NC0021873_Speculative Limits_20000302

NPDES DOCIMENT SCANNING 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:
March 2, 2000
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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
March 2, 2000
Ms. Debra E. Cardwell, Town Manager
Town of Mayodan
210 West Main Street
Mayodan, North Carolina 27027
e�A
NCDENR
Subject: Speculative Effluent Limitations
NPDES Permit No. NC0021873
Mayodan WWTP
Rockingham County
Dear Ms. Cardwell:
Reference is made to your request, dated February 3, 2000, for speculative limits for the proposed
expansion of the above referenced wastewater treatment plant. We are hereby supplying the following
speculative limits for a facility increase from 3.0 MGD to 4.5 MGD at the existing discharge location into the
Mayo River:
Parameter
Monthly Avg. Effluent Limit (uni
BOD5 (Summer/Winter)
NHSN (Summer/Winter)
TSS
pH
Fecal Coliform
Residual Chlorine
Total Phosphorus
Total Nitrogen
30/30 (mg/L)
9.3/27.5 (mg/L)
30/30 (mg/L)
6-9 (Standard Units)
200 (Colonies / 100 ml)
28 (µg/L)
Monitor
Monitor
A quarterly whole effluent toxicity test limit would also be assigned in the NPDES permit. The test
assigned would be a chronic test at a concentration of 8.5%. It should also be noted that if the treatment plant
continues to serve any Significant Industrial Users, the facility will be required to maintain a pretreatment
program. In addition, a complete evaluation of limits and monitoring requirements for metals and other
toxicants will need to be addressed when a formal NPDES permit application is filed.
Under current DWQ procedure, dechlorination and residual chlorine limits are required For all new or
expanding dischargers proposing the use of chlorine for disinfection. The level of residual chlorine in your
effluent necessary to ensure against acute toxicity given above. The process of chlorination/dechlorination or
an alternate form of disinfection, such as ultraviolet radiation, should allow the facility to comply with the
residual chlorine limit. Should an alternative form of disinfection be employed, the requirement to monitor
residual chlorine will be waived.
Please be advised that response to this request does not guarantee that the Division will issue an
NPDES permit to discharge treated wastewater into these receiving waters. It should be noted that the
1617 Mail Service Center, Raleigh, North Carolina 27699-1617 - Telephone [phone] FAX [phone]
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Speculative Limits for 11,tt°odan
February 1.1. 2000
Page 2
expansion of an existing facility involving an expenditure of public funds or use of public (state) lands and
having a design capacity of 0.5 MGD or greater, will require preparation and submittal of an environmental
assessment (EA) by the applicant. DWQ will not accept a permit application for a project requiring an EA until
the document has been approved by the Department of Environment and Natural Resources, and a Finding of
No Significant Impact (FONSI) has been sent to the state Clearinghouse for review and comment. The EA
should contain a clear justification for the proposed facility and an analysis of potential alternatives, which
should include a thorough evaluation of non -discharge alternatives. In addition, an EA should show how water
reuse, conservation and inflow/infiltration reductions have been considered. Nondischarge alternatives, such as
spray irrigation, water conservation, inflow and infiltration reduction or connection to a regional treatment and
disposal system, are considered to be environmentally preferably to a surface water discharge. North Carolina
General Statutes require that a practicable waste treatment and disposal alternative with the least adverse
impact on the environment be implemented. If the EA demonstrates that the project may result in significant
adverse affects on the quality of the environment, an Environmental Impact Statement will be required. Gloria
Putnam of the Water Quality Planning Branch can provide further information regarding the requirements of
the N.C. Environmental Policy Act and can be contacted at [phone], extension 567.
Please note that the limits given herein are speculative and are not binding unless they are part of an
issued NPDES permit. All information pertaining to the request has been sent to our Central Files for storage.
If it becomes necessary to request an NPDES permit, please submit a complete application package including
appropriate fees.
Should you have any questions or comments regarding this speculative limits request, please do not
hesitate to contact Mark McIntire at [phone], extension 553.
Sincerely,
avid A. Goodrich
Supervisor, NPDES Unit
cc: Central Files (with attachments)
Winston-Salem Regional Office, Water Quality Section
NPDES Unit Files (with attachments)
Gloria Putnam, DWQ Planning Branch

