NC0021873_Environmental Assessment_19920129

NPDES DOCYNENT 5CANNINC COVER SHEET
NPDES Permit:
NC0021873
Mayodan WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
January 29, 1992
This document its printed on reuse paper - ignore any
content on the rezrerse side

State of North Carolina
Department of Environment, Health, and Natural Resources
Division of Environmental Management
512 North Salisbury Street • Raleigh, North Carolina 27604
James G. Martin, Governor
George T. Everett, Ph.D.
William W. Cobey, Jr., Secretary Director
January 29, 1992
MEMORANDUM
TO: Don Safrit, Permits and Engineering
FROM: Alan Clark Planning Branch
SUBJECT: EA/FONSI for Proposed Mayodan Wastewater Treatment Plant Expansion
Attached is a letter from Secretary of Administration James Lofton stating that no further State
Clearinghouse review action will be required of DEM for compliance with the NC Environmental Policy
Act. Accordingly, processing of the permit application for the subject wastewater treatment plant expansion
may proceed. However, permit issuance and approval of the Authorization to Construct, if appropriate,
must take into consideration the mitigation measures outlined in the Finding of No Significant Impact
(FONSI), the environmental assessment (EA) and the supplement to the EA prepared by DEM. These
measures include: a) de -chlorination (with backup dechlorination) of the chlorinated effluent or use of an
alternate disinfection method, b) possible phosphorus monitoring (consult with Technical Support Branch),
and c) consideration of development of contingency nutrient plans for possible future nutrient limits
(consult with Technical Support Branch).
Please feel free to contact me if you have any questions.
Enclosure
Mayodan. mem/WB-1
cc: Harlan Britt
Steve Tedder
Dale Overcash
Trevor Clements
B.T. Hart
Melba McGee
Asheville Fayetteville Mooresville Raleigh Washington Wilmington Winston-Salem
704/251-6208 919/486-1541 704/663-1699 919/733-2314 919/946-6481 919/395-3900 919/896-7007
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone [phone]
An Equal Opportunity Affirmative Action Employer
Pollution Prevention Pays

North Carolina
Department of Administration
�: ;r.� "Jr:(.;i,. O1
:- r: • r. J
`'Pi EI GI,� r
James G. Martin, Governor James S. 'Lofton, Secretary
January 22, 1992
Mr. Alan Clark
N.C. Department of Environment,
Health, and Natural Resources
Division of Environmental Management
Archdale Building
Raleigh, North Carolina 27611
Dear Mr. Clark:
Re: SCH File #92-E-4300-0422; Environmental Assessment and
Finding of No Significant Impact for the Proposed Town of
Mayodan Wastewater Treatment Plant Expansion
The above referenced environmental impact information has been
reviewed through the State Clearinghouse under the provisions of
the North Carolina Environmental Policy Act.
Attached to this letter are comments made by state/local
agencies in the course of this review. Because of the nature of
the comments, it has been determined that no further State
Clearinghouse review action on your part is needed for
compliance with the North Carolina Environmental Policy Act.
The attached comments should be taken into consideration in
project development.
Best regards.
Sincerely,
ames S. Lofton
JSL:jt
Attachments
cc: Region G
116 West Jones Street • Raleigh, North Carolina 27603-8003 • Telephone [phone]
State Courier 51-01-00
An Equal Opportunity / Affirmative Action Employer

PIEDMONT TRIAD COUNCIL OF GOVERNMENTS
Intergovernmental Review Process
2216 W. Meadowview Road
Greensboro, North Carolina 27407-3480
Telephone: [phone]
REVIEW & COMMENT FORM
The State Clearinghouse sent us the enclosed information about a proposal which
could affect your jurisdiction. Please circulate it to the people you believe
need to be informed.
If you need more information about the proposal, please contact the applicant
directly. The name and phone number of a contact person are listed on the
attached "Notification of Intent."
If you wish to comment on the proposed action, complete this form and return
it to the PTCOG office by N)04,1(ACWril 151 1 qq
We will send your comments to the State. Clearinghouse to be included in a re-
commendation to the proposed funding agency.
State Application Identifier # 9 a - f -'-/i 0 0
Commenter' s Name & Title CO.-A14731r
Representing TOLA.)n 0.4 odo L'
(local goverment)
Mgi l i 9 Add ss 0,l 0 i ). ��
�
Au
(signature)
Col ments: (You may attach additional sheets.)
Phone # (q') � '7 - 0014/
odaii-, IC- 7 va
Date Signed 1/15/92
Mayodan is very eager to move ahead with this project. This expansion
will provide for additional jobs greatly needed in Rockingham County
for many people.
0(31,1718/ MICIIVID
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JAN 19 2 J/\. 0 2 1991
c �'
... TOWN Of MAYWAN
CQETMyS OfF -,;
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Akin- Cort puf t �,
(kan. &. ex u �: (la`s or(ek.t . •
Departmentof �..... �........� .......l.
512 North Salisbury Street • Raleigh, Nortl
James G. Martin, Governor
William W. Cobey, Jr., Sery
MEMORANDUM
TO: Alan Clark
FROM: Melba McGee
ft.
—� oC- f
Doti
.k-s'sr....w_ci. . c o'4 t
To ILA �.L- s .'•+..A-e «.?1 -1c
lass w-o-C-G5A7.5C-`
TA(fr % .
RE: #444 - Mayodan Wastewater Treatment Plant Expansion
DATE: December 23, 1991
The referenced project has been circulated among our
internal divisions for review. The attached comments are for
your consideration and file.
Thank you for the opportunity to respond. Project can be
forwarded to the State Clearinghouse for further review.
attachment
P.O. Box 27687, Raleigh, North Carolina 27611.7687 Telephone [phone]
An Equal Opportunity Affirmative Action Employer

