NC0070157_Draft Permit_20171129

K1- r.;.,
Water Resources
Environmental Quality
November 29, 2017
Mr. Ken Flatt, Utilities Director
Dare County Water Department
600 Mustian Street
Kill Devil Hills, NC 27948
ROY COOPER
Governor
MICHAEL S. REGAN
Seci etary
LINDA CULPEPPER
Interim Dnectoi
Subject. Draft NPDES Permit NCO070157
North RO WTP (PC -1)
600 Mustian Street, Killl Devil Hills 27948
Dare County
Dear Mr. Flatt:
In response to your request to renew the subject NPDES permit, the Division of Water Resources (DWR or
the Division) hereby transmits this draft for your review and comment. Please review this document to assure
your understanding of the permit limits and monitoring conditions, and to correct errors, if any
The Division understands that you have made no significant changes to your facility since the last permit
renewal. We have made the following updates to your previous permit.
1. The facility map has been updated.
2. Regulatory citations have been added.
3. Electronic reporting of discharge monitoring reports (eDMR) has been added in Section A. (4).
4. In accordance with the WTP permitting strategy for membrane technologies the following changes
have been made for the permit renewal:
a. The effluent flow limit has been removed.
b. Toxicity monitoring have been changed to grab sampling.
c. Toxicity monitoring has been changed to Chronic (Mysidopsis bahia) Pass/Fail monitor only
at an effluent concentration of 5.5 % during January, April, July and October [see A (2.)]
Toxicity monitoring has changed to Chronic because modeling with a dilution factor of
18.2:1 has been applied giving a chronic instream waste concentration (IWC%) of 5.5%.
d. Turbidity monitoring has been added with a frequency of 2/month.
5. Total Lead and Total Zinc monitoring have been removed because they do not show reasonable
potential to exceed water quality standards.
6 Due to a toxicity failure in the last four quarters, a Discharge Alternatives Evaluation and permit re -
opener condition for whole effluent toxicity has been added as described in Sections A. (5.) and A.
(6.).
Whole Effluent Toxicity test results submitted during the past three years have demonstrated that the
Water Treatment Plant's effluent is showing potential for causing aquatic toxicity in the receiving
stream. As a result, the County of Dare shall perform a Discharge Alternatives Evaluation as described in
Section A. (5.) of this permit. This evaluation is being requested to determine whether there are any
economical and technologically feasible alternatives available to the County of Dare to comply with all
NC Water Quality Standards. The permittee will be given approximately one permit cycle to evaluate and
document possible treatment/discharge alternatives to eliminate aquatic toxicity. The evaluation shall be
submitted with the permittee's next permit renewal application and will be carefully reviewed by the
State of North Carolina I Environmental Quality
1617 Mail Service Center I Raleigh, North Carolina 27699-1617
919-707-9000

Mr. Flatt
November 29, 2017
Page 2 of 2
Division and the results will be used in the development of a compliance schedule or possible variance
request for the County of Dare.
Concurrent with this notification, the Division will solicit public comment on this draft by publishing a notice
in newspapers having circulation in the general Dare County area, as required by the NPDES Program. Please
provide your comments, if any, to me via email [derek [e-mail]] or write to my attention care of
DEQ / DWR / NPDES Program no later than December 29, 2017. Your written comments are welcome but
not mandatory.
Following the mandatory 30 -day public comment period, the Division will review all pertinent comments on
your permit draft, and take appropriate action prior to issuing your NPDES permit final. If you have questions
concerning tlus draft, please e-mail me or call my direct line [phone].
Sincerely,
Derek Denard, Environmental Specialist
Compliance & Expedited Permitting Unit
Division of Water Resources, NCDEQ
Enclosure: NPDES Permit NC0070157 (renewal DRAFT)
he NPDES Program Files
ec DWR/WARD, Robert Tankard [robert tankare@ncdenr gov]
Wastewater Operator Certification Group / Maureen Kinney [Maureen Kinney@ncdenr gov]
Aquatic Toxicology Branch / Susan Meadows [susan meadows@ncdenr gov], Cindy Moore [curdy moore@ncdenr gov]
Ken Flatt, Utilities Director, County of Dare [ <enf@darenc com]

