NC0085707_Draft Permit_20210112

.-",;„STATE a
ROY COOPER
Governor
MICHAEL S.REGAN Y'., 40..^ ;'_
Secretary 114 au0vntrei
S.DANIEL SMITH NORTH CAROLINA
Director Environmental Quality
January 12, 2021
Mr. Patrick Irwin
Dare County Director of Utilities
600 Mustain St
Kill Devil HI,N.C. 27948
Subject: DRAFT NPDES PERMIT NC0085707
Cape Hatteras RO WTP
Grade I PC WPCS [15A NCAC 08G .0306]
Dare County
Dear Mr. Irwin: •
Enclosed with this letter is a copy of the draft permit for your facility. Please review the draft very
carefully to ensure thorough understanding of the conditions and requirements it contains. Your
permit is among several in the Tar Pamlico River Basin that the Division has targeted for expedited
renewal.
This draft contains the following changes from the existing permit:
> Regulatory citations were added throughout the permit.
> The outfall map was updated.
➢ The outfall description on the supplement to cover page has been updated to include the
HUC and Stream Index number for the outfall location.
> The language in section A.(2)has been updated to include methods for electronic
reporting of toxicity results.
> The language in section A.(3)has been updated to be consistent with the finalization of
federal requirements for electronic reporting.
➢ Instream and effluent temperature monitoring were removed from the permit.
Temperature monitoring is no longer a requirement for WTPs.
> Footnote 3 of the effluent table previously required copper to be sampled in conjunction
with Chronic Toxicity testing. Concurrent sampling is no longer a requirement, so the
footnote has been removed.
➢ Turbidity monitoring(no limit) has been added to the effluent monitoring table in section
A.(1.). Turbidity monitoring is required for all WTPs.
The NPDES.standard conditions(Parts II, III, and IV)that are a part of the permit are not
included in this draft document(cover, map, and Part I).The conditions are the same as in your
current permit.The latest version is available at https://bit.ly/2BZ4xxx and can be viewed online
or downloaded as a PDF file.
public comment on this draftpermit bypublishing
this notification,the Division will solicit ub c
p
a notice in newspapers having circulation in the general Dare County area,per EPA requirements.
Please provide your comments, if any,to me no later than 30 days after receiving this draft
permit.
D E �V Quality Divrc
_ Q J/ 512 NorthNorthCarolina SalisburyDepartment Street 1617of Mail
Environmental Service Center Raleigh,ision NorthofWater CarolinaResou 27699es 1617
NCfiI H(".Ali(I INA v
o.c.,u..n of �m.m.i P.nn 919.707.9000

Following the 30-day public comment period,the Division will review all pertinent comments and
take appropriate action prior to issuing a final permit. If you have questions concerning the draft,
please contact me via email at[[e-mail]] or call 919-707-9125.
Sincerely,Emily DelDuco
Environmental Specialist II
NPDES Program
ec: NPDES files
Washington Regional Office
Page 2 of 2

Permit NC0085707
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
In compliance with the provision of North Carolina General Statute 143-215.1, other lawful standards
and regulations promulgated and adopted by the North Carolina Environmental Management
Commission, and the Federal Water Pollution Control Act,as amended,
Dare County
is hereby authorized to discharge wastewater from a facility located at the
Cape Hatteras Reverse Osmosis Water Treatment Plant
50225 Water Association Road
Frisco, NC
Dare County
to receiving waters designated as the Pamlico Sound in the Pasquotank River Basin in accordance with
effluent limitations, monitoring requirements, and other applicable conditions set forth in Parts I, II, III
and IV hereof.
This permit shall become effective ----
This permit and authorization to discharge shall expire at midnight on December 31, 2025.
Signed this day
S. Daniel Smith, Director
Division of Water Resources
By Authority of the Environmental Management Commission
Page 1 of 7