NCDENR/DIVISION OF WATER QUALITY
Water Quality Section/NPDES Unit
February 10, 2000
MEMORANDUM
To: File
From: Mark Mclntire144
Subject: Town of Mayodan, NC0021873
Speculative Limits Request
The Division received a speculative limits request from the Town of Mayodan on February 7. 2000. The Town
is proposing an expansion of their existing facility at its existing location from 3.0 MGD to 4.5 MGD. A model
was developed and run for a former request to expand to 6.0 MGD. No contravention of the DO standard was
predicted at that flow. As such. no contravention of the DO standard at 4.5 MGD is anticipated. Ammonia
limitations have been developed to protect against toxic effects.
Parame to r
BOD5 (Summer/Winter)
NH3N (Summer/Winter)
TSS
pH
Fecal Coliform
Residual Chlorine
Chronic Toxicity
Units
mg/L
mg/L
mg/L
Standard Units
Colonies / 100 ml
µg/L
NA
Monthly Avg.. Effluent Limitation
30.0 / 30.0
9.3 / 27.5
30.0
6.0 — 9.0
200
28 (daily maximum)
8.5 %
The Town will need to complete an EA prior to submitting an application for expansion.

TOWN OF MAYODAN
— 4?7er
4160/F )/8/04
OFFICE OF THE TOWN MANAGER
210 W. MAIN STREET • MAYODAN, N.C. 27027 • [phone]
FAX [phone]
February 3, 2000
North Carolina Department of Environment and Natural Resources
Division of Water Quality
P.O. Box 29535
Raleigh, North Carolina 27626-0535
Dear Sir:
POIrsi
RE: Mayodan Wastewater Treatment Plant
Speculative Limits
NPDES Permit Number NC0021873
On March 9, 1999, I wrote to Mr. David Goodrich of your division requesting speculative
limits for an addition to Mayodan's Wastewater Treatment Plant. A copy of that letter is attached
for your review.
To date, we have not received a reply. We need this information to furnish to our engineer
to be used in the design of the proposed expansion. Please furnish this requested information as soon
as possible.
Thank you for your attention to this matter.
Sincerely,
�.J 1 V Vl' ,
Debra E. Cardwell
Town Manager
cc: WestRock Engineers
B.T. Hart, PE
Hobbs, Upchurch & Associates
Bill Lester, PE

TOWN OF MAYODAN
OFFICE OF THE TOWN MANAGER
210 W. MAIN STREET • MAYODAN, N.C. 27027 • [phone]
FAX [phone]
March 9, 1999
Mr. David Goodrich
North Carolina Department of Environment and Natural Resources
Division of Water Quality
P . 7 . Box 29535
Raieigh, N. C. 27626-0535
RE: Mayodan Wastewater Treatment Plant
Speculative Limits
NPDES Permit Number NC0021873
Dear Mr. Goodrich:
The Town of Mayodan currently operates a 3.0 MGD Wastewater Treatment Plant under
NPDES Permit No. NC0021873. Because of agreements with the Towns of Stoneville and
Madison, the Mayodan plant will become a regional facility with a proposed interim capacity of
4.5 MGD. The discharge from the Mayodan plant will be at the same location into the Mayo
River utilizing the existing effluent pipeline. The discharges from the Stoneville plant into the
Mayo River and the Madison plant into the Dan River will be eliminated when the proposed
connections and plant expansion are completed.
The Town of Mayodan requests speculative limits for the plant at the proposed increase
to 4.5 MGD. Mayodan is currently involved with Stoneville and Madison in the preparation of
a 201 Facilities Planning Report covering the proposed plant and pipeline improvements. This
report will be reviewed by the State Grant and Loan agency under the direction of Mr. Bobby
Blowe, PE, with the end result being the receipt of grant and/or loan funds for the construction
of the proposed improvements.