North Carolina Wildlife Resources Commission
512 N. Salisbury Street, Raleigh, North Carolina 27604-1188, 919-733-3391
Charles R. Fullwood, Executive Director
MEMORANDUM
TO: Melba McGee, Planning and Assessment
Dept. of Environment, Health and Nat. Res.
FROM: Dennis Stewart, Manager
Habitat Conservation Program
DATE: December 18, 1991
SUBJECT: Supplement to the Environmental Assessment (EA) for
Mayodan Wastewater Treatment Plant Expansion,
Rockingham County, North Carolina.
The Wildlife Resources Commission (WRC) has reviewed the
Supplement to the Environmental Assessment (EA) for the Mayodan
Wastewater Treatment Plant Expansion. Our comments are based on
reviews by biologists on our staff familiar with habitat values
of the project area, and are provided in accordance with
provisions of the North Carolina Environmental Policy Act (G.S.
113A-1 et seq., as amended; 1 NCAC 25) and the Fish and Wildlife
Coordination Act (48 Stat. 401, as amended; 16 U.S.C. 661-667d).
WRC has reviewed the additional information provided by
Division of Environmental Management (DEM) about WRC concerns
relating to the proposed project. WRC will agree that based upon
the data presented in the supplement, that secondary wastewater
treatment at the Mayodan site should be adequate to protect the
fish and aquatic resources of the Mayo and Dan Rivers. Also, WRC
supports the recommendation that the plant consider including
contingency nutrient removal plans for future possible nutrient
limits.
Thank you for the opportunity to comment on this Supplement
to the EA. If we can provide further assistance, please call on
us.
DLS/lp
cc: Shari L. Bryant, District 5 Fishery Biologist
Stephen Pozzanghera, Habitat Conservation Biologist

. Av&.2->we../ 46e4:44a,/
State of North Carolina
Department of Environment, Health, and Natural Resources
Division of Environmental Management
512 North Salisbury Street • Raleigh, North Carolina 27604
James G. Martin, Governor George T. Everett, Ph.D.
November 13, 1991
William W. Cobey, Jr., Secretary
Regional Offices
Asheville
704/251-6208
Fayetteville
919/486-1541
Mooresville
704/663-1699
Rakigh
919/733-2314
Washington
919/946-6481
Wilmington
919/395-3900
Winston-Salem
919/896-7007
Mr. B. T. Hart, P.E.
1803 Vandora Springs Road
Garner, NC 27529
Dear Mr. Hart:
Director
This is in reference to the EA for the Mayodan wastewater
treatment plant expansion. Enclosed for your review is a
memorandum and an EA supplement that I propose sending to the
Division of Parks and Recreation and the Wildlife Resources
Commission in response to their comments on the original EA.
Please review the supplement and let me know of any suggested
changes. If possible, please check on the sediment control
requirements for the plant construction. I am assuming that the
disturbed work area will encompass more than an acre and will
therefore require a state sediment and erosion control plan. If
this is not correct, let me know.
Also, DEM is considering the need to require a backup
dechlorination unit. This has been recommended by the Wildlife
Resources Commission. Would the town be amenable to providing a
backup unit? As a consideration, if the plant expansion will
entail adding another treatment train, as opposed to simply
expanding the existing system, then a separate chlorinator and
dechlorinator could be added. Interconnecting these with the
existing chlorinator and adding a new dechlorinator unit would
provide dual chlorination and dechlorination. Is this a
possibility?
I will forward the supplement on to the parks and wildlife
agencies as soon as I have heard back from you. Please feel free
to contact me if you have any questions.
BTHart.Ltr/SEPA5
Enclosures
Sincerely,
A,
Alan R. Clark
Environmental Review Coordinator
P.O. Box 29535, Raleigh, North Carolina 27064)535 Telephone [phone] / Pollution Prevention Pay,
An Equal ( Jptxiruatity Athrnt.mvr Action Empluvvr

State of Nor*'
Department of Envirc'-7
Division n
512 North Salisbury
James G. Martin, Governor
William W. Cobey, Jr., Secretary
Regional Offices MEMORANDUM
Asheville
704/251-6208
Fayetteville FROM:
919/486-1541
Nove
ural Resources
27604
George T. Everett, Ph.D.
Director
TO: Melba McGee, Division of Planning and Assessment •
Alan Clark, Water Quality Planning Branch
Mooresville SUBJECT: Project No. 431; EA for Proposed Mayodan Wastewater
704/6634699 Treatment Plant Expansion, Rockingham County
Raleigh
919/733-2314
Washington
919/946-6481
Wilmington
919/395-3900
Winston-Salem
919/896-7007
Attached is a Supplement to be added to the subject EA that
addresses comments provided by the Division of Parks and
Recreation and the Wildlife Resources Commission during a recent
inhouse review. These agencies had requested that the treatment
level of the plant be upgraded, that nutrients be removed from
the effluent, and that chlorine dissinfection be eliminated.
DEM has reexamined its recommended effluent limits. Based on
this reexamination, we continue to believe the treatment level is
appropriate and that there is no justification for requiring
nutrient removal. However, the town will be required to either
add dechlorination or consider alternate means of disinfection.
Please circulate this Supplement to the appropriate review
agencies and provide us with any followup comments that may need
to be addressed.
Enclosure
cc: Trevor Clements (w/ enclosure)
B.T. Hart (w/ enclosure)
NOV 2 71991
ts.:tA,NCH
{
P.O. Box 29535. Raleigh, North Carolina 27626-0535 Telephone [phone] / Pollution Prevention Pays
An Equal Opportunity Affirmative Action Employer

