NC0061425_Fact Sheet_20230613

NCDEQ / DWR / NPDES
EXPEDITED FACT SHEET - NPDES PERMIT RENEWAL
NPDES Permit NCO061425
Catherine Shadwell, Compliance & Expedited Permitting Unit / 919-707-3613
FACILITY INFORMATION
Facility Name
Willow Valley Resort WWTP
Paul Isenhour, President
Applicant Address
P.O. Box 1167
Banner Elk, NC 28604
Facility Physical Address
NCSR 1109
Boone, NC 28607
Permitted Flow (MGD)
0.03 MGD
Type of Waste
100% Domestic, < 1 MGD
Facility Class
WW-2
County
Watauga
Permit Status
Renewal
Regional Office
WSRO
STREAM CHARACTERISTICS
Receiving Stream
Laurel Fork
Stream
Classification
C; Tr
Stream Segment
8-10
Outfall Lat.
360 12' 18" N
7Q 10 - Summer (cfs)
1.9
Outfall Long.
810 44' 12" W
7Q10 - Winter (cfs)
2.8
Drainage basin
Watauga
30Q2 (cfs)
4.3
Subbasin
04-02-01
Average Flow (cfs)
12.4
HUC
060101030303
IWC (%)
Summer: 2.39%
Winter: 1.63%
303(d) List
Not listed.
Facility Summary
Water Quality Utilities Inc operates a 100% Domestic wastewater facility called Willow Valley Resort
WWTP which is a private WWTP that operates for a subdivision of about 67 people. It's a minor facility
with a design flow and permitted discharge of 0.03 MGD. The permit for this site was originally issued in
1985.
♦ Dual extended aeration plant with flow equalization 36012' 18" N 81° 44' 12" W
♦ Bar screen
♦ Aeration basin
♦ Clarifier
♦ Tertiary filter
♦ UV disinfection
♦ Flow monitoring and recording
♦ Generator for stand-by power
Fact Sheet for Permit Renewal
May 2023 - NPDES Permit NCO061425 - Page 1

Renewal Summary
This renewal contains the following changes:
• Added the facility grade to Section A. (1.).
• Updated the effluent table in Section A. (1.) with eDMR parameter codes.
• Updated Section A. (3) to reflect current federal requirements for Electronic Reporting of
Discharge Monitoring Reports.
• Many limits noted as stricter than what was calculated on IWC in Section A. (1.) parameters were
not changed to determine compliance with antidegradation policy [ 15A NCAC 02B .0201 ]
• Added effluent monitoring for turbidity to determine compliance with 15A NCAC 02B.0211 (21).
Compliance History
Last enforcement was 2012. Only 1 NOV in the last 5 years, and it was due to UV system malfunctioning.
Last inspection in 2020 found site to be in compliance.
Comments on Draft Permit
Fact Sheet for Permit Renewal
May 2023 - NPDES Permit NC0061425 - Page 2

IWC Calculations
Facility: Willow Valley Resort WWTP
Permit No.: NC0061425
Prepared By: Catherine Shadwell
Enter Design Flow (MGD): 0.03
Enter s7Q10 (cfs): 1.9
Enter w7Q10 (cfs): 2.8
Total Residual Chlorine (TRC)
Ammonia (Summer)
Daily Maximum Limit (ug/1)
Monthly Average Limit (mg NH3-N/1)
Design Permitted
Design
Permitted
s7Q10 (CFS) 1.9 1.9
s7Q10 (CFS)
1.9 €
1.9
DESIGN FLOW (MGD) 0.03 0.2
DESIGN FLOW (MGD)
0.03 €
0.2
DESIGN FLOW (CFS) 0.0465 0.31
DESIGN FLOW (CFS)
0.0465
0.31
STREAM STD (UG/L) 17.0 17
STREAM STD (MG/L)
1.0
1
Upstream Bkgd (ug/I) 0 0
Upstream Bkgd (mg/I)
0.22
0.22
IWC (%) 2.39 14.03
IWC (%)
2.39
14.027149
Allowable Conc. (ug/I) 712 121
Allowable Conc. (mg/1)
32.9
5.8
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/1)
Design Permitted
Design
Permitted
Fecal Coliform
w7Q10 (CFS)
2.8
2.8
Monthly Average Limit: 200/100ml 200/100ml
DESIGN FLOW (MGD)
0.03 €
0.2
(If DF >331; Monitor)
DESIGN FLOW (CFS)
0.0465 €
0.31
(If DF<331; Limit)
STREAM STD (MG/L)
1.8 €
1.8
Dilution Factor (DF) 41.86 7.13
Upstream Bkgd (mg/1)
0.22
0.22
IWC (%)
1.63
9.97
Allowable Conc. (mg/1)
96.9
16.1
*2B .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
Fecal Coliform
1. Monthly Avg limit x 2 = 400/100 ml = Weekly Avg limit (Municipals) = Daily Max limit (Non -Muni)