NC0086924_Draft Permit_20240430

ROY COOPER
Governor
ELIZABETH S. B1SER
Secretary
RICHARD E. ROGERS, JR.
Director
David L. Clegg, County Manager
Tyrrell County
PO Box 449
Columbia, NC 27925-0449
Dear Permittee:
NORTH CAROLINA
EnWronmsntal Quality
April 30, 2024
Subject: Draft NPDES Permit NCO086924
Tyrrell County Reverse Osmosis WTP
Not Classified — Physical Chemical WPCS
Tyrrell County
The Division has reviewed your request to renew the subject permit. Enclosed with this letter is a copy of the draft
permit for your facility. Please review this draft carefully to ensure your thorough understanding of the
information, conditions, and requirements it contains.
The draft permit includes the following significant changes from the existing permit:
➢ The effluent table in Section A. (1) has been updated to be consistent with the instream monitoring
requirements for Dissolved Oxygen and Salinity as specified in Section A. (4).
➢ Total Kjeldahl Nitrogen (TKN) and Nitrate + Nitrite Nitrogen (NO3-N + NO2-N) have been added to the
effluent table in Section A. (1) as reportable parameters with a corresponding footnote. The Sample Type
for Total Nitrogen has been updated from "Grab" to "Calculated".
➢ Limits for Total Zinc have been added to the effluent table in Section A. (1) as there is a reasonable
potential to exceed water quality standards based on an analysis of the discharge data. A Compliance
Schedule has been added to the permit for these new limits (see Section A. (5)).
➢ The Compliance Schedule condition for Total Copper has been removed from the permit as the date for
achieving compliance has passed and the facility should be able to meet the Copper limits in the permit.
➢ Section A. (2) has been updated to reflect the new submission requirements for Whole Effluent Toxicity
Testing results.
➢ Section A. (4) has been updated to remove Temperature as a required parameter for instream monitoring
as this was removed from the effluent table in the previous permit renewal, but mistakenly left in the
permit condition.
➢ Section A. (6) has been updated to reflect current federal requirements for Electronic Reporting of
Discharge Monitoring Reports (DMRs).
Please note that the practical quantitation limit (PQL) for Total Nickel is 2 µg/L (per the Inorganic Chemistry
Branch of the Division of Water Resources Water Sciences Section), and monitoring data should be reportable
down to these levels. This facility has currently been reporting this parameter down to 10 µg/L. Limits for water
treatment plants are determined by evaluating DMR data submitted to the Division, along with a dilution factor (if
applicable) and the maximum monthly average flow reported in the previous 3 years at the time the review is
completed.
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 1). The conditions are the same as in your current permit except that agency and
division names have been updated. The latest version is available at https://bit.ly/3k5NFaL and can be viewed
online or downloaded as a PDF file.
D_F
Q North Carolina Department of Environmental Quality 1 Division of Water Resources
512 North Salisbury Street 1 1617 Mail Service Center 1 Raleigh. North Carolina 27699-1617
N c;8 a 9I9.707 9000

Page 2 of 2
Tyrrell County
DRAFT Permit Renewal - NC0086924
With this notification, the Division will solicit public comment on this, draft permit by publishing a notice in
newspapers having circulation in the general Tyrrell County area, per EPA requirements.
Please provide your comments, if any, to me at the address below no later than 30 days after receiving this
draft permit.
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 at
919-707-3712, or via e-mail at svdney.deuterman(a,deg.nc.gov.
Sincerely,
4bj�7
Sydney Deuterman, Environmental Specialist II
NPDES Compliance and Expedited Permitting Unit
Division of Water Resources
cc: NPDES File [Laserfiche]
WQ Regional Operations — Washington [Laserfiche]
Operator Certification Program
Aquatic Toxicology Unit

NPDES Permit NCO086924
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 Water Pollution Control Act, as amended, the
Tyrrell County
is hereby authorized to discharge wastewater from a facility located at the
Tyrrell County Reverse Osmosis WTP
3868 Albemarle Church Road
Columbia
Tyrrell County
to receiving waters designated as Bull Bay in the Pasquotank River Basin, in accordance with effluent
limitations, monitoring requirements, and other conditions set forth in Parts I,11, III and IV hereof.
This permit shall become effective
This permit and authorization to discharge shall expire at midnight on July 31, 2029.
If the permittee intends to continue to discharge at the facility beyond the term of this permit, a renewal
application must be submitted no later than February 1, 2029 (180 days before the expiration of this permit).
Signed this day
John E. Hennessy, Section Chief Regional Operations
Division of Water Resources
By Authority of the Environmental Management Commission
Pagel of 9

NPDES Permit NCO086924
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, andprovisions included herein.
Tyrrell County
is hereby authorized to:
1. Continue to operate a water treatment plant with a discharge of reject water from reverse osmosis
units. This water treatment plant currently has a design potable flow rate of 0.936 MGD and a
maximum, monthly average wastewater discharge of approximately 0.132 MGD. This facility is
located at the Tyrrell County Reverse Osmosis WTP at 3868 Albemarle Church Road, Columbia in
Tyrrell County. Water and wastewater treatment includes the following components:
• RO Unit
• Subaqueous diffuser
2. Discharge from said treatment works via Outfall 001 at the location specified on the attached map
into Bull Bay, currently classified SB waters [Stream Index: 30-14] located within sub -basin 03-01-
53 [HUC: 0301020502071 of the Pasquotank River Basin.
Page 2 of 9

