NC0084409_Fact Sheet_20240109

NCDEQ / DWR / NPDES
EXPEDITED FACT SHEET - NPDES PERMIT RENEWAL
NPDES Permit NCO084409
Catherine Shadwell, Compliance & Expedited Permitting Unit / 919-707-3613 Jan 2024
FACILITY INFORMATION
Applicant/Facility Name
Aqua North Carolina, Inc. (Lauren Raup-Plummer)
Wellesley Place Subdivision WWTP
Applicant Address
202 MacKenan Court Cary, NC 27511
Facility Physical
Address/Mailing Address
Off West side of Laurel Creek Rd, Lewisville, NC 27023
Permitted Flow (MGD)
0.06 MGD
Type of Waste
100% Domestic, < 1 MGD
Facility Class
WW-2
County
Forsyth
Permit Status
Renewal
Regional Office
WSRO
STREAM CHARACTERISTICS
Receiving Stream
Mill Creek
Stream
Classification
WS-IV
Stream Segment
12-82
Outfall Lat.
360 07' 05.2" N
7Q10 - Summer (cfs)
0.21
Outfall Long.
800 25' 07.0" W
7Q10 - Winter (cfs)
0.31
Drainage basin
Yadkin -Pee Dee
30Q2 (cfs)
0.36
Subbasin
03-07-02
Average Flow (cfs)
1.17
HUC
030401011203
IWC (%)
30.69% (summer) /
23.08% (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?
No, but needs one for High Rock Lake
Does permit have instream monitoring?
No
New expiration date:
December 31, 2028
Facility Summary
Wellesley Subdivision operates a private, closed collection system that sends 100% domestic wastewater to
its Wellesley Place Subdivision WWTP for its residents. In 2022, they received an authorization to
construct a rotary screen and sodium hydroxide feed system, this update will not increase the design or
permitted capacity. Wellesley has not yet installed this new system. The Wellesley Place Subdivision
WWTP is a minor facility (flow < 1 MGD) with a design capacity and permitted wastewater discharge of
0.06 MGD. The WWTP was originally permitted in 1995. This facility utilizes the following treatment
components:
• Inlet bar screen
• Equalization basin
• Dual pumps and blower
• Flow splitter box
• Dual aeration basins w/ fine bubble diffusers and blowers
• Dual -basin clarifier
• UV disinfection
• Chlorine contact chamber w/ dual tablet chlorinators and dichlorination equipment (backup)
Fact Sheet for Permit Renewal
Jan 2024 - NPDES Permit NCO084409 - Page 1

• Aerated sludge holding tank
• Effluent flow meter with weir
Authorization to Construct allows the installation of the following treatment components:
• 0.78 MGD rotary screen
• 330-gallon HDPE storage tank with spill containment
• 0.017 GPM diaphragm chemical feed pump
Renewal Summary
This renewal contains the following changes:
• Updated Section A. (3.) to reflect current federal requirements for Electronic Reporting of
Discharge Monitoring Reports.
• Added Section A.(2.) Nutrient Reopener for High Rock Lake since this facility is upstream from
High Rock Lake.
• Updated outfall map
• Added new winter ammonia nitrogen limits to be in compliance with 2B .0404(c) - Winter Limits
can be no less stringent than 2 times the summer limits. New limits will go into effect January 1,
2028.
Compliance History
Looking through the last 5 years, Wellesley Place Subdivision WWTP has only received 1 NOD for a daily
max exceedance of BOD in 2019.
Comments on Draft Permit
Address of facility updated to be more accurate, per request from WSRO
Fact Sheet for Permit Renewal
Jan 2024 - NPDES Permit NCO084409 - Page 2

IWC Calculations
Facility: Wellesley Place WWTP
Permit No.: NCO084409
Prepared By: Catherine Shadwell
Enter Design Flow (MGD): 0.06
Enter s7Q10 (cfs): 0.21
Enter w7Q10 (cfs): 0.31
0.2 <= Permitted Flow if Different from Design
Total Residual Chlorine (TRC)
Ammonia (Summer)
Daily Maximum Limit (ug/1)
Monthly Average Limit (mg NH3-N/1)
Design
Permitted
Design
Permitted
s7Q10 (CFS)
0.21
0.21
s7Q10 (CFS)
0.21
0.21
DESIGN FLOW (MGD)
0.06
0.2
DESIGN FLOW (MGD)
0.06
0.2
DESIGN FLOW (CFS)
0.093
0.31
DESIGN FLOW (CFS)
0.093
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 (%)
30.69
59.62
IWC (%)
30.69
59.615385
Allowable Conc. (ug/1)
55
29
Allowable Conc. (mg/1)
2.8
1.5
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/1)
Design
Permitted
Design
Permitted
Fecal Coliform
w7Q10 (CFS)
0.31
0.31
Monthly Average Limit:
200/100mi
200/100mi
DESIGN FLOW (MGD)
0.06
0.2
(If DF >331; Monitor)
DESIGN FLOW (CFS)
0.093
0.31
(If DF<331; Limit)
STREAM STD (MG/L)
1.8
1.8
Dilution Factor (DF)
3.26
1.68
Upstream Bkgd (mg/1)
0.22
0.22
IWC (%)
23.08
50.00
Allowable Conc. (mg/1)
7.1
3.4
*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)