NC0023736_Permit (Issuance)_20240222

DocuSign Envelope ID:80C5E69C-C2CB-4A9D-809A-52516C7F8323
ROY COOPER };
1.
Governor
JOHN NICHOLSON
Interim Secretary
S.DANIEL SMITH NORTH CAROLINA
Director Environmental Quality
February 22, 2024
Ms. Elisa Triplett, WWTP Superintendent
City of Lenoir, Public Utilities
PO Box 958
Lenoir,North Carolina 28645
Subject: Final NPDES Permit Modification
Permit NC0023736
Gunpowder Creek WWTP
Caldwell County
Grade III Biological WPCS
SIC Code 4952
Dear Ms. Triplett:
Division personnel have reviewed and approved your request for major modification of the subject permit.
Accordingly,we are forwarding the attached modified pages of the NPDES permit.This permit is modified
effective April 1, 2024,pursuant to the requirements of North Carolina General Statute 143-215.1 and the
Memorandum of Agreement between North Carolina and the U.S. Environmental Protection Agency dated
October 15,2007 (or as subsequently amended).
The following change has been made to the permit sent to you on January 9,2024:
• Quarterly monitoring for Chlorinated Phenols was removed as it was inserted by mistake.
The final permit maintains the major modification made to the permit sent to you on January 9,
2024; no other changes have been made to the previously issued permit.
• Based on review of the submitted Water Effects Ratio(WER)study for evaluation of site-specific Total
Copper limits and results of a reasonable potential analysis run on effluent copper data against the
current limits and those recommended by the WER study,and finding no reasonable potential to exceed
the WER-based allowable concentrations,Total Copper limits and monitoring have been removed from
the permit.
• Based on the above permit decision, the compliance schedule special condition to meet the Total
Copper limits has been removed from the permit.
• To allow the Permittee the option to continue using WER-based allowable concentrations for Total
Copper limit development in the next permit cycle, a special condition requiring the Permittee to
conduct and submit the results of a WER study confirmation test for review with the permit renewal
application.
If any parts, measurement frequencies or sampling requirements contained in this modified permit are
unacceptable to you, you have the right to an adjudicatory hearing upon written request within thirty (30)
days following receipt of this letter. This request must be in the form of a written petition, conforming to
Chapter 150B of the North Carolina General Statutes,and filed with the Office of Administrative Hearings
(6714 Mail Service Center, Raleigh, North Carolina 27699-6714). Unless such demand is made, this
decision shall be final and binding.
D E QQ North Carolina Department of Environmental Quality I Division of Water Resources
R- 512 North Salisbury Street 1 1617 Mall ServIce Center I Raleigh.North Carolina 27699-1617
Oyr1r,IN6�Y�WCrr♦�
919.707.9000

DocuSign Envelope ID:80C5E69C-C2CB-4A9D-809A-52516C7F8323
Please note that this permit is not transferable except after notice to the Division.The Division may require
modification or revocation and reissuance of the permit.This permit does not affect the legal requirements
to obtain other permits which may be required by the Division of Water Resources or any other Federal,
State,or Local governmental regulations.
If you have any questions concerning this permit,please contact Gary Perlmutter at(919) 707-3611 or via
email at [e-mail].
Sincerely,
LAA..Do'cruSignad byy:��� �y ��•',`
tL hthtstla.rt.�W
C464531431644FE
Michael J. Montebello,NPDES Permitting Branch Chief
Division of Water Resources,NCDEQ
Hardcopy: NPDES Files(pages, 3,4, 10)
eCopy: US EPA Region 4
DWR/Asheville Regional Office/Water Quality/Daniel Boss
DWR/Municipal Permitting Unit/Keyes McGee
Page 2 of 2

