NC0076066_Fact Sheet_20230815

NCDEQ / DWR / NPDES
EXPEDITED FACT SHEET - NPDES PERMIT RENEWAL
NPDES Permit NCO076066
Catherine Shadwell, Compliance & Expedited Permitting Unit / 919-707-3613 Aug 2023
FACILITY INFORMATION
Applicant/Facility Name
Wilkes County School (Thomas J. Spicer, ORC)
North Wilkes High School WWTP
Applicant Address
wA
613 Cherry St North Wilkesboro, NC 28659
Facility Physical
Address/Mailing Address
2986 Traphill Rd Hays, NC 28635
Permitted Flow (MGD)
0.0105 MGD
Type of Waste
100% Domestic, < 1 MGD
Facility Class
WW-1
County
Wilkes
Permit Status
Renewal
Regional Office
WSRO
STREAM CHARACTERISTICS
Receiving Stream
Wolf Branch
Stream
Classification
B
Stream Segment
12-46-3-1
Outfall Lat.
360 16' 30" N
7Q10 - Summer (cfs)
0.46
Outfall Long.
810 06' 18" W
7Q10 - Winter (cfs)
0.69
Drainage basin
Yadkin -Pee Dee
30Q2 (cfs)
0.79
Subbasin
03-07-01
Average Flow (cfs)
1.6
HUC
030401010404
IWC (%)
3.42% (summer) /
2.3% (winter)
303(d) List
Not listed.
BASIC INFO FOR EXPEDITED PERMIT RENEWAL
Does permit need Daily Max NH3 limits?
Already present in permit
Does permit need TRC limits/footnote?
Already present in permit
Does permit have toxicity testing?
No
Does permit have any Special Conditions?
Yes, nutrient reopener for High Rock Lake
Does permit have instream monitoring?
No
Few expiration date:
Sep 30, 2028
Facility Summary
North Wilkes High School WWTP was originally issued a permit in 1989. This facility utilizes the
following treatment components:
Septic tank
Dual bell siphons
Sandfilter beds
Calcium hypochlorite disinfection
Sodium sulfite dechlorination
Effluent pump station/force main
Renewal Summary
This renewal contains the following changes:
• Added the facility grade to Section A. (L).
• Updated the effluent table in Section A. (L) with eDMR parameter codes.
Fact Sheet for Permit Renewal
Aug 2023 - NPDES Permit NCO076066 - Page 1

• Updated Section A. (3.) to reflect current federal requirements for Electronic Reporting of
Discharge Monitoring Reports.
Compliance History
• Most recent NOV was in 2017.
Comments on Draft Permit
Fact Sheet for Permit Renewal
Aug 2023 - NPDES Permit NC0076066 - Page 2

IWC Calculations
Facility: North Wilkes High School WWTP
Permit No.: NCO076066
Prepared By: Catherine Shadwell
Enter Design Flow (MGD): 0.0105
Enter s7Q10 (cfs): 0.46
Enter w7Q10 (cfs): 0.69
Total Residual Chlorine (TRC)
Ammonia (Summer)
Daily Maximum Limit (ug/1)
Monthly Average Limit (mg NH3-N/1)
Design
Permitted
Design
Permitted
s7Q10 (CFS)
0.46
0.46
s7Q10 (CFS)
0.46
0.46
DESIGN FLOW (MGD)
0.0105
0.2
DESIGN FLOW (MGD)
0.0105
0.2
DESIGN FLOW (CFS)
0.016275
0.31
DESIGN FLOW (CFS)
0.01628
0.31
STREAM STD (UG/L)
17.0
17
STREAM STD (MG/L)
1.0
1
Upstream Bkgd (ug/1)
0
0
Upstream Bkgd (mg/1)
0.22
0.22
IWC (%)
3.42
40.26
IWC (%)
3.42
40.25974
Allowable Conc. (ug/1)
497
42
Allowable Conc. (mg/1)
23.0
2.2
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/1)
Design
Permitted
Design
Permitted
Fecal Coliform
w7Q10 (CFS)
0.69
0.69
Monthly Average Limit:
200/100mi
200/100mi
DESIGN FLOW (MGD)
0.0105
0.2
(If DF >331; Monitor)
DESIGN FLOW (CFS)
0.01628
0.31
(If DF<331; Limit)
STREAM STD (MG/L)
1.8
1.8
Dilution Factor (DF)
29.26
2.48
Upstream Bkgd (mg/1)
0.22
0.22
IWC (%)
2.30
31.00
Allowable Conc. (mg/1)
68.8
5.3
*213 .0404 (c) Applies
Total Residual Chlorine
1. Cap Daily Max limit at 28 ug/I to protect for acute toxicity
Ammonia (as NH3-N)
1. If Allowable Conc > 35 mg/I, Monitor Only
2. Monthly Avg limit x 3 = Weekly Avg limit (Municipals)
3. Monthly Avg limit x 5 = Daily Max limit (Non-Munis)
If the allowable ammonia concentration is > 35 mg/L, no limit shall be imposed
* By Policy dischargers < 1 MGD get limits no lower than 2 & 4 due to BAT
* From 2B .0404(c) - Winter Limits can be no less stringent than 2 times the summer limits
Feral (.nlifnrm
1. Monthly Avg limit x 2 = 400/100 ml = Weekly Avg limit (Municipals) = Daily Max limit (Non -Muni)