NC0047562_Speculative Effluent Limits_20170424

WaterResources
ENVIRONMENTAL QUALITY
ROY COOPER
MICHAEL S. REGAN
S. JAY ZIMMERMAN
April 24, 2017
Johnathan Blanton, City Manager
City of Hamlet
201 West Main St.
PO Box 1229
Hamlet, North Carolina 28345
Subject: Speculative Effluent Limits
Hamlet WWTP
Permit No. NCO047562
Richmond County
Yadkin -Pee Dee River Basin
Dear Mr. Blanton:
This letter provides speculative effluent limits for 2 million gallons per day (MGD) and 3 MGD
at the Hamlet WWTP. The Division received the speculative limits request in a letter dated
October 3, 2016 from Marcus Abernethy former City Manager. Please recognize that
speculative limits may change based on future water quality initiatives such as establishment of
nutrient criteria or nutrient management strategies. It is highly recommended that the applicant
verify the speculative limits with the Division's NPDES Unit prior to any engineering design
work.
Receiving Stream. Marks Creek is located within the Yadkin -Pee Dee River Basin. Marks
Creek has a stream classification of C, and waters with this classification have a best usage
for aquatic life propagation and maintenance of biological integrity, wildlife, secondary
recreation and agriculture. Marks Creek has a summer 7Q10 flow of 2.5 (cubic feet per
second) cfs, a winter 7Q10 flow of 6.4 cfs, and an annual average flow of 15 cfs.
Marks Creek is currently listed as an impaired waterbody on the 2016 North Carolina 303(d)
Impaired Waters List for biological integrity. There are no specific permitting strategies for
Marks Creek in the Yadkin -Pee Dee River Basinwide Water Quality Plan. Marks Creek
ultimately drains into the Pee Dee River in South Carolina.
Based upon a review of information available from the North Carolina Natural Heritage
Program Online Map Viewer, there are Federally Listed aquatic species of concern
identified within a 5 -mile radius of the proposed discharge location. If there are any
identified threatened/ endangered species, it is recommended that the applicant discuss the
proposed project with the US Fish and Wildlife Service to determine whether the proposed
discharge location might impact such species.
State of North Carolina I Environmental Quality I Water Resources
1617 Mail Service Center I Raleigh, North Carolina 27699-1617
919 707 9000

Speculative Effluent Limits. Based on Division review of receiving stream conditions and
water quality modeling results, speculative limits for the proposed expansion to 2 MGD and
3 MGD are presented in Tables 1 and 2, respectively. A complete evaluation of these limits
and monitoring requirements for metals and other toxicants, as well as potential instream
monitoring requirements, will be addressed upon receipt of a formal NPDES permit
application. Some features of the speculative limit development include the following:
BOD/ NH3 Limits. Given the low instream dissolved oxygen levels reported in
Marks Creek, and impairment for biological integrity, these speculative limits are
based on freezing current permitted BOD ultimate loading (i.e., facility will not be
allowed to discharge oxygen -consuming waste above what is currently permitted).
The resultant limits at expanded flows are considered technologically -feasible.
Ammonia limits are based on the criteria of 1.0 mg/L for summer and 1.8 mg/L for
winter.
TABLE 1. Speculative Limits for City of Hamlet WWTP (Proposed Expansion to 2 MGD)
Effluent Characteristic
Effluent Limitations
Monthly Weekly Daily
Averak;e Average Maximum
Flow
2.0 MGD
12.0 mg/ L
BOD5
18.0 mg/ L
(April 1 -October 31)
BOD5
15.0 mg/L
22.5 mg/L
November 1 -March 31)
NH3 as N
1.6 mg/L
4.8 mg/L
A ri11-October 31)
NH3 as N
5.1 mg/ L
15.3 mg/ L
(November 1 -March 31
Dissolved Oxygen
>_5.0 mg/L
(minimum)
TSS
30 mg/ L
45 m / L
TRC
28 µ / 1
Fecal coliform (geometric
200/100 ml
400/100 ml
mean
Total Phosphorus
Total Nitrogen
Chronic Toxicity Pass/Fail
55%
Quarter! test

TABLE 2. Sueculative Limits for Citv of Hamlet WWTP (Prnnnsed Fvnancinn to 3 MG
Effluent Characteristic
Effluent Limitations
Monthly
Average
Weekly
Average
Daily
Maximum
Flow
3.0 MGD
j
BOD5
(April 1 -October 31)
8.0 mg/ L
10.0 mg/ L
12.0 mg/ L
15.0 mg/ L
_
BOD5
November 1 -March 31)
NH3 as N
(April 1 -October 31)
1.4 mg/ L
4.0 mg/ L
4.2 mg/ L
12.0 mg/L
_
>_5.0 mg/ L
45 mg/ L
_
NH3 as N
November 1 -March 31)
Dissolved Oxygen
(minimum)
TSS
30 m,/L
TRC
—
400/100 ml
26 g/l_
Fecal coliform (geometric
mean)
200/100 ml
Total Phosphorus
Total Nitrogen
Chronic Toxicity Pass/ Fail
(Quarterly test)
65% 1
J
Engineering Alternatives Analysis (EAA). Please note that the Division cannot guarantee
that an NPDES permit for a new or expanding discharge will be issued with these
speculative limits. Final decisions can only be made after the Division receives and
evaluates a formal permit application for the new/expanded discharge. In accordance with
North Carolina Administrative Code 15A NCAC 21-1.0105(c), the most environmentally
sound alternative should be selected from all reasonably cost effective options. Therefore,
as a component of all NPDES permit applications for new or expanding flow, a detailed
engineering alternatives analysis (EAA) must be prepared. The EAA must justify requested
flows and provide an analysis of potential wastewater treatment alternatives. A copy of the
Division guidance for preparing EAA documents is attached.
State Environmental Policy Act (SEPA) EA/ EIS Requirements. A SEPA EA/ EIS document
may be required for projects that: 1) involve $10 Million or more of state funds; or 2) will
significantly and permanently impact 10 or more acres of public lands. Please check with
the DWR SEPA coordinator (David Wainwright, 919-807-6442) as to whether your project
requires SEPA review. For projects that are subject to SEPA, the EAA requirements
discussed above will need to be folded into the SEPA document. Additionally, if subject to
SEPA, the NPDES Unit will not accept an NPDES permit application for a new/ expanding
discharge until the Division has approved the SEPA document and sent a Finding of No
Significant Impact (FONSI) to the State Clearinghouse for review and comment.

Should you have any questions about these speculative limits or NPDES permitting
requirements, please feel free to contact David Hill at [phone] or Julie Grzyb at (919)
807-6390.
Respectfully,
Julie Grzyl�'� f
+ ,/Supervisor, NPDES Complex Permitting Unit
Attachment: EAA Guidance Document
Hardcop
ventral Files
A PDES Permit File
Electronic Copy:
NC WRC, Inland Fisheries, [e-mail]
US Fish and Wildlife Service, [e-mail]
DWR/Water Quality Fayetteville Regional Office
DWR/Basinwide Planning, Ian McMillan
DWR/NPDES Server>Specs