L with chemical (alum) addition. The influent BODs/TP ratio is adequate to achieve
enhanced biological phosphorus removal at the plant by providing external anaerobic
selector tanks. Provision of external anaerobic tanks would also eliminate or reduce the
at the plant with use of BNR processes.
The overall plant performance evaluation reveals that the plant has not experienced any
compliance problems with the effluent parameter limits included in the NPDES Permit.
However, the plant exceeded its allocated annual Total Nitrogen discharge of 21,400 I
chemical dependency for phosphorus removals at the plant.
The plant is not capable of complying with the annual nitrogen discharge allocation of
21,400 Ib/year at both the current flow (1.5 mgd) and design flow (2.5 mgd) conditions at
the plant. Addition of nitrogen removal facilities such as upgrading the aeration capacities
in the existing oxidation ditches and providing new first stage anoxic tanks, nitrate
recycle, second stage anoxic tanks with reaeration or Tetra type denite filters with a
methanol feed system will be required to comply with the Total Nitrogen discharge
requirements.
Considering the allowance for residential, commercial, and industrial growth in and
surrounding the Clayton area, the design influent wastewater characteristics used in
evaluation of nutrient removal alternatives are: ADF = 2.5 mgd; BODs = 250 mg/L; TSS =
250 mg/L; TKN + 40 mg/L; NHa-N = 25; Total P = 8 mg/L; Total Alkalinity = 130 mg/L;
pH = 6.8 - 7.0 S.U.; and Temperature - Summers 28° C, Winter = 12° C.
Additional sludge thickening and aerobic sludge stabilization/storage facilities will be
required as a part of the overall nutrient removal strategy.
10. Five stage process (Bardenpho type) or three stage process followed by denite filter
system (Tetra type) is required for high levels of Total Nitrogen and Total PhosphorusI
denite filter system are capable of producing a effluent total nitrogen of less than 3.0
mg/L, most biological nutrient removal plants, for all practical purposes, are designed to
consistently achieve effluent total nitrogen of 3.0 mg/L.
11. Seven nutrient removal alternatives (as described in Section 6.0) were evaluated to provide
the most cost-effective solution to the Town’s wastewater treatment needs in terms of
I compliance with the effluent limitations, including nutrient removal requirements, given in
the July 10, 2000 Speculative Limit letter. The Construction Cost Opinion, annual
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below:I
Present Worth CostAnnual O&M CostsAlternatives
$13,936,000$847,500Alternative No. 1
14,932,500837,0006,609,500Alternative No. 2
13,218,000864,0004,495,500Alternative No. 3
I 14,721,500854,0006,190,000Alternative No. 4
13,989,600876,0005,153,500Alternative No. 5
15,005,500866,0006,360,000Alternative No. 6
t 19,661,500939,50011,141,000Alternative No. 7
12. Alternative No. 3, as described in Section 6.3, provides the most cost-effective solution
Total Nitrogen and Total Phosphorus.
Alternative No. 1 or No. 5 is recommended for implementation. Also, despite the high
Page 4Town of Clayton
cost of providing Tetra denite filter system, the Tetra denite filter system is suggested for
the Town’s consideration to provide state-of-art technology in nitrogen removal to comply
Construction Cost
Opinion
$ 5,417,000
for complying with the discharge limitations on
However, based upon the reliability concerns and discussion provided in Section 6.8,
operation cost and the present worth cost of the alternatives evaluated are summarized
removal. In spite of the fact that five stage process or three stage process followed by a
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State.
14. The effluent reuse for construction and street washing activities would reduce
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a group compliance association.
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i diPage 5Town of Clayton
with stringent total nitrogen discharge limitations.
13. Pine Hollow Golf Course management has shown positive interest in reuse of the
LCWRF reclaimed wastewater for golf course irrigation. The construction cost opinion
for this reuse project is $733,000.00. The total nitrogen reduction through this reuse
alternative is estimated to be 1,351 lb TN/year. Such a reduction in total nitrogen
discharge would help in terms of compliance with the allocated total nitrogen discharge of
21,400 lb TN/year at an effluent TN concentration of approximately 3.0 mg/L instead of
2.811 mg/L at the rerated plant capacity of 2.5 mgd. In terms of nutrient offset payment to
the State, the reduction of 1,351 lb TN/year nitrogen discharge to the Neuse River could
save the Town $891,660.00 if the town elects to buy nutrient offset payments from the
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2. Upgrade and expand the LCWRF as described in Section 6.1 — Alternative No. 1 or
Section 6.5 - Alternative No. 5 with Alternative No. 1 as a preferred alternative. If
approximately 187 lb TN/year in the discharge and in terms of nutrient offset payments the
Town could save approximately $123,420.00.
Based upon the findings of this study, the following recommendations are made for
nutrient management that will allow the Clayton LCWRF to operate at 2.5 mgd and staying in
compliance with the effluent discharge limitations on Total Nitrogen and Total Phosphorus.
1. Join the Lower Neuse Basin Association. This will help the Town in not complying with
its individual annual total nitrogen discharge allocation of 21,400 Ib/year. The Town will
be responsible for group compliance limits. The Town will not get a notice of violation
from the N.C. Division of Water Quality for non-compliance with its individual total
nitrogen discharge limit. This will also help the Town in complying with the less stringent
quarterly average Total Phosphorus limit of 2.0 mg/L when compared with more stringent
monthly average Total Phosphorus limit of 2.0 mg/L for a facility who is not a member of
provision of Tetra denit filtersI
Alternative No. 2 or Section 6.6 - Alternative No. 6 with Alternative No. 2 as the
preferred alternative. The construction cost opinions for these alternatives are given as
follows:
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3.
I 4.
I existing service area and for future development
I management plan.
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Page 6Town of Clayton
Alternative No. 1
Alternative No. 2 (with Tetra Filter System)
Alternative No. 5
Alternative No. 6 (with Tetra Filter System)
Implement projects involving effluent reuse for Pine Hollow Golf Course irrigation and
for construction and street washing activities as a part of the total nitrogen management
plan. The Town should apply for grants from either Clean Water Bond Fund (by March
2001) or Clean Water Trust Fund. The Town can also apply for funding from the State
$ 5,417,000.00
$ 6,609,500.00
$ 5,153,500.00
$ 6,360,000.00
are considered by the Town to incorporate state-of-art
Revolving Loan Program.
Explore decentralized innovative/altemative collection and treatment systems involving on­
site disposal options to handle the wastewater treatment needs of a certain portion of the
as a part of the overall nutrient
technology, then upgrade and expand the LCWRF as described in Section 6.2 -
IINTRODUCTION2.0
1.9 mgd Little Creek Water Reclamation Facility
(LCWRF) which discharges its effluent into the nutrient sensitive Neuse River. As per the Neuse
River Basin Nutrient Sensitive Water Management Strategy/NCAS Temporary Rule .0214, the
I
existing influent pump station, aeration facilities, clarifiers and sludge recirculation/waste pumping
facilities; (2) addition of a new 65-foot diameter secondary clarifier and a polymer feed pump, and
1(3) modification to sludge and polymer feed piping. The NSWMS rule also requires that the
proposed improvements are designed for the purpose of rerating the LCWRF to 2.5 mgd and
compliance with all the speculative effluent parameters limits with the exception of Total Nitrogen
1and Total Phosphorus limits as required by the rule. Accordingly, the purpose of this study is to
develop a nutrient management plan that will allow the LCWRF to operate at 2.5 mgd while
staying in compliance with the minimum nutrient control requirements for the LCWRF discharge
(annual mass limit for Total Nitrogen = 21,400 Ib/year and monthly average Total Phosphorus =
1.0 mg/L) and/or other requirements for expanding facilities established in the rule and in the July
10, 2000 letter directed to the Town of Clayton concerning speculative limits issued by the State.
Page 7Town of Clayton
Clayton LCWRF (based upon its permitted flow of 1.9 mgd) will be required to comply with the
annual Total Nitrogen Permit limit of 21,400 Ib/year and quarterly average Total Phosphorus limit
expanding facilities shall comply with the annual Total Nitrogen permit limit of 21,400 Ibs/year and
monthly average Total Phosphorus limit of 1.0 mg/L, beginning with calendar year 2003. The
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of 2.0 mg/L, beginning with calendar year 2003. In order to deal with the recent growth trend, the
Town of Clayton has already initiated the process of increasing its permitted wastewater discharge
flow to 2.5 mgd. The increase in the LCWRF capacity to 2.5 mgd will be achieved by preparing an
environmental assessment, filing an application for the NPDES permit modifications, preparation
of plans and specifications of the LCWRF improvements and obtaining an authorization to
construct permit. The Town has already submitted a Draft Environmental Assessment to the State
for review and approval. The proposed LCWRF improvements include: (1) upgrading of the
The Town of Clayton operates a
EFFLUENT LIMITATIONS/NUTRIENT REMOVAL REQUIREMENTS3.0
speculative limits are summarized below:
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6-9
(1)
(2)
I (3)
(4)
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Page 8Town of Clayton
On July 10, 2000 the NC Division of Water Quality has issued the speculative effluent
limits for the proposed expansion (hydraulic rerating to 2.5 mgd) at the Clayton LCWRF. These
Summer
Apr. - Oct.
2.5
5
30~
1
200
28
No Limit
No Limit
Effluent Limitations
Winter
Nov. - Mar.
2.5
10
30
2
200
2?
No Limit
No Limit
21,400 (annual mass loading)
1
Monitoring
Frequency
■__________________________________________________________________________________
Continuous
Daily
Daily
Daily
Daily
Daily
Daily
Weekly
Monthly
Annually
Weekly
Daily
Daily
Quarterly
Daily
Ceriodaphnia Pass/Fail at 2.0%
6-9 [
Total Nitrogen. The Nutrient Management Strategy (NMS) rule (adopted December 1997 and
revised February 2000) requires that point sources in the Neuse River Basin, including the
Little Creek WRF/Clayton WWTP, meet annual mass limits for Total Nitrogen (IN)
beginning with calendar year 2003. Clayton’s initial allocation is approximately 21,400 Ib/yr
TN.
The monthly average effluent BODs and Total Suspended Residue concentrations shall not
exceed 15% of the respective influent value (85% removal).
The daily average dissolved oxygen effluent concentration shall not be less than 6.0 mg/L.
Total residual chlorine is required only if chlorine is used as a disinfectant (or elsewhere in the
process).
Effluent Characteristics
'. ■
Flow, monthly average, mgd___________
BODs day 20° C , <1> mg/L_____________
Total Suspended Residue(1), mg/L
NHj as N, mg/L
Dissolved Oxygen ,(2) mg/L
Fecal Coliform, #/100 mL, geometric mean
Total Residual Chlorine <3), ug/L
Total Nitrogen,(4) mg/L
Ib/month
Ib/year
Total Phosphorus as P,(5) mg/L
Temperature,0 C__________________
Conductivity, mohm/cm2
Chronic Toxicity (6)
ph daily maximum
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(5)
I(6)
(7)
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Page 9Town of Clayton
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The NMS rule establishes additional requirements for facilities planning to expand beyond
their 1995 permitted flows. An expanding facility must acquire any nitrogen allocation it needs
for the added discharge before it can apply for the necessary NPDES permit modification. The
facility can (1) provide additional treatment in order to meet its original allocation, (2) acquire
additional allocation from existing point sources, or (3) acquire additional allocation from
nonpoint sources through the Wetlands Restoration Fund. In the last case, the facility must
obtain 30 years allocation prior to permit application. In any event, the facility’s total
allocation cannot be greater than the annual mass limit equivalent to 3.5 mg/L TN at the
expanded flow.
Facilities joining a group compliance association are not subject to individual limits but will be
responsible as a group for meeting their collective allocation. Clayton has expressed its intent
to join such an association, so much of this explanation does not apply directly to its discharge
requirements. However, the discussion is still relevant to the Town’s nitrogen allocation and
the limit the association must meet. The Permittee shall notify the Division in writing within
five (5) working days if, at any time during the term of the permit, the permittee elects not to
join the association, otherwise loses its membership in the association.
Note that the Division expects to complete a more comprehensive modeling effort in early
2001 and will use those results to better define the nitrogen reduction target for the Neuse
River estuary. It is not clear from preliminary results whether the target will need to be
changed. Be aware that if the target level is lowered, it could lead to further reductions in the
point source allocations.
To reiterate, design considerations must include the ability to achieve an annual load based on
a concentration of 3.5 mg/L at 2.5 MGD, regardless of the Town’s chosen route of
compliance. (Please refer to 15A NCAC 2B .0234).
The quarterly average for total phosphorus shall be the average of composite samples collected
weekly during the calendar quarter (January-March, April, July, October-December).
As per the NMS rule for expanding facilities, Clayton shall meet the phosphorus limit of 1.0
mg/L beginning Januyy 1, 2003 if any time or during the term of the permit Clayton elects
not to join the association, or if it withdraws or otherwise loses its membership in the
association. In such case the Town of Clayton shall notify the Division in writing within five
(5) working days.
Chronic Toxicity (Ceriodaphnia dubia) P/F at 2.0%: March, June, September and December.
The pH shall not be less than 6.0 Standard Units nor greater than 9.0 Standard Units and shall
be monitored daily at the effluent by grab sample.
For ease of understanding, the nutrient control requirements established in the Nutrient
Sensitive Waters Management Strategy rule 0.0214 (see copy included in Appendix 1) and in the
speculative limits are explained as follows:
1. Nutrient Controls for Existing Facilities
As per the paragraph (6) of the rule, the nutrient controls requirement for the Clayton
LCWRF are as follows:
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2.
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2.
I = 2.81 mg/L
Page 10Town of Clayton
(b) Effective January 1, 2003, the Clayton LCWRF shall meet a quarterly average total
phosphorus limit of 2.0 mg/L.
Nutrient Controls for Expanding Facilities
As per paragraph (8) of the rule, the nutrient controls requirement for the Clayton
LCWRF are as follows:
(a) Beginning with calendar year 2003, the Clayton LCWRF with a permitted flow of
1.9 mgd shall be subject to a total annual mass nitrogen permit limit of 21,400
Ib/year.
(a) The Town of Clayton shall evaluate all practical alternatives to surface water
discharge pursuant to 15A NCAC 2H .0105 (c) (2), prior to submitting an
application to discharge the expanded flow.
Reduce sources of nitrogen to the LCWRF such as through pretreatment
programs, oil and grease discharge controls in the sewer system and not
accepting septage pump outs.
Increase nitrogen removal capability of the LCWRF, i.e. design the expanded
2.5 mgd LCWRF improvements to reduce concentration of the total nitrogen in
effluent at expanded flow so that annual total nitrogen discharge does not
exceed the allowable 21,400 lb. total nitrogen/year.
Example Calculation:
Existing permitted flow =1.9 mgd
Total nitrogen discharge allocation =3.7 mg/L
= 21,400 Ib/year
Proposed plant expansion permitted flow = 2.5 mgd
Total nitrogen discharge concentration at expanded flow:
21,400 lb TN/year
8.34 x 2.5 mgd x 365 day/year
(b) The Town of Clayton shall make every reasonable effort to minimize increases in
their nitrogen discharge using the following options:
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3.
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Total nitrogen discharge at estuary at exp. flow 14,079 Ib/yr
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70%Transport factor to estuary
118,264 Ib/yrTotal nitrogen discharge allocation at estuary
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Page 11Town of Clayton
Facility X:
Existing pennitted flow
Total nitrogen discharge allocation, end of pipe
Transport factor to estuary
Total nitrogen discharge allocation at estuary
Expanded permitted flow
Total nitrogen discharge at expanded flow
The Clayton LCWRF needs to obtain by transfer of 14,079 - 10,700 = 3,379
Ib/year additional estuary from facility X. In this situation the end of pipe total
nitrogen allocation of 3379/0.70 = 4827 Ib/year would be deducted from the
discharge permit of facility X and 3379/0.5 = 6758 Ib/year would be added to
the Clayton LCWRF discharge permit. It should be noted that this option
requires willingness of facility X to transfer the required total nitrogen
discharge allocation to the Clayton LCWRF for long-term at a mutually agreed
payment by Clayton LCWRF to Facility X.
15 mgd
3.7 mg/L
168,948 Ib/yr
1.9 mgd
3.7 mg/L
21,400 Ib/yr
50%
10,700 Ib/yr
2.5 mgd
3.7 mg/L
28,158 Ib/yr
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If the expanded 2.5 mgd LCWRF is designed and operated to achieve 2.81
mg/L total nitrogen on an annual average basis, no other requirements for
nitrogen controls would be imposed as a condition of the NPDES Permit for
LCRWF expansion to 2.5 mgd. The annual mass load of total nitrogen,
21,400 Ib/year, allowed by the permit would not change.
Obtain additional estuary allocations by transfer of estuary allocation(s) from
another discharger(s). A sample calculation for the Clayton LCWRF obtaining
the additional allocation from facility X is provided as follows:
Clayton LCWRF:
Existing permitted flow
Total nitrogen discharge allocation, end of pipe
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Total nitrogen annual mass discharge for expanded flow:
= 3.5 mg/L TN x 8.34 x 2.5 mgd x 365 day/yr = 26635.87 lb TN/year
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x 30 year x 200%
= $3,455,674
I Page 12Town of Clayton
(c) If the Town of Clayton does not meet the estuary allocation (10,700 lb TN/year) by
taking the measures described in items 2 (a) and 2 (b) above, then it may purchase a
portion of the nonpoint source load allocation for a period of 30 years at a rate 200
percent of the cost $11/lb to implement practices designed to offset the loading
created by the expanded facility. Payment for each 30-year portion of the nonpoint
source load allocation shall be made prior to the ensuing permit issuance. The intent
of the offset payment is to provide for construction of wetlands to reduce nonpoint
source nitrogen by an amount equal to the increase in point source discharge. For the
Clayton LCWRF expanded flow the offset payment is determined as follows:
(d) The expanded (2.5 mgd) Clayton LCWRF will be required to meet a total nitrogen
annual mass permit limit calculated using a concentration of 3.5 mg/L and maximum
monthly average flow limit in the NPDES Permit. The intent of this requirement is to
The nutrient offset payment for purchase of 5235.87 lb TN/year from nonpoint
source land allocation is estimated as follows:
= 26635.87 - 21,400
= 5235.87 lb TN/year
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Considering the Clayton LCWRF total nitrogen discharge allocation of 21,400 lb
TN/year, the required purchase from nonpoint source total nitrogen load allocation
is:
= 5235 lb TN/year x $ 11/lb
4. Join a group compliance association to collectively meet nutrient load
allocations. Stipulations for nitrogen control requirements for expansion of
individual dischargers will be included in the group compliance association
agreement with the Environmental Management Commission (EMC). Facilities
joining the group compliance association are not subject to individual limits but
will be responsible as a group for meeting their collective allocation. The Town
of Clayton has submitted a request to join the Lower Neuse Basin Association
(LNBA).
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= 3.5 mg/L TN x 8.34 x 2.5 mgd x 365 day/year
= 26635.87 lb TN/year
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Page 13Town of Clayton
(e) The expanded (2.5 mgd) Clayton LCWRF will be required to meet a monthly
average total phosphorus limit of 1.0 mg/L, beginning January 1, 2003, unless the
Town is a member in good standing of a group compliance association in which case
the Town will meet a quarterly average total phosphorus limit of 2 mg/L. Since the
Town has expressed its intent to join the Lower Neuse Basin Association (LNB A)
the Town will be required to meet a quarterly average total phosphorus limit of 2.0
mg/L.
establish a cap on the amount of total nitrogen discharge from the expanded
LCWRF. In order to comply with this requirement, the July 10, 2000 letter
concerning speculative limits also states that the design considerations must include
the ability to achieve annual load based on Total Nitrogen concentration of 3.5 mg/L
at 2.5 mgd regardless of the Town’s chosen route of compliance. The maximum
amount of total nitrogen discharge allowed from the LCWRF will be:
1
Considering the current total nitrogen discharge allocation of 21,400 Ib/year the
LCWRF can meet the increase in total nitrogen discharge of 26635.87-21,400 =
5235.87 Ib/year for expansion by using the following options: (1) purchasing
additional allocation of 5235.87 Ib/year and constructing and operating the LCWRF
improvements to limit its total nitrogen discharge to 26635.87 Ib/year, (2)
constructing and operating the LCWRF improvements to limit its nitrogen discharge
to its unexpanded allocation of 21,400 Ib/year (2.81 mg/L), and (3) combination of
reduced concentration of nitrogen discharge and purchase of additional allocation. In
case of the last option if the LCWRF improvements are constructed and operated to
achieve total nitrogen discharge concentration of 3.0 mg/L then the Town would be
required to purchase an additional total nitrogen discharge allocation of (3.0 mg/L x
8.34 x 2.5 mgd x 365) - 21,400 = 1430.75 lb TN/year.
