NC0087670_Fact Sheet_20240718

Docusign Envelope ID:926lA1A3-363F-4lF7-83F9-47EAC6A9DED6
NCDEQ/DWR/NPDES
EXPEDITED FACT SHEET - NPDES PERMIT RENEWAL
NPDES Permit NCO087670
Caroline Robinson/Compliance&Expedited Permitting Unit/caroline.robinson(kdeq.nc.gov/June 2024
FACILITY INFORMATION
Applicant/Facility Name Currituck County(Cody Edwards, Superintendent)
Southern Outer Banks Water System WTP
Applicant Address 734 Ocean Trail Corolla,NC 27927
Facility Physical Address/Mailing 734 Ocean Trail Corolla,NC 27927
Address
Max. Monthly Avg Flow(MGD) 1.02 MGD
Type of Waste Reverse osmosis reject wastewater,greensand filter backwash,
and ion-exchange wastewater
Facility Class PC-1 County Currituck
Permit Status Renewal Regional Office WaRO
STREAM CHARACTERISTICS
Receiving Stream Atlantic Ocean Stream SB
Classification
Stream Segment 99-(7) Outfall Lat. 360 18' 55"N
7Q10 - Summer(cfs) Tidal Outfall Long. 750 48' 15" W
7Q10 -Winter(cfs) Tidal Drainage basin Pasquotank River Basin
30Q2 (cfs) Tidal Subbasin 03-01-54
Average Flow(cfs) Tidal HUC 030102051702
IWC (%) 0.67% 303(d)List No
BASIC INFO FOR EXPEDITED PERMIT RENEWAL
Does permit need Daily Max NH3 limits? No
Does permit need TRC limits/footnote? No -Already present in permit.
Does permit have toxicity testing? Yes, Chronic Toxicity P/F Permit Monitoring
Does permit have any Special Conditions? Yes, Chronic Toxicity P/F Permit Monitoring
Does permit have instream monitoring? No
New expiration date: June 30,2029
FACILITY SUMMARY
Southern Outer Banks Water System WTP utilizes two(2)separate treatment trains to produce potable
water from groundwater. One train applies reverse osmosis(RO)to treat deep-well water(yield to 3.050
MGD);the second train combines greensand and ion-exchange(IO)technology to treat raw water from
shallow wells(yield to 1.345 MGD). The Permittee's flow diagram, estimates RO reject at 71%of
discharge. Actual flow average between Feb 2021-March 2024=0.805 MGD [Max= 1.02 MGD; Min=
0.537 MGD]
The Permittee treats wastewaters using duel trains,blends them together, samples the final effluent for
compliance,then discharges to the Atlantic Ocean via Outfall 001 located approximately 250 feet offshore
at Corolla Beach. Discharge terminates at an effluent diffuser consisting of dual 200-foot long,20-slot
wellscreens, each buried approximately 18 feet below the bottom of the ocean floor;modeled by CORMIX
to establish IWC.Approximate annually,RO filter sludge is transported across the street to the local
WWTP for treatment.
Fact Sheet for Permit Renewal
June 2024-NPDES Permit NCO087670-Page 1