Permit NC0085707
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility,whether for operation or discharge,are hereby revoked. The exclusive
authority to operate this facility arises under this permit. The authority to operate the facility under previously issued
permits bearing this number is no longer effective. The conditions,requirements,terms and provisions of this permit
authorizing discharge under the NPDES govern discharges from this facility.
Dare County is hereby authorized to:
1. Continue to discharge combined concentrate wastewaters from reverse osmosis reject water,
anion backwash/regeneration treated wastewater, and pressure sand filter backwash treated
wastewater, at a modelled discharge flowrate of 0.743 MGD and a maximum, monthly average
discharge of 0.70 MGD, from a 1.8 MGD drinking water treatment facility via a diffuser. This
facility is located at the Cape Hatteras Reverse Osmosis Water Treatment Plant (50225 Water
Association Road,Frisco)NC in Dare County,with water and wastewater treatment that includes
the following components:
o Replaceable filter cartridges
o Two(2)reverse osmosis units
o Two(2)Anionic exchange system
o Three(3) Pressure sand filters
o 240,000 gallon settling basin
o Basin effluent transfer pumps
o Diffuser
2. Discharge from said drinking water treatment facility at the location specified on the attached
map into the Pamlico Sound [HUC: 030201050305; Stream Index: 30-22], which is currently
classified SA HQW waters in the Pasquotank River Basin.
Page 2 of 7

Permit NC0085707
PART I
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
Grade I Physical Chemical WPCS [15A NCAC 08G .0306]
During the period beginning on the effective date of the permit and lasting until expiration, the Permittee is
authorized to discharge through a diffuser from Outfall 001. Such discharges shall be limited and monitored' by
the Permittee as specified below:
LIMITS MONITORING REQUIREMENTS
EFFLUENT CHARACTERISTICS Monthly Daily Measurement Sample Sample
Average Maximum Frequency Type Location 2
•
Flow, MGD (50050) Continuous Recording Effluent
Total Suspended Solids(TSS) (C0530) 20.0 mg/I 30.0 mg/I Weekly Grab Effluent
pH (00400) Not less than 6.8 S.U. nor more Weekly Grab Effluent
than 8.5 S.U.
pH (00400) 2/Month Grab U&D
Total Dissolved Solids, mg/I (70295) 2/Month Grab Effluent
Turbidity(NTU) (00070) 2/Month Grab Effluent
Dissolved Oxygen(DO)mg/I (00300) 2/month Grab E, U, D
Conductivity, Nmhos/cm (00094) 2/Month Grab E, U, D
Salinity, ppt (00480) 2/Month Grab E, U, D
Ammonia as Nitrogen, mg/I (C0610) Monthly Grab Effluent
Total Copper, pg/I (01042) Quarterly Grab Effluent
Total Nitrogen(TN), mg/I Quarterly Grab Effluent
TN=(NO2-N+NO3-N)+TKN (C0600)
Total Phosphorus(TP),mg/I (C0665) Quarterly Grab Effluent
Chronic Toxicity 3 (TGP3E) Quarterly Grab Effluent
Footnotes:
1. The permittee shall submit discharge monitoring reports electronically using NC DWR's eDMR
system. See Special Condition A. (3).
2. E= Effluent and samples shall be collected at a point after mixing of effluent wastewater from all
treatment units and prior to discharge, unless otherwise noted. Upstream (U) = 50 feet north of the
diffuser, Downstream (D)= 50 feet south of the diffuser.
3. Chronic Toxicity Monitoring(Mysidopsis bahia)@ 6.5%,during the months of January,April,July,
and October. See Part I, Condition A. (2.).
There shall be no discharge of floating solids or visible foam in other than trace amounts.
Page 3 of 7