SUPPLEMENT TO THE ENVIRONMENTAL ASSESSMENT
FOR THE
MAYODAN WASTEWATER TREATMENT PLANT EXPANSION
Prepared by the Division of Environmental Management
November 13, 1991
This Supplement has been prepared by the Division of
Environmental Management (DEM) in response to comments (attached)
made by the Division of Parks and Recreation and the Wildlife
Resources Commission on the original environmental assessment
(EA) for the Mayodan Wastewater Treatment Plant. The comments,
which address the type of treatment to be used at the expanded
plant, are responded to below. They are based, in large part, on
input from DEM's Technical Support Branch (see attached October
26, 1991 memorandum). This supplement, including the attached
agency comments, will become a part of the final EA.
The Technical Support Branch is responsible for reviewing all
discharge permit applications and developing the appropriate
wasteload allocations. The allocations are based on -a number of
factors including, but not limited to, the volume and
characteristics of the effluent, the flow and waste assimilative
capacity of the receiving stream, the nature of aquatic
resources, the presence of downstream uses such as recreational
activities and waters supplies, and the stream standards which
must be protected. In this stretch of the river, the waters have
a C classification.
Listed below are the key comments from the Division of Parks
and Recreation (DPR) and the Wildlife Resources Commission (WRC)
followed by DEM's response.
Comment (DPR) - No consideration is given to the addition of
a dechlorination step following disinfection, even though
this step, or the use of alternatives to chlorination, are
gaining widespread acceptance throughout the state,
particularly where unique aquatic habitats are involved.
Response (DEM) - DEM will be requiring that chlorination
followed by dechlorination or some other alternative
disinfection process be used for the proposed plant
expansion. The plant will be required to meet a 28 ug/1
limit on chlorine residuals. Chlorine residuals from
chlorination typically range from 100 to over 800 ug/l.
Comment (WRC) - WRC does not oppose the expansion of the current
wastewater treatment plant, but strongly feels that the plant
should also be upgraded to provide tertiary treatment of the
wastewater including nutrient removal.
Response (DEM) - DEM has reexamined its recommended wasteload
allocation and continues to believe that the recommended
limits and secondary treatment without nutrient removal will
maintain the Class C stream standards in the Mayodan and Dan
Rivers.

The model predicts a sag in dissolved oxygen (DO) resulting
from the plant expansion at the confluence of the Mayodan and
the Dan Rivers. The predicted DO level at the confluence
will be 7.50 mg/1. Another DO sag is predicted 8.8 miles
further downstream due the interaction of effluent from the
Mayodan and Madison wastewater treatment plants. The
predicted DO level will be 7.22 mg/l. The minimum stream
standard for DO is 5.0 mg/l. Thus, even with the sags, the
DO levels will be well above the established stream standard.
It should also be pointed out that the sags are predicted at
7Q10 conditions. At higher flow, the actual impacts on DO
will be diminished. The model results, which have been
confirmed by samples taken at a downstream ambient monitoring
station (#02071000), indicate that tertiary treatment is
unnecessary to protect DO stream standards.
DEM has also taken a closer look at the nutrient removal
recommendation. Nutrients do not pose water quality problems
in and of themselves in the concentrations that come from
wastewater treatment plants. However, nutrients can be a
problem in warm quiescent waters with enough light
penetration to allow algal growth. For the most part, these
conditions are found in ponds, lakes and estuaries and
occasionally in the pools of streams with little or no flow
in the summer. Under the conditions described above, algae
blooms can occur. The blooms can dramatically reduce DO
levels in the water through respiration in the pre -dawn hours
and through their decomposition.
The conditions for algal blooms in the Mayodan and Dan Ri
are marginal. And our Environmental Sciences Branch, whi
is responsible for DEM's statewide biomonitoring and ambi
water quality sampling programs, is unaware of any past
eutrophication problems in the vicinity of the project.
However, consideration is being given to requiring phosph
monitoring in the discharge permit. In addition, a
recommendation will be included in the final wasteload
allocation that the facility consider including contigenc
nutrient removal plans for future possible nutrient limit
Comment (WRC) - We also recommend exploring alternate
disinfection (i.e. ultraviolet or ozonation). If
chlorination is the only option, then a dechlorination unit
and a backup dechlorination unit should be installed to
prevent excessive chlorine levels from entering the river.
means o
As noted above, chlorine residuals in the effluent will have
to held at or below 28 ug/1 thus necessitating dechlorination
or an alternative disinfection method. Ozonation is an
expensive and difficult means of disinfection. UV is
reliable and more affordable but is most effective when used
in conjunction with tertiary treatment. Chlorination
followed by dechlorination is probably the least costly
disinfection method and provides a reliable means of
controlling chlorine residuals. Consideration will be given
to requiring a back-up dechlorination unit if dechlorination
is selected as the preferred disinfection process.
.ram
kr' 1pc ` .05°f -Ls t
ems`

Comment (WRC) - WRC also recommends implementation of erosion and
sedimentation measures to prevent excessive runoff and
siltation in the river during plant construction.
Response (DEM) - DEM and the town fully support this
recommendation. An erosion and sediment control plan will be
prepared and implemented in accordance with the state
sedimentation control regulations.