(f) As per the rule, the director of Division of Water Quality may establish more
stringent limits for nitrogen or phosphorus upon finding that such limits are
necessary to protect water quality standards in localized areas.
4.0
4.1
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4.2
I 1.
2.
3.
4.
Page 14Town of Clayton
EVALUATION OF THE EXISTING FACILITIES FOR NUTRIENT
REMOVAL
Description of the Existing Facilities
The Town of Clayton operates a 1.9 mgd Little Creek Water Reclamation Facility
(LCWRF) which discharges its effluent into the nutrient sensitive Neuse River. The plant consist
of a mechanically cleaned bar screen, a manually cleaned bar screen (by-pass), pista (Vortex) type
grit removal system, 9-inch Parshall Flume for influent flow metering, influent wastewater
pumping, extended aeration Carrousel type oxidation ditches, secondary clarifiers, sludge
recirculation /waste pumping, magnesium hydroxide feed system for pH and alkalinity controls,
alum feed system for chemical phosphorus removal, polymer feed system for enhanced
clarification, tertiary shallow bed traveling bridge filters, UV disinfection, chlorination/
dechlorination facilities (back-up only), effluent pumping to Neuse River, aerobic sludge digestion
tank, polymer sludge conditioning and thickening by drum thickener, sludge storage tank, sludge
drying beds and sludge loading station for sludge disposal by land application. Detailed design
data of the LCWRF are given in Table 1. Exhibit 1 is a schematic flow diagram of the existing
LCWRF.
Description of the Proposed Improvements
The current proposed improvements for upgrading and rerating of LCWRF to 2.5 mgd are
described as follows:
Replacement of the three existing extended shaft centrifugal pumps with submersible
centrifugal pumps, each rated at 2,170 gpm. Provide variable frequency drive for
two of the pumps.
Improvement to the existing hydraulic split at influent pump station by addition of a
slide gate for diversion to the existing trickling filter plant influent pump station.
Improvements to the existing splitter box to the oxidation ditches by addition of weir
gates to allow control of flow split to each oxidation ditch.
Improvements to the oxidation ditches aeration capacities by: (1) replacement of one
of the 25 hp aerators in 0.75 MG oxidation ditch with a 50 hp aerator, (2)
5.
6.
Addition of one new 65 ft. diameter secondary clarifier.7.
8.>
9.
10.
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Page 15Town of Clayton
I
replacement of one of the 50 hp aerator in the 1.15 MG ditch with a 60 hp aerator,
and (3) replacement of the existing effluent weirs with adjustable weirs to control the
oxygen input in the oxidation ditches.
Improvements to the existing clarifiers hydraulics by the installation of Stanford
baffles in both the existing clarifiers and installation of an energy dissipation influent
well in the 65 ft. diameter clarifier.
Improvements to the existing polymer feed system by addition of one polymer feed
pump for reliability and providing additional polymer feed piping to the clarifier
splitter box for optimization of the clarifier’s performance.
Improvements to the sludge recirculation and waste pump station and piping by: (1)
replacement of the existing 600 gpm pump with a new 1750 gpm capacity pump and
(2) addition of one new 200 gpm pump for sludge wasting to either rotary thickener
or the aerobic digester with necessary piping modification.
Improvements to the existing clarifier splitter box by the addition of weir gates to
allow control of flow split to each clarifier.
Provide additional float controls in the tertiary filter backwash wetwell to allow
improved operation of the filter backwash waste pumps.
4.75
2.20I240
22
7
120
Effluent Limitations (NPDES Permit No. NC 0025453)
Effluent Parameter Effluent Limits, Monthly Average
Summer <0 Winter W
2
I (5)
Town of Clayton Page 16
(1)
(2)
(3)
(4)
Design Influent Wastewater Characteristics
Average daily flow
Maximum daily flow
Peak daily flow
BODs, (Biochemical Oxygen Demand, 5 day at 20° C), mg/L
TSS (Total Suspended Solids), mg/L
NHa-N (Ammonia Nitrogen as N), mg/L
Total Phosphorus as P, mg/L
Total Alkalinity as CaCOs, mg/L
April 1 through October 31
November 1 through March 31
The daily average dissolved oxygen effluent concentration shall not be less than 6.0 mg/L
Total residual chlorine is required only if chlorine is used as a disinfectant (or elsewhere in the
process)
The quarterly average for total phosphorus shall be the average of composite samples collected
weekly during the calendar quarter (January - March, April - June, July - September, October
- December)
TABLE I
DESIGN DATA OF THE EXISTING CLAYTON LCWRF
1.9
10
30
4
200
6
28
20
45
8
400
6
28
1.9
3.8
Flow, mgd
BODs, mg/L
TSR, mg/L
NHs as N, mg/L
Fecal Coliform, geom. mean #/100 mL
Dissolved Oxygen, mg/L
Total Residual Chlorine, ug/L
Total Nitrogen (NO2+NO3+TKN), mg/L
Total Phosphorus as P, mg/L
Chronic Toxicity
pH, Standard Units
2
Pass/Fail at 1.6%, quarterly
6-9 6-9
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Town of Clayton Page 17
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Grit Removal System
Number of units, Pista Vortex Type
Unit capacity, mgd
Grit chamber diameter, ft.
Grit chamber depth, ft.
Grit chamber volume, gal.
Grit hopper diameter, ft.
Grit hopper depth, ft.
Grit storage volume, cu. ft.
Propeller drive horsepower, hp
Grit pump capacity, gpm
Grit pump drive horsepower, hp
Electrical service
Accessories:
By-Pass Manual Bar Screen
Number of units
Unit capacity, mgd
Channel width, inch
Bar spacing, inch
Screen opening, inch
Method of cleaning
1
4
8
4
1,503
3
5
32
1
TABLE 1
DESIGN DATA OF THE EXISTING CLAYTON LCWRF
(Continued)
1
5.8
30
1
1
Manual
I
Mechanical Screen/By-Pass Manual Bar Screen
Mechanical Screen
Number of units. Water Link Helisieve type 1
Peak hydraulic unit capacity, mgd 5.8
Channel width, inch 30
Screen opening, inch 0.25
Drive horsepower, hp 2
Electrical service 460 Volt, 3 Phase, 60 Hertz
Accessories: level control and timer for operation of the screen, screenings container
460 Volt, 3 Phase, 60 Hertz
Screw classifier for grit dewatering and discharge to grit container, controls
with manual and time based operation of the grit pump and screw classifier.
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Organic loading.
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Page 18Town of Clayton
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Trickling Filter System (designed for avg. daily flow of 0.6 mgd)
Clarigester:
Number of clarigesters
Clarigester diameter, ft.
Clarigester, depth, ft.
Secondary Clarifier
Number of clarifiers, 30 ft. diam. x 7.25 ft. SWD
1
35
7.25
20.75
28
961.6
624
52.149
2.08
109.9
5,459
149,254
TABLE 1
DESIGN DATA OF THE EXISTING CLAYTON LCWRF
(Continued)
1
2,375
0.0545
252.63
505.26
11.0
22.0
3,030
69.5
100
Clarifier
Digester
Total
Clarifier surface area, sq. ft.
Clarifier surface overflow rate, gpd / sq. ft.
Clarifier volume, gal.
Hydraulic retention time for clarifier, hr.
Clarifier weir length, ft.
Weir overflow rate, gpd / lin. ft.
Digester volume, gal.
Parshall Flume for Influent Flow Measurement
Parshall Flume size (throat width), inch 9
Flume capacity, mgd 0.058 - 5.73
Accessories: Ultrasonic level sensor, flow transmitter, indicator, totalizer and recorder.
Trickling Filters
Number of trickling filters, 55 ft. diam. x 5’ media depth
Trickling filter area, sq. ft.
acre
Hydraulic loading, gpm/sq. ft. at 0% recirc. flow
at 100% recirc. flow
mgd/ac, at 0% recirc. flow
at 100% recirc. flow
lb BODs/day/ac-ft.
lb BODs/1000 cu. ft.
Recirculation, percent
Note: Organic loading assumes 25% BODs removal in clarigester.
=i
6
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Number of units:
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Town of Clayton Page 19
Influent Pumps
Number of 4-inch pumps, extended shaft centrifugal
Number of 6-inch pumps
Number of 4-inch pumps
Capacity, gpm, 6-inch pump, each
4-inch pump, each
Drive horsepower, hp, 6-inch pump, each
4-inch pump, each
2
2
2
Clarifier volume, gal.
Hydraulic retention time, hr. at avg. daily flow (0.6 mgd)
Clarifier surface area, sq. ft.
Surface overflow rate, gpd/sq. ft.
Weir overflow rate
38,313.5
1.53
706.5
94.2
6,369.4
1
1
1.90
24
2
2
150
78.95
3.5
525
4,000
25
0.8
TABLE 1
DESIGN DATA OF THE EXISTING CLAYTON LCWRF
(Continued)
60
40
480 volt, 3 phase, 60 hertz
0.75 MG capacity
1.15 MG capacity
Total volume, mil. gal
Hydraulic retention time, hr, at 1.9 mgd avg. daily flow
Number of 25 hp aerators in 0.75 MG tank
Number of 50 hp aerators in 1.15 MG tank
Total aeration horsepower, hp
Aeration horsepower capacity, hp/mil. gal.
Aeration capacity of the aerator, lb (h/hp/hr at stand, condition
Total aeration capacity, lb (h/hr
Operating MLSS concentration, mg/L
Sludge retention time, days
MLVSS/MLSS ratio
Electrical service
Accessories: Overload protection and automatic operation by level control system.
Note: In the proposed upgrade and rerating to 2.5 mgd, two of the 6-inch, 60 hp pumps
are replaced with dry pit submersible 75 hp pumps and one of the 4-inch, 40 hp pump
is replaced with 2,170 gpm, 75 hp, dry pit submersible pumps.
Aeration Tanks (Oxidation Ditches)
I
Clarifier volume, gal.
Drive horsepower, hp.
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Town of Clayton Page 20
Clarifiers
Number of clarifiers,
Total weir length, ft.
Weir overflow rate, gpd/lin. ft.
Solids loading rate, lb solids/sq. ft./day, including sludge recycle flow
600 gpm capacity
800 gpm capacity
1000 gpm capacity
600 gpm capacity pump
800 gpm capacity pump
1000 gpm capacity pump
55 ft. diam. x 12 ft. SWD
65 ft. diam. x 14 ft. SWD
55 ft. diam. clarifier
65 ft. diam. clarifier
3,486
13.72
0.0687
0.75
100
BODs loading, lb BODs/day
lb BODVIOOO cu. ft./day
F/M ratio, lb BODs/lb MLVSS/day
Net sludge yield, lb solids/lb BODs removal
Sludge recycle ratio, percent
1
1
213,146
347,317
5,690
334
172.7
204.1
376.8
5,042
22.27
TABLE 1
DESIGN DATA OF THE EXISTING CLAYTON LCWRF
(Continued)
1
1
1
10
15
20
480 volt, 3 phase, 60 hertz
Sludge Recirculation/Waste Pumps
Number of pumps,
Total surface area, sq. ft.
Surface overflow rate, gpd/sq. ft., at avg. daily flow
Clarifier weir length, ft., 55 ft. diam. clarifier
65 ft. diam. clarifier
Electrical Service
Accessories: Control panel for pumps operation and alarm condition.
Note: At present, sludge is wasted to aerobic sludge digester through sludge recirculation
line. In the proposal upgrading and rerating, the existing 600 gpm pump will be
replaced by 1750 gpm pumps with drive horsepower of 40 hp. Also, one new 200
gpm pump will be added for dedicated sludge wasting to either the rotary drum
thickener or the 90,000 gallon aerobic digester.
-1
Magnesium Hydroxide Feed System (For alkalinity and pH adjustment)
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Filter media:
f
Town of Clayton «1Page 21
Polymer Feed System (for flocculation and improved clarification)
Number of 1,250 gal. mix tank with mixer
Number of polymer solution transfer pump
Transfer pump capacity, gpm
Number of 500 gal. polymer solution storage tanks
Number of polymer feed pumps
Polymer feed pump capacity, gal/hr
Polymer blending system 0-24 gallon of neat polymer per day
Tertiary Filtration
Number of 6,000 gal. bulk storage tanks
Number of metering pumps
Metering pump capacity, gal/hr, each
Feed point
2
608.33
1,216.66
1.084
2.168
2.168
4.336
Alum Feed System (For chemical phosphorus removal and clarification)
Number of 7,500 gal. bulk storage tanks
Number of 500 gal. day tanks
Number of metering pumps
Metering pump capacity, gal/hr
Feed points
TABLE 1
DESIGN DATA OF THE EXISTING CLAYTON LCWRF
(Continued)
Material
Course Sand
Silica Sand
Anthracite
Effective Size
0.80 to 1.20 mm
0.55 to 0.65 mm
1.00 to 1.10 mm
1
1
2
0-20
Aeration Tanks
1
1
25
3
1
20
1
2
0-20
Aeration Tanks
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Number of filters (48’-8” x 12’-6”, each) DAVCO traveling bridge type
Filter area, sq. ft., each
Total filter area, sq. ft.
Filtration rate, gpm/sq. ft., at avg. daily flow - both filters online
one filter online
at max. daily flow - both filters online
one filter online
Depth
9 inches
5 inches
6 inches
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Accessories:
Page 22Town of Clayton
Chlorination (Back-up Only)
Chlorine Contact Tank
Number of tanks
Tank volume, each
Total volume, gal
Hydraulic retention time at avg. daily flow
Chlorine Feed System
Number of chlorinators
Chlorinator capacity, lb C12/day, each
Number of 150 lb. cylinders
Dechlorination System (Back-up only)
Number of sulfonator
Sulfonator capacity, lb S02/day, each
Number of 150 lb. sulfur dioxide gas cylinder
Effluent Pump Station
Number of pumps
Pump capacity, gpm, each at 158 ft. TDH
Drive horsepower, hp, for each pump
Electrical service
2
39,000
78,000
59
1
2
13
8
104
7
2
100
2
2
50
2
TABLE 1
DESIGN DATA OF THE EXISTING CLAYTON LCWRF
(Continued)
3
1,650
100
480 volt, 3 phase, 60 hertz
Accessories: level control system for pump’s operation and alarms.
Filter backwash pumps, traveling bridges, controls, and filter backwash waste
recycle pumps.
UV Disinfection
Number of UV channel, 3’-3” x 2’ - 0” SWD
Number of UV banks
Number of UV modules per bank
Number of lamps per UV module
Total number of UV lamps
Hydraulic retention time, seconds, at avg. daily flow
Accessories: Control and instrumentation panel, automatic level controller
and portable cleaning tank.
Town of Clayton Page 23
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Sludge Loading Station (for disposal of sludge by land application)
Number of sludge loading pumps
Pump capacity, gpm, at 32 ft. TDH
Sludge Drying Beds
Number of sludge drying beds, 97’ x 20’, each
Bed area, sq. ft., each
Total bed area, sq. ft.
Aerobic Sludge Digester/Holding Tank
Number of sludge holding tanks 71’-6” diam. x 12 ft. SWD
Tank capacity, gal.
Number of 30 hp floating mixers
Number of aeration blowers
Blower capacity, SCFM
Drive horsepower for blower, hp
Aerobic Sludge Digester
Number of sludge digestion tanks, 35’ - 8” diam. x 12 ft. SWD
Digester volume, gal.
Number of 5 hp mixers
Number of aeration blowers
Blower capacity, SCFM
Drive horsepower for blower, hp
9
1,940
17,460
1
360,000
1
1
1,100
60
1
90,000
1
1
220
15
1
800
TABLE 1
DESIGN DATA OF THE EXISTING CLAYTON LCWRF
(Continued)
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^2
1
Sludge Thickener (Parkson drum type)
Number of thickeners 1
Thickener capacity, gpm, at 0.7 to 1.0 percent feed solids 75 to 95
Thickened solids concentration, percent 3.5 to 5.0
Accessories: polymer feed system, flocculation tank, washwater supply and controls.
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D.B.
r
r
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Filter Backwash
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P.S.P.S.
Drain
Sludge Recirc.
T.F.P.S.
I II
Decant
*
*T_ !
P.S.
To Neuse
Eff. Pump Sta.
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'-o'
P.S
Clerigester
Exhibit 1
Schematic Flow Diagram of Clayton LCWRF
Trickling
Filter
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Chem Feed
& Sludoe
Waste
Sludge
Clarifier
No. 1
Clarifier
No. 2^
UV Disinf /
Chlorination -
Dechlorination
Ox. Basin No. 1
Ox. Basin No. 2
•n
I Sludge
Drying Beds
"l
Legend
----------Wastewater / Effluent
----------Sludge
----------Decant / Filter Backwash / Bed Underdrainage
----------Scum
/ Influent
Pump Sta.
| Chemical
: Stor. Area
Sludge
Holding Tank
Secondary
Clarifier
Screening *
& Grit Rem.
Sludge
Loading
Sta.
i Aerobic
: Digester'
Tertiary
/k Filters
Sludge
Drying Beds
y-Clar. Dist. Box
JL. /_
rd S
P.S.
o
Evaluation of the Existing Facilities for Nutrient Removal4.3
I
wastewater characteristics that are of importance in design and operation of a BNR system include:
the NPDES Permit limits.
I
Page 25Town of Clayton
the monitoring reports covering the period from January 1999 through February 2000, were
reviewed to evaluate the influent wastewater characteristics for biological nutrient removal and
pH, temperature, BODs, COD, TSS, TKN, NHa-N, Total P, Alkalinity, COD/ BODs ratio,
BODs/P ratio, COD/P ratio, and BODs/TKN ratio. Operating data (Tables 2 and 3), as reported in
establishment of design influent wastewater characteristics for design and evaluation of nutrient
removal alternatives. The overall plant performance is also evaluated in terms of compliance with
The performance of a biological nutrient removal (BNR) system is greatly affected by the
characteristics of the wastewater to each zone (anaerobic, anoxic, aerobic) of the BNR system. The
pH: Referring to Table 2, the average influent pH during the period ranged from 6.70 to
7.09 S.U. and averaged 6.93 S.U. The wastewater pH plays an important role in growth rates of
Poly-P bacteria, nitrifiers and the floc forming bacteria that significantly affect the performance of a
BNR system. The recommended operating pH range of a BNR system is 6.5 to 8.5 S.U. The
optimum pH values for biological phosphorus removal is in the range of 6.5 to 7.0. The optimum
pH values for nitrification and denitrification processes are 8.4 and 7.3, respectively. Since the
nitrification process destroys about 7.14 mg/L alkalinity per each mg/L ammonia nitrogen nitrified,
the mixed liquor pH in the aeration tank will be lowered if sufficient alkalinity is not available in the
influent wastewater. Operation records of the activated sludge system indicates that the mixed
liquor pH has dropped below 7.0 and at times to 6.0 when sufficient alkalinity levels were not
maintained. It should be noted that below pH of 6.5 the phosphorus uptake rate in biological
phosphorus removal system will progressively decline due to the fact that the growth rate of Poly-
P bacteria will steadily decline as the pH drops below 6.5 and will cease at pH below 6.0.
Considering that low pH levels significantly affect Poly-P bacteria, nitrifier and floc formers
growth rate and subsequent performance of the biological phosphorus and nitrogen removal
1 . Wastewater Characteristics and Overall Plant Performance
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Town of Clayton Page 26
BODs: Average monthly influent BODs concentrations during the period ranged from 128
mg/L to 271 mg/L and averaged 228 mg/L. Design influent BODs concentration for the existing
plant is 220 mg/L. Referring to Table 2, the reported maximum month (July 1999) average BODs
is 271 mg/L and the influent BODs values exceeded the design value of 220 mg/L in the months of
March, May, June, July, August, November and December of 1999 and January and February of
2000. This indicates that approximately 64 percent of the time during the period, the influent BODs
concentrations at the plant exceeded its design value. The increase in the influent BODs
concentration at the plant may be attributed to the Town’s continuing efforts of reducing
infiltration/inflow in the sewer system, installation of new collection lines to accommodate the
residential, commercial and industrial growth, water conservation efforts and industrial waste
discharges with higher BODs concentration. Considering the existing influent BODs
concentrations, the Town’s continuing efforts of reducing the I/I in the sewer system, allowance
process, a design influent and mixed liquor pH value of 6.8 will be used for evaluation of
biological nutrient removal alternatives.
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The average effluent pH values during the period ranged from 6.8 to 7.27 and averaged
7.09. The effluent discharge limitations on pH, as given in the NPDES Permit, are 6.0 to 9.0. This
indicates that the plant is within its permit limits on pH.
