NC0027103_Speculative NPDES Permit_20130408

A '.
DENR-FAC
AVA APR 10 2013
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Pat McCrory Charles Wakild, P. E. John E. Skvarla, III
Governor Director Secretary
April 8, 2013
Mr. Oryan D. Lowry, Manager
The Town of Pembroke
P.O. Box 866
Pembroke, North Carolina 28372
Subject: Speculative Effluent Limits
Pembroke WWTP
NPDES Permit No. NC0027103
Robeson County
Lumber River Basin
Dear Mr. Lowry:
This letter provides speculative effluent limits for 2 MGD and 2.66 MGD at the Pembroke
WWTP. The Division received the speculative limits request in a letter dated October 24, 2012.
Please recognize that speculative limits may change based on future water quality initiatives,
and 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. Lumber River is located within the Lumber River Basin. The Lumber River
has a stream classification of WS-IV B Swamp HQW, and waters with this classification have a
best usage for a source of water supply for drinking, culinary, or food processing purposes,
primary recreation, and are a subset of waters with quality higher than the standards. Lumber
River has an estimated summer 7Q10 flow of 120 cfs and an annual average flow of 387.7 cfs.
The Lumber River is no longer listed on the 2012 NC Impaired Streams List as impaired for
water column mercury. However, the Town should be advised that as part of the
implementation of the NC Statewide Mercury TMDL (Total maximum daily load) approved
by USEPA in January 2013, a mercury minimization plan may be required to be developed
and annual mercury monitoring may be included in the permit.
Based upon a review of information available from the North Carolina Natural Heritage
Program Online Map Viewer, there are not any Federally Listed threatened or endangered
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
Location: 512 N. Salisbury St. Raleigh, North Carolina 27604
Phone: [phone] FAX: [phone]
Internet: www.ncwaterouality.org
NorthCarolina
Naturally
An Equal Opportunity \ Affirmative Action Employer

Mr. Lowry
April 8, 2013.
Page 2 of 4
aquatic species identified within a 5 mile radius of the 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 expansion might impact such species.
Speculative Effluent Limits. Based on Division review of receiving stream conditions and
state regulations for high quality waters (HQW), speculative limits for the proposed
expansion to 2 MGD and 2.66 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.
A feature of the speculative limit development includes the following:
• BOD/NH3 Limits. Based on state regulation 15A NCAC 02B. 0224 (1) (c), these
speculative limits are based on wasteflow expansion with no increase in 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
the expanded flows are considered technologically -feasible.
TABLE 1. Speculative Limits for Town of Pembroke WWTP (Proposed Expansion to 2.0
MGD)
Effluent Characteristic
Effluent Limitations
Monthly
Average
Weekly
Average
Daily
Maximum
Flow
2.0 MGD
BOD5
11.9 mg/L
17.8 mg/L
NH3 as N
8.0 mg/L
24.0 mg/L
Dissolved Oxygen
Not less than 5.0 mg/L daily average
Total Suspended Solids
20 mg/L
30 mg/L
Total Residual Chlorine
28 ug/I
Fecal coliform (geometric
mean)
200/100 ml
400/100 nil
Total Kjeldahl Nitrogen
(TKN)
Monitor and report
Nitrite/Nitrate Nitrogen
Monitor and report
Total Phosphorus
Monitor and report
Total Nitrogen
Monitor and report
Chronic Toxicity Pass/Fail
(Quarterly test)
2.5%

Mr. Lowry
April 8, 2013
Page 3 of 4
TABLE 2. Speculative Limits for Town of Pembroke WWTP (Proposed Expansion to 2.66
MGD)
Effluent Characteristic
Effluent Limitations
Monthly
Average
Weekly
Average
Daily
Maximum
Flow
2.66 MGD
BOD5
9 mg/L
13.5 mg/L
NH3 as N
6.0 mg/ L
18.0 mg/ L
Dissolved Oxygen
Not less than 5.0 mg/L daily average
Total Suspended Solids
20 mg/L
30 mg/L
Total Residual Chlorine
28 ug/1
Fecal coliform (geometric
mean)
200/100 nil
400/100 nil
Total Kjeldahl Nitrogen
(TKN)
Monitor and report
Nitrite/Nitrate Nitrogen
Monitor and report
Total Phosphorus
Monitorand report
Total Nitrogen
Monitor and report
Chronic Toxicity Pass/Fail
(Quarterly test)
3.3%
Engineering Alternatives Analysis (EAA). Please note that the Division cannot guarantee
that an NPDES permit for an expanded 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 expanded discharge. In accordance with the North Carolina
General Statutes, the practicable wastewater treatment and disposal alternative with the
least adverse impact on the environment is required to be implemented. 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
Division guidance for preparing EAA documents is attached.
State Environmental Policy Act (SEPA) EA/EIS Requirements. A SEPA EA/EIS document
must be prepared for all projects that: 1) need a permit; 2) use public money or affect public
lands; and 3) might have a potential to significantly impact the environment. For existing
discharges, significant impact is defined as an expansion of > 500,000 gpd additional flow.
Since the Town of Pembroke is proposing an expansion >500,000 gpd flow, the Town
must prepare a SEPA document that evaluates the potential for impacting the quality of
the environment. The NPDES Unit will not accept an NPDES permit application for the
expanded 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. A
SEPA Environmental Assessment (EA) should contain a clear justification for the proposed
project. If the SEPA EA demonstrates that the project may result in a significant adverse

Mr. Lowry
April 8, 2013
Page 4 of 4
effect on the quality of the environment, you must then prepare a SEPA EIS (Environmental
Impact Statement). Since your expanded discharge is subject to SEPA, the EAA
requirements discussed above will need to be folded into the SEPA document. The SEPA
process will be delayed if all EAA requirements are not adequately addressed. If you have
any questions regarding SEPA EA/EIS requirements, please contact Hannah Stallings with
the DWQ Planning Branch at [phone].
Should you have any questions about these speculative limits or NPDES permitting
requirements, please feel free to contact Jackie Nowell at [phone] or Tom Belnick at
[phone].
Respectfully,
014
om Belnick
Supervisor, NPDES Complex Permitting Unit
cc: US Fish and Wildlife Service, Ecological Services, PO Box 33726, Raleigh, NC 27636-3726
Attrt: Sara Myers
NC WRC, Inland Fisheries, 1721 Mail Service Center, Raleigh, NC, 27699-1721 Attn:
Fred Harris
( Fayetteville Regioal-Office/Sixrface-Water Protection -
Kathy Stecke`r%Modeling-TMDL Unit --- -- l
Hannah Headrick/Planning Section
Central Files
NPDES Permit File/NC0027103