Docusign Envelope ID:926lA1A3-363F-4lF7-83F9-47EAC6A9DED6
• two (2) each influent settling/equalization(EQ)basins for raw water from different sources
• dual(2)treatment trains
• reverse osmosis(RO) for deep-well source water
• geensand/ion-exchange(I0) for shallow-well source water
• wastewater blending tank[receives effluent from both trains]
• disinfection facilities (chlorination and dechlorination)
• final effluent sampling port
• appurtenant piping to outfall
• dual(2) effluent diffusers (ocean discharge)
Chemical Additives
• Calcium Bisulfate
• Sodium Hypochlorite
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 additives list at the water treatment plant to the Supplement to Permit Cover
Sheet.
• Added the facility grade to Section A. (L).
• Updated eDMR parameter codes on the effluent table in Section A. (L).
• Updated footnotes in the effluent table in Section A. (1.).
• Updated Whole Effluent Toxicity testing language in Part 1. A. (2).
• Updated eDMR language for electronic data submission in Part 1. A. (3).
• Updated the map.
• Reporting for Total Nitrogen(TN)now includes the constituent parameters used in calculating TN.
Total Kj eldahl Nitrogen(TKN) and Nitrate+Nitrite Nitrogen(NO3-N+NO2-N)have been added
to the effluent table in Section A. (1)with a corresponding footnote. The Sample Type for Total
Nitrogen has been updated from"Grab"to"Calculated".
• Added an effluent flow limit to the effluent table in Section A. (1)to comply with the current
NCDEQ water treatment plant strategy.
• Aquatic Toxicology Branch Staff approved the draft permit.
COMPLIANCE HISTORY
Southern Outer Banks Water System WTP has had no enforcements on record. The facility has been issued
one proceed to NOD for a Total Suspended Solids frequency violation in Sept 2020.
Most recent inspection(April 2021) showed the facility to be compliant.
WHOLE EFFLUENT TOXICITY(WET)TESTING
In accordance with current strategies designating this facility as a Membrane/Ion-Exchange/Greenland
water treatment plant,WET testing is required in this permit as saltwater Chronic [TGP3E] Pass/Fail
Quarterly monitoring with Mysidopsis bahia at an effluent concentration of 0.67%. The previous 12
quarterly whole effluent toxicity tests have passed.
Date Parameter Sample UoM Value Location
TGP3E-Pass/Fail Static Renewal 7Day
10/7/2019 Chronic Americam sis M sid. Bahia Composite pass/fail 1 Effluent
4/6/2020 TGP3E-Pass/Fail Static Renewal 7Day Composite pass/fail 1 Effluent
Chronic Americamysis(Mysid.)Bahia
Fact Sheet for Permit Renewal
June 2024-NPDES Permit NCO087670-Page 2

Docusign Envelope ID:926lA1A3-363F-4lF7-83F9-47EAC6A9DED6
7/13/2020 TGP3E-Pass/Fail Static Renewal May Composite pass/fail 1 Effluent
Chronic Americam sis M sid. Bahia
10/5/2020 TGP3E-Pass/Fail Static Renewal May Composite pass/fail 1 Effluent
Chronic Americam sis M sid. Bahia
1/4/2021 TGP3E-Pass/Fail Static Renewal May Composite pass/fail 1 Effluent
Chronic Americam sis M sid. Bahia
4/6/2021 TGP3E-Pass/Fail Static Renewal May Composite pass/fail 1 Effluent
Chronic Americam sis M sid. Bahia
7/13/2021 TGP3E-Pass/Fail Static Renewal May Composite pass/fail 1 Effluent
Chronic Americam sis M sid. Bahia
10/4/2021 TGP3E-Pass/Fail Static Renewal May Composite pass/fail 1 Effluent
Chronic Americam sis M sid. Bahia
TGP3E-Pass/Fail Static Renewal May1/3/2022 Chronic Americam sis M sid. Bahia Composite pass/fail 1 Effluent
TGP3E-Pass/Fail Static Renewal May4/4/2022 Chronic Americam sis M sid. Bahia Composite pass/fail 1 Effluent
TGP3E-Pass/Fail Static Renewal May7/11/2022 Chronic Americam sis M sid. Bahia Composite pass/fail 1 Effluent
TGP3E-Pass/Fail Static Renewal May10/5/2022 Chronic Americam sis M sid. Bahia Composite pass/fail 1 Effluent
1/4/2023 TGP3E-Pass/Fail Static Renewal May Composite pass/fail 1 Effluent
Chronic Americam sis M sid. Bahia
4/5/2023 TGP3E-Pass/Fail Static Renewal May Composite pass/fail 1 Effluent
Chronic Americam sis M sid. Bahia
7/12/2023 TGP3E-Pass/Fail Static Renewal May Composite pass/fail 1 Effluent
Chronic Americam sis M sid. Bahia
10/4/2023 TGP3E-Pass/Fail Static Renewal May Composite pass/fail 1 Effluent
Chronic Americam sis M sid. Bahia
1/3/20 14 TGP3E-Pass/Fail Static Renewal May Composite pass/fail 1 Effluent
Chronic Americam sis M sid. Bahia
REASONABLE POTENTIAL ANALYSIS
There are currently no parameters of concern generating data appropriate for an RPA. A maximum
monthly average flow of 1.02 MGD was calculated using data from the past three years.
Fact Sheet for Permit Renewal
June 2024-NPDES Permit NC0087670-Page 3