Division of Environmental Management
Water Quality Section/Instream Assessment Unit
October 26,1991
Memorandum
To: Alan Clark
Thru: Carla Sanderson a
fr
Ruth Swanek 2�
From: Norman Bedwell
Subject: Response to Departmental comments on the town of
Mayodan Wastewater Treatment Plant Expansion (NPDES
Permit NC0021873)
This memo is in response to the comments from the Wildlife Resources
Commission and the Division of Parks and Recreation concerning the Town of
Mayodan's proposed expansion. The agency concerns are addressed as follows:
Chlorine: Residual chlorine is recommended limited to 28µg/1 effluent
concentration to protect water quality. At this level, the facility should be advised to
either dechlorinate or use an alternate disinfection method.
Tertiary Treatment: The Mayodan WWTP model predicts a DO sag of 7.50 mg/1
where the Mayo river meets the Dan river 1.2 miles below the plant. At this point
there is an interaction between Mayodan and Madison WWTP causing another DO
sag of 7.20 mg/1, 8.8 miles from the confluence of the Mayo river with the Dan. The
DO concentration predicted at the end of the model is 7.22 mg/1; NBOD is 1.62 mg/1;
CBOD is 2.22 mg/1 (stream background conditions: DO,7.4 mg/1; NBOD, 1.0 mg/1;
CBOD, 2.0 mg/1). Ambient monitoring station #02071000 at Dan river mile 8.4 of
the model confirms model results at present conditions. The model indicates
tertiary treatment is not needed to protect Do stream standards.
Nutrient Removal: Dianne Reid (ESB) knows of no nutrient problems on the Dan
or Mayo rivers. Ambient data show no high levels of TP on the Dan river,
however, these data are several years old. No new data are available on nutrients in
this area of the Mayo/Dan. The facility is not expected to cause nutrient problems as
the effluent will only make up 6% of the stream during low flow conditions. A
recommendation will be included in the WLA that the facility consider including
contingency nutrient removal plans for future possible nutrient limits.

r�
State of North Carolina
Department of Environment, Health, and Natural Resources
512 North Salisbury Street • Raleigh, North Carolina 27611
James G. Martin, Governor
William W. Cobey, Jr., Secretary
MEMORANDUM
TO: Alan. Clark
Division of Environmental Management
FROM: Melba McGee
Project Review Coordinator
RE: #431 - Mayodan Wastewater Treatment Plant
Expansion, Rockingham County
DATE: October 18, 1991
Douglas G. Lewis
Director
Planning and Assessment
The proposed project was circulated among our internal
divisions for review. The attached comments are a result of this
review.
As the state lead agency for this proposal, the Division of
Environmental Management is responsible for seeing that concerns
are incorporated and that our commenting divisions are in
complete agreement with the revisions. After revisions have been
made, I recommend the revised document be circulated again
through our in-house review process for verification.
MM:bb
Attachments
P.U. Box 27687, Raleigh, North Carolina 27611-7687 Telephone [phone]

mAI
North Carolina Wildlife Resources Commission 0
512 N. Salisbury Street, Raleigh, North Carolina 27604-1188, 919-733-3391
Charles R. Fullwood, Executive Director
MEMORANDUM
TO: Melba McGee, Planning and Assessment
Dept. of Environment, Health and Nat. Res.
FROM: Dennis Stewart, Manager
Habitat Conservation Program
DATE: October 18, 1991
SUBJECT: Environmental Assessment (EA) for Mayodan Wastewater
Treatment Plant Expansion, Rockingham County, North
Carolina.
The Wildlife Resources Commission (WRC) has reviewed the
Environmental Assessment (EA) for the Mayodan Wastewater
Treatment Plant Expansion. Our comments are based on reviews by
biologists on our staff familiar with habitat values of the
project area, and are provided in accordance with provisions of
the North Carolina Environmental Policy Act (G.S. 113A-1 et seq.,
as amended; 1 NCAC 25) and the Fish and Wildlife Coordination
Act (48 Stat. 401, as amended; 16 U.S.C. 661 et seq.).
The proposed project site is located on the Mayo River
approximately one-half mile upstream from the confluence with the
Dan River in Rockingham County, North Carolina. This section of
the Mayo River has an ecological classification of
Catfish/Sucker. Fish species present include bluegill, redbreast
sunfish, largemouth bass, catfish, carp and sucker. The Dan
River has a similar fish assemblage, however, 2 species of
special concern, bigeye jumprock and riverweed darter, may
inhabit this section of the Dan River and downstream.
The EA does not adequately address the potential impacts to
aquatic resources in the Mayo River. The EA suggests that 30
mg/1 BOD is acceptable for the expanded plant because 'quick
recovery of DO in the receiving stream was indicated'. What does
'quick recovery of DO' mean - 10 feet, 100 feet, 1000 feet or 1
mile? Also, simply because the Mayo River is not classified as
nutrient sensitive this does not mean that nitrogen and
phosphorus concentrations will not pose a problem. Excessive

