NC0079740_Draft Fact Sheet_20240123

NCDEQ / DWR / NPDES
EXPEDITED FACT SHEET - NPDES PERMIT RENEWAL
NPDES Permit NCO079740
Caroline Robinson / Compliance & Expedited Permitting Unit / caroline.robinsongdeq.nc. og_v / Nov 2023
FACILITY INFORMATION
Applicant/Facility Name
City of Kings Mountain (Mr. Rick Duncan, Public Infrastructure
Director)
T.J. Ellison WTP
Facility Physical
Address/Applicant Address
1432 Oak Grove Road, Kings Mountain, NC 28086
Mailing Address
PO Box 429, Kings Mountain, NC 28086
Max, Monthly Avg Flow (MGD)
0.107 MGD
Type of Waste
Decant from gravity thickened backwash wastewater from John
H Moss Lake; Conventional Water Treatment Plant
Facility Class
PC-1
County
Cleveland
Permit Status
Renewal
Regional Office
MRO
STREAM CHARACTERISTICS
Receiving Stream
Buffalo Creek
Stream
Classification
C
Stream Segment
9-53-(5)
Outfall Lat.
350 16' 32" N
7Q10 - Summer (cfs)
9.6
Outfall Long.
810 27' 21" W
7Q 10 - Winter (cfs)
21.7
Drainage basin
Broad River Basin
30Q2 (cfs)
28.8
Subbasin
03-08-05
Average Flow (cfs)
92
HUC
030501050804
IWC (%)
1.70% (summer) /
0.76% (winter)
303(d) List
No
BASIC INFO FOR EXPEDITED PERMIT RENEWAL
Does permit need Daily Max NH3 limits?
No
Does permit need TRC limits/footnote?
Already present in permit.
Does permit have toxicity testing?
Yes, chronic toxicity testing
Does permit have any Special Conditions?
Yes, chronic toxicity testing
Does permit have instream monitoring?
Yes — Upstream for Hardness
New expiration date:
Aug 31, 2028
FACILITY SUMMARY
City of Kings Mountain operates a conventional WTP designed for a potable flowrate of 12.0
MGD. The facility generates backwash with an intermittent discharge of 4 days per week for 6
hours. When the WTP expanded from 8 MGD to 12 MGD, the plant switched from chlorine gas to
a 10% sodium hypochlorite for disinfection, constructed a decant discharge well that measures
discharge flow, and constructed a dichlorination feed system using sodium thiosulfate 30%. The
original permit for this WTP was issued in April 1991. This facility utilizes the following
treatment components:
• Primary settling tank
• Overflow tank
• Decant well
• Dechlorination unit utilizing sodium thiosulfate
Fact Sheet for Permit Renewal
Nov 2023 - NPDES Permit NCO079740 - Page 1

• Sludge dewatering system
Chemical usage consists of:
• Alum/Aluminum Sulfate
• Fluoride
• Potassium Permanganate
• Sodium Hydroxide
• Sodium Hypochlorite
• Sodium Thiosulfate
RENEWAL SUMMARY
This renewal contains the following changes:
• Updated the maximum, monthly average wastewater discharge on the Supplement to
Permit Cover Sheet
• Added the chemical usage list at the water treatment plant to the Supplement to Permit
Cover Sheet
• The effluent concentration has been updated to 1.70% for Whole Effluent Toxicity testing
in Sections A. (1) and A. (2).
• Whole Effluent Toxicity testing has been changed from monitoring to a Pass/Fail limit per
the updated permitting strategy for water treatment plants. Section A. (1) and Section A. (2)
have been updated accordingly.
• Updated eDMR language for electronic data submission in Part I. A. (3)
COMPLIANCE HISTORY
T.J. Ellison WTP has had no enforcements since 2011. The facility has been issued one NOV for a
total suspended solids frequency monitoring violation since the permit was originally issued in
January 2018.
Most recent inspection (October 2022) showed the facility to be in compliance. Passed 12 of the
last 12 toxicity tests from July 2020 to July 2023.
CHRONIC WHOLE EFFLUENT TOXICITY (WET) TESTING
In accordance with current strategies designating this facility as a conventional water treatment
plant, WET testing is required in this permit as freshwater Chronic [TGP3B] Pass/Fail Quarterly
limit with Ceriodaphnia dubia at an effluent concentration of 1.70%. This facility has passed all
17 of the last 17 toxicity tests from July 2019 to July 2023.
NCG59 GENERAL PERMIT ELIGIBILITY
• They've passed 100% of TOX tests within the last 3 years (Jul 2020-Jul 2023) — eligible
• They do not have limits for any metals or fluoride based on most recent RPA — eligible
• Conclusion: Eligible for NCG59 General Permit.
• Emailed Mr. Duncan and Mr. Henson on 11/29 to notify the permittee that this plant is
eligible for coverage under NCG590000 and gave the permittee two weeks to respond to
this notice.
• No response was received by 12/18, therefore the division will proceed with the renewal of
individual permit NC0079740.
Fact Sheet for Permit Renewal
Nov 2023 - NPDES Permit NCO079740 - Page 2

REASONABLE POTENTIAL ANALYSIS
A reasonable potential analysis (RPA) was conducted on effluent data collected between July 2019
and July 2023. A flow of 0.107 MGD was used in the RPA based on the maximum, monthly
average flow during the past three years.
There were a few inconsistencies with the data for copper and fluoride that have been brought to
the permittee's attention and corrected on the RPA using lab result pdfs.
Based on this analysis, the following permitting actions are proposed for this permit:
• Copper — no reasonable potential to exceed water quality standards; predicted max < 50%
of allowable concentration; monitoring kept at quarterly as copper is a parameter of
concern for conventional WTPs.
• Fluoride — no reasonable potential to exceed water quality standards; predicted max < 50%
of allowable concentration; monitoring kept at quarterly as facility indicated fluoride has
the potential to be discharged.
COMMENTS ON DRAFT PERMIT
Jeffrey Talbott (Operator Certification Group) noted that the facility is classified as a PC-1, with the
ORC and all Backup ORC's active and in good standing with the program.
Fact Sheet for Permit Renewal
Nov 2023 - NPDES Permit NCO079740 - Page 3