Temperature: The average influent temperatures during the period ranged from 13.71° C
to 35.38° C and averaged 21.10° C. The design aeration tank (oxidation ditch) mixed liquor
minimum and maximum temperatures are 15° C and 28° C, respectively. The average effluent
temperatures during the period ranged from 11.33’ C to 27.41’ C and averaged 18.56’ C. The low
effluent temperatures are the result of the enhanced heat loss from wastewater to the ambient
environment, induced by surface aerators in the oxidation ditches and subsequent downstream
treatment units. Since the wastewater temperature significantly affects the design and performance
of the BNR system, more particularly nitrification and denitrification processes and aeration system
design, a minimum temperature of 12° C and maximum temperature of 28° C will be used for
design and evaluation of BNR alternatives.
I
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~pS^7r
&^8lltkos,r^ i^S .‘iF^PbWermT
WLrl W
fimtte § <?rfe£$il arl‘nef^te $W?cm??M ^percenPan?’
SP<^^^^^t[bffRcRW^^>?^2u?rS<p^
tfSf iS^irApfyii^XvJWS^ percenPfie 'F^rerhoval require§iehL°r
summe^2&9^^^¥K$»
TJ'^tS^eSausT'iEe^ffPSl conSnfra?icjneoA'?i^>sarnet
SBPfe5e’^X^61^^%W^®^ii{|^P^ipe£$vi3y s WJt^m&lJrS’comjme or^affi'Sitrogen5
ffiFSRliKSffi^ on the design influent TKN is available except for the
influent^ffl^^8fld^folteJWt^1.69SgMt^?onii^nhg1?lie^infR]e?P?l3^1coricen?ra?ions}e
J^ftASr^Pe^^tJS^e^foi^Fi^g^froiiPfijb ’rPres^Riaf^cornmercVal ^i®e
fitoit^ lh-p%Rici^c^8I?¥iy^sv^?fmT,s}u&gerl^fcSemng,ra^Tobic sfu^gelSgesdon^ii?11
99 ^^e^Arnplfanc^wiS? i?er ann’iSD ^^SV^Sro^enOJisc6§ge^
Wf fW£ W9F,e9 trW WS^IPati^ w&i Wr Kd
^^Aa^i^gPffia MWn’ffMWate Wr^e^lhFy^effiPnfTO?1
(?’8RS^fltfe?I9iS1dlftiB^<tfi9tiJ8r?(9d%SfSf?Jo^R <toSrn^L^to'^C^mg5t and averaged 3.0 mg/L.
There i^e^Y^tRN^t
di^iffl S^Vhe^SnugerS^fiscliirge iiimtation^n'
M(^^iI9^^¥i?1tJffi^t^Jlabililt? WtRe o?^enSSiut!-ogen con failed in d
dt^^Sfly^AteT.^ey^^ ffif ^^f^tilJlf cflS’^^ea^&Pfn3il9tS^{kt fte1 a verag^organiPm&oger/ ’
8P^°r^ » TpWS^Wy1^ |ra^nWp5ePcTntnt
i^^tef^5.^fi^§v^^&Mii^c/it^K1,ni?&^i?88^2yi?tt?fi?8nacl4rni^diet per%^a^ge’d^oVfin
3Ftfie>efffuentUqu<aliPy of most6
IM®
SW W^a^IlJil!11
TSS concentrations during the period ranged from 2.00 mg/L to 17.71 mg/L and averaged 5.51I
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Page 29Town of Clayton
Average monthly TKN removals at the plant ranged from 51.69 percent to 96.71 percent and
averaged 84.37 percent.
NHa-N: Average monthly Nhh-N concentrations during the period ranged from 11.97
mg/L to 22.06 mg/L and averaged 17.84 mg/L. The design influent NHs-N concentration is 22.0
mg/L. Typical average NHs-N concentration in domestic wastewater is 25.0 mg/L. Considering
the allowance for increase in ammonia nitrogen loading from future residential, commercial and
industrial growth and in-plant recycle flows and compliance with the stringent discharge limitation
on NHa-N and total nitrogen, a design influent NHs-N concentration of 25 mg/L will be
considered for design and evaluation of BNR alternatives. Average monthly effluent concentrations
during the period ranged from 0.50 mg/L to 4.65 mg/L and averaged 1.98 mg/L. The effluent
NH4-N limitations for summer and winter months, as given in the NPDES Permit, are 4.0 mg/L
and 8.0 mg/L, respectively. This indicates that the plant has had no problems in complying with
the discharge limitation on NHs-N. Average monthly NHa-N removals ranged from 70.19 percent
to 97.52 percent and averaged 88.74 percent. This indicates that the plant is capable of nitrifying
and excellent NHa-N removal can be achieved at the plant.
Total P: Average monthly TP concentrations during the period ranged from 4.74 mg/L to
8.71 mg/L and averaged 6.58 mg/L. No design influent TP value is available. Considering the
influent TP concentrations at the plant and providing an allowance for increase in total phosphorus
loading from future residential, commercial and industrial growth and in-plant recycle flows and to
ensure compliance with the effluent limits on TP (1.0 mg/L), a design influent TP concentration of
8.0 mg/L is considered for design and evaluation of nutrient removal alternatives. Average monthly
effluent TP concentrations during the period ranged from 0.40 mg/L to 3.24 mg/L, and averaged
1.33 mg/L. The NPDES permit requires compliance with the effluent TP limit of 2.0 mg/L on a
quarterly average basis. The plant has had no problem in compliance with the effluent TP limit.
Average monthly TP removals at the plant ranged from 75.19 percent to 92.45 percent and
averaged 80.72 percent. This indicates excellent TP removals at the plant.
ITotal Alkalinity: Limited monitoring data are available on influent alkalinity, secondary
clarifier alkalinity and the plant effluent alkalinity. Review of the Total Alkalinity monitoring data
(refer to Appendix 3) from the period covering April 24, 2000 through May 4, 2000 indicates that
the influent Total Alkalinity at the plant ranged from 90 mg/L to 180 mg/L and averaged 136 mg/L.
Design influent Total Alkalinity is 120 mg/L. Availability of Total Alkalinity is an important factor
in biological nitrification process and maintaining a quality of biomass in an activated sludge
system that has good settling characteristics. In nitrification, approximately 7.14 mg/L Total
Alkalinity is required for each 1.0 mg/L NHa-N nitrified. If sufficient Total Alkalinity is not
available in the influent wastewater, then it will limit the nitrification process which may result in
higher concentration of NHj-N in effluent and subsequent non-compliance with the effluent NHa-
N and TN limit in the NPDES permit. Also, if sufficient alkalinity is not available in the influent
N, TN and pH limits. Considering the limited Total Alkalinity monitoring data, a design influent
Total Alkalinity of 130 mg/L will be considered for design and evaluation of BNR alternatives. The
secondary clarifier effluent Total Alkalinity during the period ranged from 20 mg/L to 45 mg/L and
averaged 31.43 mg/L. In order to ensure that sufficient Total Alkalinity is available for biological
that the plant effluent has higher values of Total Alkalinity when compared with the secondary Iclarifier effluent. The increase in the plant effluent alkalinity could be attributed to partial
denitrification occurring in the secondary clarifiers.ICOD/BODs Ratio: Limited monitoring data on influent and effluent COD are available.
Town of Clayton Page 30
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Review of the available monitoring data on COD/BODs indicates that the ratios ranged from 1.022
to 3.680 and averaged 1.917. The reported higher ratio of 3.680 seems to be significantly high and
nitrification and to maintain a mixed liquor pH of 6.5, and more preferably to 6.8 for efficient
operation of a BNR system, it is suggested that the Total Alkalinity in the secondary clarifier
effluent should be maintained in the range of 50 mg/L to 75 mg/L. The plant effluent Total
Alkalinity during the period ranged from 25 mg/L to 50 mg/L and averaged 35 mg/L. It is noticed
wastewater, then due to nitrification the pH in the mixed liquor may drop to a point that may impact
the overall performance of the treatment system in terms of compliance with the effluent TP, NHs-
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Page 31Town of Clayton
could be associated with either discharge of unexpected abnormal industrial waste containing high
COD value or higher value of influent COD due to possible interference with reduced inorganic
species such as iron, manganous, manganese, and sulfide that are normally found in septic
wastewater. Typical COD/BODs ratios in municipal wastewater are in the range of 1.5 to 2.0. The
COD/BODs ratio is an important factor in design of anaerobic selector tanks for biological
phosphorus removal. Higher COD/BODs ratio for examples greater than 2.0 indicate that the
wastewater may need more anaerobic hydraulic retention time for fermentation and maintaining
higher anaerobic biomass fraction to maximize biological phosphorus removal. A COD/BODs ratio
of 2.0 will be used for design and evaluation of BNR alternatives.
BODs/TP Ratio: The average influent BODs/TP ratios during the period ranged from
24.23 to 53.17 and averaged 35.57. The BODs/TP ratio is very important in design and successful
operation of a biological phosphorus removal plant. In order to achieve an effluent TP
concentration of 1.0 mg/L or less the influent BODs/TP ratio should be in the range of 20 to 35,
depending upon the operating and design SRT (Sludge Retention Time) of the system. The system
operated at higher SRT requires a higher BODs/TP ratio to produce effluent TP concentrations of
1.0 mg/L or less. A system such as Clayton LCWRF operated at a higher SRT may require the
BODs/TP in the range of 30 to 40 for biological phosphorus removal. It should be noted that to
maximize biological phosphorus removal, systems that are designed for biological nutrient removal
should not be operated with SRT values in excess of that required for overall treatment needs.
COD/TP Ratio: The average influent COD/TP ratios during the period (April 24 - May 4,
2000) ranged from 32.70 to 98.71 and averaged 56.58. In a biological phosphorus removal plant
treating municipal wastewater, approximately 40 to 60 mg/L COD is consumed per mg/L of
phosphorus removed. It has been reported that in order to achieve an effluent TP concentration of
1.0 mg/L or less, the influent COD/TP ratio should be greater than 40. For systems operating at
higher SRTs, the ratio would be higher. If the influent COD/TP ratio is less than 40, then it may be
difficult to achieve effluent TP concentrations of 1.0 mg/L or less. If the required effluent TP
concentration cannot be obtained by biological phosphorus removal with the process influent
I
COD/TP or BODs/TP ratios, then either pre fermentation to supplement the influent SCVFAs (Short
Chain Volatile Fatty Acids) or effluent polishing by chemical precipitation of phosphorus will be
necessary. In cases where the influent COD/TP ratio is considerably higher than 40 whereas
BODs/TP ratio is considerably lower than 20, then it indicates that the wastewater has not
undergone substantial fermentation and the anaerobic selector tank will have to be designed for
higher hydraulic retention time to accomplish the desired level of fermentation to generate SCVFAs
that are essential for biological phosphorus removal. Considering the low influent COD/BODs
ratios at Clayton LCWRF, the reported COD/TP ratios should be adequate to accomplish biological
phosphorus removal at the plant. It should be noted that in order to maintain desired COD/TP or
BODs/TP ratios for phosphorus removal, the sludge handling operations will have to be optimized
to reduce the phosphorus content in the recycle flows such as filtrate from rotary drum thickener
and supernatant withdrawal from aerobic sludge stabilization/storage tanks.
BODs/TKN Ratio: Average influent BODs/TKN ratios during the period ranged from
I5.82 to 14.46 and averaged 8.62. Typical influent BODs/TKN ratios in municipal wastewater is in
the range of 5.0 to 8.5. The influent BODs/TKN ratios are important to make sure that sufficient
Icarbon source (BODs) is available for floc forming biomass growth and biological denitrification.
As per the stoichiometry of biological nutrient removal in municipal wastewater, 5.8 mg/L BODs is
needed to reduce 1.0 mg/L nitrate nitrogen to nitrogen gas. This indicates that a large fraction of
influent BODs will be required to remove nitrate nitrogen by denitrification. At low BODs/TKN
ratios, the denitrification will be limited to the available BODs for carbon source and greater
reliance on supplemental carbon addition (methanol feed) or endogenous respiration is necessary to
optimize the denitrification process.
Town of Clayton Page 32
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TABLE - 2
LITTLE CREEK WATER RECLAMATION FACILITY PERFORMANCE DATA
Eff.Eff.Inf.Inf.Eff.Inf.Eff.Inf.Eff.Inf.
96.69166.90 5.5392.999.00128.4012.5315.476.96 7.27Jan. 1999 1.33
188.40 7.70 95.9193.97218.90 13.2016.79 14.157.217.03Feb. 1999 1.25
81.7094.26 280 51207.40 11.9096.966.78222.7013.7416.007.196.97Mar. 1999 1.27
17.71 91.9897.20 220.906.10218.0019.00 17.557.187.08Apr. 1999 1.23
5.33 97.9598.37 259.90251.60 4.1121.0521.707.247.091.13May 1999
<25 89.5898.98 240223.20 2.2798.24234.80 4.1425.29 24.917.151.13 6.99Jun. 1999
99.192.2997.87 283.605.76271.0026.1026.627.246.941.12Jul. 1999
99.18275.80 2.2797.92259.70 5.4127.86 27.416.92 7.141.20Aug. 1999
<253.52 98.29 69097.87 205.80187.40 4.2135.38 24.206.806.70Sep. 1999 1.89
98.063.6798.66 189.302.70201.2020.5223.056.886.821.64Oct. 1999
2.00 99.1998.42 247.604.05256.2018.6321.536.956.87Nov. 1999 1.39
94.442.25 98.97 450 <2598.58 218.903.75263.2015.2018.107.056.87Dec. 1999 1.25
7.30 97.0197.69 243.805.39' 232.9012.4514.956.976.941.32Jan. 2000
98.33204.80 3.4397.23246.20 6.8111.3313.717.046.77Feb. 2000 1.70
90.5231.5224.02 5.51 97.43 41597.275.82228.0118.5621.107.096.931.35Averages
96.37 |
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TABLE - 3
LITTLE CREEK WATER RECLAMATION FACILITY PERFORMANCE DATA
c
Inf.Inf.Eff.Inf.Eff.Eff.Eff.Inf.Inf.Eff.
5.30 0.40 5.84 24.230.50 22.40 5.23 76.65 92.4577.36 17.83 3.81 78.63 0.44Jan. 1999 22.00 4.98
69.14 91.35 46.180.16 0.90 29.10 8.98 4.74 0.41 7.55Feb. 1999 29.00 72.14 19.27 4.45 76.918.08
34.4249.55 6.47 1.09 83.15 14.463.97 78.96 0.05 0.40 15.58 7.8651.69 18.87Mar. 1999 15.40 7.44
37.5935.30 6.29 82.18 5.80 1.93 66.72 167.69*20.90 2.99 85.69 34.00 3.51Apr. 1999 1.30*2.88 121.54
5.76 8.45 3.14 62.84 7.19 29.781.43 92.56 0.50 4.70 35.50 83.77May 1999 96.34 19.2235.00 1.28
31.9928.05 4.39 84.35 7.34 1.15 84.33 8.391.07 94.95 0.05 2.70Jun. 1999 93.79 21.1728.00 1.74
33.7987.78 8.02 1.99 75.19 11.780.50 96.95 0.05 1.90 23.00 2.8195.83 16.40Jul. 1999 23.00 0.96
3.29 34.29 6.51 1.05 83.87 108.21*39.890.75 95.47 0.05 2.40 2.45*16.56Aug. 1999 2.40*0.94 60.83
6.99 8.92 26.819.74 53.62 0.67 90.411.40 88.30 0.05 7.63 21.0011.97Sep. 1999 21.00 89.902.12
95.43 7.21 74.70 5.00 76.00 7.06 40.240.05 6.10 28.50 1.2015.33 0.70Oct. 1999 96.6028.50 0.97
69.2632.20 5.25 83.70 7.71 2.37 9.15 33.2320.13 0.50 97.52 4.20 3.85Nov. 1999 95.0028.00 1.40
90.01 8.71 30.222.37 35.25 3.52 1.92 77.96 7.5222.06 0.60 97.28 0.45Dec. 1999 35.00 96.711.15
3.52 91.21 6.40 0.69 89.22 5.82 36.390.93 0.05 2.08 40.0514.41 93.55Jan. 2000 40.00 95.131.95
7.07 72.13 4.63 0.59 87.26 9.85 53.170.37 0.97 25.3715.60 4.65 70.1975.60Feb. 2000 25.00 6.10
73.79 1.33 80.72 8.62**35.5728.56 5.78 6.582.89 2.8617.84 1.98 88.7487.033.0027.49
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Averages
** The TKN/BOD values for the months of April and August 1999 are deleted in estimating average because of questionable TKN values reported in the respective months.
♦ Values deleted from discussion because of questionable TKN values reported in the respective months.
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Page 35Town of Clayton
Evaluation of the Existing Facilities for Nutrient Removal
A. Phosphorus Removal
Phosphorus removal in a wastewater treatment plant involves conversion of
phosphorous to a particulate form and removed as a particulate by sedimentation, filtration and
other solids removal processes. Biological phosphorus removal and chemical phosphorus removal
are the two most widely used processes for phosphorus removal in a wastewater treatment system.
In biological phosphorus removal process, either phosphorus is taken up as nutrient requirement
for normal microbial growth or under certain conditions phosphorus is taken up in access of the
nutritional requirement for microbial growth. The latter is referred to as enhanced biological
phosphorus removal. Typically biomass in an activated sludge system contains 1.5 to 2.5 percent
phosphorus, based on dry weight basis using volatile solids. The biomass in an activated sludge
system, using enhanced biological phosphorus removal process, contains 6.0 to 8.0 percent
phosphorus. The phosphorus removal efficiency of a biological system depends on the
phosphorus content of the sludge removed and the efficiency of the solids separation facilities. In
chemical phosphorus removal, phosphorus is first converted into particulate chemical species by
addition of metal salts, specifically aluminum and iron salts, and lime and later removed by
flocculation and solids removal by sedimentation, filtration, and other processes. The efficiency of
chemical phosphorus removal process is dependent upon the chemical equilibrium between the
phosphorus liquid and solid phases and the efficiency of solids removal processes. Phosphorus
levels of less than 0.1 mg/L P can be achieved by chemical addition and well designed filtration
facilities.
The existing facilities at the Clayton LCWRF were evaluated for biological and chemical
phosphorus removal, using the plant operation data (Table 2) and Nitrogen Study data (See
Appendix 2) collected during the period from April 24, 2000 through May 4, 2000. Review of the
operation data indicate that the effluent Total P concentration at the plant ranged from 0.40 to 3.14
mg/L and averaged 1.33 mg/L. The plant did not have compliance problems with the 2.0 mg/L
quarterly effluent Total Phosphorus limit. The percent TP removal ranged from 75.19 to 92.45
percent and averaged 80.72 percent. It should be noted that alum was added for phosphorus
removal. Review of the effluent Total Phosphorus concentrations during the nitrogen study Iindicate that the effluent TP concentrations raised from 2.21 to 2.90 mg/L and averaged 2.77
mg/L. The percent TP removal ranged from 55.91 to 69.80 percent and averaged 61.39 percent.
The low TP removals during the nitrogen study could be attributed to no alum feed during the
nitrogen study, lack of desired environment available for growth of phosphorus removing
microorganisms, and possible phosphorus release through cells lying in the system oxidation
ditches during the endogenous operation phase. For efficient phosphorus removal, it is essential to
have anaerobic selector zone requiring absence of dissolved oxygen and nitrate for production and
availability of adequate fermentation products (volatile fatty acids) to give competitive growth
advantage to phosphorus removing microorganisms when compared to the normally occurring
microorganisms in activated sludge systems. The phosphorus removing microorganisms are
relatively slow growing bacteria and prefer simple carbohydrate substrate for their growth and
Itherefore, without anaerobic phase, they may not be present at significant level in the Clayton
oxidation ditch type activated sludge system. Accordingly, in conjunction with the existing
oxidation ditches, external anaerobic selector tanks will be required for efficient biological
phosphorus removal. Provision of external anaerobic selector tanks would also eliminate or reduce
the chemical dependency for phosphorus removals at the plant.
B. Nitrogen Removal
The Clayton LCWRF includes 1.9 mgd Carrousel type oxidation system which is
primarily designed to achieve effluent BODs and NHa-N concentrations of 10 mg/L and 4 mg/L. In
an oxidation ditch system the amount of total nitrogen removal is a function of aeration capacity.
channel configuration and aerator placement, DO concentration leaving the aerator, channel
velocity, BODs and nitrogen loading, system sludge retention time, mixed liquor suspended solids,
pH, and temperatures. The level of nitrogen removal will depend upon maintaining DO
Iconcentration between 0.1 and 0.5 mg/L and the type of organic nitrogen, i.e. biodegradable or
non-biodegradable (refractory), content in the wastewater. Generally without the DO and aeration
Town of Clayton Page 36
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Page 37Town of Clayton
control system, more operator attention is needed to carry out DO control to maximize nitrogen
removal. In oxidation ditches maintenance of low DO in a channel zone downstream of the aeration
zone promotes depletion of DO with the sludge floc which provides anoxic conditions necessary
for denitrification. However, it should be noted that when the aeration is reduced too far to
maximize denitrification, sufficient aeration volume for maximum nitrification may not exist in the
system and would result into higher ammonia concentration in the effluent.