Memo Page 2 October 18, 1991
influx of nutrients can lead to eutrophication of water bodies
and should be limited. Further a chlorine level of 0.3 mg/1 is
not acceptable. Chlorine is highly toxic to fish and other
aquatic life, therefore, all effluent should be dechlorinated
prior to discharging into the Mayo River.
WRC does not oppose the expansion of the current wastewater
treatment plant, but strongly feels that the plant should also be
upgraded to provide tertiary treatment of the wastewater
including nutrient removal. We also recommend exploring
alternate means of disinfection (i.e. ultraviolet or ozonation).
If chlorination is the only option then a dechlorination unit and
a backup dechlorination unit should be installed to prevent
excessive chlorine levels from entering the river. WRC also
recommends implementation of erosion and sedimentation measures
to prevent excessive runoff and siltation in the river during
plant construction.
Thank you -for the opportunity to comment on this EA. If we
can provide further assistance, please call on us.
DLS/lp
cc: Shari L. Bryant, District 5 Fishery Biologist

10.18.-91
15:21 $919 'silt 6843
WIRKSH 1 RE -- ARCHDALE 461002
DIVISION OF PARKS AND RECREATION
October 14. 1991
Memorandum
TO: Melba McGee
THROUGH: Carol Tingley
G
FROM: Stephen Hall, Natural Heritage Program
SUBJECT: EA -- WWTP, Mayorla n
REFERENCE: 431
As mentioned in the document, the Natural Heritage Program
database contains records for two species of rare fish occurring
in the vicinity of the project. Both the bigeye jumprock
(Moxostoma arionuum), state -listed as special concern, and the
riverweed darter (Etheostoma padostemone), also state -listed as
special_ concern, have been found in the Dan River near the Mayo
River confluence.
In the scoping phase of this project, we suggested several steps
that could be used to minimize the impacts of this project on the
sensitive aquatic habitat present downstream. These include
control of any s i ltation resulting from the project, reduction of
nitrogen, phosphorus and toxic chemicals in the effluent,
including the chlorine used as a disinfectant.
Although, most of these issues have been addressed in the document,
we remain concerned about the use of chlorins, which is well-known
to be toxic to many aquatic animals. The document acknowledges
that a lower limit on chlorine levels in the effluent may be
imposed upon issuance of a new NPDES permit (p. 6), but proposes
no change in operation until that time. No consideration is given
to .the addition of a dechlorination step following disinfection,
even though this step, or the use of alternatives to chlorination,
are gaining widespread acceptance throughout the state,
particularly where unique aquatic habitats are involved. Once
again, we strongly urge that such measures be included in the
plant upgrade_

•
State of North Carolina
• Department of Environment, Health, and Natural Resources
Reviewing Office:
INTERGOVERNMENTAL -REVIEW — PROJECT COMMENTS
Project Number.
31
Due Date:
t tj isjci 1
After review of this project it has been determined that the EHNR permit(s) indicated must be obtained in order for this project to
comply with North Carolina Law.
Questions regarding these permits should be addressed to the Regional Office indicated on the reverse of the form.
All applications, information and guidelines relative to these plans and permits are available from the same
Regional Office.
Normal Process
PERMITS
❑
SPECIAL APPLICATION PROCEDURES or REQUIREMENTS
(statutory time
limit)
ermit to construct & operate wastewater treatment
facilities, sewer system extensions, & sewer
systems not discharging into state surface waters.
Application 90 days before begin construction or award of
construction contracts On -site inspection. Post -application
technical conference usual
•
30 days
(90 days)
NP ES - permit to discharge into surface water and/or
ermit to operate and construct wastewater facilities
IA
discharging Into state surface waters.
Application 180 days before begin activity. On -site inspection.
Pre -application conference usual. Additionally, obtain permit to
construct wastewater treatment facility -granted after NPDES. Reply
time, 30 days after receipt of plans or issue of NPDES
permit -whichever is later.
90-120 days
(NIA
Water Use Permit
Pre -application technical conference usually necessary
30 days
(NIA)
Well Construction Permit ..
NIA
7 days
(15 days)
redge and Fill Permit
Application copy must be served on each riparian property owner.
On -site inspection. Pre -application conference usual. Filling
may require Easement to Fill from N.C. Department of
Administration and Federal Dredge and Fill Permit.
55 days
(90 days)
Permit to construct & operate Air Pollution Abatement
facilities and/or Emission Sources
N/A
60 days
(90 days)
Any open burning associated with subject proposal
must be in compliance with 15 NCAC 2D.0520.
NIA
60 days
(90 days)
Demolition or renovations of structures containing
asbestos material must be In compliance with
NCAC 2D.0525 which requires notification and removal
prior to demolition.
Complex Source Permit required under 15 NCAC 2D.0800.
/he Sedimentation Pollution Control Act of 1973 must be properly addressed for any land disturbing activity. An erosion & sedimentation control plan
will be required if one or more acres to be disturbed. Plan filed with proper Regional Office (Land Quality Sect.) at least 30 days before begin activity.
The Sedimentation Pollution Control Act of 1973 must be addressed with respect to the referrenced Local Ordinance:
Mining Permit
On -site Inspection usual. Surety bond filed with EHNR as shown:
Any area mined greater than one acre must be permited.
AFFECTED LAND AREA AMOUNT OF BOND
Less than 5 acres $ 2,500
5 but less than 10 acres 5,000
10 but less than 25 acres 12,500
25 or more acres 5,000
30 days
(60 days)
North Carolina Burning permit
On -site inspection by N.C. Division Forest Resources If permit
exceeds 4 days
1 day
(N/A)
Special Ground Clearance Burning Permit • 22
counties in coastal N.C. with organic soils
On -site Inspection by N.D. Division Forest Resources required "if more
than five acres of ground clearing activities are involved. Inspections
should be requested at least ten days before actual burn is planned."
1 day
(N/A)
Oil Refining Facilities
N/A
90-120 days
(N/A)
Dam Safety Permit
if permit required, application 60 days before begin construction.
Applicant must hire N.C. qualified engineer to: prepare plans,
inspect construction, certify construction Is according to EHNR approv-
ed plans. May also require permit under mosquito control program. An a
404 permit from Corps of Engineers.
30 days
(NIA)
PS-t05
Continued on reverse