Permit NC0085707
A.(2.) CHRONIC TOXICITY PASS/FAIL PERMIT MONITORING(QUARTERLY)
[15A NCAC 02B .0200 et seq.]
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant
mortality to Mysidopsis bahia at an effluent concentration of 6.5 %.
The permit holder shall perform at a minimum, quarterly monitoring using procedures described below
to establish compliance with the permit condition.The tests will be performed during the months of
January,April,July,and October. These months signify the first month of each three month toxicity
testing quarter assigned to the facility. Effluent sampling for this testing must be obtained during
. representative effluent discharge and shall be performed at the NPDES permitted final effluent
discharge below all treatment processes.The test procedure will be based on EPA Method 1007.0,
Mysid,Mysidopsis bahia, Survival, Growth, and Fecundity Test, as described in Short-Term Methods
for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Marine and Estuarine
Organisms, Third Edition,EPA-821-R-02-014. The procedure will be performed as written with the
following exceptions:
• The test treatments will consist of a control and a 6.5%effluent concentration.
• Mortality for pass/fail tests will be evaluated using the t test described in Section 11.3 in
Methods for Measuring the Acute Toxicity of Effluents to Freshwater and Marine Organisms,
Fifth Edition. EPA-821-R-02-012, October 2002,applying an alpha level of 0.05.
• The growth endpoint for pass/fail tests will be determined using Appendix G of Short-Term
Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Marine and
Estuarine Organisms, Third Edition,EPA-821-R-02-014,October 2002,applying an alpha level
of 0.01.
• Mortality and growth endpoints for multiple-concentration tests will be determined using
hypothesis testing as described in EPA Method 1007.0,Mysid,Mysidopsis bahia,Survival,
Growth, and Fecundity Test,as described in Short-Term Methods for Estimating the Chronic
Toxicity of Effluents and Receiving Waters to Marine and Estuarine Organisms, Third Edition,
EPA-821-R-02-014,October 2002.
• The test will be performed at 20 ppt salinity.
• Fecundity will not be evaluated.
All toxicity testing results required as part of this permit condition will be entered electronically using
the Division's eDMR system for the months in which tests were performed. For pass/fail results, report
using the parameter code TGP3E and the DWR Form AT-4(original),which is to be sent to the
address below.
Attention: North Carolina Division of Water Resources
Water Sciences Section/Aquatic Toxicology Branch
1623 Mail Service Center
Raleigh,North Carolina 27699-1623
Or,results can be sent to the email,[e-mail].
Completed Aquatic Toxicity Test Forms shall be filed with the Water Sciences Section no later than 30
days after the end of the reporting period for which the report is made.
Test data shall be complete, accurate, include all supporting chemical/physical measurements and all
concentration/response data, and be certified by laboratory supervisor and ORC or approved designate
Page 4 of 7

Permit NC0085707
signature. Total residual chlorine of the effluent toxicity sample must be measured and reported if
chlorine is employed for disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity monitoring is
required,the permittee will complete the information located at the top of the aquatic toxicity(AT)test
form indicating the facility name, permit number, pipe number,county, and the month/year of the
report with the notation of"No Flow"in the comment area of the form. The report shall be submitted
to the Water Sciences Section at the address cited above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required,
monitoring will be required during the following month. Upon submission of a valid test,this monthly
test requirement will revert to quarterly in the months specified above. Should any test data from this
monitoring requirement or tests performed by the North Carolina Division of Water Resources indicate
potential impacts to the receiving stream,this permit may be re-opened and modified to include
alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum control
organism survival,minimum control organism reproduction, and appropriate environmental controls,
shall constitute an invalid test and will require immediate follow-up testing to be completed no later
than the last day of the month following the month of the initial monitoring.
A. (3.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS
[G.S. 143-215.1(b)]
Federal regulations require electronic submittal of all discharge monitoring reports(DMRs) and
program reports. The final NPDES Electronic Reporting Rule was adopted and became effective on
December 21, 2015.
NOTE: This special condition supplements or supersedes the following sections within Part II of this
permit(Standard Conditions for NPDES Permits):
• Section B. (11.) Signatory Requirements
• Section D. (2.) Reporting
• Section D. (6.) Records Retention
• Section E. (5.) Monitoring Reports
1. Renortine Requirements (Supersedes Section D. (2.)and Section E.(5.)(a)1
The permittee shall report discharge monitoring data electronically using the NC DWR's
Electronic Discharge Monitoring Report(eDMR) internet application.
Monitoring results obtained during the previous month(s) shall be summarized for each month and
submitted electronically using eDMR. The eDMR system allows permitted facilities to enter
monitoring data and submit DMRs electronically using the internet. The eDMR system may be
accessed at: https://deq.nc.gov/about/divisions/water-resources/edmr.
If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the
facility being physically located in an area where less than 10 percent of the households have
broadband access,then a temporary waiver from the NPDES electronic reporting requirements
Page5of7