The plant operation data (Tables 2 and 3) and the Nitrogen study data (See Appendix 2)
were evaluated for total nitrogen removal at the plant. Review of the plant operation data indicate
that the influent Total Nitrogen at the plant ranged from 15.58 to 40.05 mg/L and averaged 28.56
mg/L. The effluent Total Nitrogen ranged from 3.52 to 9.74 mg/L and averaged 5.78 mg/L.
Considering the annual average daily flow of 1.35 mgd and annual average effluent Total Nitrogen
concentration of 5.78 mg/L, the annual Total Nitrogen discharge in the effluent is estimated to be
23,753 Ib/year which is more than the allocated Total Nitrogen discharge of 21,400 Ib/year. The
percent Total Nitrogen removal at the plant ranged from 49.55 to 91.21 percent and averaged
73.79 percent. Considering the fact that biodegradability of the organic nitrogen present in
wastewater plays an important role in terms of compliance with the effluent limitation on Total
Nitrogen, the effluent organic nitrogen data were reviewed which indicated that the organic
nitrogen in the effluent ranged from 0.19 to 3.63 mg/L and averaged 1.2 mg/L. The reported
higher effluent organic nitrogen concentration in some instances may be attributed to partial
mineralization of the organic nitrogen either due to inadequate aeration, low system pH, or lower
sludge retention time in the system. The majority of the influent organic nitrogen at the plant is
biodegradable and the plant is capable of achieving the average effluent organic nitrogen of 1.0 to
1.2 mg/L which is in the typical range of effluent organic nitrogen of 1.0 to 1.25 mg/L in BNR
plants treating municipal wastewater.
The plant performance data gathered during the Nitrogen Study indicated that the influent
Total Nitrogen concentration at the plant ranged from 32.42 to 51.22 mg/L and averaged 42.33
mg/L. The effluent Total Nitrogen ranged from 12.23 to 16.98 mg/L and averaged 15.24 mg/L.
The percent Total Nitrogen removal ranged from 61.08 to 68.57 percent and averaged 65.16
percent. The effluent NCh/NCh concentrations ranged from 11.4 to 15.80 mg/L and averaged
14.20. The effluent TKN concentrations ranged from 0.83 to 1.48 mg/L and averaged 1.04 mg/L.
The effluent NHa-N concentrations were <0.5 mg/L. Considering the make-up of the effluent Total
Nitrogen, the NCh/NCh constitutes a major portion of the effluent Total Nitrogen. During the study
the operating average MLSS, MLVSS, F/M and SRT were 3,443 mg/L, 2,602 mg/L, 0.0622 lb
BODs/MLVSS/day, and 19 days, respectively. During the study the total nitrogen removal was
reported less than the nitrogen removal reported in the plant monitoring data. The possible
explanation for lower total nitrogen removal during the study would be the higher influent total
nitrogen concentrations, very low F/M loading to the system and difficulty of maintaining low DO
zones for denitrification in the system.
A theoretical evaluation of the existing Carrousel system for the Total Nitrogen removal at Ithe current (1.5 mgd) and design (2.5 mgd) operating conditions revealed that at current operating
conditions the system is capable of producing effluent NOs concentrations of approximately 9.71 Img/L. Considering effluent organic nitrogen and ammonia nitrogen concentrations of 1.0 mg/L and
0.5 mg/L, respectively, the system is capable of producing effluent TN concentrations of 11.21
mg/L. At the design operating conditions the system is capable of producing effluent NCh
concentrations of 33.39 mg/L. Considering effluent organic nitrogen and ammonia nitrogen
concentrations of 1.0 mg/L and 0.5 mg/L, respectively, the system is capable of producing effluent
TN concentrations of 34.89 mg/L. For details, refer to Evaluation of the Existing Carrousel
System for Nitrogen Removal, given in Appendix 2. The anticipated total nitrogen discharges at
the current and design operating conditions are 51,186.5 lb TN/year and 265,521.6 lb TN/year
which are significantly higher than the allocated total nitrogen discharge of 21,400 lb TN/year.
Accordingly, to comply with the total nitrogen discharge requirements, the rerated 2.5 mgd plant
should be provided with adequate biological nitrogen removal facilities such as first stage anoxic
Itanks, nitrate recycle, second stage anoxic tanks followed by reaeration and tertiary filtration or
Tetra denite filters with a methanol feed system as a substitute for second stage anoxic tanks and
Town of Clayton Page 38
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reaeration tanks. In operation of the second stage anoxic tanks more operation attention will be
required to ensure that no anaerobic conditions are created to prevent secondary release of
phosphorus.
DESIGN BASIS5.0
Wastewater Flows and Characteristics5.1
Considering the Town of Clayton’s request to the N.C. Division of Water Quality for
expansion (hydraulic rerating) of the existing wastewater treatment plant (LCWRF) to 2.5 mgd and
review and evaluation of the wastewater characteristics as described in Section 4.3.1 of this report.
the following wastewater flows and characteristics were developed for evaluation of the nutrient
removal alternatives to select the most cost-effective solution for compliance with the discharge
limitations and nutrient removal requirements.
5.2 Effluent Limitation and Nutrient Removal Requirements
On July 10, 2000 the N.C. Division of Water Quality has issued the speculative effluent
limits, including nutrient removal requirements, for the proposed expansion (hydraulic rerating to
2.5 mgd) of the Clayton LCWRF. These speculative effluent limits, including the nutrient removal
requirements are summarized in Section 3.0 of this report.
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Town of Clayton Page 40
Average daily flow, mgd
Maximum daily flow, mgd
Peak daily flow, mgd
BODs, mg/L
TSS, mg/L
TKN, mg/L
NH3-N, mg/L
Total Phosphorus as P, mg/L
Total Alkalinity as CaCOs, mg/L
pH, standard units
Temperature, ° C
= 2.5
= 5.0
= 6.25
= 250
= 250
= 40
= 25
= 8
= 130
= 6.8 - 7.0
Winter = 12; Summer = 28
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NUTRIENT REMOVAL ALTERNATIVES6.0
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Make maximum use of the existing facilities.2.
3.
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State/EPA reliability criteria must be met at reasonable costs.
Construction of the treatment units should be arranged in logical stages.
The following nutrient removal alternatives have been evaluated to provide the most cost-
effective solution to the Town of Clayton’s present and projected wastewater treatment needs in
terms of compliance with the effluent limitations including nutrient removal requirements given in
Section 3.0 of this report. The primary objectives considered in evaluation of the alternatives are
listed as follows:
A high degree of wastewater treatment must be achieved to comply with the
established effluent limitations in the NPDES Permit and the State and EPA 503
sludge regulations.
5. Provision of flexibility in design and operation of unit operations/processes should
be incorporated in the plant.
Operator’s familiarity with the operation of unit operation or process.
Operating cost of treatment facilities should be kept at a minimum.
Flexibility should be afforded for future upgrading and/or expansion or application
of technology at a later date to provide for the reclaiming or recycling of water or
otherwise eliminate the discharge of pollutants.
It should be noted that relocation of the Clayton LCWRF effluent discharge to the Cape
Fear River Basin and discharging a portion of Clayton’s wastewater to the City of Raleigh s sewer
system for treatment and discharge were also evaluated as alternatives to comply with the nutrient
removal requirements and for providing adequate wastewater treatment needs for handling the
Town of Clayton’s projected residential, commercial and industrial growth.
In the alternative considering discharge of Clayton LCWRF effluent into the Cape Fear
River Basin, approximately 27 miles of forcemain and booster pump stations would be required.
The most direct route would be to follow NC Hwy. 42 west for approximately 21.1 miles to its
juncture with NC Hwy. 1301 just east of Fuquay-Varina. The forcemain would then parallel NC
Hwy. 1301 south to NC Hwy. 1446 for approximately 2.3 miles, the forcemain would intersect
NC Hwy. 1441, then turn west and parallel NC Hwy. 1441 for approximately 770 feet until 1
discharging into Kenneth Creek, a major tributary to the Cape Fear River. The permitting issues
and construction costs associated with transporting Clayton LCWRF’s effluent to the Cape Fear
River Basin would raise several issues and concerns. One primary issue would be the interbasin
transfer of water from the Neuse River Basin to the Cape Fear River Basin. There are also other
costly environmental concerns that would emerge when the public is informed about transfer of
Clayton LCWRF’s effluent to the Cape Fear River. Considering the construction cost, permitting
issues and environmental concerns associated with the discharge of Clayton LCWRF effluent into
the Cape Fear River, this alternative was deleted from further considerations.
In evaluation of the alternative considering discharge of a portion of the Clayton wastewater
into the City of Raleigh sewer system for treatment and disposal, a request was made to the City of
Raleigh for accepting up to 2.5 mgd of Clayton’s wastewater flow and providing cost of sewer
service to the Town of Clayton. In response to the request, the City of Raleigh has informed us
that the City is not considering any additional requests for contract wastewater treatment capacity
sales at this time and therefore, no capacity is available to the Town of Clayton. A copy of the letter
to the City of Raleigh concerning this matter is included in Appendix 2.
It should also be noted that the proposed improvements for rerating of LCWRF to 2.5 mgd
that are currently underway with the exception of the improvements to the oxidation ditches as
described in Section 4.2 of this report are not included in the evaluation of nutrient removal
alternatives. Also, considering the fact that the sludge handling facilities play an important role in
Itreatment system performance in terms of nutrient removals and compliance with the nutrient
removal requirements, provision of adequate sludge facilities are considered as an integral part in
evaluation of nutrient removal alternatives.
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Alternative No. 1
This alternative (Exhibits 2, 2a and 2b) considers providing anaerobic tanks, modifying the
existing Carrousel Oxidation Ditches to include first stage anoxic tanks and denitrification gates for
use as a Carrousel denit R system, and providing second stage anoxic tanks with a methanol feed
system and reaeration tanks for nutrient removal. The existing alum and polymer feed systems will
be used for either polishing chemical phosphorus removal or improved clarification, when
necessary. The existing magnesium hydroxide or caustic feed system will be used for pH and
alkalinity control, when necessary, for improved phosphorus removal and nitrification. The
existing traveling bridge filters will be used as an integrated part of the nutrient removal strategy
since removal of suspended solids by filters will help remove nitrogen and phosphorus associated
with the solids. This alternative also considers expansion of the sludge thickening and aerobic
sludge stabilization/storage facilities. A detailed description and cost analysis of this alternative are
given as follows.
Description
The principal components of this alternative are described as follows:
1. Provide a three pass anaerobic selector tank for biological phosphorus removal
process. The anaerobic selector tank will be designed for 2.0 hours of hydraulic
retention time at an average daily design flow of 2.5 mgd and will be equipped
with 3 - 5.0 hp mixers (one for each pass). Relocate the influent and sludge
recirculation piping to the anaerobic selector tank. Provide the flexibility of
influent piping to the anaerobic tank such that the influent can be fed through
either the first or second pass of the anaerobic tank. By feeding the influent to
the second pass, the first pass can be used for nitrate removal from the sludge
recycle and true anaerobic conditions in the second and the third pass can be
maintained for the biological phosphorus removal process. Also removal of the
nitrate from the sludge recycle will help avoid loss of easily biodegradable BODs
(volatile fatty acids) through biochemical oxidation and subsequently maintain
the desired influent BOD/TP ratio for improved performance of the biological
phosphorus removal process. Refer to Appendix 3 for supporting design
calculations.
2.
3.
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effluent weir in the ditch. Provide a SymBio process control system consisting
Page 44Town of Clayton
is included for optimum operation of BNR process under diurnal flows and
waste loadings variation and subsequent energy and chemical savings at the
plant. Refer to Appendix 3 for supporting design calculations.
Modify the existing 0.75 MG Carrousel ditch to include first stage anoxic tank
and denite gate for use of the ditch as Carrousel denit R system. The first stage
anoxic tank will be designed for 4.0 hours of hydraulic retention time at an ADF
of 2.5 mgd and will be equipped with two 5.0 hp mixers. The denit R gate will
be designed to provide internal (nitrate) recycle flow rate of 3 to 15 times the
ADF of 2.5 mgd. Upgrade the aeration capacity in the oxidation ditch by
replacing the existing two - 25 hp five-speed aerators with the two 50 hp
aerators,removed from the 1.15 MG Carrousel ditch. Install an adjustable
Modify the existing 1.15 MG Carrousel ditch to include first stage anoxic tank
and denite gate for use of the ditch as Carrousel denit R system. The first stage
anoxic tank will be designed for 4.0 hours of hydraulic retention time at an ADF
of 2.5 mgd and will be equipped with two 7.5 hp mixers. The denit R gate will
be designed to provide internal (nitrate) recycle flow rate of 3 to 15 times the
ADF of 2.5 mgd. Upgrade the aeration capacity in the oxidation ditch by
replacing the existing two - 50 hp two-speed aerators with two new 75 hp
aerators, each equipped with a variable frequency drive. The two removed 50 hp
aerators will be used in replacing the two existing 25 hp aerators in the 0.75 MG
Carrousel ditch. Install an adjustable effluent weir in the ditch. Provide a
SymBio process control system consisting of NADH and DO sensors, PLC, PC
with modem and screenware software for SCADA. The process control system
4.
5.
I 6.
I
Page 45Town of Clayton
of NADH and DO sensors, PLC, PC with modem and screenware software for
SCADA. It should be noted that PC with modem and screenware software for
SCADA will be common for both ditches. The process control system is
included for optimum operation of BNR process under diurnal flows and waste
loadings variation and subsequent energy and chemical savings at the plant.
Refer to Appendix 3 for supporting design calculations.
Use the existing alum and polymer feed system for polishing chemical
phosphorus removal and/or improved clarification, when necessary.
Use the existing magnesium hydroxide/sodium hydroxide feed system for pH
control and alkalinity addition for optimizing performance of the nitrification
process and also improved sludge settling characteristics by promoting growth
of the floc forming organisms. For reliable nitrification and improved sludge
quality, it is recommended that the minimum residual Total Alkalinity in the
clarifiers’ effluent should be maintained at 50 mg/L.
Provide second stage anoxic tanks for biological denitrification, using
endogenous respiration. The second stage anoxic tanks will be designed for 4.0
hours of hydraulic retention time at ADF of 2.5 mgd. The anoxic tanks will be
designed as dual train, two-stage per train and each stage will be equipped with a
7.5 hp mixer. In order to provide flexibility and reliable operation, the influent
piping to anoxic tanks will be designed such that in each train the influent can be
fed to either first or second stage to control anoxic detention time necessary to
achieve denitrification and to make sure that anaerobic conditions are not created
in the anoxic tanks. Another option to control anoxic hydraulic retention time and
anaerobic conditions is to install a diffused air system in the second stage of each
train to maintain the anoxic/ aerobic conditions to a point that the desired
denitrification can be achieved.
7.Provide reaeration tanks equipped with fine bubble diffused air system to
assimilate any BODs, TP or NH3-N released through cells lysing in second stage
anoxic tanks. The reaeration tanks will be designed for 1.0 hour of hydraulic
8.Provide a methanol feed system to feed supplemental carbon, if needed, for the
denitrification process. The methanol feed system will consists of one 6,000
monitoring system.
9.Use the existing traveling bridge filters for the suspended solids removal and
associated Total Nitrogen, Total Phosphorus, and BODs removal.I10.
washwater system, thickened sludge pump and all the necessary controls and
thickeners.
11.
additional aerobic sludge stabilization/storage tank (71’-6” diam. x 12’-0 SWD)
equipped with a 30 hp floating mixer, coarse bubble diffused air system, two (2)
1100 SCFM 60 hp blowers, decant facilities and stabilized sludge piping. One of Ithe blowers will be used as a standby unit and all three blowers, including the
existing one, will be alternated for duty.
12.Dispose of the stabilized sludge by land application by using a private contractor
engaged in land application of sludge in accordance with the State and EPA 503
sludge regulations.
Town of Clayton Page 46
. i
I
. .i
Provide one new rotary drum thickener (designed to handle 93 gpm sludge at
0.8 percent feed solids) with a liquid polymer feed system, a flocculation tank.
gallon bulk storage tank, spill containment structures, two metering pumps,
controls and piping. The metering pumps will be paced with the flow and nitrate
retention time at ADF of 2.5 mgd. Refer to Appendix 3 for supporting design
calculations.
I
standby unit and for alternated duty operation for both the existing and new
Expand the aerobic sludge stabilization/storage facilities by providing one
piping. Also, provide one additional thickened sludge pump to serve as a
B . Construction Cost Opinion
$310,000.00
500,500.00
$
$
209,500.00Salaries, including fringe benefits
Utilities:
Chemicals:
50,000.00Maintenance and Repairs
Contracted Services:
2,500.00Continuing education and training
Page 47Town of Clayton
Electric
Telephone
Alum
Caustic
Polymer
Methanol
Laboratory testing
Pretreatment
Sludge disposal
385,500.00
2,500.00
1,500.00
1,000.00
20,000.00
2,500.00
20,000.00
10,000.00
30,000.00
575,500.00
660,000.00
575,000.00
130,000.00
168,000.00
487,000.00
613,000.00
410,000.00
4,429,000.00
443,000.00
384,000.00
5,000.00
25,000.00
106,000.00
10,000.00
15,000.00
5,417,000.00
Anaerobic selector tank
First stage anoxic tank for 0.75 MG oxidation ditch,
including structural modifications
First stage anoxic tank for 1.15 MG oxidation ditch,
including structural modifications
Oxidation ditches aeration upgrading
Second stage anoxic/reaeration tanks
Methanol feed system
Expansion to sludge thickening facilities
Expansion to aerobic sludge stab ^storage facilities
Sitework and piping (18%)
Electrical, instrumentation and controls (12%)
Total Construction Cost
Contingencies
Engineering and Construction Administration
Geotechnical work
Legal and administration
State Construction loan fee (2%)
Startup Services
Operation and Maintenance Manual
Total Project Cost
C. Annual Operation and Maintenance Manual (for 2.5 mgd plant)
$
7,500.00Permit fees and dues
$847,500.00
D. Estimated Salvage Value
$1,476,000.00
$1,476,000.00Total Estimated Salvage Value
E. Economic Analysis
1.
2.
5,417,000.00$
8,891,800.00
c.
$
3.
1,328,240.00$
Page 48Town of Clayton
Departmental supplies
Wastewater transmission cost
Insurance and Bonds
Capital Outlay
Total Annual Operation and Maintenance Cost
g-
h.
9,000.00
51,000.00
5,000.00
40,000.00
!
I
c.
d.
a.
b.
e.
f.
a.
b.
I
!
372,800.00
13,936,000.00
Basic Considerations
Planning period: 20 years
Capital cost of the project: $5,417,000.00
Annual O&M costs: $847,500.00
Salvage value at the end of 20 years: $1,476,000.00
Interest rate: 7.125 percent
Single Payment Present Worth Factor @ 7.125% for 20 years: 0.25245
Uniform Series PWF @ 7.125% for 20 years: 10.4918
Capital Recovery Factor @ 7.125 for 20 years: 0.09531
Present Worth Cost
Initial Capital Cost
Present Worth of Annual O&M Costs
$847,500.00 x 10.4918
Present Worth of Salvage Value
$1,476,000.00 x 0.25245
Net Present Worth Cost (a + b -c)
Annual Equivalent Cost
$13,936,000.00 x 0.09531
I
!
!
Treatment Work: (1 - -|^-j x $4,429,000.00
r
Methanol Feed System
-M-M
e )
ooIooo D.B.
J P.S.*
Sou iInfluentm-/'z/Clarifier
No. 2
Anoxic Tank
I
Sludge Recirc.
•Drain
Sludge Recirc./Waste
A-
P.S.
D.B.
Scum Waste to
Aerobic Digester
Waste Sludge to
Thickener /
Aerobic Digester
I
I
Clarifier
No. 1-^
I
I
Second Stage Anoxic Tanks
—---------- ----- — Reaeration Tanks
I
I
Clarifier
No. 3
Sludge Recirc.