1.1:Z1 Pt, 111 rsi 044;
1 l.IRKSH I RE
--- ARCHDALE l4I002
DIVISION OF PARKS AND RECREATION
October 14, 1991.
Memorandum
TO: Melba McGee
THROUGH: Carol Tingley
FROM:
SUBJECT: EA -- WWTP, Mayodsn
R ERENCE: 431
Stephen Hall, Natural Heritage Program
As mentioned in the document, the Natural Heritage Program
database contains records for two species of rare fish occurring
in the vicinity of the project. Both the bigeye jumprock
(Moxostoma ariormnum) , state -listed as special concern, and the
riverweed darter (Etheostoma podostemone), also state -listed as
special concern, have been found in the Dan River near the Mayo
River confluence.
In the scoping phase of this project, we suggested several steps
that could be used to minimize the impacts of this project on the
sensitive aquatic habitat present downstream. These include
control of any siltation resulting from the project, reduction of
nitrogen, phosphorus and toxic chemicals in the effluent,
including the chlorine used as a disinfectant.
Although. most of these issues have been addressed in the document,
we remain concerned about the use of chlorine, which is well-known
to be toxic to many aquatic animals. The' document acknowledges
that a lower limit on chlorine levels in the effluent may be
imposed upon issuance of a new N?DES permit (p. 6), but proposes
no change in operation until -that time. No consideration is given
to the addition of a dechlorination step following disinfection,
even though this step, or the use of alternatives to chlorination,
are gaining widespread acceptance throughout the state,
particularly where unique aquatic habitats are involved. Once
again, we strongly urge that such measures be included in the
plant upgrade_

SUPPLEMENT TO THE ENVIRONMENTAL ASSESSMENT
FOR THE
MAYODAN WASTEWATER TREATMENT PLANT EXPANSION
Prepared by the Division of Environmental Management
November 22, 1991
This Supplement has been prepared by the Division of
Environmental Management (DEM) in response to comments (attached)
made by the Division of Parks and Recreation and the Wildlife
Resources Commission on the original environmental assessment
(EA) for the Mayodan Wastewater Treatment Plant. The comments,
which address the type of treatment to be used at the expanded
plant, are responded to below. They are based, in large part, on
input from DEM's Technical Support Branch (see attached October
26, 1991 memorandum). This supplement, including the attached
agency comments, will become a part of the final EA.
The Technical Support Branch is responsible for reviewing all
discharge permit applications and developing the appropriate
wasteload allocations. The allocations are based on a number of
factors including, but not limited to, the volume and
characteristics of the effluent, the flow and waste assimilative
capacity of the receiving stream, the nature of aquatic
resources, the presence of downstream uses such as recreational
activities and waters supplies, and the stream standards which
must be protected. In this stretch of the river, the waters have
a C classification.
Listed below are the key comments from the Division of Parks
and Recreation (DPR) and the Wildlife Resources Commission (WRC)
followed by DEM's response.
Comment (DPR) - No consideration is given to the addition of
a dechlorination step following disinfection, even though
this step, or the use of alternatives to chlorination, are
gaining widespread acceptance throughout the state,
particularly where unique aquatic habitats are involved.
Response (DEM) - DEM will be requiring that chlorination
followed by dechlorination or some other alternative
disinfection process be used for the proposed plant
expansion. The plant will be required to meet a 28 ug/1
limit on chlorine residuals. Chlorine residuals from
chlorination typically range from 100 to over 800 ug/l.
Comment (WRC) - WRC does not oppose the expansion of the current
wastewater treatment plant, but strongly feels that the plant
should also be upgraded to provide tertiary treatment of the
wastewater including nutrient removal.
Response (DEM) - DEM has reexamined its recommended wasteload
allocation and continues to believe that the recommended
limits and secondary treatment without nutrient removal will
maintain the Class C stream standards in the Mayodan and Dan
Rivers.