NPDES Permit NCO070157
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
NPDES
In compliance with the provisions 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 Watet Pollution Control Act, as amended,
Dare County Water Department
is hereby authorized to discharge wastewater and stormwater from a facility located at the
Dare County North Reverse Osmosis Water Treatment Plant
600 Mustian Street, Kill Devil Hills 27948
Dare County
to receiving waters designated as the Atlantic Ocean contiguous to the Pasquotank River Basin, in
accordance with effluent limitations, monitoring requirements, and other conditions set forth in Parts I,
II, III and IV hereof.
This permit shall become effective , 2018.
This permit and authorization to discharge shall expire at midnight on , 2022.
Signed this day 92018.
Linda Culpepper, Interim Director
Division of Water Resources
By Authority of the Environmental Management Commission
Page 1 of 8

NPDES Permit NCO070157
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby
revoked. As of this permit issuance, any previously issued permit bearing this number is no longer
effective. Therefore, the exclusive authority to operate and discharge from this facility arises under the
permit conditions, requirements, terms, and provisions included herein.
Dare County Water Department
is hereby authorized to:
1. continue to generate reverse osmosis (RO) reject concentrate and secondary -containment
stormwater / process -monitoring wastewater from existing potable water treatment plant (WTP)
facilities;
located at the Dare County North Reverse Osmosis Water Treatment Plant (WTP), 600 Mustian
Street, Kill Devil Hills in Dare Count}; and
2. discharge from said treatment works via Outfall 002, at the location specified on the attached map,
into the Atlantic Ocean [stream segment 99-(7)], currently classified SB waters below Subbasin
03-01-56 [HUC: 030102051704] con-iguous to the Pasquotank River Basin.
Page 2 of 8

NPDES Permit NCO070157
PART I
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge from Outfall 002. Such discharges shall be limited, monitored and
reported' by the Permittee as specified below:
EFFLUENT
CHARACTERISTIC
[PARAMETER CODESI
LIMITS
MONITORING REQUIREMENTS'
Monthly Daily Measurement Sample Sample
Average Maximum Frequency Type Location
Flow (MGD)
50050
Contmuous
Recordmg
Effluent
Total Dissolved Solids (TDS) (mg/1)
70295
Monitor & Report
2/Month
Grab
Effluent
PH (su)
00400
Not < 6.8 or > 8.5
standard units
2/Month
Grab
Effluent
Salinity (ppth)
00480
Monitor & Report
2/Month
Grab
Effluent
Conductivity (umhos/cm)
00094
Monitor & Report
2/Month
Grab
Effluent
Turbichty (ntu)
00070
Monitor & Report
2/Month
Grab
Effluent
Total Copper ( g/L)
01042
2/Month
Grab
Effluent
Chronic Toxicity 2
TGP3E
Monitor & Report
Quarterly
Grab
Effluent
Footnotes:
1. The Permittee shall begin submitting Discharge Monitoring Reports electronically using NC DWR's eDMR
application system. See Condition A. (4.).
2. Chronic Toxicity (Mysidopsis bahia) P/F: monitor only @ 5.5 % during January, April, July and
October [see A. (2)].
Conditions:
The Permittee shall discharge no floating solids or foam visible in other than trace amounts.
Page 3 of 8

NPDES Permit NCO070157
A. (2). CHRONIC TOXICITY PASS/FAIL PERMIT MONITORING (QUARTERLY)
[15A NCAC 02B .0500 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 5_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 5.5% 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.
• Fecundity will not be evaluated.
All toxicity testing results required as part of this permit condition will be entered on the Effluent
Discharge Monitoring Form (MR -1) 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
1621 Mail Servide Center
Raleigh, North Carolina 27699-1621
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
signature. Total residual chlorine of the effluent toxicity sample must be measured and reported if
chlorine is employed for disinfection of the waste stream.
Page 4 of 8

NPDES Permit NCO070157
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. (4.) 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 pernat
(Standard Conditions for NPDES Permits):
• Section B. (11.) Signatory Requirements
• Section D. (2.)
• Section D. (6.)
• Section E. (5 )
Reporting
Records Retention
Monitoring Reports
1. Reporting 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. Until such time that the state's eDMR application
is compliant with EPA's Cross -Media Electronic Reporting Regulation (CROMERR), permittees will be
required to submit all discharge monitoring data to the state electronically using eDMR and will be required
to complete the eDMR submission by printing, signing, and submitting one signed original and a copy of
the computer printed eDMR to the following address:
Page 5 of 8

