NC0026441_Increased Monitoring_20220512

DocuSign Envelope ID: 794E35A0-7630-46FB-98CA-57B2B6805F6C
ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
RICHARD E. ROGERS, JR. NORTH CAROLINA
Director Environmental Quality
5/12/2022
Bill Zell, Interim Town Manager
Town of Siler City
PO Box 769
Siler City, NC 27344
Subject: Increased Monitoring
Siler City WWTP
NPDES Permit NC0026441
Grade IV Biological WPCS
Chatham County
Dear Mr. Zell:
As a result of the continuing nature of the Town of Siler City's wastewater treatment plant non-compliance, the
Division of Water Resources is requiring that the Town begin increased wastewater treatment plant monitoring
[15A NCAC 02B .0508 (b)(2) and G.S. 143-215.66]. Effective upon receipt of this letter, the Town of Siler City
shall monitor at a minimum frequency of Daily for the following parameters from the wastewater treatment plant
effluent discharge: BOD5, TSS, and Fecal Coliform. Additionally, monitoring for Chronic WET testing shall be
increased to Monthly and will be performed as a multiple -concentration toxicity test, as described in "North
Carolina Phase II Chronic Whole Effluent Toxicity Test Procedure" (Revised- December 2010) or subsequent
versions. The Town shall also monitor for Total Iron, Ammonia Nitrogen, NO2-N + NO3-N, and TKN at the
influent to the wastewater treatment plant at the frequencies stated in Table 2.
These samples shall be analyzed and the results of the analyses reported at the end of each month on the facility's
Discharge Monitoring Report form.
In addition, the Town of Siler City is required to increase monitoring in the pretreatment permit for Industrial
User Mountaire Farms Inc. (IUP 004). The following parameters shall be monitored at a minimum frequency of
Daily: BOD, TSS, Ammonia Nitrogen, Total Nitrogen and Total Phosphorous.
A summary of the requirements for all increased and additional monitoring are detailed in Tables 1-3 on page
three of this letter.
This supplemental self -monitoring shall begin immediately and shall continue until the DWR notifies the Town in
writing that the increased monitoring is no longer required. The monitoring requirements listed in this
notification exist as a supplement to the monitoring required in the Town's NPDES permit (NC0026441), and
does not remove any requirements stated in the NPDES permit.
The condition of the wastewater treatment plant for the Town of Siler City is a serious concern to the Division of
Water Resources and steps must be taken immediately to return the facility to compliance with the NPDES permit
and prevent ongoing water quality standards violations that are occurring downstream of the discharge.
LD_E
NORTH CAROLINA
Mryrh,lent of Fnh,onnianbl 9ual
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: 794E35A0-7630-46FB-98CA-57B2B6805F6C
Increased Monitoring
Siler City WWTP — NC0026441
Page 2 of 3
If you have any questions regarding this matter, please contact the Water Quality Regional Operations staff of our
Raleigh Regional Office at [phone]. You can also contact Sydney Carpenter of the Compliance &
Expedited Permitting Unit at [phone] or via e-mail at [e-mail].
Sincerely,
�DocuSigned by:
(/
8328B44CE9EB4A1...
Richard E. Rogers Jr., Director
Division of Water Resources
ec: NPDES Permit Files [Laserfiche]
Municipal Permitting Unit
Aquatic Toxicity Branch
Raleigh Regional Office
Jenifer Johnson, Town of Siler City
Chris McCorquodale, Town of Siler City
Brittany York, Town of Siler City
Blakely Hildebrand, SELC
Jean Zuang, SELC

DocuSign Envelope ID: 794E35A0-7630-46FB-98CA-57B2B6805F6C
Increased Monitoring
Siler City WWTP — NC0026441
Page 3 of 3
Table 1. Effluent Monitoring Requirements — Siler City WWTP
PARAMETER
[eDMR Code]
MONITORING REQUIREMENTS
Measurement
Frequency
Sample Type
Sample Location
BOD, 5-day, 20°C (mg/I)
[C0310]
Daily
Composite
Effluent
Total Suspended Solids (TSS) (mg/L)
[C0530]
Daily
Composite
Effluent
Fecal Coliform (geometric mean)
[31616]
Daily
Grab
Effluent
Chronic Toxicity
[THP3B]
Monthly
Composite
Effluent
Table 2. Influent Monitoring Requirements — Siler City WWTP
PARAMETER
[eDMR Code]
MONITORING REQUIREMENTS
Measurement
Frequency
Sample Type
Sample Location
Total Iron (as Fe) (ug/L)
[01045]
Daily
Composite
Influent
Ammonia (NH3 as N) (mg/L)
[C0610]
Weekly
Composite
Influent
NO2-N + NO3-N (mg/L)
[00630]
Weekly
Composite
Influent
TKN (mg/L)
[00625]
Weekly
Composite
Influent
Table 3. Pretreatment Monitoring Requirements — Mountaire Farms Inc.
PARAMETER
MONITORING REQUIREMENTS
Measurement
Frequency
Sample Type
Sample Location
BOD (mg/I)
Daily
Composite
Effluent
Total Suspended Solids (TSS) (mg/L)
Daily
Composite
Effluent
Ammonia (NH3 as N) (mg/L)
Daily
Composite
Effluent
Total Phosphorous (TP) (mg/L)
Daily
Composite
Effluent
Total Nitrogen (TN) (mg/L)
Daily
Composite
Effluent