The model predicts a sag in dissolved oxygen (DO) resulting
from the plant expansion at the confluence of the Mayodan and
the Dan Rivers. The predicted DO level at the confluence
will be 7.50 mg/1. Another DO sag is predicted 8.8 miles
further downstream due the interaction of effluent from the
Mayodan and Madison wastewater treatment plants. The
predicted DO level will be 7.22 mg/1. The minimum stream
standard for DO is 5.0 mg/1. Thus, even with the sags, the
DO levels will be well above the established stream standard.
It should also be pointed out that the sags are predicted at
7Q10 conditions. At higher flow, the actual impacts on DO
will be diminished. The model results, which have been
confirmed by samples taken at a downstream ambient monitoring
station (#02071000), indicate that tertiary treatment is
unnecessary to protect DO stream standards.
DEM has also taken a closer look at the nutrient removal
recommendation. Nutrients do not pose water quality problems
in and of themselves in the concentrations that come from
wastewater treatment plants. However, nutrients can be a
problem in warm_quiescent waters with enough light
penetration to allow algal growth. For the most part, these
conditions are found in ponds, lakes and estuaries and
occasionally in the pools of streams with little or no flow
in the summer. Under the conditions described above, algae
blooms can occur. The blooms can dramatically reduce DO
levels in the water through respiration in the pre -dawn hours
and through their decomposition.
The conditions for algal blooms in the Mayodan and Dan Rivers
are marginal. And our Environmental Sciences Branch, which
is responsible for DEM's statewide biomonitoring and ambient
water quality sampling programs, is unaware of any past
eutrophication problems in the vicinity of the project.
However, quarterly phosphorus monitoring will be required in
the discharge permit. In addition, a recommendation will be
included in the final wasteload allocation that the facility
consider including contingency nutrient removal plans for
future possible nutrient limits. The town, through a letter
from its consultant, Mr. B.T. Hart, has indicated that it
will pursue the development of a plan to address nutrient
removal for possible future nutrient limits.
Comment (WRC) - We also recommend exploring alternate means of
disinfection (i.e. ultraviolet or ozonation). If chlorination is the only option, then a dechlorination unit
and a backup dechlorination unit should be installed to
prevent excessive chlorine levels from entering the river.
As noted above, chlorine residuals in the effluent will have'
to held at or below 28 ug/1 thus necessitating dechlorination
or an,alternative disinfection method. Ozonation is an
expensive and difficult means of disinfection. UV is
reliable and more affordable but is most effective when used
in conjunction with tertiary treatment. Chlorination
followed by dechlorination is probably the least costly
disinfection method and provides a reliable means of

controlling chlorine residuals.
The town, through a November 18, 1991 letter from Mr. Hart
has agreed to dechlorinatetheits chlorinatedeffluent.
expanded
The
letter from Mr. Hart also indicates thatpended
treatment capacity will be handled by adding an additional
treatment train to the existing phew train3. A eparate
Dechlorinators
chlorinator will be added to the
can then be added to the end of both systems. With planned
interconnections between the trains at various points, there
should be sufficient flexibility to provide backup
chlorination and dechlorination.
Comment (WRC) - WRC also recommends implementation of erosion and
sedimentation measures to prevent excessive runoff and
siltation in the river during plant construction.
Response (DEM) - DEM and the town fully support this
recommendation. An erosion and sedimentcontrol plan will be
prepared and implemented in accordance with the state
sedimentation control regulations. Even if the cleared area
at the site falls below the one acre threshhold for requiring
a state permit, the town has indicated that appropriate and
effective sediment control measures will implemented.

RATING SCALE FOR CLASSIFICATION OF FACILITIES
Name of Plant: /nal T
Owner or Contact Person: \I 4,,,,. Ca.,,-( C ► -1 4r.
Mailing Address: t 1 o LJ . rrta.; r. S f.
County: :` �f C, P.,.,... Telephone: 9/ 9 - �e7 - O?- sl%
NPDES Permit No. kg
a Nondisc. Per. No.
IssueDate: / .F 9 2- Expiration Date: 2
Existing Facility - New Facility
Rated By: . Date: 1 YYl
• Reviewed (Train. & Cert.) Reg. Office or ( )1;EtA.A.e
Reviewed (Train. & Cert.) Central Offi
OR C ! c. w„ O k..: Grade 'ice
Industrial Pretreatment Units and/or
Industrial Pretreatment Program
(see definition No. 33)
DESIGN FLAW OF PLANT IN GPD
(not applicable to non -contaminated cooling
waters. sludge handling facilities for water
purification plants. totally closed cycle
systems (del. No. 11), and facilities
consisting only of Item (4) (d) or Items (4) (d)
and (11) (d))
0 -- 20,000
20,001 — 50.000
50.001 — 100.000
100.001 — 250.000
250,001 — 500.000
500.001 --1.000.000
1.000,001 -- 2.000,000
2.000,001 (and up) -
Design Flow (9Pd)
rate 1 point additional for each
200.000 gpd capacity up to a
maximum of 30
o•ao 000
(3) PRELIMINARY UNITS (see definition no. 32)
(a) Bar Screens
or
(b) Mechanical Screens. Static Screens or
Comminuting Devices
(c) Grit Removal
or
(d) Mechanical or Aerated Grit Removal
(e) Flow Measuring Device
or
(f) Instrumented
Flow Measurement
2
(h) Influent Flow Equalization
▪ (i) Grease or Oil Separators - Gravity
Mechanical
Dissolved Air Flotation.
(j) Prechlorination
2
2
3
8
5
POINTS ITEM
POIN?
(4) PRIMARY TREATMENT UNITS
(a) Septic Tank (see definition no. 43) 2
(b) Imhoff Tank S
(c) Primary Clarifiers 5
(d) Settling Ponds or Settling Tanks for Inorganic
Non -toxic Materials (sludge handling facilities
for water purification plants, sand, gravel,
stone, and other mining operations except
recreational activities such as gem or gold
mining)
1 (5) SECONDARY TREATMENT UNITS
2 (a) Carbonaceous Stage
3 (i)Aeration - High Purity Oxygen System • 2 0
4 Diffused Air System 10
5 Mechanical Air System (fixed,
8 floating or rotor) Q
Separate Sludge Reaeration 3
(i i) Trickling Filter
High Rate 7
Standard Rate 5
Packed Tower 5
(i i i) Biological Aerated Filter or Aerated
Biological Filter
(iv) Aerated Lagoons
(v) Rotating Biological Contactors
(vi) Sand Filters -
intermittent biological ....
recirculating biological
(vii) Stabilization Lagoons
(viii)Clarifier (�j
(ix) Single stage system for combined
carbonaceous removal of BOD and
2 nitrogenous removal by nitrification
(see def. No. 12) (Points for this item
1 have 'to be in addition to items (5) (a)
(I) through (5) (a) (vi i)
(x) Nutrient additions to enhance BOO
removal
(xi) Biological Culture ('Super Bugs') addition
to enhance organic compound removal
2
10
10
10
2
3
8
5
5