Clarifier Effluent
to Tertiary Filters/
UV Disinf. System
Magnesium
Hydroxide
Feed or
Sodium
Hydroxide
Legend
-----------Wastewater / Effluent
-----------Sludge
-----------Scum
—M— Methanol Feed System
Magnesium Hydroxide Feed
Alum Feed
Polymer Feed
Pump Station
Distribution Box
VI
Tl -- ■Uq*
"G._Jtp.s.i
Exhibit 2
Schematic Flow Diagram of Alternative 1
Clayton LCWRF Upgrading for Nutrient Removal
•! i
I-----------
I
I
I
I Ai Anaerobic
' Tank
■M----------
Ox. Basin No. 2 (1.15 MG)
I ,,
i
I n
I
I
F—---------u.
Alum Feed x I F
Polymer Feed -P-^ I /
— Ox. Basin No. 1 (0.75 MG) ' \
—. X i \
I >
I (
I (
I \
I \
I
m d.b.
i cY ip.sj
Lt
Methanol Feed System
-M-
!
o
oIo o
D.B.
J P.S.
Influent
ScuiD.B.
f /'/Clarifier
No. 2
o
o
I
Sludge Recirc.
•rain
Sludge Recirc./Waste
Legend
A-
IIItel
1 (
>P.S.
t
JTP.S.
I
yi
11
I
I
P.S.
D.B.
Scum Waste to
Aerobic Digester
Exhibit 2a
Schematic Flow Diagram of Alternative 1
Clayton LCWRF Upgrading for Nutrient Removal
Waste Sludge to
Thickener /
Aerobic Digester
I
I
Clarifier
No. 1 -7
Second Stage Anoxic Tanks
—---------- -----— Reaeration Tanks
!i I
I
I
Clarifier
No. 3
Clarifier Effluent
to Tertiary Filters/
UV Disinf. System
ilk
----------- Wastewater / Effluent
-----------Sludge
-----------Scum
—M— Methanol Feed System
—m— Magnesium Hydroxide Feed
Alum Feed
Polymer Feed
Pump Station
Distribution Box
Ox. Basin No. 2 (1.15 MG) |r-----
i
i
i
I A
I Anaerobic
I Tank
IS
Sludge Recirc.
Alum Feed X I
Polymer Feed -P-^ |
*— Ox. Basin No 1 (0.75 MG) | IIMagnesium
Hydroxide
Feed or
Sodium
Hydroxide
First Stage .
Anoxic Tank
M-
Flocculation Tanks
Rotary Drum Thickener
F
1
Sludge Drying Beds
Clayton LCWRF Sludge Handling Facilities
Thickened
Sludge
Aerobic
Sludge
Digester
I
I
I
I
i
i
Polymer
Feed Systems
Waste Activated
Sludge
I
Ln
------1
==^I
B
>0
p
F
B
□
\
\
\
\
Legend
----------Sludge
Filtrate / Decant
Sludge Pumps
Flow Meters
Aeration Blowers
Existing Facilities
New Facilities
7-------—Decant
Exhibit 2b
Schematic Flow Diagram of Alternative 1
/ /J /
/ /
/
./
Aerobic Sludge
Digester / Holding
Tanks
Sludge
Loading Station
To Drainage Recycle
Pump Station
P-
IAlternative No. 26.2
A.
1.
I
Page 52Town of Clayton
. 2
The principal components of this alternative are described as follows:
Provide a three pass anaerobic selector tank for biological phosphorus removal
process. The anaerobic selector tank will be designed for 2.0 hours of hydraulic
retention time at an average daily design flow of 2.5 mgd and will be equipped
with 3 - 5.0 hp mixers (one for each pass). Relocate the influent and sludge
recirculation piping to the anaerobic selector tank. Provide the flexibility of
influent piping to the anaerobic tank such that the influent can be fed through
either the first or second pass of the anaerobic tank. By feeding the influent to
the second pass, the first pass can be used for nitrate removal from the sludge
recycle and true anaerobic conditions in the second and the third pass can be
maintained for the biological phosphorus removal process. Also removal of the
nitrate from the sludge recycle will help avoid loss of easily biodegradable BODs
(volatile fatty acids) through biochemical oxidation and subsequently maintain
the desired influent BOD/TP ratio for improved performance of the biological
phosphorus removal process. Refer to Appendix 3 for supporting design
I
»
I
!
!
!
This alternative (Exhibits 3, 3a and 2b) considers providing anaerobic tanks, modifying the
existing Carrousel Oxidation Ditches to include first stage anoxic tanks and denitrification gates for
use as a Carrousel denite R system, and providing new Tetra denite filters for nutrient removal.
The existing alum and polymer feed systems will be used for either polishing chemical phosphorus
removal or improved clarification, when necessary. The existing magnesium hydroxide or liquid
sodium hydroxide feed systems will be used for pH and alkalinity control, when necessary, for
improved phosphorus removal and nitrification. The existing traveling bridge filters will be used
for back up or converted into effluent storage for reuse purposes. This alternative also considers
expansion of the sludge thickening and aerobic sludge stabilization/storage facilities. A detailed
description and cost analysis of this alternative are given as follows.
Description
2.
I
3.
I
I
Page 53Town of Clayton
calculations.
Modify the existing 1.15 MG Carrousel ditch to include first stage anoxic tank
and denite gate for use of the ditch as Carrousel denit R system. The first stage
anoxic tank will be designed for 4.0 hours of hydraulic retention time at an ADF
of 2.5 mgd and will be equipped with two 7.5 hp mixers. The denit R gate will
be designed to provide internal (nitrate) recycle flow rate of 3 to 15 times the
ADF of 2.5 mgd. Upgrade the aeration capacity in the oxidation ditch by
replacing the existing two - 50 hp two-speed aerators with two new 75 hp
aerators, each equipped with a variable frequency drive. The two removed 50 hp
aerators will be used in replacing the two existing 25 hp aerators in the 0.75 MG
Carrousel ditch. Install an adjustable effluent weir in the ditch. Provide a
SymBio process control system consisting of NADH and DO sensors, PLC, PC
with modem and screenware software for SCADA. The process control system
is included for optimum operation of BNR process under diurnal flows and
waste loadings variation and subsequent energy and chemical savings at the
plant. Refer to Appendix 3 for supporting design calculations.
Modify the existing 0.75 MG Carrousel ditch to include first stage anoxic tank
and denite gate for use of the ditch as Carrousel denit R system. The first stage
anoxic tank will be designed for 4.0 hours of hydraulic retention time at an ADF
of 2.5 mgd and will be equipped with two 5.0 hp mixers. The denit R gate will
be designed to provide internal (nitrate) recycle flow rate of 3 to 15 times the
ADF of 2.5 mgd. Upgrade the aeration capacity in the oxidation ditch by
replacing the existing two - 25 hp five-speed aerators with the two - 50 hp
aerators, removed from the 1.15 MG Carrousel ditch. Install an adjustable
effluent weir in the ditch. Provide a SymBio process control system consisting
of NADH and DO sensors, PLC, PC with modem and screenware software for
SCADA. It should be noted that PC with modem and screenware software for
ISCADA will be common for both ditches. The process control system is
4.
5.
6.
1
7.
8.
9.
i
■
Page 54Town of Clayton
included for optimum operation of BNR process under diurnal flows and waste
loadings variation and subsequent energy and chemical savings at the plant.
Refer to Appendix 3 for supporting design calculations.
Use the existing alum and polymer feed system for polishing chemical
phosphorus removal and/or improved clarification, when necessary.
Use the existing magnesium hydroxide/sodium hydroxide feed system for pH
control and alkalinity addition for optimizing performance of the nitrification
process and also improved sludge settling characteristics by promoting growth
of the floc forming organisms. For reliable nitrification and improved sludge
quality, it is recommended that the minimum residual Total Alkalinity in the
clarifiers’ effluent should be maintained at 50 mg/L.
Provide a Tetra denite filter system consisting of three (3) filters, 9.5’ x 34.67’,
each equipped with all the pertinent piping and accessories such as backwash
pumps, air bumping, controls for methanol feed system, backwash waste
storage and recycle pumps, aeration blowers and filter building. Refer to
Appendix 3 for Tetra denite filter system supporting design calculations.
Provide a methanol feed system to feed supplemental carbon, if needed, for the
denitrification process. The methanol feed system will consist of one 6,000
gallon bulk storage tank, spill containment structures, two metering pumps,
controls and piping. The metering pumps will be paced with the flow and nitrate
monitoring system.
Use the existing traveling bridge filters for backup or convert into effluent
storage for reuse purposes.
Provide one new rotary drum thickener (designed to handle 93 gpm sludge at
0.8 percent feed solids) with a liquid polymer feed system, a flocculation tank,
washwater system, thickened sludge pump and all the necessary controls and
J
!
f
1
I
10.
11.
I
Page 55Town of Clayton
piping. Also, provide one additional thickened sludge pump to serve as a
standby unit and for alternated duty operation for both the existing and new
thickeners.
Expand the aerobic sludge stabilization/storage facilities by providing one
additional aerobic sludge stabilization/storage tank (71’-6” diam. x 12’-0 SWD)
equipped with a 30 hp floating mixer, coarse bubble diffused air system, two (2)
1100 SCFM 60 hp blowers, decant facilities and stabilized sludge piping. One of
the blowers will be used as a standby unit and all three blowers, including the
existing one, will be alternated for duty.
Dispose of the stabilized sludge by land application by using a private contractor
engaged in land application of sludge in accordance with the State and EPA 503
sludge regulations.
B . Construction Cost Opinion
$310,000.00Anaerobic selector tank
500,500.00
I
C. Annual Operation and Maintenance Manual (for 2.5 mgd plant)
$209,500.00Salaries, including fringe benefits
Utilities:
50,000.00Maintenance and Repairs
Contracted Services:
I
2,500.00Continuing education and training
Page 56Town of Clayton
First stage anoxic tank for 0.75 MG oxidation ditch,
including structural modifications
First stage anoxic tank for 1.15 MG oxidation ditch,
including structural modifications
Oxidation ditches aeration upgrading
Tetra denite filters
Methanol feed system
Expansion to sludge thickening facilities
Expansion to aerobic sludge stabVstorage facilities
Sitework and piping (18%)
Electrical, instrumentation and controls (12%)
Total Construction Cost
Contingencies (10%)
Engineering and Construction Administration
Geotechnical work
Legal and administration
State Construction loan fee (2%)
Startup Services
Operation and Maintenance Manual
Total Project Cost
Electric
Telephone
Laboratory testing
Pretreatment
Sludge disposal
20,000.00
10,000.00
30,000.00
370,000.00
2,500.00
1,500.00
1,000.00
20,000.00
7,500.00
■ii
!
I
f
I
575,500.00
660,000.00
1,360,000.00
130,000.00
168,000.00
487,000.00
754,500.00
503,000.00
$ 5,448,500.00
545,000.00
431,500.00
5,000.00
25,000.00
129,500.00
10,000.00
15,000.00
$ 6,609,500.00
Chemicals: Alum
Caustic
Polymer
Methanol
7,500.00Pennit fees and dues
I
$
I D. Estimated Salvage Value
$1,816,000.00x $5,448,500.00
$1,816,000.00Total Estimated Salvage Value
E. Economic Analysis
1.
2.
I 6,609,500.00$
8,781,500.00
c.
$
3.
1,423,200.00$
Page 57Town of Clayton
'L
Departmental supplies
Wastewater transmission cost
Insurance and Bonds
Capital Outlay
Total Annual Operation and Maintenance Cost
g-
h.
c.
d.
a.
b.
e.
f.
a.
b.
458,500.00
14,932,500.00
9,000.00
51,000.00
5,000.00
40,000.00
837,000.00
. L 20Treatment Work: 11 -
Annual Equivalent Cost
$14,932,500.00 x 0.09531
Basic Considerations
Planning period: 20 years
Capital cost of the project: $6,609,500.00
Annual O&M costs: $837,000.00
Salvage value at the end of 20 years: $1,816,000.00
Interest rate: 7.125 percent
Single Payment Present Worth Factor @ 7.125% for 20 years: 0.25245
Uniform Series PWF @ 7.125% for 20 years: 10.4918
Capital Recovery Factor @ 7.125 for 20 years: 0.09531
Present Worth Cost
Initial Capital Cost
Present Worth of Annual O&M Costs
$837,000.00 x 10.4918
Present Worth of Salvage Value
$1,816,000.00 x 0.25245
Net Present Worth Cost (a + b -c)
Sludge Recirc.
o oooo D.B.
J P.S.
ScumInfluentD.B.-m-
IAnoxic Tank
Sludge Recirc.
rain
M
Sludge Recirc./Waste
MLegend
OM
Methanol Feed System
A-
▼
I )?l i.
1 <
I P.S.
I
t
_TTp.s.
I
y\II
P.S.
D.B.
r
i
i
i
i
i
Scum Waste to
Aerobic Digester
\ Waste Sludge to
X Thickener /
Aerobic Digester
I
I
Clarifier
No. 1
Tetra Denlte
Filters -----
//Clarifier
' No. 2-^
Clarifier
No. 3
Effluent to
UV Disinf.
I
&
M
Magnesium
Hydroxide
Feed or
Sodium
Hydroxide
-_Uk
----------- Wastewater / Effluent
-----------Sludge
-----------Scum
—M— Methanol Feed System
Magnesium Hydroxide Feed
Alum Feed
Polymer Feed
Pump Station
Distribution Box
Exhibit 3
Schematic Flow Diagram of Alternative 2
Clayton LCWRF Upgrading for Nutrient Removal
'k
Alum Feed -A-XX^~ I
Polymer Feed-P-^ I
— Ox. Basin No. 1 (0.75 MG) |
X. I X)
----------** I
Ox. Basin No. 2 (1.15 MG)
I
I
I
I
I
I
I
I
Sludge Recirc.
o )
*
ooooo D.B.
P.S.
Influent ScumD.B.
/'//Clarifier
No. 2
o
I
Sludge Recirc.
I
•Drain
M
Sludge Reclrc./Waste
M-Legend
O------M
Methanol Feed System
■iI
I
I P.S.
I
P.S.
D.B.
Scum Waste to
Aerobic Digester
\ Waste Sludge to
\ Thickener /
Aerobic Digester
Clarifier
No. 1
I
I
Tetra Denite
Filters -----
Effluent to
UV Disinf.
I
I
Clarifier
No. 3
LA
O
Alum Feed -A- / '
Polymer Feed-P-^ I
— Ox. Basin No. 1 (0.75 MG) ]
I
I
I
I
I
I
I
----------- Wastewater / Effluent
-----------Sludge
-----------Scum
—M— Methanol Feed System
—m— Magnesium Hydroxide Feed
—A— Alum Feed
-----------Polymer Feed
Pump Station
Distribution Box
Exhibit 3a
Schematic Flow Diagram of Alternative 2
Clayton LCWRF Upgrading for Nutrient Removal
ii I
Magnesium
Hydroxide
Feed or
Sodium
Hydroxide
First Stage
Anoxic Tank
r
I First Stage —
I Anoxic Tank
I
I AI Anaerobic —7
' Tank
Ox. Basin No. 2 (1.15 MG)
-------z-----------I
I
I
I
I
I
I
I
O
1 (J
'p.sd
M
Alternative No. 36.3
I
I
I
as follows.
DescriptionA.
I
1.
I
I
I
I
I
J
Page 60Town of Clayton
The principal components of this alternative are described as follows:
Provide a three pass anaerobic selector tank for biological phosphorus removal
process. The anaerobic selector tank will be designed for 2.0 hours of hydraulic
retention time at an average daily design flow of 2.5 mgd and will be equipped
with 3 - 5.0 hp mixers (one for each pass). Relocate the influent and sludge
recirculation piping to the anaerobic selector tank. Provide the flexibility of
influent piping to the anaerobic tank such that the influent can be fed through
either the first or second pass of the anaerobic tank. By feeding the influent to
the second pass, the first pass can be used for nitrate removal from the sludge
recycle and true anaerobic conditions in the second and the third pass can be
maintained for the biological phosphorus removal process. Also, removal of the
nitrate from the sludge recycle will help avoid loss of easily biodegradable BODs
(volatile fatty acids) through biochemical oxidation and subsequently maintain
the desired influent BOD/TP ratio for improved performance of the biological
This alternative (Exhibit 4 and 2b) considers providing anaerobic tanks, first stage anoxic
tanks, upgrading the aeration capacity of the existing 0.75 MG and 1.15 MG Carrousel type
oxidation ditches, and providing second stage anoxic tanks with methanol feed system and
reaeration tanks for nutrient removal. The existing alum and polymer feed systems will be used for
either polishing chemical phosphorus removal or improved clarification, when necessary. The
existing magnesium hydroxide or liquid sodium hydroxide feed systems will be used for pH and
alkalinity control, when necessary, for improved phosphorus removal and nitrification. The
existing traveling bridge filters will be used for back up or converted into effluent storage for reuse
purposes. This alternative also considers expansion of the sludge thickening and aerobic sludge
stabilization/storage facilities. A detailed description and cost analysis of this alternative are given
2.
3.
I
4.
I
5.
I
I
Page 61Town of Clayton
L
I
I
phosphorus removal process. Refer to Appendix 3 for supporting design
calculations.
Provide first stage anoxic tanks for biological denitrification. The anoxic tanks
will be designed to provide 4.0 hours of hydraulic retention time at ADF of 2.5
mgd and will be equipped with two - 15 hp mixers.
Provide a nitrate recycle pump station to recycle the mixed liquor containing
nitrate from both the ditches to the first stage anoxic tanks. The pump station will
be equipped with two recycle pumps, each designed to recycle 10 mgd which is
four times the design ADF of 2.5 mgd. Both pumps will be equipped with a
manually control variable frequency drive for adjustment of nitrate recycle flow.
One of the pumps will be used as a standby unit and alternated for July.
Upgrade the aeration capacity in the 1.15 MG Carrousel oxidation ditch by
replacing the existing two - 50 hp two-speed aerators with two new 75 hp
aerators, each equipped with a variable frequency drive. The two removed 50 hp
aerators will be used in replacing the two existing 25 hp aerators in the 0.75 MG
Carrousel ditch. Install an adjustable effluent weir in the ditch. Provide a
SymBio process control system consisting of NADH and DO sensors, PLC, PC
with modem and screenware software for SCADA. The process control system
is included for optimum operation of BNR process under diurnal flows and
waste loadings variation and subsequent energy and chemical savings at the
plant. Refer to Appendix 3 for supporting design calculations.
Upgrade the aeration capacity in the 0.75 MG Carrousel oxidation ditch by
replacing the existing two - 25 hp five-speed aerators with the two - 50 hp
aerators, removed from the 1.15 MG Carrousel ditch. Install an adjustable
effluent weir in the ditch. Provide a SymBio process control system consisting
of NADH and DO sensors, PLC, PC with modem and screenware software for
SCADA. It should be noted that PC with modem and screenware software for
I
6.
7.
8.
I
denitrification can be achieved.
9.
I
Page 62Town of Clayton
ri
I
I
!
I
!
SCADA will be common for both ditches. The process control system is
included for optimum operation of BNR process under diurnal flows and waste
loadings variation and subsequent energy and chemical savings at the plant.
Refer to Appendix 3 for supporting design calculations.
Use the existing alum and polymer feed system for polishing chemical
phosphorus removal and/or improved clarification, when necessary.
Use the existing magnesium hydroxide/sodium hydroxide feed system for pH
control and alkalinity addition for optimizing performance of the nitrification
process and also improved sludge settling characteristics by promoting growth
of the floc forming organisms. For reliable nitrification and improved sludge
quality, it is recommended that the minimum residual Total Alkalinity in the
clarifier’s effluent should be maintained at 50 mg/L.
Provide second stage anoxic tanks for biological denitrification, using
endogenous respiration. The second stage anoxic tanks will be designed for 4.0
hours of hydraulic retention time at ADF of 2.5 mgd. The anoxic tanks will be
designed as dual train, two-stage per train and each stage will be equipped with a
7.5 hp mixer. In order to provide flexibility and reliable operation, the influent
piping to anoxic tanks will be designed such that in each train the influent can be
fed to either first or second stage to control anoxic detention time necessary to
achieve denitrification and to make sure that anaerobic conditions are not created
in the anoxic tanks. Another option to control anoxic hydraulic retention time and
anaerobic conditions is to install a diffused air system in the second stage of each
train to maintain the anoxic/aerobic conditions to a point that the desired
Provide reaeration tanks equipped with a fine bubble diffused air system to
assimilate any BODs, TP or NHs-N released through cells lysing in second stage
anoxic tanks. The reaeration tanks will be designed for 1.0 hour of hydraulic
I
I retention time at ADF of 2.5 mgd. Refer to Appendix 3 for supporting design
10.
11.
I
12.
13.
I
14.
I
Page 63Town of Clayton
calculations.
