NC0026441_Pretreatment_IUP_Additional_Information_Request_20230421

DocuSign Envelope ID: C7CC3F62-825E-4E2E-9FAF-5FA1D18A27F1
ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
RICHARD E. ROGERS, JR.
Director
NORTH CAROLINA
Environmental Quality
4/21/2023
Via Electronic Mail (cmccorquodalegsilerci , .or )
Mr. Chris McCorquodale
Director of Public Works & Utilities
Town of Siler City
P.O. Box 769
Siler City, NC 27344
Subject: Pretreatment Review of Industrial User Pretreatment Permit Draft Renewal
Program: Town of Siler City
Wastewater Treatment Plant: Town of Siler City WWTP
NPDES #: NC0026441, Chatham County
Dear Mr. McCorquodale:
The Municipal Unit of the Division of Water Resources has reviewed the Industrial User Pretreatment
Permits (IUP) draft renewals submitted by the Town of Siler City for the following Significant Industrial
Users (SIUs). The first drafts of these ]UPS were received by the Division on December 1st, 2022.
IUP #
SIU NAME
003
Brookwood Farms, Inc.
004
Mountaire Farms Inc.
005
Town of Siler City Water Treatment Plant
The Division requests the following changes and additional information to the submitted draft LUPs. In
reference to Siler City's NPDES permit the Division will expect a quarterly report on the construction status
for SIUs with compliance schedules (see our comments below). This condition aims to confirm that the
limits proposed in the permit drafts are sufficient to comply with the issued Special Order of Consent (SOC).
All IUPs —
• Include engineering calculations for the derived IUP limits of BOD5, Total Nitrogen, and Total
Phosphorus. The engineering calculations must include all SIU aggregate contributions for each pollutant
listed above. This will verify that Siler City can meet the final nutrient limits after their compliance
schedule with the identified final SIU limits. In addition, please insure that each SIU's compliance
schedule aligns with the issued NPDES permit.
• A separate units column should be added to the draft permit's "Effluent Limits and Monitoring
Requirements" table located in Part I, F. Some values are mg/l, pH is Standard Units, 1,4 dioxane and
PFAS compounds are ug/1 and ng/1 respectively.
• Please specify a detection limit of 1 µg/l for 1,4, Dioxane as a footnote to the table in Part I, F.
And follow EPA's guidance on detection for PFAS compounds.
• In the table in Part I, F, footnotes 2 and 4 refer to special conditions No. 6 and No. 7, please
include the part/section of the permit where the special conditions are located, for example, "Part 111,
Special Condition 6".
North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 1 1611 Mail Service Center I Raleigh, North Carolina 27699-1611
NORTH CARCLINA
919.707.9000

DocuSign Envelope ID: C7CC3F62-825E-4E2E-9FAF-5FA1D18A27F1
Mountaire Farms Inc. (IUP# 004) — Include a full-size scan of the site map in Part I, E. The full-
size scan will be included as a supplemental document to the permit. Additionally, the sample location must
be clearly marked on the supplemental site map. The SIU will be required to supply a quarterly report
detailing the progress with the compliance schedule stated in Part III (8) of the IUP. Additional language
in the IUP is required to be added to Part III (8) to comply with the quarterly report.
Town of Siler City Water Treatment Plant (IUP# 005) — Include a site schematic and site map
to Part I, E of the IUP. The site map must include a clear location for the sample location [so that a person
not familiar with the site can easily find the sample location]. A site map like the one found in Brookwood's
IUP will be sufficient to fulfill this request.
Provide further information on how monitoring duties will be allocated between the SIU and the
POTW. The "Monitoring Frequency" column in Part I, F should be changed from "Town" to "POTW" and
"Permittee" to "SIU". Since the "Town" as an entity can be interpreted as both the Permittee and Control
Authority. The Water Plant SIU will be required to supply a quarterly report detailing the progress with the
compliance schedule stated in Part III (8) of the IUP. Additional language in the IUP is required to be added
to Part III (8) to comply with the quarterly report.
The Division requests this information to be provided within fifteen days. This completes all pending
comments on these draft IUP's.
If you have any questions or comments, please contact Keyes McGee at [phone] [email:
[e-mail]] or Octavio Henriquez at [phone] [email:
octavio.henriqueznncdenr. og_v] Thank you for your continued support of the Pretreatment Program.
Sincerely
�AD•o'c'u.Siigneld by:
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IVU&Ad khKit �I h
C464531431644FE...
Michael Montebello, Section Chief
NPDES Permit Branch
Division of Water Resources
oih/slc_silercity_iup_review
Ec: Municipal Unit File
Cheng Zhang, RRO
Central Files (Laserfiche)
REQ5 North Carolina Department ofEnvironmental Quality I Division ofWater Resources
512 North Salisbury Street 1 1611 Mail Service Center I Raleigh, North Carolina 27699-1611
NORTH CAROLINA 919.707.9000
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