(b) Nitrogenous Stage
(i) Aeration - High Purity Oxygen System
Diffused Air System
Mechanical Air System (fixed.
floating. or rotor)
Separate Sludge Reaeration
(ii) Trickling Filter -
High Rate
Standard Rate
Packed Tower
(i ii) Biological Aerated Filter or Aerated
Biological Filter
(iv) Rotating Biological Contactors
(v) Sand Filter -
intermittent biological
recirculating biological
(vi) Clarifier
20
10
8
3
7
5 (8)
5
10
10
2
3
5
(6) TERTIARY OR ADVANCED TREATMENT UNIT
(a) Activated Carbons Beds -
without carbon regeneration 5
with carbon regeneration 15
(b) Powdered or Granular Activated Carbon Feed -
without carbon regeneration 5
with carbon regeneration 15
(c) Air Stripping 5
(d) Denitrification Process (separate process) 10
(e) Electrodiatysis » 5
(i) Foam Separation 5
(g) Ion Exchange 5
(h) Land Application of Treated Effluent
(see definition no. 22b) (not applicable for
sand. gravel, stone and other similar mining
operations)
.z(i) on agriiculturaily managed sites (See def.
No. 4) 10
(ii) by high rate infiltration on non -agriculturally
managed sites (includes rotary distributors
and similar fixed nozzle systems) 4
(iii) by subsurface disposal (includes low pressure
pipe systems and gravity systems except at
plants consisting of septic tank and nitrifica-
tion lines only) » 4
Microscreens 5
Phosphorus Removal by Biological Processes
(See def. No. 26) 20
(k) Polishing Ponds - without aeration 2
with aeration 5
(1) Post Aeration - cascade 0
diffused or mechanical ... 5
(m) Reverse Osmosis 5
(n) Sand or Mixed -Media Filters - low rate 2
• high rate 5
(o) Treatment processes for removal of metal or
(i)
U)
(7) SLUDGE TREATMENT
(a) Sludge Digestion Tank - Heated 10
Aerobic
Unheated 3
(b) Sludge Stabilization (chemical or thermal)
(c) Sludge Drying Beds - Gravity ., 6
Vacuum Assisted 5
(d) Sludge Elutriation 5
(e) Sludge Conditioner (chemical or thermal) 5
(f) Sludge Thickener (gravity) 5
(g) Dissolved Air Flotation Unit
(not applicable to a unit rates as (3) (1)
(h) Sludge Gas Utilization (including gas storage) ... .
(p) Treatment processes for removal of toxic
(i) Sludge Holding Tank - Aerated
Non -aerated 2
(II) Sludge Incinerator - (not including activated
carbon regeneration) 10
(k) Vacuum Filter. Centrifuge or Filter Press or other
similar dewatering devices 10
SLUDGE DISPOSAL (including incinerated ash)
(a) Lagoons
(b) Land Application (surface and subsurface)
(see definition 22a)
-where the facility holds the land app. permit ...
-by contracting to a land application operator who
holds the land application permit 2
-land application of sludge by a contractor who does
not hold the permit for the wastewater treatment
facility where the sludge is generated 10
(c) Landfilled (burial) 5
(9) DISINFECTION
(a) Chlorination
(b) Dechiorination
(c) Ozone
(d) Radiation
(10) CHEMICAL ADDITION SYSTEM (S) (See definition No. 9)
(not applicable to chemical additions rated as item
(3) (j), (5) (a) (xi), (6) (a), (6) (b). (7) (b). (7) (e),
(9) (a). (9) (b). or (9) (c) 5 points each: List:
(11)
MISCELLANEOUS UNITS
(a) Holding Ponds. Holding Tanks or Settling Ponds
for Organic or Toxic Materials including wastes
from mining operations containing nitrogen and/or
phosphorous compounds in amounts significantly
greater than is common for domestic wastewater 4
(b) Effluent Flow Equalization (not applicable to storage
basins which are inherent in land application systems)2
(c) Stage Discharge (not applicable to storage basins
inherent in land application systems 5
2
Q
5
(d)
(e) Stand -By Power Supply...».....»...».»».»...».....».»».»».»».»».». 4
(f) Thermal Pollution Control Device
5
5
5
5
TOTAL POINTS
CLASSIFICATION
cyanide 15 Class
................
Class11..».......»........»».».N.»N»»».»»...»...•
materials other than metal or cyanide 15 C
Class IV.
5 - 25 Points
26- 50 Points
51- 65 Points
66- Up Points
Facilities having a rating of one through four points. inclusive,
do not require a certified operator. Classification of all other
facilities requires a comparable grade operator in responsible
charge.
Facilities having an activated sludge process will be assigned
a minimum classification of Class iI.
Facilities having treatment processes for the removal of metal
or cyanide will be assigned a minimum classification of Class Ii.
8 Facilities having treatment processes for the biological removal
2 of phosphorus will be assigned a minimum classification of Class`
111.