Provide a methanol feed system to feed supplemental carbon, if needed, for the
denitrification process. The methanol feed system will consist of one 6,000
gallon bulk storage tank, spill containment structures, two metering pumps,
controls and piping. The metering pumps will be paced with the flow and nitrate
monitoring system.
Use the existing traveling bridge filters for the suspended solids removal and
associated Total Nitrogen, Total Phosphorus, and BODs removal.
Provide one new rotary drum thickener (designed to handle 93 gpm sludge at
0.8 percent feed solids) with a liquid polymer feed system, a flocculation tank,
washwater system, thickened sludge pump and all the necessary controls and
piping. Also, provide one additional thickened sludge pump to serve as a
standby unit and for alternated duty operation for both the existing and new
thickeners.
Expand the aerobic sludge stabilization/storage facilities by providing one
additional aerobic sludge stabilization/storage tank (71’-6” diam. x 12 -0 SWD)
equipped with a 30 hp floating mixer, coarse bubble diffused air system, two (2)
1100 SCFM 60 hp blowers, decant facilities and stabilized sludge piping. One of
the blowers will be used as a standby unit and all three blowers, including the
existing one, will be alternated for duty.
Dispose of the stabilized sludge by land application by using a private contractor
engaged in land application of sludge in accordance with the State and EPA 503
sludge regulations.
I
B . Construction Cost Opinion
310,000.00$Anaerobic selector tank
I
I
$
$
I 209,500.00Salaries, including fringe benefits
Utilities:
Chemicals:
50,000.00Maintenance and Repairs
Contracted Services:I
2,500.00Continuing education and training
7,500.00Permit fees and dues
Page 64Town of Clayton
Electric
Telephone
Alum
Caustic
Polymer
Methanol
Laboratory testing
Pretreatment
Sludge disposal
402,000.00
2,500.00
1,500.00
1,000.00
20,000.00
2,500.00
20,000.00
10,000.00
30,000.00
510,000.00
290,000.00
660,000.00
575,000.00
130,000.00
168,000.00
487,000.00
563,500.00
375,500.00
4,069,000.00
407,000.00
366,500.00
5,000.00
25,000.00
98,000.00
10,000.00
15,000.00
4,995,500.00
First stage anoxic tank for 0.75 MG and 1.15 MG
oxidation ditches
Nitrate Recycle Pump Station
Oxidation ditches aeration upgrading
Second stage anoxic/reaeration tanks
Methanol feed system
Expansion to sludge thickening facilities
Expansion to aerobic sludge stabVstorage facilities
Sitework and piping (18%)
Electrical, instrumentation and controls (12%)
Total Construction Cost
Contingencies
Engineering and Construction Administration
Geotechnical work
Legal and administration
State Construction loan fee (2%)
Startup Services
Operation and Maintenance Manual
Total Project Cost
C. Annual Operation and Maintenance Manual (for 2.5 mgd plant)
$
$
D. Estimated Salvage Value
$1,356,500.00
$1,356,500.00Total Estimated Salvage Value
E. Economic Analysis
1.
I2.
$4,995,500.00 I
9,065,000.00
c.
$
3.
$1,259,807.00
I
Page 65 .Town of Clayton
Departmental supplies
Wastewater transmission cost
Insurance and Bonds
Capital Outlay
Total Annual Operation and Maintenance Cost
g-
h.
c.
d.
e.
f.
a.
b.
1
a.
b.
342,500.00
13,218,000.00
9,000.00
51,000.00
5,000.00
40,000,00
864,000.00
Basic Considerations
Planning period: 20 years
Capital cost of the project: $4,995,500.00
Annual O&M costs: $864,000.00
Salvage value at the end of 20 years: $1,356,500.00
Interest rate: 7.125 percent
Single Payment Present Worth Factor @ 7.125% for 20 years: 0.25245
Uniform Series PWF @ 7.125% for 20 years: 10.4918
Capital Recovery Factor @ 7.125 for 20 years: 0.09531
Present Worth Cost
Initial Capital Cost
Present Worth of Annual O&M Costs
$864,000.00 x 10.4918
Present Worth of Salvage Value
$1,356,500.00 x 0.25245
Net Present Worth Cost (a + b -c)
Annual Equivalent Cost
$13,218,000.00 x 0.09531
!
J
fl
w-
( 20 \Treatment Work: 11 - 1 x $4,069,000.00
-M-
)
oo
aoo
T
Influent -m-
D.B.
*
I
Sludge Recirc.Ox. Basin No. 1 (0.75 MG)
DrainP.S.
“ I
Sludge Reclrc./Waste
Legend
IZI
i'
P.S.
D.B.
Anoxic
Tanks
Scum Waste to
Aerobic Digester
Waste Sludge to
Thickener /
Aerobic Digester
I
I
Clarifier
No. 1-;
I
I
Second Stage Anoxic Tanks
—---------- ----- — Reaeration Tanks
Clarifier Effluent
to Tertlar
UV Disinl
I
I
Clarifier
No. 3
_ P.S.
Alum Feed -A-
Polymer Feed -P-Magnesium
Hydroxide
Feed or
Sodium
Sydroxide
r z
Nitrate Recycle -
I
$
----------- Wastewater / Effluent
-----------Sludge
-----------Scum
—M— Methanol Feed System
—m— Magnesium Hydroxide Feed
—A— Alum Feed
-----------Polymer Feed
Pump Station
Distribution Box
M-
■“I
Ox. Basin No. 2 (1.15 MG) I
I
I
I
I
I
I
I
1 r
i
i
i
i
i
i
i
i
i
i
i 1 c •p.sJ Li
I---------------
I
I
I
I Ai Anaerobic
' Tank
Exhibit 4
Schematic Flow Diagram of Alternative 3
Clayton LCWRF Upgrading for Nutrient Removal
i! i
L-k
— Sludge Recirc.
D.B.
-----p.s^z
Scum —^/ /
s. / / ^Clarifier
No. 2-^
j— Methanol Feed System
Alternative No. 46.4
1
A.
1.
Page 67Town of Clayton
The principal components of this alternative are described as follows:
Provide a three pass anaerobic selector tank for biological phosphorus removal
process. The anaerobic selector tank will be designed for 2.0 hours of hydraulic
retention time at an average daily design flow of 2.5 mgd and will be equipped
with 3 - 5.0 hp mixers (one for each pass). Relocate the influent and sludge
recirculation piping to the anaerobic selector tank. Provide the flexibility of
influent piping to the anaerobic tank such that the influent can be fed through
either the first or second pass of the anaerobic tank. By feeding the influent to
the second pass, the first pass can be used for nitrate removal from the sludge
recycle and true anaerobic conditions in the second and the third pass can be
maintained for the biological phosphorus removal process. Also removal of the
nitrate from the sludge recycle will help avoid loss of easily biodegradable BODs
(volatile fatty acids) through biochemical oxidation and subsequently maintain
the desired influent BOD/TP ratio for improved performance of the biological
J
I
I
I
—.-k
aux
I
i-Jf
I
I
This alternative (Exhibits 5 and 2b) considers providing anaerobic tanks, first stage anoxic
tanks, nitrate recycle pump station, upgrading aeration capacities of the existing 0.75 MG and 1.15
MG Carrousel type oxidation ditches and providing denite filters with a methanol feed system for
nutrient removal. The existing alum and polymer feed systems will be used for either polishing
chemical phosphorus removal or improved clarification, when necessary. The existing magnesium
hydroxide or caustic feed system will be used for pH and alkalinity control, when necessary, for
improved phosphorus removal and nitrification. The existing traveling bridge filters will be used
for backup or converted into effluent storage for reuse purposes. This alternative also considers
expansion of the sludge thickening and aerobic sludge stabilization/storage facilities. A detailed
description and cost analysis of this alternative are given as follows.
Description
1
I
2.
3.
4.
I
I
5.
I
Page 68Town of Clayton
phosphorus removal process. Refer to Appendix 3 for supporting design
calculations.
Provide first stage anoxic tanks for biological denitrification. The anoxic tanks
will be designed to provide 4.0 hours of hydraulic retention time at ADF of 2.5
mgd and will be equipped with two 15 hp mixers.
Provide a nitrate recycle pump station to recycle the mixed liquor containing
nitrate from both ditches to the first stage anoxic tank.The pump station will be
equipped with two recycle pumps, each designed to recycle 10 mgd which is
four times the design ADF of 2.5 mgd. Both pumps will be equipped with a
manually controlled variable frequency drive for adjustment of nitrate recycle
flow. One of the pumps will be used as a standby unit and alternated for duty.
Upgrade the aeration capacity in the 1.15 MG Carrousel oxidation ditch by
replacing the existing two - 50 hp two-speed aerators with two new 75 hp
aerators, each equipped with a variable frequency drive. The two removed 50 hp
aerators will be used in replacing the two existing 25 hp aerators in the 0.75 MG
Carrousel ditch. Install an adjustable effluent weir in the ditch. Provide a
SymBio process control system consisting of NADH and DO sensors, PLC, PC
with modem and screenware software for SCADA. The process control system
is included for optimum operation of BNR process under diurnal flows and
waste loadings variation and subsequent energy and chemical savings at the
plant. Refer to Appendix 3 for supporting design calculations.
Upgrade the aeration capacity in the 0.75 MG Carrousel oxidation ditch by
replacing the existing two - 25 hp five-speed aerators with the two 50 hp
aerators, removed from the 1.15 MG Carrousel ditch. Install an adjustable
effluent weir in the ditch. Provide a SymBio process control system consisting
of NADH and DO sensors, PLC, PC with modem and screenware software for
SCADA. It should be noted that PC with modem and screenware software for
6.
7
8.
I
9.
10.
11.
I
Page 69Town of Clayton
i
I
I
f
I
i
f
SCADA will be common for both ditches. The process control system is
included for optimum operation of BNR process under diurnal flows and waste
loadings variation and subsequent energy and chemical savings at the plant.
Refer to Appendix 3 for supporting design calculations.
Use the existing alum and polymer feed system for polishing chemical
phosphorus removal and/or improved clarification, when necessary.
Use the existing magnesium hydroxide/sodium hydroxide feed system for pH
control and alkalinity addition for optimizing performance of the nitrification
process and also improved sludge settling characteristics by promoting growth
of the floc forming organisms. For reliable nitrification and improved sludge
quality, it is recommended that the minimum residual Total Alkalinity in the
clarifiers’ effluent should be maintained at 50 mg/L.
Provide a Tetra denite filter system consisting of three (3) filters, 9.5’ x 34.67’,
each equipped with all the pertinent piping and accessories such as backwash
pumps, air bumping, controls for methanol feed system, backwash waste
storage and recycle pumps, aeration blowers and filter building. Refer to
Appendix 3 for Tetra denite filter system supporting design calculations.
Provide a methanol feed system to feed supplemental carbon, if needed, for the
denitrification process. The methanol feed system will consist of one 6,000
gallon bulk storage tank, spill containment structures, two metering pumps,
controls and piping. The metering pumps will be paced with the flow and nitrate
monitoring system.
Use the existing traveling bridge filters for the backup or convert it into effluent
storage for reuse purposes.
Provide one new rotary drum thickener (designed to handle 93 gpm sludge at
0.8 percent feed solids) with a liquid polymer feed system, a flocculation tank,
washwater system, thickened sludge pump and all the necessary controls and
I
new
12.
I
13.
I
I
I
I
Page 70Town of Clayton
I
piping. Also, provide one additional thickened sludge pump to serve as a
standby unit and for alternated duty operation for both the existing and
thickeners.
Expand the aerobic sludge stabilization/storage facilities by providing one
additional aerobic sludge stabilization/storage tank (71 -6 diam. x 12 -0 SWD)
equipped with a 30 hp floating mixer, coarse bubble diffused air system, two (2)
1100 SCFM 60 hp blowers, decant facilities and stabilized sludge piping. One of
the blowers will be used as a standby unit and all three blowers, including the
existing one, will be alternated for duty.
Dispose of the stabUized sludge by land application by using a private contractor
engaged in land application of sludge in accordance with the State and EPA 503
sludge regulations.
B . Construction Cost Opinion
$310,000.00 I
$209,500.00Salaries, including fringe benefits
Utilities:
Chemicals:
50,000.00Maintenance and Repairs
Contracted Services:
2,500.00Continuing education and training
7,500.00Permit fees and dues
Page 71Town of Clayton
L
Electric
Telephone
Alum
Caustic
Polymer
Methanol
Laboratory testing
Pretreatment
Sludge disposal
1,500.00
1,000.00
20,000.00
7,500.00
20,000.00
10,000.00
30,000.00
387,000.00
2,500.00 I
I
510,000.00
290,000.00
660,000.00
1,360,000.00
130,000.00
168,000.00
487,000.00
705,000.00
470,000.00
$ 5,090,000.00
509,000.00
415,000.00
5,000.00
25,000.00
121,000.00
10,000.00
15,000.00
$ 6,190,000.00
Anaerobic selector tank
First stage anoxic tanks for 0.75 MG and 1.15 MG
oxidation ditches
Nitrate Recycle Pump Station
Oxidation ditches aeration upgrading
Tetra denite filters
Methanol feed system
Expansion to sludge thickening facilities
Expansion to aerobic sludge stab ./storage facilities
Sitework and piping (18%)
Electrical, instrumentation and controls (12%)
Total Construction Cost
Contingencies
Engineering and Construction Administration
Geotechnical work
Legal and administration
State Construction loan fee (2%)
Startup Services
Operation and Maintenance Manual
Total Project Cost
C. Annual Operation and Maintenance Manual (for 2.5 mgd plant)
I
f
I
i
J
$
D. Estimated Salvage Value
$ 1,697,000.00x $5,090,000.00
$ 1,697,500.00Total Estimated Salvage Value
E. Economic Analysis
I 1.
c.
I
I 2.
$ 6,190,000.00
8,960,000.00
I c.
I 3.
$ 1,403,100.00
1
Page 72Town of Clayton
g-
h.
Departmental supplies
Wastewater transmission cost
Insurance and Bonds
Capital Outlay
Total Annual Operation and Maintenance Cost
a.
b.
a.
b.
e.
f.
428,500.00
$ 14,721,500.00
9,000.00
51,000.00
5,000.00
40,000.00
854,000.00
( 20Treatment Work: 1 -
Basic Considerations
Planning period: 20 years
Capital cost of the project: $6,190,000.00
Annual O&M costs: $854,000.00
d. Salvage value at the end of 20 years: $ 1,697,000.00
Interest rate: 7.125 percent
Single Payment Present Worth Factor @ 7.125% for 20 years: 0.25245
Uniform Series PWF @ 7.125% for 20 years: 10.4918
Capital Recovery Factor @ 7.125 for 20 years: 0.09531
Present Worth Cost
Initial Capital Cost
Present Worth of Annual O&M Costs
$854,000.00 x 10.4918
Present Worth of Salvage Value
$1,697,000.00 x 0.25245
Net Present Worth Cost (a + b -c)
Annual Equivalent Cost
$14,721,500.00 x 0.09531
Sludge Recirc.
<■
oo
o oo
D.B.
P.S.
Influent Scum
■>
I
Ox. Basin No. 1 (0.75 MG)Sludge Recirc.
•Drain
M
Sludge Reclrc./Waste
M-Legend
-M-o
Methanol Feed System
A
L I C <•
*.<■«•
I
I
P.S.
D.B.
Anoxic
Tanks
Scum Waste to
Aerobic Digester
x. Waste Sludge to
\ Thickener /
Aerobic Digester
Exhibit 5
Schematic Flow Diagram of Alternative 4
Clayton LCWRF Upgrading for Nutrient Removal
l
l
I
l
l
l
l
l
l
I
I
l
l
Clarifier
No. 1
Tetra Denite
Filters -----
il (
L-k
Clarifier
No. 3
Effluent to
UV Disinf.
J P.S.
Alum Feed-A-
Polymer Feed -P-
]
■>; •. n
“O
£
Uj
I
M
Magnesium
Hydroxide
Feed or
Sodium
Hydroxide
----------- Wastewater / Effluent
-----------Sludge
-----------Scum
—M— Methanol Feed System
—m— Magnesium Hydroxide Feed
Alum Feed
Polymer Feed
Pump Station
Distribution Box
/'/Clarifier
No. 2 —
D.B. L
CH
i
i
i
i
I A
I Anaerobic
I Tank
A Nitrate .
J Recycle
1 GJ
ip.sj
Ur
Ox. Basin No. 2 (1.15 MG)
I
I
I
I
I
I
I
I
I
-<■
j y1r < 1 _L-Ut?
._ _TTp.s.
I
I
6.5 Alternative No. 5
This alternative (Exhibits 6 and 2b) considers providing anaerobic tanks, first stage anoxic
tank for 1.15 MG Carrousel oxidation ditch, first stage anoxic tank for 0.75 MG Carrousel
oxidation ditch, nitrate recycle pump stations, upgrading aeration capacities of the existing 0.75IMG and 1.15 MG oxidation ditches, providing second stage anoxic tanks with a methanol feed
system and reaeration tanks for nutrient removal. The existing alum and polymer feed systems will
be used for either polishing chemical phosphorus removal or improved clarification, when
I necessary. The existing magnesium hydroxide or caustic feed system will be used for pH and
alkalinity control, when necessary, for improved phosphorus removal and nitrification. TheIexisting traveling bridge filters will be used as an integrated part of the nutrient removal strategy
since removal of suspended solids by filters will help remove nitrogen and phosphorus associatedIwith the solids. This alternative also considers expansion of the sludge thickening and aerobic
sludge stabilization/storage facilities. A detailed description and cost analysis of this alternative are
given as follows.
DescriptionA.
The principal components of this alternative are described as follows:I Provide a three pass anaerobic selector tank for biological phosphorus removal1.
I process. The anaerobic selector tank will be designed for 2.0 hours of hydraulic
retention time at an average daily design flow of 2.5 mgd and will be equipped
I with 3 - 5.0 hp mixers (one for each pass). Relocate the influent and sludge
recirculation piping to the anaerobic selector tank. Provide the flexibility ofIinfluent piping to the anaerobic tank such that the influent can be fed through
either the first or second pass of the anaerobic tank. By feeding the influent to
the second pass, the first pass can be used for nitrate removal from the sludge
I recycle and true anaerobic conditions in the second and the third pass can be
maintained for the biological phosphorus removal process. Also, removal of the
nitrate from the sludge recycle will help avoid loss of easily biodegradable BODs
I
Town of Clayton Page 74
jL
I
(volatile fatty acids) through biochemical oxidation and subsequently maintain
2.
3.
I
4.
5.
I
Town of Clayton Page 75
pumps will be equipped with a manually controlled variable frequency drive for
adjustment of nitrate recycle flow. One of the pumps will be used as a standby
unit and alternated for duty.
Provide a nitrate recycle pump station to recycle the mixed liquor containing
nitrate from a 1.15 MG oxidation ditch to the anoxic tanks.The pump station will
be equipped with two recycle pumps, each rated at 6.0 mgd which is four times
the design influent flow of 1.513 mgd to the 1.15 MG oxidation ditch. Both
Provide a first stage anoxic tank for a 0.75 MG oxidation ditch train for
biological denitrification. The anoxic tanks will be designed to provide 4.0 hours
of hydraulic retention time at an ADF of 0.987 mgd and equipped with two 5.0
hp mixers.
Provide a first stage anoxic tank for 1.15 MG oxidation ditch train for biological
denitrification. The anoxic tanks will be designed to provide 4.0 hours of
hydraulic retention time at ADF of 1.513 mgd and equipped with two 7.5 hp
mixers.
the desired influent BOD/TP ratio for improved performance of the biological
phosphorus removal process. Refer to Appendix 3 for supporting design
calculations.
J
I
I
J
I
Provide a nitrate recycle pump station to recycle the mixed liquor containing
nitrate from a 0.75 MG oxidation ditch to the anoxic tanks. The pump station
will be equipped with two recycle pumps, each rated at 4.0 mgd which is
approximately four times the design influent flow of 0.987 mgd to the 0.75 MG
oxidation ditch. Both pumps will be equipped with a manually controlled
variable frequency drive for adjustment of nitrate recycle flow. One of the pumps
will be used as a standby unit and alternated for duty.
I
i
6.
7.
SCADA. It should be noted that PC with modem and screenware software for
8.
9.
Page 76Town of Clayton
Upgrade the aeration capacity in the 1.15 MG Carrousel oxidation ditch by
replacing the existing two - 50 hp two-speed aerators with two new 75 hp
aerators, each equipped with a variable frequency drive. The two removed 50 hp
aerators will be used in replacing the two existing 25 hp aerators in the 0.75 MG
Carrousel ditch. Install an adjustable effluent weir in the ditch. Provide a
SymBio process control system consisting of NADH and DO sensors, PLC, PC
with modem and screenware software for SCADA. The process control system
is included for optimum operation of BNR process under diurnal flows and
waste loadings variation and subsequent energy and chemical savings at the
plant Refer to Appendix 3 for supporting design calculations.
Upgrade the aeration capacity in the 0.75 MG Carrousel oxidation ditch by
replacing the existing two - 25 hp five-speed aerators with the two 50 hp
aerators,removed from the 1.15 MG Carrousel ditch. Install an adjustable
effluent weir in the ditch. Provide a SymBio process control system consisting
of NADH and DO sensors, PLC, PC with modem and screenware software for
SCADA will be common for both ditches. The process control system is
included for optimum operation of BNR process under diurnal flows and waste
loadings variation and subsequent energy and chemical savings at the plant.
Refer to Appendix 3 for supporting design calculations.
Use the existing alum and polymer feed system for polishing chemical
phosphorus removal and/or improved clarification, when necessary.
Use the existing magnesium hydroxide/sodium hydroxide feed system for pH
control and alkalinity addition for optimizing performance of the nitrification
process and also improved sludge settling characteristics by promoting growth
of the floc forming organisms. For reliable nitrification and improved sludge
quality, it is recommended that the minimum residual Total Alkalinity in the
clarifier’s effluent should be maintained at 50 mg/L.
10.Provide second stage anoxic tanks for biological denitrification, using
endogenous respiration. The second stage anoxic tanks will be designed for 4.0
hours of hydraulic retention time at ADF of 2.5 mgd. The anoxic tanks will be
designed as dual train, two-stage per train and each stage will be equipped with a
7.5 hp mixer. In order to provide flexibility and reliable operation, the influent
piping to anoxic tanks will be designed such that in each train the influent can be
fed to either first or second stage to control anoxic detention time necessary to
achieve denitrification and to make sure that anaerobic conditions are not created
in the anoxic tanks. Another option to control anoxic hydraulic retention time and
anaerobic conditions is to install a diffused air system in the second stage of each
train to maintain the anoxic/ aerobic conditions to a point that the desired
denitrification can be achieved.I11.Provide reaeration tanks equipped with a fine bubble diffused air system to
assimilate any BODs, TP or NHa-N released through cells lysing in second stage
anoxic tanks. The reaeration tanks will be designed for 1.0 hour of hydraulic
retention time at ADF of 2.5 mgd. Refer to Appendix 3 for supporting design
calculations.
12.Provide a methanol feed system to feed supplemental carbon, if needed, for the
denitrification process. The methanol feed system will consist of one 6,000
gallon bulk storage tank, spill containment structures, two metering pumps,
controls and piping. The metering pumps will be paced with the flow and nitrate
monitoring system.
13.Use the existing traveling bridge filters for the suspended solids removal and
associated Total Nitrogen, Total Phosphorus, and BODs removal.
14.Provide one new rotary drum thickener (designed to handle 93 gpm sludge at
Town of Clayton Page 77
I
J
J
f
I
J
I
0.8 percent feed solids) with a liquid polymer feed system, a flocculation tank.
washwater system, thickened sludge pump and all the necessary controls and
piping. Also, provide one additional thickened sludge pump to serve as a
thickeners.
Expand the aerobic sludge stabilization/storage facilities by providing one15.
additional aerobic sludge stabilization/storage tank (71*-6” diam. x 12’-0 SWD)
equipped with a 30 hp floating mixer, coarse bubble diffused air system, two (2)
1100 SCFM 60 hp blowers, decant facilities and stabilized sludge piping. One of
the blowers will be used as a standby unit and all three blowers, including the
existing one, will be alternated for duty.I Dispose of the stabilized sludge by land application by using a private contractor16.
engaged in land application of sludge in accordance with the State and EPA 503
sludge regulations.
I
I Page 78Town of Clayton
standby unit and for alternated duty operation for both the existing and new
B . Construction Cost Opinion
$310,000.00Anaerobic selector tank
$
$
C. Annual Operation and Maintenance Manual (for 2.5 mgd plant)
Salaries, including fringe benefits $209,500.00 !
Utilities:
Maintenance and Repairs 50,000.00 IContracted Services:
I
Continuing education and training 2,500.00
I
Town of Clayton Page 79
First stage anoxic tank for 0.75 MG and 1.15 MG
oxidation ditches
Nitrate Recycle Pump Station for 1.15 MG ditch
Nitrate Recycle Pump Station for 0.75 MG ditch
Oxidation ditches aeration upgrading
Second stage anoxic/reaeration tanks
Methanol feed system
Expansion to sludge thickening facilities
Expansion to aerobic sludge stab ^storage facilities
Sitework and piping (18%)
Electrical, instrumentation and controls (12%)
Total Construction Cost
Contingencies
Engineering and Construction Administration
Geotechnical work
Legal and administration
State Construction loan fee (2%)
Startup Services
Operation and Maintenance Manual
Total Project Cost
Electric
Telephone
Laboratory testing
Pretreatment
Sludge disposal
414,000.00
2,500.00
1,500.00
1,000.00
20,000.00
2,500.00
20,000.00
10,000.00
30,000.00
543,000.00
193,000.00
176,000.00
660,000.00
575,000.00
130,000.00
168,000.00
487,000.00
583,500.00
389,000.00
4,214,500.00
421,000.00
362,000.00
5,000.00
25,000.00
101,000.00
10,000.00
15,000.00
5,153,500.00
Chemicals: Alum
Caustic
Polymer
Methanol
I
I Permit fees and dues 7,500.00
$
D. Estimated Salvage Value
$x $4,214,500.00 1,405,000.00
$Total Estimated Salvage Value 1,405,000.00
E. Economic Analysis
1.
2.
$5,153,500.00
9,190,800.00
c.
$
3.
$1,333,350.00
I
Page 80Town of Clayton
Departmental supplies
Waste water transmission cost
Insurance and Bonds
Capital Outlay
Total Annual Operation and Maintenance Cost
g-
h.
a.
b.
c.
d.
a.
b.
e.
f.
354,700.00
13,989,600.00
9,000.00
51,000.00
5,000.00
40,000.00
876,000.00
Basic Considerations
Planning period: 20 years
Capital cost of the project: $5,153,500.00
Annual O&M costs: $876,000.00
Salvage value at the end of 20 years: $1,405,000.00
Interest rate: 7.125 percent
Single Payment Present Worth Factor @ 7.125% for 20 years: 0.25245
Uniform Series PWF @ 7.125% for 20 years: 10.4918
Capital Recovery Factor @7.125 for 20 years: 0.09531
Present Worth Cost
Initial Capital Cost
Present Worth of Annual O&M Costs
$876,000.00 x 10.4918
Present Worth of Salvage Value
$1,405,000.00 x 0.25245
Net Present Worth Cost (a + b -c)
Annual Equivalent Cost
$13,675,500.00 x 0.09531
( 20Treatment Work: 11 - —
Methanol Feed System
•M-M-
o o o ©]oo )I
Influent o o
D.B.
P.S.I P.S.
Scumm-
P.S.
0
Ox. Basin No. 1 (0.75 MG)Sludge Reclrc.
Sludge Recirc./Waste
Legend
-M-
-A-
Im s
1 c ip.s.
i
t
i
i
I
I
I
I
P.S.
D.B.
Nitrate
Recycle
Anoxic
Tank
Scum Waste to
Aerobic Digester
Waste Sludge to
Thickener/
Aerobic Digester
-A-
-P-
/ I ' Alum Feed |
Polymer Feed |
I
I
I
I
I
I
I
I
I
Clarifier
No. 1 -7
Second Stage Anoxic Tanks
—i---------- -----— Reaeration Tanks
Clarifier
No. 3
Exhibit 6
Schematic Flow Diagram of Alternative 5
Clayton LCWRF Upgrading for Nutrient Removal
■ i
“Q
OJQ
Oo
■'I
'•k
Clarifier Effluent
to Tertiary Filters/
UV Disinr. System
Magnesium
Hydroxide
Feed or
Sodium
Hydroxide
Q
L D.B.
G 1
------ Wastewater / Effluent
-----Sludge
------Scum
Methanol Feed System
—m— Magnesium Hydroxide Feed
Alum Feed
Polymer Feed
Pump Station
Distribution Box
//Clarifier
c/ No. 2 —
— Sludge Recirc.
1
4 Anoxic
Tank
_l I PS Drain
I
-M-------
Ox. Basin No. 2 (1.15 MG)
I
I M
I
I
I ::
Anaerobic
Tank y
Alternative No. 66.6
This alternative (Exhibits 7 and 2b) considers providing anaerobic tanks, first stage anoxic
I tank for 1.15 MG Carrousel oxidation ditch, first stage anoxic tank for 0.75 MG Carrousel
I
DescriptionA.
1.
I
I
Page 82Town of Clayton
oxidation ditch, nitrate recycle pump stations, upgrading aeration capacities of the existing 0.75
MG and 1.15 MG oxidation ditches, and providing denite filters with a methanol feed system for
nutrient removal. The existing alum and polymer feed systems will be used for either polishing
chemical phosphorus removal or improved clarification, when necessary. The existing magnesium
hydroxide or caustic feed system will be used for pH and alkalinity control, when necessary, for
improved phosphorus removal and nitrification. The existing traveling bridge filters will be used
for back up or converted into effluent storage for reuse purposes. This alternative also considers
expansion of the sludge thickening and aerobic sludge stabilization/storage facilities. A detailed
description and cost analysis of this alternative are given as follows.
The principal components of this alternative are described as follows:
Provide a three pass anaerobic selector tank for biological phosphorus removal
process. The anaerobic selector tank will be designed for 2.0 hours of hydraulic
retention time at an average daily design flow of 2.5 mgd and will be equipped with
3 - 5.0 hp mixers (one for each pass). Relocate the influent and sludge recirculation
piping to the anaerobic selector tank. Provide the flexibility of influent piping to the
anaerobic tank such that the influent can be fed through either the first or second
pass of the anaerobic tank. By feeding the influent to the second pass, the first pass
can be used for nitrate removal from the sludge recycle and true anaerobic conditions
in the second and the third pass can be maintained for the biological phosphorus
removal process. Also, removal of the nitrate from the sludge recycle will help avoid
loss of easily biodegradable BODs (volatile fatty acids) through biochemical
oxidation and subsequently maintain the desired influent BOD/TP ratio for improved
performance of the biological phosphorus removal process. Refer to Appendix 3 for
2.
denitrification. The anoxic tanks will be designed to provide 4.0 hours of hydraulic
retention time at ADF of 1.513 mgd and equipped with two 7.5 hp mixers.
Provide a nitrate recycle pump station to recycle the mixed liquor containing nitrate3.
from a 1.15 MG oxidation ditch to the anoxic tank.The pump station will be
equipped with two recycle pumps, each rated at 6.0 mgd which is four times the
design influent flow of 1.513 mgd to the 1.15 MG oxidation ditch. Both pumps will
be equipped with a manually controlled variable frequency drive for adjustment of
nitrate recycle flow. One of the pumps will be used as a standby unit and alternated
for duty.
Provide a first stage anoxic tank for a 0.75 MG oxidation ditch train for biological4.
denitrification. The anoxic tanks will be designed to provide 4.0 hours of hydraulic
retention time at an ADF of 0.987 mgd and equipped with two 5.0 hp mixers.
Provide a nitrate recycle pump station to recycle the mixed liquor containing nitrate5.
from a 0.75 MG oxidation ditch to the anoxic tanks. The pump station will be
equipped with two recycle pumps, each rated at 4.0 mgd which is approximately
four times the design influent flow of 0.987 mgd to the 0.75 MG oxidation ditch.
Both pumps will be equipped with a manually controlled variable frequency drive
for adjustment of nitrate recycle flow. One of the pumps will be used as a standby
unit and alternated for duty.
Upgrade the aeration capacity in the 1.15 MG Carrousel oxidation ditch by replacing6.
the existing two - 50 hp two-speed aerators with two new 75 hp aerators, each Iequipped with a variable frequency drive. The two removed 50 hp aerators will be
used in replacing the two existing 25 hp aerators in the 0.75 MG Carrousel ditch.
Install an adjustable effluent weir in the ditch. Provide a SymBio process control
Page 83Town of Clayton
supporting design calculations.
Provide a first stage anoxic tank for 1.15 MG oxidation ditch train for biological
I
I
7.
8.
9.
10.
Page 84Town of Clayton
I
should be maintained at 50 mg/L.
Provide a Tetra denite filter system consisting of three (3) filters, 9.5’ x 34.67 , each
equipped with all the pertinent piping and accessories such as backwash pumps, air
bumping, controls for methanol feed system, backwash waste storage and recycle
pumps, aeration blowers and filter building. Refer to Appendix 3 for total filter
system consisting of NADH and DO sensors, PLC, PC with modem and
screenware software for SCADA. The process control system is included for
optimum operation of BNR process under diurnal flows and waste loadings
variation and subsequent energy and chemical savings at the plant. Refer to
Appendix 3 for supporting design calculations.
Upgrade the aeration capacity in the 1.15 MG Carrousel oxidation ditch by replacing
the existing two - 25 hp five-speed aerators with the two 50 hp aerators,removed
from the 1.15 MG Carrousel ditch. Install an adjustable effluent weir in the ditch.
Provide a SymBio process control system consisting of NADH and DO sensors,
PLC, PC with modem and screenware software for SCADA. It should be noted that
PC with modem and screenware software for SCADA will be common for both
ditches. The process control system is included for optimum operation of BNR
process under diurnal flows and waste loadings variation and subsequent energy and
chemical savings at the plant. Refer to Appendix 3 for supporting design
calculations.
Use the existing alum and polymer feed system for polishing chemical phosphorus
removal and/or improved clarification, when necessary.
Use the existing magnesium hydroxide/sodium hydroxide feed system for pH
control and alkalinity addition for optimizing performance of the nitrification process
and also improved sludge settling characteristics by promoting growth of the floc
forming organisms. For reliable nitrification and improved sludge quality, it is
recommended that the minimum residual Total Alkalinity in the clarifiers effluent
11.I
12.
for reuse.
Provide one new rotary drum thickener (designed to handle 93 gpm sludge at 0.813.
14.
alternated for duty.
Dispose of the stabilized sludge by land application by using a private contractor15.
engaged in land application of sludge in accordance with the State and EPA 503
sludge regulations.
Page 85Town of Clayton
system.
Use the existing traveling bridge filters for backup or convert into effluent storage
percent feed solids) with a liquid polymer feed system, a flocculation tank,
washwater system, thickened sludge pump and all the necessary controls and
piping. Also, provide one additional thickened sludge pump to serve as a standby
unit and for alternated duty operation for both the existing and new thickeners.
I
I
system supporting design calculations.
Provide a methanol feed system to feed supplemental carbon, if needed, for the
denitrification process. The methanol feed system will consist of one 6,000 gallon
bulk storage tank, spill containment structures, two metering pumps, controls and
piping. The metering pumps will be paced with the flow and nitrate monitoring
Expand the aerobic sludge stabilization/storage facilities by providing one additional
aerobic sludge stabilization/storage tank (71’-6” diam. x 12’-0 SWD) equipped with
a 30 hp floating mixer, coarse bubble diffused air system, two (2) 1100 SCFM 60
hp blowers, decant facilities and stabilized sludge piping. One of the blowers will be
used as a standby unit and all three blowers, including the existing one, will be
B . Construction Cost Opinion
$310,000.00
I
$209,500.00Salaries, including fringe benefits
Utilities:
Chemicals:
50,000.00Maintenance and Repairs
Contracted Services:I
2,500.00Continuing education and training
Page 86Town of Clayton
Electric
Telephone
Alum
Caustic
Polymer
Methanol
Laboratory testing
Pretreatment
Sludge disposal
20,000.00
10,000.00
30,000.00
Anaerobic selector tank
First stage anoxic tank for 0.75 MG and 1.15 MG
oxidation ditches
Nitrate Recycle Pump Station for 1.15 MG ditch
Nitrate Recycle Pump Station for 0.75 MG ditch
Oxidation ditches aeration upgrading
Tetra denite filters
Methanol feed system
Expansion to sludge thickening facilities
Expansion to aerobic sludge stab ./storage facilities
Sitework and piping (18%)
Electrical, instrumentation and controls (12%)
Total Construction Cost
Contingencies
Engineering and Construction Administration
Geotechnical work
Legal and administration
State Construction loan fee (2%)
Startup Services
Operation and Maintenance Manual
Total Project Cost
399,000.00
2,500.00
1,500.00
1,000.00
20,000.00
7,500.00
543,000.00
193,000.00
176,000.00
660,000.00
1,360,000.00
130,000.00
168,000.00
487,000.00
725,000.00
483,000.00
$ 5,235,000.00
523,500.00
421,500.00
5,000.00
25,000.00
125,000.00
10,000.00
15,000.00
$ 6,360,000.00
C. Annual Operation and Maintenance Manual (for 2.5 mgd plant)
Permit fees and dues 7,500.00
$
D. Estimated Salvage Value
$1,745,000.00
$Total Estimated Salvage Value 1,745,000.00 IE. Economic Analysis
1.
2.I$6,360,000.00
9,086,000.00
c.
$
3.
$1,430,174.00
j J
Town of Clayton Page 87
I
Departmental supplies
Waste water transmission cost
Insurance and Bonds
Capital Outlay
Total Annual Operation and Maintenance Cost
g-
h.
e.
f.
a.
b.
a.
b.
c.
d.
440,500.00
15,005,500.00
9,000.00
51,000.00
5,000.00
40,000.00
866,000.00
Basic Considerations
Planning period: 20 years
Capital cost of the project: $6,360,000.00
Annual O&M costs: $866,000.00
Salvage value at the end of 20 years: $1,745,000.00
Interest rate: 7.125 percent
Single Payment Present Worth Factor @ 7.125% for 20 years: 0.25245
Uniform Series PWF @ 7.125% for 20 years: 10.4918
Capital Recovery Factor @ 7.125 for 20 years: 0.09531
Present Worth Cost
Initial Capital Cost
Present Worth of Annual O&M Costs
$866,000.00 x 10.4918
Present Worth of Salvage Value
$1,745,000.00 x 0.25245
Net Present Worth Cost (a + b -c)
Annual Equivalent Cost
$15,005,500.00 x 0.09531
Treatment Work: (1 - x $5,235,000.00
-M-
)
0
©D.B.
p.s/j/
Influent
D.B.
I
Ox. Basin No. 1 (0.75 MG)Sludge Recirc.
•DrainP.S.
~ I
Sludge Reclrc./Waste
Legend
Eff. Pump Sta.
—m-
I
I
P.S.
D.B.
Anoxic
Tanks
Scum Waste to
Aerobic Digester
Waste Sludge to
Thickener /
Aerobic Digester
I
I
I
I
I
I
I
I
I
I
I
Clarifier
No. 1-^
I
I
Second Stage Anoxic Tanks
-------------------— Reaeration Tanks
I
I
Clarifier
No. 3
| P.S.
Alum Feed-A—
Polymer Feed -P-
1
UV Dislnf /
Chlorination -
Dechlorination
&
&
cz
ZJ t
Nitrate Recycle
Magnesium X
Hydroxide —'
Feed or
Sodium
Sydroxide
1 ~
—J
1 c jp.SJ
t -_L-
----------- Wastewater / Effluent
-----------Sludge
---------Scum
—M— Methanol Feed System
—m— Magnesium Hydroxide Feed
—A— Alum Feed
Polymer Feed
Pump Station
Distribution Box
M-
■“1
Ox. Basin No. 2 (1.15 MG) I
I
I
I
I
I
I
I
I
I-----------
I
I
I
I Anaerobic
! Tank
Exhibit 8
Schematic Flow Diagram of Alternative 7
Clayton LCWRF Upgrading for Nutrient Removal
! I I
L-H
y To Effluent Storage Lagoon
at Land Application Site
Scum
///Clarifier
No. 2 —
Tertiary
Filters
— Sludge Recirc.
------------
t" To Neuse River
Eff. Pump Sta.
y\I
-W
j— Methanol Feed System
. 36 mgal Storage Lagoon /
i
Exhibit 9
Effluent Transport from Clayton WWTP to Proposed Land Application Site
Maps: USGS Clayton & Powhatan, North Carolina
)
I 0
»
wl
g
tJSSBRWF' W(l ’ W Pw-<'WW;
I®, \ B-l■'’OSk /■ •" -•.■■<■■ • Vr'jX'
>
■ W
W-'W"12” Force Main
~ '8
305 acre Land Application Site
As?
!> i’ur?jj ■ .-■>->....--,,■ .J/> y ,■{ s
-^w•L>
||rA;
/■/LSI <A'
OSg^g)
Alternative No. 76.7
I
1.
