NC0039420_Fact Sheet_20240123

NCDEQ / DWR / NPDES
EXPEDITED FACT SHEET - NPDES PERMIT RENEWAL
NPDES Permit NCO039420
Caroline Robinson / Compliance & Expedited Permitting Unit / caroline.robinsongdeq.nc. og_v / Jan 2024
FACILITY INFORMATION
Applicant/Facility Name
Virginia Department of Transportation (Allen Campbell, State
Program Manager)
I-77 Rest Area WWTP
Applicant Address/Facility
Physical Address
Interstate Highway 77 NB on the NC / VA state line, Surry County, NC
27024
Mailing Address
1401 East Broad Street, Richmond, VA 23219
Permitted Flow (MGD)
0.02 MGD
Type of Waste
100% Domestic, < 1 MGD
Facility Class
WW-2
County
Surry
Permit Status
Renewal
Regional Office
WSRO
STREAM CHARACTERISTICS
Receiving Stream
Naked Run
Stream
Classification
WS-IV; Tr
Stream Segment
12-72-9-2
Outfall Lat.
360 33' 36" N
7Q10 - Summer (cfs)
02
Outfall Long.
800 44' 39" W
7Q10 - Winter (cfs)
0.39
Drainage basin
Yadkin -Pee Dee Basin
30Q2 (cfs)
0.4
Subbasin
03-07-03
Average Flow (cfs)
1.6
HUC
030401010804
IWC (%)
13.42% (summer) /
7.36% (winter)
303(d) List
No
BASIC INFO FOR EXPEDITED PERMIT RENEWAL
Does permit need Daily Max NH3 limits?
Due to regulation 2B .0404(c) the winter ammonia limit
can be no less stringent than 2 times the summer limits.
Therefore, the winter ammonia limit was changed to
12.0 mg/L.
Does permit need TRC limits/footnote?
No — Already present in permit.
Does permit have toxicity testing?
No — not a complex wastestream
Does permit have any Special Conditions?
Yes — Nutrient Reopener for High Rock Lake
Does permit have instream monitoring?
Yes — U & D for Temp due to Trout Waters
New expiration date:
Feb 28, 2029
FACILITY SUMMARY
The Virginia Department of Transportation operates a 100% domestic wastewater treatment plant for an
estimated 2,000-5,000 traveling peoples per day with an estimated peak of 8,500 people a day. The I-77
Rest Area WWTP is a minor facility (flow < 1 MGD) with a design capacity and permitted wastewater
discharge of 0.02 MGD. The NPDES permit for this WWTP was originally issued in December 1977. This
facility utilizes the following treatment components:
• Grinder & basket
• Aerated equalization basin (ca. 14,000-gallon capacity)
• Soda ash feed
• Flow splitter box
• Three extended aeration package plants rated for 10,000 gallon each. Each plant includes:
Fact Sheet for Permit Renewal
Jan 2024 - NPDES Permit NCO039420 - Page 1

• Aeration basin
• Secondary clarifier
• Sludge holding basin
• UV disinfection system
• Backup chlorine disinfection system with dechlorination
• Post aeration
• Ultrasonic flow meter
RENEWAL SUMMARY
This renewal contains the following changes:
• Added revised monthly average winter ammonia limit, based on the instream waste concentration
calculations and 2016 NH3 guidance document. The revised limit includes a monthly winter limit
of 12.0 mg/L. This change is shown in the table in Part L A. (1).
• Added effluent monitoring for turbidity to the table in Section A. (1.) to determine compliance with
15A NCAC 02B.0211 (21) for Trout waters.
• Added effluent monitoring for dissolved oxygen to the table in Section A. (L) to determine
compliance with 15A NCAC 02B.0211 (6) for Trout waters.
• Updated Section A. (3) to reflect current federal requirements for Electronic Reporting of
Discharge Monitoring Reports.
• Public Water Supply Section staff approved the draft permit.
• Operator Certification Program staff approved the draft permit.
COMPLIANCE HISTORY
I-77 Rest Area WWTP has not had an enforcement on record since October 2009. The facility has been
issued one NOD for a BOD limit violation in 2022, since the permit was issued in March 2019. Most recent
inspection (April 2019) showed the facility to be in compliance.
Fact Sheet for Permit Renewal
Jan 2024 - NPDES Permit NCO039420 - Page 2