Docusign Envelope ID:9261A1A3-363F-41F7-83F9-47EAC6A9DED6
Wnole trrluent I oxlclty I esting ana pelt Ivlonitoring Summary
South Durham WRF NCO047597/001 County: Durham Region: RRO Basin: CPF05 Jan Apr Jul Oct SOC JOC:
Ceri7dPF Begin: 11/1/2011 chr lim:90% NonComp: Single 7Q10: 0.15 PF: 20.0 IWC: 99.5 Freq: Q
J F M A M J J A S O N D
2020 Pass - - Pass - - Pass - - Pass - -
2021 Pass - - Pass - - Pass - - Pass - -
2022 Pass - - Pass - - Pass - - Pass - -
2023 Pass - - Pass - - Pass - - Pass - -
2024 Pass - - - - - - - - - - -
South Fork-(formerly Delta Apparel) NC0006190/001 County: Catawba Region: MRO Basin: CTB35 Mar Jun Sep Dec SOC JOC:
Cer7dChV Begin: 2/1/2019 chr lim:12%**AM NonComp: Single 7Q10: 12 PF: 1.1 IWC: 11 Freq: Q
J F M A M J J A S O N D
2020 - - 16.97 - - Pass - - >48 - - 4.2
2021 4.2 <3 <3 8.5 >48 33.9 - - >48 - - 4.2 INC)
2022 <3 INC) 4.2 INC) 8.5 INC) 17 17 17 33.9 - 69.3 - - 33.9
2023 - - 33.9 - - 33.9 - - 69.3 - - 17
South Harnett County Regional WWTP NCO088366/001 County: Harnett Region: FRO Basin: CPF14 Jan Apr Jul Oct SOC JOC:
Ceri7dPF Begin: 2/1/2018 Chr Lim:34%@ 15 M NonComp: 70.10: 45.46 PF: 5.0 IWC: 15 Freq: Q
J F M A M J J A S O N D
2020 >100(P)Pass - - Pass - - Pass - - Pass - -
2021 INVALID Pass - Pass - - Pass - - Pass - -
2022 Pass - - Pass - - Pass - - Pass - -
2023 >100 Pass - - Pass - - Pass - - Pass - -
2024 Pass - - - - - - - - - - -
South Mills Water Association WTP NC0007978 County: Camden Region: WARD Basin: Pas50 Jan Apr Jul Oct SOC JOC:
Ceri7dPF Begin: 8/1/2014 Chr monit:90% NonComp: 7Q10: N/A PF: 0.045 IWC: N/A Freq: Q
J F M A M I I A S O N D
2020 Fail - - Fail - - Fail - - Fail - -
2021 Fail - - Pass - - Fail - - Fail - -
2022 Fail - - Fail - - Pass - - Pass - -
2023 Pass - - Fail - - H NR H H H H -
Southern Outer Banks(RO)WTP NCO087670/001 County: Currituck Region: WARO Basin: PAS54 Jan Apr Jul Oct SOC JOC:
Mysd24PF Begin: 4/1/2018 Chr Monit 24hr PF:0. NonComp: 7Q10: Tidal PF: 0.6 IWC: NA Freq: Q
J F M A M J J A S O N D
2020 - Pass - Pass - - Pass - - Pass - -
2021 Pass - - Pass - - Pass - - Pass - -
2022 Pass - - Pass - - Pass - - >0.67 - -
2023 Pass - - Pass - - Pass - - Pass - -
2024 Pass - - - - - - - - - - -
Southern Piedmont Wood Co NCO087572/002 County: Chatham Region: RRO Basin: CPF10 Feb May Aug Nov SOC JOC:
Ceri48PF Begin: 12/1/2011 Ac Monit: 0.22% NonComp: 7Q10: 22 PF: 0.42 IWC: Freq: W*
J F M A M J J A S O N D
2020 - H - - - - - - - - - -
Leeend: P=Fathead minnow(PimDhales oromelas).H=No Flow(facilitv is active).s=Split test between Certified Labs Page 91 of 107

