NC0027103_Speculative Limits_20220602

DocuSign Envelope ID: 613E3B54-8867-4E64-AA80-851742A6DC2C
ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
RICHARD E. ROGERS, JR.
Director
Mr. Tyler Thomas, Town Manager
Town of Pembroke
P.O. Box 866
Pembroke, North Carlina 28372
Dear Sir:
NORTH CAROLINA
Environmental Quality
June 2, 2022
Subject: Speculative Effluent Limits (revised)
Pembroke WWTP
Permit No. NC0027103
Robeson County
Lumber River Basin
This letter provides updated speculative effluent limits for 2.0 MGD at the Pembroke WWTP. The Division
received permit modification request for expansion dated August 13, 2021, from Miles R. Galloway, P.E., of
Wooten. 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. The Lumber River is located within the Lumber River Basin. The Lumber River has a stream
classification of WS-IV,B;Sw,HQW, and waters with this classification have a best usage for aquatic life
propagation and maintenance of biological integrity, wildlife, secondary recreation and agriculture. The USGS
responded to a low flow request from the Division on April21, 2022 with the following revised flows: The
Lumber River has a summer 7Q10 flow of 65.8 cfs, a winter 7Q10 flow of 161 cfs, a 30Q2 flow of 144 cfs, and
an annual average flow of 503 cfs.
The Lumber River is currently not listed as an impaired waterbody on the 2020 North Carolina 303(d) Impaired
Waters List for biological integrity. There are no specific permitting strategies for the Lumber River in the Lumber
River Basinwide Water Quality Plan.
Speculative Effluent Limits. Based on Division review of receiving stream conditions and specific proposed
discharge location, speculative limits for the proposed expansion in Table 1. A complete evaluation of these limits
and monitoring requirements for metals and other toxicants, as well as potential instream monitoring
requirements, will be addressed as part of the review of the NPDES permit application (presently under review by
staff).
Every applicant shall also submit documentation of any additional pollutants for which there are certified methods
with the permit application if their discharge is anticipated. These pollutants may be found in 40 CFR Part 136, if
there are additional pollutants with certified methods to be reported, please submit the Chemical Addendum to
NPDES Application (unless this was completed earlier) and, if applicable, list the selected certified analytical
method used.
DpperhnyMe Frn n,r nMI Ouul\
DE
NORTH CAROLINA
North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 11617 Mail Service Center I Raleigh, North Carolina 27699-1617
919.707.9000

DocuSign Envelope ID: 613E3B54-8867-4E64-AA80-851742A6DC2C
Some features of the speculative limit development include the following:
TABLE 1. Speculative Limits for Town of Pembroke WWTP (Proposed Expansion to 2.0 MGD)
EFFLUENT
CHARACTERISTICS
EFFLUENT LIMITS
Monthly
Average
Weekly
Average
Daily
Maximum
Flow
2.0 MGD
BOD5, 20°C
12.0 mg/L
18.0 mg/L
NH3 as N
8.0 mg/L
24.0 mg/L
Dissolved Oxygen (minimum)
Daily average > 5.0 mg/1
TSS
20 mg/L
30 mg/L
TRC
28 ug/L
Fecal coliform (geometric mean)
200/100 mL
400/100 mL
Total Kjeldahl Nitrogen (TKN)
Monitor & Report
Nitrite / Nitrate Nitrogen
Monitor & Report
Total Nitrogen
Monitor & Report
Total Phosphorus
Monitor & Report
Chronic Toxicity Pass/Fail (Quarterly test)
4.5%
• BOD / NH3 Limits. In accordance with [15A NCAC 02B .0224(c)], expanded NPDES wastewater
discharges in High Quality Waters shall comply with Subparagraph (2) of this Paragraph, except for those
existing discharges that expand with no increase in permitted pollutant loading. These speculative limits
are based on the 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
resulting proposed limits at the expanded flow are considered technologically feasible.
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 expanded discharge.
In accordance with North Carolina Administrative Code 15A NCAC 2H.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 and expanding flow includes a detailed engineering alternatives analysis (EAA) that
must be prepared. The EAA must justify the requested design flow and provide an analysis of potential wastewater
treatment alternatives. The EAA was approved by the Division on March 7, 2022.
In addition to the EAA, please review information available from the North Carolina Natural Heritage Program
Online Map Viewer. If the approved EAA did not include this information, please confirm if there are/are not any
Federally Listed threatened or endangered aquatic species identified within a 5-mile radius of the proposed
discharge location. If there are any identified threatened/endangered species, the applicant may consider
reviewing the proposed project with the US Fish and Wildlife Service to determine whether the proposed
expanded discharge might impact such species.
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
1:)..E
NORTH CAAOLINA
Werhnerd pi Frn nr nMI Ouullt
North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 11611 Mail Service Center I Raleigh, North Carolina 27699-1611
919.707.9000

DocuSign Envelope ID: 613E3B54-8867-4E64-AA80-851742A6DC2C
more acres of public lands. Please check with the DWR SEPA coordinator (David Wainwright, 919-707-9045) 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. If required, a FONSI must be issued prior to
issuance of the NPDES permit for the expansion.
We understand this expansion project is moving forward rapidly; however, we would expect that any request for
NPDES permitting action for the expansion be taken within a five-year period from the date of this letter, or the
noted speculative limits in Table 1 would be subject to reassessment and review.
Should you have any questions about these speculative limits or NPDES permitting requirements, please
feel free to contact Derek Denard at [phone] / [e-mail] or Doug Dowden at (919)
707-3605 / [e-mail]
Respectfully,
DocuSigned by:
Powdun,
57287E56E81A40D..
Douglas Dowden
Supervisor, NPDES Industrial Permitting Unit
Attachment: EAA Guidance Document
Link to Chemical Addendum Form
Link to NPDES application information
cc: NPDES Files [Laserfiche]
Mr. Carl Scharfe, P.E. - [e-mail]
GDE
NORTH CAAOLINA
Werhnerd pi Frn nr nMI Ouullt
North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 11611 Mail Service Center I Raleigh, North Carolina 27699-1611
919.707.9000