NPDES Permit NCO086924
PART I
A. (1) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[15A NCAC 02B .0400 et seq., 02B .0500 et seq.]
Not Classified - Physical Chemical WPCS [15A NCAC 08G .0306]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge reverse osmosis reject water from Outfall 001. Such discharges
shall be limited and monitored] by the Permittee as specified below:
EFFLUENT CHARACTERISTICS
eDMR Code
EFFLUENT LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample
Location2
Flow (MGD)
50050
Monitor & Report
Continuous
Recording
Effluent
Dissolved Oxygen (mg/L)
00300
Monitor & Report
Monthly
Grab
Effluent
Dissolved Oxygen (mg/L)
00300
Monitor & Report
2/Month
Grab
U & D
Salinity (ppth)
00480
Monitor & Report
Monthly
Grab
Effluent
Salinity (ppth)
00480
Monitor & Report
2/Month
Grab
U & D
Conductivity (pmhos/cm)
00094
Monitor & Report
Monthly
Grab
Effluent,
U & D
pH (s.u.)
00400
Not < 6.8 nor > 8.5
standard units
2/Month
Grab
Effluent,
U & D
Total Residual Chlorine (pg/L) 3
50060
13 pg/L
2/Month
Grab
Effluent
Total Dissolved Solids (mg/L)
70295
Monitor & Report
Monthly
Grab
Effluent
Turbidity (NTU)
00070
Monitor & Report
Monthly
Grab
Effluent
Total Copper (pg/L)
01042
3.70 pg/L
5.80 pg/L
Monthly
Grab
Effluent
Total Chloride (mg/L)
00940
Monitor & Report
Monthly
Grab
Effluent
Total Nickel (pg/L)
01067
Monitor & Report
Quarterly
Grab
Effluent
Total Fluoride (pg/L)
00951
Monitor & Report
Monthly
Grab
Effluent
Total Zinc (pg/L) 4
01092
85.6 pg/L 4
1 95.1 pg/L 4
Monthly
Grab
Effluent
Ammonia Nitrogen (mg/L)
C0610
Monitor & Report
Monthly
Grab
Effluent
TKN (mg/L)
00625
Monitor & Report
Quarterly
Grab
Effluent
NO3-N + NO2-N (mg/L)
00630
Monitor & Report
Quarterly
Grab
Effluent
Total Nitrogen (mg/L) 5
C0600
Monitor & Report
Quarterly
Calculated
Effluent
Total Phosphorous (mg/L)
C0665
Monitor & Report
Quarterly
Grab
Effluent
Whole Effluent Toxicity Testing 6
TGE3E
Monitor & Report
Quarterly
Grab
Effluent
Footnotes:
1. The permittee shall submit discharge monitoring reports electronically using the Division's eDMR system [see
Section A. (6)].
Page 3 of 9

NPDES Permit NCO086924
2. Sample Locations: U — Upstream at Location B, D — Downstream at Location M6. See Section A. (4) for
locations and frequencies.
3. Limit and monitoring requirements apply only if the facility adds chlorine or chlorine derivatives to water
that is eventually discharged. The Division shall consider all effluent TRC values reported below 50 µg/L to
be in compliance with the permit. However, the Permittee shall continue to record and submit all values
reported by a North Carolina certified laboratory (including field certified), even if these values fall below
50 µg/L.
4. See Section A. (5) for a compliance schedule for Total Zinc limits.
5. For a given wastewater sample, TN = TKN + NO3-N + NO2-N, where TN is Total Nitrogen, TKN is Total
Kjeldahl Nitrogen, and NO3-N and NO2-N are Nitrate and Nitrite Nitrogen, respectively.
6. Acute Toxicity monitoring (Mysidopsis bahia) 24-hour Pass/Fail static test at 90% in January, April, July,
and October [see Section A. (2)].
All samples collected should be from a representative discharge event.
THERE SHALL BE NO DISCHARGE OF FLOATING SOLIDS OR VISIBLE FOAM IN OTHER THAN
TRACE AMOUNTS.
A. (2) ACUTE TOXICITY PASS/FAIL MONITORING (QUARTERLY)
[15A NCAC 02B .0200] [15A NCAC 02B .05001
The permittee shall conduct acute toxicity tests on a quarterly basis using protocols defined in the
North Carolina Procedure Document entitled "Pass/Fail Methodology For Determining Acute Toxicity
In A Single Effluent Concentration" (Revised -December 2010, or subsequent versions). The
monitoring shall be performed as a Mysid Shrimp (Mysidopsis bahia) 24-hour static test. The effluent
concentration at which there may be at no time significant acute mortality is 90% (defined as treatment
two in the procedure document). 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.
All toxicity testing results required as part of this permit condition will be entered electronically using
the Division's eDMR system for the month in which it was performed, using the parameter code
TGE3E. Additionally, DWR Form AT-2 (original) is to be sent to the following address:
North Carolina Division of Water Resources
Water Sciences Section/Aquatic Toxicology Branch
1621 Mail Service Center
Raleigh, NC 27699-1621
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.
Page 4 of 9

NPDES Permit NC0086924
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.
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, then
monthly monitoring will begin immediately. Upon submission of a valid test, this monthly test
requirement will revert to quarterly in the months specified above.
Should any test data from either these monitoring requirements 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 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) DISCHARGE SPECIAL CONDITION
[G.S. 143-215.1(b)]
The effluent diffuser must be designed to prevent surface turbulence and bottom scour. Should the
location of the discharge cause visible turbulence within Bull Bay, the Division may require that the
discharge be relocated.
The diffuser must be submerged during low tide conditions.
A. (4) INSTREAM MONITORING REQUIREMENTS
[G.S. 143-215.661
The following parameters shall be monitored within Bull Bay (at the locations indicated) at a
frequency of 2/Month year-round.
Page 5 of 9

NPDES Pen -nit NCO086924
Parameter
Location
Frequency
Months
Salinity (ppt)
D.O. m /1
B, M6
2/Month
January through
December ear
B — