NC0066516_Environmental Assessment_19890912

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DIVISION OF ENVIRONMENTAL MANAGEMENT
September 12, 1989
M E M O R A N D U M
TO: Alan Clark
THROUGH: Trevor Clements"
SUBJECT: Revised Draft Environmental Assessment for the Proposed
Fuquay-Varina WWTP on Terrible Creek
NPDES No. NCO066516
Wake County
Technical Support's comments on the initial Draft Environmental Assessment (EA)
for the Fuquay-Varina WWTP (see memo dated f9/21/89) recommended that the ramifications
of a total phosphorus limit of 0.5 mg/1 to 2 mg/1 and a total nitrogen limit of 3 mg/1
to 6 mg/1 be discussed in terms of alternative plant designs and associated costs.
The intent of this recommendation was to promote an analysis of the environmental and
economic trade-offs between biological and chemical nutrient removal. The proposed
activated sludge treatment facility consists of a single stage extended aeration pro-
cess with chemical feed for phosphorus removal. Nitrogen removal is not addressed in
the EA. Apparently the potential for a total nitrogen limit was interpreted as a
more stringent limit on ammonia.
There is growing evidence that BOD, phosphorus, and nitrogen can be simulta-
neously removed from municipal wastewater at little or no additional expense than
removing BOD alone. This is attributed to the potential savings from reduced
chemical storage and feed equipment costs and reduced sludge handling expenses.
For facilities that nitrify, there may be a cost savings in incorporating de -
nitrification in the treatment process. Mention; - is made in the EA of the ex-
istence of several technologies for biological BOD, phosphorus, and nitrogen
removal, however, no cost comparisons are developed.
The EA states that.if the NPDES permit is modified)a comparison between biologi-
cal and chemical nutrient removal would be made. It is recommended that the Environ-
mental Assessment include a biological nutrient removal alternative explicitly tar-
geted at developing a comparison between chemical and biological removal of total
phosphorus to 0.5 mg/1 to 2 mg/l and total nitrogen to 3 mg/l to 6 mg/l.
If you need further assistance on this matter, please contact me at ext. 515.
cc: Tim Donnely

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State of North Carolina
Department of Natural Resources and Community Development
Division of Environmental Management
512 North Salisbury Street • Raleigh, North Carolina 27611
James G. Martin, Governor �Tuly 19 , 19 8 9
William W. Cobey, Jr., Secretary
Mr, Al.an R. Keith, P.E.
Diehl. and Phillips, P.A.
219 East Chatham Street
Cary, NC 27611
` Dear Mr. Keith:
R. Paul Wilms
Director
The Division of Environmental Management has reviewed the
Enviroiunentai Assessment— (EA) for the Town of Fuquay-Varina' s
proposed Terrible Creek wastewater treatment plant. Despite the
lengthiness of the comments, presented below, the EA is generally
thorough in identifying and discussing the major primary and
secondary environmental impacts associated with construction and
operation of the proposed plant.
1. Permit Limits and Plant Design
The permit limits discussed in the EA are those that were
issued in a draft NPDES permit in December 1986. However', an
Environmental Management Commission (EMC) ruling in January 1988,
that reclassified the Neuse River watershed as nutrient
sensitive, requires that proposed new and expanding NPDES waste
treatment facilities must limit phosporus to a maximum
concentration of 2 mg/1 and that all plants must be meeting this
phosphorus lirnit by May 1, 1993. In addition, ongoing
studies in the Neuse River Basin indicate that further
reductions in phosphorus and/or nitrogen may be needed in the
future. It. possible that nutrient limits may be set from 2 mg/1
to 0.5 mg/1 for phosphorus and from 6gm/1 down to 3 mg/1 for
nitrogen.
Even though the Terrible Creek WWTP NPDES discharge permit
application was submitted to DEM prior to January of 1988, the
plant site has not yet been identified and no formal_ plant design
work has begun. Therefore, there is a strong liklihood that DEM
will consider imposing nutrient limits if a permit is approved
for this project and the plant is operational prior to May 1,
1993. However, even if the permit does not contain a phosphorus
limit until May 1993, the plant should be designed for phosporus,
and possibly nitrogen, removal in anticipation of having to meet
the May 1993 requirement. The EA, therefore, needs.to discuss
P.O. Box 27687, Raleigh, North Carolina 27611-7687 Telephone [phone]
An Equal Opportunity Affirmative Action Employer

Mr. Alan R. Keith
July 19, 1989
Page two
what will be done to meet the May 1, 1993 phosphorus limit and
should also discuss the ramifications in terms of cost and plant
design to meet the possible tighter nutrient limits presented in
the preceding paragraph.
2. Sludge Management
Sludge disposal from this plant will require a separate
permit and possibly a separate EA or EIS. However, for the
purposes of this EA, some additional information should be
provided on sludge management since it is an integral part of the
wastewater treatment process. It is recommended that the EA
include an estimate of the volume of sludge that will be
generated by the plant at full capacity and to estimate the
acreage of land that will be required for land application of the
sludge at agronomic rates. For the purposes of these
estimations, it should be assumed that the plant is designed and
operated to meet the range of nutrient limits presented earlier
(0.5 to 2.0 mg/l for phophorus and 3.0 to 6.0 mg/l for nitrogen)
The EA should also state that there is a reasonable liklihood
that the Town can purchase or obtain permission from a sufficient
number of private property owners to meet this acreage
requirement.
3. Nonpoint Source Impacts
The EA does a reasonably good job in addressing the potential
increase in nonpoint source (NPS) pollution associated with urban,
growth in the Terrible Creek watershed but the mitigation
measures outlined in Section 7.6 are inadequate. Existing
sedimentation and erosion control measures will help limit the
impacts of land disturbing activities while work is in progress
but they would not be expected to limit long term NPS pollutant
loading rates associated with development. Also, it unclear how
building code restrictions and industrial pretreatment
regulations will have a significant affect on limiting NPS
pollution. If the local government has any watershed management
or stormwater ordinances that would would address NPS pollution,
it would be helpful to describe them in the EA or include them in
an appendix. The EA should also address the need to develop such
ordinances, if they do not exist, and to offer examples of some
measures that might be reasonably employed to limit NPS
pollution.
4. Project Alternatives
The fact that the Town has applied for a permit and is
preparing an EA attests to the fact that it desires, or sees a
need for the proposed project; however, in reading the EA, a
strong argument could be made for the no build alternative.
The EA states that the area will be developed whether the plant

Mr. Alan R. Keith
July 19, 1989
Page Three
is built or not. The main advantage the proposed plant has
over the no build alternative is that it would allow higher
density development and would centralize wastewater treatment
facilities in the basin as opposed to the possiblity of having
several package plants (which is speculative and controllable
through land development controls). The no build alternative, on
the other hand, would seemingly cost the Town much less and would
have much less impact on the creek and Neuse River by greatly
decreasing the overall volume of point discharges, generating
considerably less NPS pollution and eliminating the need for
sludge disposal.
The purpose for making these remarks is not necessarily to
discourage construction of the plant nor to dictate how the area
should be developed. Rather, it is being suggested that it would
be helpful to include some additional thoughts and information on
why the plant is needed/desired in light of the fact that it
would seem less expensive and more environmentally sound not to
build it. It would be good to include a discussion, from the
Town's standpoint, on why higher density development (5 units per
acre) is preferred over lower density development in the Terrible
Creek basin (cost of services? quality of life? others?)? If
there is a long range land use plan for the basin, it should be
included in the EA to more clearly illustrate the Town's vision
for development in this area.
5. Fish and Their Habitats
Section 6.15 needs further work. It should at least include
a list of the prominent fish species found in the stream and some
assessment as to whether there is any fishing activity. It
should then assess, in at least a qualitative manner, what
effects the proposed discharge and the increase in nonpoint
source runoff would have on fishery resources (and fishing?) in
the creek looking at both water quality and water quantity
effects. Depending on the findings of this -additional
assessment, it may be necessary to add a new mitigation section
in Part 7 to address impacts to fisheries.
6. Other Agency Comments
Inclusion of agency letters in the Appendix was helpful in
determining what concerns, if any, other agencies had toward this
proposal. Other than DEM water quality -related concerns,
discussed above, the two issues identified in the agency letters
that will need followup work as the project progresses (some time
subsequent to completion of the EA) will be potential impacts on
wetlands and archeological resources. It is understood that the
exact plant site and interceptor line routes are not yet known,
thus making it difficult to accurately assess the impacts on
these two resource areas at the present time. However, the EA

Mr. Alan R. Keith
July 19, 1989
Page Four
does include commitments to a) perform an archeological survey
prior to construction of the plant, b) avoid wetlands in
siting the plant, and c) work with the Corps of Engineers in
mitigating wetlands losses that may result from construction of
the collection lines. For the time being, the EA's treatment of
these issues appears to be adequate. Further work on these
issues would only be required if other review agencies call for
it during the next review stages.
In conclusion, it is recommended that you revise the EA based
on the recommendations presented above and then resubmit eight
copies of the revised document to this office for a departmental
(NRCD) review. Upon receipt, I will pass these on to our
Division of Planning and Assessment for a two -week review and
comment period. The next step after that will be to revise the
EA, if necessary, depending on the comments we receive; prepare a
Finding of No Significant Impact (if appropriate); and to forward
the EA and FONSI to the State Clearinghouse for review. If there
are no significant comments received during the Clearinghouse
review, the SEPA process will be completed.
Please call me if you have any questions.
Sincerely,
Alan R. Clark
Project Coordinator
TerCreek.Ltr
cc: Boyd Devane
Trevor Clements
Tim Donnelly
Dale Overcash
Alan Klimek

DIVISION OF ENVIRONMENTAL MANAGEMENT
June 21, 1989
MEMORANDUM
TO: Alan Clark
FROM: Juan C. Mangles
THROUGH: Tom Stockton -? ,t/
Trevor Clements
SUBJECT: Draft Environmental Assessment for Proposed
. Fuquay-Varina WWTP on Terrible Creek
I have reviewed the subject Draft Environmental Assessment.
The proposed WWTP will discharge into surface waters classified
"nutrient sensitive'.' by EMC in January, 1988. Since the WLA and
draft NPDES permit were prepared previous to this ruling, the issued
draft NPDES permit does not contain a total phosphorus limitation.
Therefore, in the absence of a total phosphorus limit in the current
draft permit, the proposed treatment works do not provide phosphorus
removal capabilities.. Although the submitted draft assessment recog-
nizes the eutrophication potential of the receiving.surface waters as
the result of the proposed discharge, it suggests that the limits
the :raft permit should minimize the nutrient load:�nn.
Current procedures recommend a 2 mg/1 total phosphorus limitation
for new and expanding facilities (defined as having an NPDES applica-
tion after January, 1988). Existing facilities with design flow
rates of 0.5 MGD or greater are required to comply with the same lim-
itation by May 1, 1993. The Division should rule on whether a 2 mg/1
total phosphorus limitation should be contained in the final permit
or a requirement to comply by May 1, 1993.
Since ongoing studies in the Neuse River basin indicate that fur-
ther reductions in phosphorus and/or nitrogen inputs may be needed in
the future, it is recommended the applicant be advised that as part
of the planning and designing process, he should study.the engineer-
ing and cost of having to comply not only with a 2 mg/1 total phos-
phorus limitation but also more stringent phosphorus and nitrogen
limitations. For engineering purposes, implications of a total phos-
phorus limit of 0.5 mg/1 to 2 mg/1 and a nitrogen limit of 3 mg/1 and
6 mg/1 should be considered..
Tb,. provided environmental assessment predicts toxicants and
nutrient loading rates to increase from non -point sources as the area
is further developed. It is recommended the Non-P.oint,Source Plan-
ning Group reviews the section on the "Effects of Terrible Creek WWTP
and Interceptor Sewers on Non -Point Source Pollution". Other aspects
of the impact of the proposed treatment works on the water quality of
the receiving surface waters seem to have been properly addressed in
the assessment.

If you need further assistance on this matter, please contact me
at ext. 510.
cc: Dale Overcash
Bill Kreutzberger