2.
harvesting and site management.
Page 90Town of Clayton
This alternative (Exhibits 8, 9 and 2b) considers discharging 0.6 mgd of the effluent flow
by land application and the remaining 1.9 mgd to the Neuse River for rerating of the plant to 2.5
mgd. The detailed description and cost analysis for this alternative are summarized as follows. It
should be noted that a non-discharge alternative considering land application and elimination of the
entire 2.5 mgd discharge to the Neuse River was also considered for rerating of the plant to 2.5
mgd. However, the alternative was eliminated from further considerations due to the following
reasons: (1) At an average hydraulic loading rate of 0.75 inch/wk, the wetted area required for land
application of 2.5 mgd flow is 860 acres. Allowing area requirements for buffers, access roads,
effluent storage lagoon, and uneconomic remnant, it is estimated that the total area required for the
land application system would be approximately 1,200 acres; (2) difficulty of acquiring land
parcel(s) needed for land application of wastewater; (3) environmental concern associated with
transport of effluent to land application site(s) and use of potential site(s) for land application of the
effluent, and (4) significant cost associated with the alternative.
3. Provide a 36 million gallon effluent storage lagoon for storage of effluent when
land application of effluent cannot take place due to inclement weather
conditions, saturated soils and high groundwater conditions, cover crop
A. Description
Provide the preapplication treatment system as described in Section 6.3,
Alternative No. 3. Such a preapplication system is necessary to consistently
comply with the allocated nitrogen discharge of 21,400 lb TN/year.
Provide a effluent transport system to convey the preapplication treatment
system effluent to effluent storage lagoon at the proposed land application site.
The effluent transport system will consist of providing an effluent pump station
equipped with two 60 hp pumps, each rated at 1,050 gpm, and 37,000 lineal
feet of 12-inch diameter ductile iron force main.
Provide a chlorination system for disinfection of effluent prior to land4.
application.
Provide a spray irrigation pump station equipped with three (3) - 1200 gpm5.
pumps, including one standby, with necessary controls and piping. Provide an
automatic strainer on the spray header piping to remove solids for efficient
operation of the spray irrigation system.
Provide header piping and sold-set type spray irrigation system for land6.
application of effluent. The average hydraulic application rate will be
approximately 0.75 inch/wk and area requirement for spray irrigation of 0.6
mgd flow is estimated to be approximately 206 acres.
Provide monitoring wells for measurement of groundwater table and sampling7.
of groundwater for compliance with the water quality parameters included in the
nondischarge permit.
Provide access roads for management and operation of the land application8.
system. Provide fencing for the effluent storage lagoon and land application site
to comply with the State regulatory requirements.
9.
B. Construction Cost Opinion
Sub Total\<»
$
$Sub TotaK2)
. j
I
Page 91Town of Clayton
1. Preapplication Treatment System
From Section 6.3.B
Provide an operation and control building and a storage and maintenance
building.
2. Effluent Transport System
Effluent pump station
37,000 LF of 12-inch D.I. forcemain
Site work and piping
Electrical
1
$
4,069,000.00
4,069,000.00
150,000.00
960,000.00
25,000.00
20,000.00
1,155,000.00
$
I Sub Totals)
C. Annual Operation and Maintenance Manual (for 2.5 mgd plant)
232,000.00$Salaries, including fringe benefits
Utilities:
Chemicals:
60,000.00Maintenance and Repairs
Page 92Town of Clayton
Electric
Telephone
Alum
Caustic
Polymer
Methanol
Chlorine
$
$
$.
$
3. Land Application System
36 mil. gal. effluent storage lagoon
Spray irrigation pump station
Chlorination system
Spray irrigation system, including header piping
Sitework and piping
Site preparation, liming and seeding
Fencing and access roads
Monitoring wells
Electrical and instrumentation
Operation and control building
Storage and maintenance building
430,000.00
2,500.00
1,500.00
1,000.00
20,000.00
2,500.00
2,000.00
Total Construction Cost (1 +2 + 3)
Contingencies
Engineering and Construction Administration
Geotechnical work
Site evaluation by soil scientist
Legal and administrative
State Construction loan fee (3%)
Start-up Services
Operation and Maintenance Manual
Land, 270 acres @ $5,000/ac.
TOTAL PROJECT COST
850,000.00
250,000.00
45,000.00
I, 133,000.00
170,000.00
103,000.00
160,000.00
10,000.00
40,000.00
60,000.00
40,000,00
2,861,000.00
8,085,000.00
808,500.00
575,000.00
10,000.00
25,000.00
35,000.00
218,000.00
15,000.00
19,500.00
1,350,000.00
II, 141,000.00
Contracted Services:
I
$
D. Estimated Salvage Value
$ 2,375,500.00
1.
I
2.
$11,141,000.00
9,857,000.00
C.
$
3.
$1,873,937.00
Town of Clayton Page 93
g-
h.
i.
Laboratory testing
Pretreatment
Sludge disposal
Continuing education and training
Permit fees and dues
Departmental supplies
Wastewater transmission cost
Insurance and Bonds
Capital Outlay
Total Annual Operation and Maintenance Cost
$
$
480,000.00
2,438,000
$ 5,293,500.00
Annual Equivalent Cost
$19,661,500.00 x 0.09531
a.
b.
c.
d.
a.
b.
I
e.
f.
1.336,500.00
19,661,500.00
25,000.00
10,000.00
30,000.00
2,500.00
8,000.00
9,000.00
51,000.00
7,500.00
45,000,00
939,500.00
Forcemain: $960,000 x 0.5
Land: $1,350,000 x 1.80611
Total Estimated Salvage Value
E. Economic Analysis
Basic Considerations
Planning period: 20 years
Capital cost of the project: $11,141,000.00
Annual O&M costs: $939,500.00
Salvage value at the end of 20 years: $5,293,500.00
Interest rate: 7.125 percent
Single Payment Present Worth Factor @ 7.125% for 20 years: 0.25245
Uniform Series PWF @ 7.125% for 20 years: 10.4918
Capital Recovery Factor @ 7.125 for 20 years: 0.09531
Land appreciation factor (EPA): 1.80611
Present Worth Cost
Initial Capital Cost
Present Worth of Annual O&M Costs
$939,500.00 x 10.4918
Present Worth of Salvage Value
$5,293,500.00 x 0.25245
Net Present Worth Cost (a + b -c)
( 20 'iTreatment Work: 1 - — x ($8,085,000.00 - $960,000)
TABLE 4
SUMMARY OF ALTERNATIVE EVALUATION
Alt. No. 7Alt. No. 6Alt. No. 4 Alt. No. 5Alt. No. 3Alt. No. 2Alt. No. 1Economic Parameters
$5,153,500 $6,360,000 11,141,000$6,190,000$4,495,5006,609,500$5,417,0001. Capital Cost of the Project
939;866,000876,000854,000864,000837,000847,5002. Annual O&M Costs
5,293,5001,405,000 1,745,0001,697,0001,356,5001,816,0001,476,0003. Salvage Value
9,857,0009,086,0009,190,8008,960,0009,065,0008,781,5008,891,800
1,336,500440,500354,700428,500342,500458,500372,800
$19,661 kO$15,005,500$13,989,600$14,721,500$13,218,000$14,932,500$13,936,000
5. Present Worth of Salvage
Value
4. Present Worth of Annual
O&M Cost
6. Net Present Worth Cost
(1+4-5)
I
£
ri •
6.8 Summary of Alternative Evaluation
A summary of the cost analysis for the alternatives evaluated is given in Table 4. Based
upon the evaluation, it is evident that Alternative 3 has the least present worth cost and provides the
most cost-effective solution to the Town for nutrient removal at a rerated plant capacity of 2.5 mgd.
The significance of this alternative is that for total nitrogen removal it considers detached, first
stage anoxic tanks and single nitrate recycle pump stations for both oxidation ditches and second
stage anoxic tank followed by reaeration tanks. More operation attention will be required to
properly operate second stage anoxic tanks because of the possibility of creating anaerobic
conditions under low flow situations and secondary phosphorus release. In this situation, a
polishing chemical (alum) feed will be required for phosphorus removal. Provision of Tetra Denite
filters with a methanol feed system is a better option when compared with the second stage anoxic
tanks followed by reaeration tanks. This is because no mixed liquor solids are involved and the
filter system operation can be effectively controlled by pacing the methanol feed system with the
effluent nitrate monitoring system and effluent flow. However, the present worth for using the
Tetra filter system (Alternative No. 4) is $1,503,500.00 higher when compared with the least cost
alternative using second stage anoxic tanks followed by reaeration tanks.
The second least present worth cost alternative is Alternative No. 1 which considers
modifying the existing oxidation ditches into Carrousel denite R process to include first stage
anoxic tanks and denitrification gates. The big advantage of this alternative is that it does not
require a nitrate recycle pump station and nitrate containing mixed liquor can be recycled up to 15
times the average daily flow to each ditch meaning more nitrate removal can be achieved through
first stage anoxic tanks. Also, this alternative offers dedicated first stage anoxic tanks for each ditch
Iand nitrate recycle flows can be varied for nitrate reduction by simple adjustment of denite gates.
The only disadvantage of this alternative is that since it involved the structural modifications to the
existing oxidation ditches, one of the ditches has to be taken out of service at a time to make
necessary modifications. Under this situation the Town will be required to obtain permission from
the N.C. Division of Water Quality for change in effluent limitations that can be met reasonably
Town of Clayton Page 95.
!J
I
effluent storage tank for backwashng, or for effluent reuse.
Page 96Town of Clayton
station train for flexible operation.
Alternative No. 7 which considers discharging 0.6 mgd of effluent flow by land application
and the remaining 1.9 mgd to the Neuse River for rerating of plant to 2.5 mgd has the highest
present worth cost and subsequently is the most costly alternative for complying with the nitrogen
discharge requirements.
Based upon the alternative evaluation it is recognized that the Alternative No. 3 provides the
most cost-effective solution to the Town for nutrient removal at the rerated flow of 2.5 mgd.
However, considering the benefits in terms of flexibility and reliability provided by Alternative No.
1 and Alternative No. 5 it is recommended the Town should consider Alternative No. 1 for
implementation. If by talking with the N.C. Division of Water Quality it is determined that getting
the permission for modifying effluent limits during the construction modifications of the existing
oxidation ditches it is not possible, then the Town should consider implementing Alternative No.
5. Considering the stringent annual total nitrogen limit of 21,400 Ib/year (2.811 mg/L) and
monthly average Total Phosphorus limits of 1.0 mg/L, provision of a Tetra filter system offers the
most reliable technological advantage when composed with the second anoxic tanks followed by
reaeration tanks. It is recognized that provision of a Tetra filter system would add $1,192,500.00
and $1,206,500.00 to the construction cost of Alternative No. 1 and Alternative No. 5,
respectively. The Town has to make a decision whether to go with the Tetra filter system state-of-
art technology. The existing filters can be modified into filter backwash storage for recycling.
with the 0.75 MG ditch in service during the construction phase. The existing trickling filter plant
can be operated to its optimum efficiency to mitigate any adverse impact during the construction
phase.
The third least present worth cost alternative is Alternative No. 5 which consider providing
a (detached) first stage anoxic tank and nitrate recycle pump station for each oxidation ditch and a
second stage anoxic tank followed by reaeration tanks for total nitrogen removal. This alternative
offers individual controls for each first stage anoxic tank, oxidation ditch and nitrate recycle pump
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EVALUATION OF EFFLUENT (RECLAIMED WATER) REUSE7.0
The State of North Carolina has published the regulatory requirements for reclaimed water
use in the North Carolina Administrative Code Section: 15 A NCAC 2H .0200-Waste Not
Discharged to Surface Waters. A copy of the regulatory requirements is included in Appendix 4 of
this report. The intent of the regulatory requirements is to encourage the beneficial use of the
State’s water resources concurrent with the protection of public health and environment.
The types of reclaimed water use that are currently practiced successfully includes irrigation
of agricultural lands, golf courses, cemeteries, parks, school grounds, industrial and commercial
site grounds, landscape areas, and highway medians. Reclaimed water can also be used for toilet
and urinal flushing, industrial cooling and process water, groundwater recharge, chiller water in
commercial air conditioning systems, vehicle washing, fire protection, street cleaning, recreational
impoundments, decorative ponds and fountains, dust control during construction, and soil
compaction for construction purposes.
Potential reuse customers within and adjacent to the Town of Clayton were contacted to
discuss reuse opportunities. The findings of the reuse opportunities are summarized as follows:
A.Clayton Agricultural Research Station
Clayton Agricultural Research Station was contacted to discuss the reuse opportunities
through irrigation of agricultural research plots. Mr. George Clark, Superintendent of the Research
Station advised us that they do control experiments and they can not use reclaimed wastewater.
Accordingly, the reuse potential at this site was deleted from further considerations.
B.Clemmons Educational State Forest
Clemmons Educational State Forest, located along Old Interstate 70, was contacted to
discuss irrigation opportunities with reuse wastewater. The discussion revealed that most of the
facility’s operations have been moved to Goldsboro, North Carolina. Tree seedlings are no longer
cultivated at the Clayton facility and the old irrigation system has been removed because systematic
irrigation is no longer performed at the site.
Town of Clayton Page 97
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Page 98Town of Clayton
Although the facility in Goldsboro performs constant irrigation and has a permanent
irrigation system installed, the expenses associated with transporting reclaimed water 35 miles to
the Goldsboro facility from Clayton are simply too high to consider this alternative.
C. Effluent Reuse for Construction and Street Washing
The water use for construction and street washing in Clayton is estimated to be
approximately 50,000 gpd. Considering 5 days/wk, 50 wk/year and allowing a factor of 60
percent for construction and street washing activities, the annual water requirement is estimated to
be approximately 7.5 million gallons. At an effluent, a TN concentration of 3.0 mg/L, the total
nitrogen reduction through such reuse of reclaimed activities will be approximately 187 lbs.
TN/year. In terms of nutrient offset payment, the Town could save approximately $123,420.
D. River Ridge Golf Course
Golf Course irrigation with reuse wastewater was discussed with River Ridge Golf
Course, located along the Neuse River southeast of the Town. The discussion revealed that River
Ridge has already established an agreement with the City of Raleigh to accept a portion of its
effluent discharge for irrigation purposes and that reuse of reclaimed wastewater from the Town of
Clayton would not be desired.
E. Pine Hollow Golf Course
The Town of Clayton has the opportunity to redirect a portion of its discharge to nearby
Pine Hollow Golf Course to manage and alleviate a portion of nitrogen discharge to the nutrient
sensitive Neuse River. Pine Hollow Golf Course is a 150 acre, public 18 hole course that irrigates
approximately 300,000 gpd for 180 days per year. After renovation in May 2001, the golf course
will require a total of 65 acres to be irrigated. Strong interest in the project has been demonstrated
from the manager of the golf course.
Pine Hollow golf course currently uses two (2) - 780 gpm pumps rated at 140 psi to
irrigate the course from 9:00 P.M. until 6:00 A.M. Irrigation water is pumped from the existing
pond on Hole #5. When the water level gets low in the pond, additional water is released from a
smaller pond, on Hole #6, which is just upstream of Hole #5. If both ponds become low, water is
1.
All essential treatment units shall be provided in duplicate.2.
The treatment process shall produce a tertiary quality effluent (filtered or equivalent)3.
a.
TSS of less than or equal to 10 mg/L.
A monthly geometric mean fecal coliform level of less than or equal to 14/100b.
mL and a daily maximum fecal coliform of less than or equal to 25/100 mL.
A monthly average BODs of less than or equal to 10 mg/L and a daily maximumc.
BODs of less than or equal to 15 mg/L.
A monthly average NHs of less than or equal to 4 mg/L and a daily maximumd.
NFL of less than or equal to 6 mg/L.
Continuous on-line monitoring and recording for turbidity or particle count and flow4.
Ishall be provided prior to reuse.
Effluent from the treatment facility shall not be discharged to the reuse distribution5.
system if either the turbidity exceeds 10 NTU or if the fecal coliform levels cannot
Ibe met. The facility must have the ability to return the effluent back to the treatment
facility or otherwise meet the effluent requirements prior to final disposition.
6.
provided.
Page 99Town of Clayton
then pumped through an above ground pipe across Hole #8 from a third pond on Hole #10 into the
pond on Hole #5. Providing consistent reuse wastewater will alleviate the hassles associated with
the manual manipulation of the pond level on Hole #5.
The regulatory requirements for reuse of reclaimed municipal wastewater for irrigation of
An automatically activated standby power source or other means to prevent
improperly treated wastewater from entering the reuse distribution system shall be
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golf courses are summarized below:
Aerated flow equalization facilities with a capacity based upon either a representative
diurnal hydrograph or at least 25 percent of the daily system design flow.
prior to reuse with the following quality:
A monthly average TSS of less than or equal to 5 mg/L and a daily maximum
classification on call 24 hours/day.
long as it can be demonstrated that other8.
utilized.
and associated cost s are summarized as follows:
a.
b.
I c.
d.
e.
f.
I g-
soil absorption and water needs of the cover crop at the site.
Page 100Town of Clayton
For other specific requirements, refer to the regulations included in Appendix 4.
Considering the willingness of the Pine Hollow Golf Course management in reuse of the Clayton
LCWRF reclaimed wastewater, a detailed description of the required facilities (Exhibits 10 and 11)
the reuse water quality requirements.
Provide approximately 24,000 linear feet of 6-inch force main to transport a
portion of the Clayton LCWRF effluent to Pine Hollow Golf Course.
Use the existing irrigation system at the Pine Hollow Golf Course.
Provide level control system in the irrigation pond at the golf course and
telemetry system for operation of the effluent pumps at the Clayton LCWRF.
Provide a continuous online flow and turbidity monitoring system for the
1. Description
Provide an effluent pump station consisting of a 8-inch diameter precast wet
well and two 200 gpm pumps with necessary piping and control.
Provide either a gas, liquid, or tablet type chlorine system for compliance with
No storage facilities are required as
permitted disposal options are available if the reclaimed water cannot be completely
effluent flow pumped to the irrigation pond.
Have the golf course site evaluated by a soil scientist, agronomist or an
individual with at least three years experience in the comprehensive evaluation
of soils to determine site specific application rate(s), considering the maximum
7. There shall be a certified operator of a grade equivalent or greater than the facility
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It should be noted that no aerated flow equalization facilities with a capacity based upon
either a representative diurnal hydrograph or at least 25 percent of the daily system design flow are
considered in the project because of the availability of the effluent storage ponds for irrigation at the
golf course, and effluent discharge can be managed by using a combination of discharge and reuse
options. Considering the present water use of 300,000 gallons per day for 180 days per year the
total irrigation volume required per year is approximately 54 million gallons. At an effluent Total
Nitrogen concentration of 3.0 mg/L, the total nitrogen reduction through this reuse alternative is
Iestimated to be 1,351 lb TN/year. Such reduction in the total nitrogen discharge would help in
terms of compliance with the allocated total nitrogen discharge of 21,400 lb TN/year at an effluent
TN concentration of approximately 3.0 mg/L instead of 2.81 mg/L at the rerated plant capacity of
2.5 mgd. In terms of nutrient offset payment to the State, the reduction of 1,351 lb TN/year
nitrogen discharge to Neuse River could save the Town $891,660.00, if the Town elects to buy
nutrient offset payments from the State. It should be noted that the effluent flow that can be
irrigated on the golf course will be determined during the site evaluation by a soil scientist or Iagronomist and therefore, the amount of effluent reuse at the golf course may vary. This option
will require a long-term agreement between the Town and the Owner of the Pine Hollow Golf
Course. The funding for this reuse project can be obtained through a Clean Water Bond Fund,
Clean Water Trust Fund and State Revolving Loan Fund.
2. Construction Cost Opinion
Town of Clayton Page 101 I
Effluent pump station
Chlorination system
24,000 LF, 6-inch diam. forcemain @ $16/LF
35 sq. yds. of pavement cut w/2’ cut width
Road crossing boring w/encasement pipe
Railroad crossing
3 minor creek crossings
5 air release valves
Erosion control
Turbidity and flow monitoring
$ 50,000.00
30,000.00
384,000.00
1,800.00
40,000.00
4,000.00
8,000.00
15,000.00
1,500.00
7,500.00
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Page 102Town of Clayton
Telemetry system
Mobilization and insurance
Electrical
Total Construction Cost
Contingencies, 10%
Engineering and construction administration
Site evaluation by soil scientist
TOTAL PROJECT COST
22,500.00
22,500.00
10,000.00
$580,500.00
58,000.00
84,500.00
10,000.00
$733,000.00
X
Source: USGS, Clayton, N.C.
Exhibit 10
Proposed Force Main Route to Pine Hollow Golf Course
Page 103
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