Docusign Envelope ID:9261A1A3-363F-41F7-83F9-47EAC6A9DED6
Permit Enforcement History by Permit
Permit: Facility: Owner:
Region: County:
Penalty Remission Enforcement EMC Collection Has
Assessment Penalty Enforcement Request Conference Hearing Memo Sent Payment Case
Case Approved Amount Costs Damages Received Held Held To AGO Total Paid Balance Due Plan Closed
Total Cases:
Total Penalties: Total Penalties after

Docusign Envelope ID:9261A1A3-363F-41F7-83F9-47EAC6A9DED6
MONITORING REPORT(MR)VIOLATIONS for: Report Date: 04/02/24 Page 1 of 1
Permit: NCO087670 MRS Betweel 4 - 2018 and 4 - 2024 Region: % Violation Category:% Program Category:NPDES WW
Facility Name:% Param Nam(% County: % Subbasin:% Violation Action:
Major Minor: % or
PERMIT: NCO087670 FACILITY: Currituck County-Southern Outer Banks Water COUNTY: Currituck REGION: Washington
System WTP
Monitoring Violation
MONITORING VIOLATION UNIT OF CALCULATED %
REPORT OUTFALL LOCATION PARAMETER DATE FREQUENCY MEASURE LIMIT VALUE Over VIOLATION TYPE VIOLATION ACTION
05-2023 001 Effluent Nitrogen,Ammonia Total(as 05/31/23 Monthly mg/I Frequency Violation No Action, Facility
N)-Concentration Reporting Error
09-2020 001 Effluent Solids,Total Suspended- 09/05/20 Weekly mg/I Frequency Violation Proceed to NOD
Concentration