Mr. David Goodrich
March 9, 1999
Page 2
Please advise us of the limits as soon as possible in order that they may be included in the
referenced report.
Sincerely.
. Debra E. Cardwell
Town Ma_..z2_
cc: WestRock Engineers
B.T. Hart. PE
Dewberry and Davis
Michael Daugherty, PE

State of North Carolina
Department of Environment,
Health and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
A. Preston Howard, Jr., P.E., Director
September 15, 1997
Ms. Debra E. Cardwell, Town Manager
Town of Mayodan
210 West Main Street
Mayodan, North Carolina 27027
Subject: Speculative Limits for Proposed
Expansion of NPDES Discharge
Permit No. NC0021873
Rockingham County
Dear Ms. Cardwell:
I am writing in response to the July 24, 1997 letter concerning a proposed expansion for the
Town of Mayodan waste water treatment plant. The proposal is for an expansion of the
discharge from the current permitted 3.0 mgd up to 6.0 mgd at the existing location on the Mayo
River.
The Mayo River, at the Mayodan wastewater treatment plant location is classified as C
waters. An empirical model was developed in 1994 and most recently updated for determining
the limits applicable for the proposed WWTP expansion. The model predicts that the expansion
will not cause the dissolved oxygen level to decrease below the standard of 5.0 mg/1. It should be
noted that this discharge decreases dissolved oxygen below normal background conditions
throughout the downstream sections of the model, (refer attached graph of modeling analysis
output).
The following outlines the Division's recommendations for a proposed 6.0 mgd disch ge at S °
the existing Mayodan WWTP site: 1' 5 L
Summer Winter
BOD5 (mg/1): 30 30
NH3— N (mg/1):
Total Suspended Solids (mg/1):
pH (SU):
6.0 93 16.0 1'1. s
30 30
6-9 6-9
Fecal Coliform (#/100 mL):
200 200
Total Residual Chlorine (µg/1):
Total Phosphorus (mg/1):
Total Nitrogen (mg/1)
28 28
monitor monitor
monitor monitor
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone [phone] Fax [phone]
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r
Proposed Mayodan WWTP Expansion
Permit No. NC0021873
The tentative ammonia limits were evaluated and based upon the protection of the Mayo
River against instream toxicity. The instream waste concentration at the 6.0 mgd waste flow is
14%. A chronic toxicity testing requirement at 14% effluent will be a requirement in the NPDES
permit at the expanded flow. A complete evaluation of limits and monitoring requirements for
metals and other toxicants will be addressed with the formal NPDES application for modification
of this permit. It is likely that limits for cadmium and mercury will be needed, and the allowable
concentrations for these parameters are 15 µg/1 and 0.09 µg/1 respectively.
Please be advised that response to this request does not guarantee that the Division will issue
an NPDES permit to discharge treated wastewater into these receiving waters. A new facility
involving an expenditure of public funds or use of public (state) lands and having a design
capacity of 0.500 mgd or greater (or a facility proposing an expansion of 0.500 mgd or greater),
or exceeding one-third of the 7Q10 of the receiving stream will require the preparation of an
environmental assessment (EA) by the applicant. DWQ will not accept a permit application for a
project requiring an EA until the document has been approved by the Department of
Environment, Health and Natural Resources and a Finding of No Significant Impact (FONSI) has
been sent to the State Clearinghouse for review and comment.
The EA should contain a clear justification for the proposed facility and an analysis of
potential alternatives which should include a thorough evaluation of non -discharge alternatives.
In addition, an EA should show how water reuse, conservation, and inflow/infiltration reductions
have been considered. Nondischarge alternatives, such as spray irrigation, water conservation,
inflow and infiltration reduction or connection to a regional treatment and disposal system, are
considered to be environmentally preferable to a surface water discharge. In accordance with the
North Carolina General Statutes, the practicable waste treatment and disposal alternative with the
least adverse impact on the environment is required to be implemented. If the EA demonstrates
that the project may result in a significant adverse impact on the quality of the environment, an
Environmental Impact Statement would be required. Michelle Suverkrubbe of the Water Quality
Planning Branch can provide further information regarding the requirements of the N.0
Environmental Policy Act.
The final NPDES effluent limitations will be determined after a formal permit application has
been submitted to the Division of Water Quality. If you have any questions regarding this matter,
please contact Dave Goodrich at [phone], extension 517.
cc: Winston-Salem Regional Office, Water Quality Section
Permits and Engineering Unit, File
Michelle Suverkrubbe, Planning
Construction Grants
Sincerely,
Donald L. Safrit,
Assistant Chief for
Point Source Branch