NPDES Permit NC0070157
NC DEQ / Division of Water Resources /Water Quality Permitting Section
ATTENTION: Central Files
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
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 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 mailing address above. 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, 2020, 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 for 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. http://www2.epa. ovg /compliance/final-national-pollutant-discharge-elimination-system-
Lipdes-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 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
Page 6 of 8

NPDES Permit NC0070157
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.) (d
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.
For eDMR submissions, the person signing and submitting the DMR must obtain an eDMR user 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:
7 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 qualfied 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. I 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.)]
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 8

NPDES Permit NCO070157
A. (5.) DISCHARGE ALTERNATIVES EVALUATION:
[15A NCAC 02H.0 105]
The Permittee shall assess potential alternatives to eliminate Whole Effluent Toxicity (WET) test failures. This
evaluation shall assess the feasibility of all the following alternatives.
1. Connect discharge to a WWTP: Determme whether the wastewater can be discharged to a wastewater
treatment plant. Approval or disapproval from the plant operator should be acquired
2. Obtain a Non -discharge permit: Eliminate the surface water discharge by obtaining a non -discharge permit
for spray irrigation, mfiltration, or subsurface disposal (on-site drainfield, infiltration
gallery, injection wells).
3 Install Wastewater Treatment: Install improved wastewater treatment to enable the facility effluent to
consistently pass the WET test. If this is not technically feasible or cost prohibitive, please
explain and provide estimated costs.
4. Use Alternative Water Treatment Source: Obtain drinking water from another source (nearest County, City,
or Town or other wells) so the discharge or toxicity problem is eliminated.
5. Use Alternative Water Treatment Method: Install alternative and/or innovative water treatment methods or
operational improvements that do not produce toxic wastewaters. For example, install a
recycle iron/manganese filtration system with no discharge or combine discharge with
WWTP or cooling water effluents.
6. Discharge to a Larger waterbody/Perform a dilution model: Relocate the facility's discharge to a larger
receiving waterbody to eliminate or reduce toxic impacts to the receiving waterbody given
the increased dilution. If applicable, perform a dilution model to receive allowance for
stream dilution in 'WET test
7. Combination of Alternatives: Employ any combination of the alternatives listed above that would result in
eliminating or decreasing toxicity until a more feasible solution becomes available
The evaluation shall include a present value of costs analysis for all technologically feasible options as outlined in
the Division's "Engineering Alternatives Analysis Guidance Document " This Document can be found at:
http://portal.ncdenr.org/web/wq/swp/ps/npdes/permits.
This evaluation is being requested to determine whether there are any economical and technologically feasible
alternatives available to the Permittee to address aquatic toxicity in the plant effluent. Based upon the evaluation,
please identify viable alternatives and present an implementation schedule and project timeline for the preferred
alternative. The Permittee shall submit the Discharge Alternatives Evaluation to the Division along with the
submission of their next permit renewal application (due 6 months prior to permit expiration on ) to:
NC DEQ / Division of Water Resources / Water Quality Permitting
NPDES, Wastewater Branch
1617 Mail Service Center, Raleigh, NC 27699-1617
A. (6.) PERMIT RE -OPENER: WHOLE EFFLUENT TOXICITY
[G.S. 143-215.1(b)]
Whole Effluent Toxicity monitoring results indicating aquatic toxicity may result in the Division of Water
Resources re -opening this permit or requesting by letter that further action be taken. Additional metals testing,
a toxicity identification evaluation, a toxicity reduction evaluation, and/or an assessment of discharge treatment
alternatives may be requested.
Page 8 of 8

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Approximate
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Dare County North Reverse Osmosis WTP
NPDES Permit NCO070157
600 Mustian Street, Kill Devil Hills 2794
Receiving Stream: Atlantic Ocean Stream Class: SB
Stream Segment: 99-(7) Sub -Basin #: 03-01-56
River Basin: Pasquotank HUC: 03010205170
County: Dare
36.0158' N,-75.6528- W
SCALE NC Grid: C36SW
1:24,000 USGS Quad: Kitty Hawk, NC
- I