Permit NC0085707
may be granted and discharge monitoring data may be submitted on paper DMR forms(MR 1, 1.1,
2, 3)or alternative forms approved by the Director. Duplicate signed copies shall be submitted to
the following address:
NC DEQ/Division of Water Resources/Water Quality Permitting Section
ATTENTION: Central Files
1617 Mail Service Center
Raleigh,North Carolina 27699-1617
See"How to Request a Waiver from Electronic Reporting"section below.
Regardless of the submission method,the first DMR is due on the last day of the month following
the issuance of the permit or in the case of a new facility, on the last day of the month following the
commencement of discharge.
Starting on December 21,2025,the permittee must electronically report the following compliance
monitoring data and reports,when applicable:
• Sewer Overflow/Bypass Event Reports;
• Pretreatment Program Annual Reports;and
• Clean Water Act(CWA) Section 316(b)Annual Reports.
The permittee may seek an electronic reporting waiver from the Division(see"How to Request a
Waiver from Electronic Reporting" section below).
2. Electronic Submissions
In accordance with 40 CFR 122.41(1)(9),the permittee must identify the initial recipient at the time
of each electronic submission. The permittee should use the EPA's website resources to identify
the initial recipient for the electronic submission.
Initial recipient of electronic NPDES information from NPDES-regulated facilities means the
entity(EPA or the state authorized by EPA to implement the NPDES program)that is the
designated entity for receiving electronic NPDES data [see 40 CFR 127.2(b)].
EPA plans to establish a website that will also link to the appropriate electronic reporting tool for
each type of electronic submission and forr each state. Instructions on how to access and use the
appropriate electronic reporting tool will be available as well. Information on EPA's NPDES
Electronic Reporting Rule is found at:
https://www.federalregister.gov/documents/2015/10/22/2015-24954/national-pollutant-discharge-
elimination-system-npdes-electronic-reporting-rule
Electronic submissions must start by the dates listed in the"Reporting Requirements" section
above.
3. How to Request a Waiver from Electronic Reporting
The permittee may seek a temporary electronic reporting waiver from the Division. To obtain an
electronic reporting waiver, a permittee must first submit an electronic reporting waiver request to
the Division. Requests for temporary electronic reporting waivers must be submitted in writing to
Page 6 of 7

Permit NC0085707
the Division for written approval at least sixty(60)days prior to the date the facility would be
required under this permit to begin submitting monitoring data and reports. The duration of a
temporary waiver shall not exceed 5 years and shall thereupon expire. At such time, monitoring
data and reports shall be submitted electronically to the Division unless the permittee re-applies for
and is granted a new temporary electronic reporting waiver by the Division. Approved electronic
reporting waivers are not transferrable. Only permittees with an approved reporting waiver request
may submit monitoring data and reports on paper to the Division for the period that the approved
reporting waiver request is effective.
Information on eDMR and the application for a temporary electronic reporting waiver are found on
the following web page:
http://deq.nc.gov/about/divisions/water-resources/edmr
4. Sienatory Requirements [Supplements Section B. (11.) (b)and Supersedes Section B.(11.)
oil
All eDMRs submitted to the permit issuing authority shall be signed by a person described in Part
II, Section B. (11.)(a)or by a duly authorized representative of that person as described in Part II,
Section B. (11.)(b). A person, and not a position,must be delegated signatory authority for eDMR
reporting purposes.
person signing and submittingthe DMR must obtain an eDMR user
For eDMR submissions, the g g
account and login credentials to access the eDMR system. For more information on North
Carolina's eDMR system, registering for eDMR and obtaining an eDMR user account,please visit
the following web page:
http://deq.nc.gov/about/divisions/water-resources/edmr
Certification. Any person submitting an electronic DMR using the state's eDMR system shall
make the following certification [40 CFR 122.22]. NO OTHER STATEMENTS OF
CERTIFICATION WILL BE ACCEPTED:
"I certify, under penalty of law, that this document and all attachments were prepared under my
direction or supervision in accordance with a system designed to assure that qualified personnel
properly gather and evaluate the information submitted. Based on my inquiry of the person or
persons who manage the system, or those persons directly responsible for gathering the
information, the information submitted is, to the best of my knowledge and belief true, accurate,
and complete. 1 am aware that there are significant penalties for submitting false information,
including the possibility of fines and imprisonment for knowing violations."
5. Records Retention [Supplements Section D. (6.)l
The permittee shall retain records of all Discharge Monitoring Reports, including eDMR
submissions. These records or copies shall be maintained for a period of at least 3 years from the
date of the report. This period may be extended by request of the Director at any time [40 CFR
122.41].
Page 7 of 7

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Dare County - Cape Hatteras RO WTP N ,
NPDES Permit NC0085707
A , _ _
1.15,000.000
Receiving Stream: Pamlico Sound Stream Class:SA;HQ\\
Stream Segment:30-22 Sub-Basin#:03-01-55
River Basin:Tar-Pamlico HUC:030201050305 SCALE 35.2667°N. -75.5894°W
County: Dare 1:24,000