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Computer Model Predited Dissolved Oxygen Levels for Proposed Mayodan Expansion
Dan River
Predicted Analysis Before Proposed Expansion Predicted Analysis After Proposed Expansion
0 0.6 0.3 0.9 0.7 1.3 1.8 2.4 3 3.5 4.1 4.7 5.1 5.7 6.6 9.2 10.9 12.2 13.3 14.5 15.4 16.0 16.5 17.1
River Mile

JUL-24-1997 09:16 FROM TOWN OF MAYODAN
TO 19197339919
P.01/03
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Fax #:
Subject:
Date:
Pages:
Mx. Don Safret
[phone]
July 24, 1997
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From the desk of...
Debra E. Csrdwoll
Town Manager
Town of Mayodan
210 West Main Street
Mayodan, NC 27027
910-427-0241
Fax: [phone]

JUL-24-1997 09:16 FROM TOWN OF MAYODAN
TO 19197339919 P.02/03
TOWN OF MAYODAN
OFFICE OF THE TOWN MANAGER
210 W. MAIN STREET • MAYODAN, N.C. 27027 • [phone]
FAX [phone]
July 24, 1997
Mr. Don Safret, Assistant Chief
Technical Support Branch
Water Quality Section
P.O. Box 29535
Raleigh, North Carolina 27626-0535
Dear Mr. Safret:
The Town of Mayodan is currently participatixtg in a 201 study which includes Mayodan,
Rockingham County, Madison, Stoneville, and the Wentworth area. Mayodan, under this plan,
would become a regional facility for the treatment of wastewater from the various entities named.
Within the last two years, the Town of Mayodan has completed an expansion of their
wastewater treatment plant from a hydraulic capacity of 1.25 MGD to 3.0 MGD. Under the
proposed 201 facilities plan and the resulting receipt of wastewater by Mayodan from the other
entities, the excess capacity which presently exists at the plant would, in effect, be utilized to the
point that another expansion would be necessary.
Considering the position of the Town of Mayodan and the fact that the Town would
become a receiver of wastewater from the other entities, the Town will, most likely, request in
the near future a .permit to increase the hydraulic capacity of the plant from 3 MGD to 5 or 6
MGD. This would allow some excess capacity for growth of Mayodan as well as allowing the
receipt of additional waste from the other entities. This increase in discharge would be requested
for the existing discharge point.
The Town of Mayodan may, in the future, request the permitting of an additional facility
about five miles downstream from the existing discharge. This would be on the Dan River below
its confluence with the Mayo River, This facility would provide service for an existing residential
development and a large part of southwestern Rockingham County. Some pumping of wastewater
from the Wentworth area and Madison could be reduced, force mains shortened, or possibly
eliminate part of the pumping.
We have been requested by Mr. Cecil Madden of Construction Loans and Grants to try
to get a response from you on the possibilities of these two items as soon as possible. We have
a meeting with Mr. Madden on July 30th to discuss some of the issues to be resolved concerning
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JUL-24-1997 09:17 FROM TOWN OF MAYODAN
TO 19197339919 P.03/03
Mr. Don Safret
July 24, 1997
Page 2
the 201 Plan. Your attention to this matter will be greatly appreciated.
Sincerely,
L. iLCoALA&
Debra E. Cardwell
Town Manager
TOTAL P.03