DocuSign Envelope ID:80C5E69C-C2CB-4A9D-809A-52516C7F8323
Permit NC0023736
Part I
A.(1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (2.0 MGD)
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
Grade III Biological Pollution Control System
[15A NCAC 08G .0302]
a. Beginning upon the effective date of the permit and lasting until permit expiration, the Permittee is
authorized to discharge treated municipal wastewater from Outfall 001. Such discharges shall be I
limited and monitored' by the Permittee as specified below:
EFFLUENT CHARACTERISTICS EFFLUENT LIMITATIONS MONITORING REQUIREMENTS
Parameter Code
Monthly Weekly Daily Measurement Sample Sample
Average Average Maximum Frequency Type Location
Flow 50050 2.0 MGD Continuous Recording Influent or
Effluent
BOD,5-day,20°C 2 C0310 30.0 mg/L 45.0 mg/L Daily Composite Influent&
Effluent
Total Suspended Solids(TSS)2 C0530 30.0 mg/L 45.0 mg/L Daily Composite Influent&
Effluent
NH3-N(Apr 1 -Oct 31) 2.0 mg/L 6.0 mg/L Daily Composite Effluent
C0610
NH3-N(Nov 1 -Mar 31) 4.0 mg/L 12.0 mg/L Daily Composite Effluent
Dissolved Oxygen(DO) 00300 Daily Average>_5 mg/L Daily Grab Effluent
Fecal Coliform 31616 200/100 mL 400/100 mL Daily Grab Effluent
(geometric mean)
pH 00400 Between 6.0 and 9.0 standard units Weekly Grab Effluent
Total Residual Chlorine 3 50060 28 pg/L 2/week Grab Effluent
Temperature 00010 Monitor and Report Daily Grab Effluent
Total Nitrogen C0600 Monitor and Report Monthly Composite Effluent
(NO2+NO3+TKN)
Total Phosphorus C0665 Monitor and Report Monthly Composite Effluent
Conductivity 00094 Monitor and Report Daily Grab Effluent
Chronic Toxicity, THP3B Monitor and Report Quarterly Composite Effluent
Total Hardness(as CaCO3) 00900 Monitor and Report Quarterly Composite Effluent
(mg/L)5
Total Chromium(as Cr) 01034 Monitor and Report Quarterly Composite Effluent
Total Lead(as Pb) 01051 5.7 pg/L 136 pg/L Monthly Composite Effluent
Total Silver(as Ag) 01077 Monitor and Report Quarterly Composite Effluent
Total Zinc(as Zn) 01092 225 pg/L 225 pg/L Monthly Composite Effluent
Effluent Pollutant Scan NC01 Monitor and Report Footnote 6 Footnote 6 Effluent
Footnotes on next page.
DocuSigned by: ,
Page 3 of 14 kid a Ittb tle
C464531431644FE
Michael Montebello, NPDES Branch Chief
Fffertive Tate• Anril 1 T074

DocuSign Envelope ID:80C5E69C-C2CB-4A9D-809A-52516C7F8323
Permit NC0023736
Footnotes:
1. The Permittee shall submit discharge monitoring reports electronically using NCDWR's eDMR application
system;see Section A.(6.).
2. The monthly average effluent BOD5 and TSS concentrations shall not exceed 15%of the respective influent
value(85%removal).
3. The facility shall monitor TRC when using chlorination for disinfection. The Division shall consider all
effluent TRC values reported below 50 µg/L to be in compliance with the permit. However, the Permittee
shall continue to record and submit all values reported by a North Carolina certified laboratory(including
field-certified),even if these values fall below 50 µg/L.
4. Whole Effluent Toxicity will be monitored using the Pass/Fail Ceriodaphnia dubia at 52%effluent.Samples
shall be taken in March,June,September,and December;see A.(3.).
5. Effluent Hardness sampling should be in conjunction with testing for hardness-dependent metals(cadmium,
chromium,copper,lead,silver,selenium and zinc).
6. The Permittee shall perform three Effluent Pollutant Scans during the term of this permit;see A.(4.).
b. There shall be no discharge of floating solids or visible foam in other than trace amounts.
�—DocuSigned by:
Page4of14 Ati Mb t b
'—C464531431844FE
Michael Montebello, NPDES Branch Chief
Effective Date: April 1, 2024

DocuSign Envelope ID:80C5E69C-C2CB-4A9D-809A-52516C7F8323
Permit NC0023736
A.(5.) WATER EFFECTS RATIO CONFIRMATION STUDY FOR TOTAL COPPER
LIMITS
[NCGS 143-215.1(b)]
If the Permittee wishes to continue usage of the Water Effects Ratio(WER)for evaluation of Total
Copper effluent data over the next permit cycle,the Permittee shall conduct one WER study round
using C:eriodaphnia dubia as the test organism. The Permittee shall submit the WER study results
and a completed WER study review checklist with the permit renewal application.
DocuSlgned by:
Page 10 of 14 filtaad MO�ati
g �C464531431644FE...
Michael Montebello,NPDES Branch Chief
Effective Date: April 1, 2024