Docusign Envelope ID:9261A1A3-363F-41F7-83F9-47EAC6A9DED6
Affidavit of Publication
Notice
STATE OF NORTH CAROLINA Public Carolina Environmental
ManemeCOUNTY OF DARE NPDESUnittCommission/
1617 Mail Service Center
Raleigh, NC 27699-1617
Before the undersigned, a Notary Public, duly Notice of Intent to Issue a
commissioned, qualified, and authorized by law to NPDES Wastewater Permit
NCO0administer oaths, personal) appeared the un- Banks at Southern outer
Y pp Banks Water System WTP-The
dersigned representative who being duly sworn, North Carolina Environmental
deposes and says that he (she) is an employee Management Commission pro-
or other officer authorized to make this affidavit poses to issue a NPDES waste-
water discharge permit to the
of Outer Banks Newsmedia, LLC, engaged
person(s) listed below. Written
publication of a newspaper known as The Coast- comments regarding the pro-
land Times, issued and entered as second class posed permit will be accepted
mailing in the Town of Manteo, N.C., in said county until 30 days after the publish
ec-
and state;that he she is authorized to make this date of this notice. The Water
(she) for of the NC Division of Water
affidavit and sworn statement; and the notice or Resources (DWR) may hold a
other legal advertisement, a true copy of which is public hearing should there be
attached hereto, was published in The Coastland a significant degree of public
interest. Please mail comments
Times on the following date(s): and/or information requests to
DWR at the above address.
04/21/24 Interested persons may visit
the DWR at 512 N. Salisbury
in which such no- street, Raleigh, NC n on to
And that the said newspaper
review the information on file.
tice, paper, document or legal advertisement was Additional information on NP-
published was at the time of each and every such DES permits and this notice
publication, a newspaper meeting all of the require- may be found on our website:
ments and qualifications of Section 1-597 of the es-hearings,
or by
(919)
q es-hearinos, or by calling (919)
General Statutes of North Carolina and was a quali- 707-3601. Currituck County ap-
fied newspaper within the meaning of Section 1-597 plied to renew NPDES permit
of the General Statutes of North Carolina. NCO087670 for Southern outer
Banks Water System WTP(734
Ocean Trail(Route 12),Corolla)
in Currituck County. This facil-
ity discharges to the Atlantic
Ocean in the Pasquotank River
Basin. Currently total residual
chlorine (TRC) is water quali-
ty limited. This discharge may
affect future wasteload alloca-
Theresa Schneider, Publisher tions in the Atlantic Ocean.
4-21c
Subscribed and sworn to before me this
21 st Day of April, 2024
`�xxNp.H'0 r r1"'
1.P�`jOTAq�GS'�,
,/ . .My Comm.Expires
11/13/2024
•.
OOUS
Hannah C. Russ, Notary Public
Dare County, NC
My commission expires November 13, 2024
Account#OTR12552
Ad # 1811112
NCDENR/NCDENQ DIV. OF WATER RE-
SOURCES
1617 MAIL SERVICE CTR
RALEIGH NC 27699

Docusign Envelope ID:9261A1A3-363F-41F7-83F9-47EAC6A9DED6
From: Nicholson,Molly
To: Robinson.Caroline
Cc: Moore,Cindy
Subject: RE: Draft Permit Review NCO087670
Date: Friday,May 10,2024 12:37:43 PM
Attachments: imaae001.Dna
Hi Caroline,
I have reviewed the tox sections of this permit and they look good. Please send me a copy of the
final permit when you send it to the permittee. Thank you.
Best,
Molly Nicholson
Environmental Specialist II - Compliance and Enforcement
Aquatic Toxicology Branch
N.C. Division of Water Resources-Water Sciences Section
N.C. Department of Environmental Quality
Please note that my phone number has changed:
919-743-8424 Office
molly.nicholson(@deq.nc.gov
1621 Mail Service Center, Raleigh, NC 27699-1623
Submit AT Forms electronically to:[e-mail]
From: Robinson, Caroline<[e-mail]>
Sent: Monday, April 8, 2024 1:45 PM
To: Bullock, Robert<[e-mail]>, Talbott, Jeffrey<[e-mail]>;
ATForms.ATB <[e-mail]>; Nicholson, Molly<[e-mail]>
Cc: Moore, Cindy<[e-mail]>; Tankard, Robert<[e-mail]>
Subject: Draft Permit Review NCO087670
Hi Robbie, Molly, and Jeffrey,
The NCO087670 draft permit renewal is readyfor review!The draft permit renewal for the
Southern Outer Banks Water System WTP(NC0087670)will go to Notice on 4/16/2024. Please
send me any comments as time permits.
Thanks,
Caroline

Docusign Envelope ID:9261A1A3-363F-41F7-83F9-47EAC6A9DED6
Caroline Robinson (she/her/hers)
Environmental Specialist ll, Division of Water Resources
North Carolina Department of Environmental Quality
Office:[phone] 1 Cell:[phone]
caroline.robinson(a)deq.nc.gov
Q:>
NORTH CAROLINA -
Department of Environmental Quality
Email correspondence to and from this address is subject to the North
Carolina Public Records Law and may be disclosed to third parties.
Email correspondence to and from this address may be subject to the North Carolina Public Records Law and may be disclosed to third
parties by an authorized state official.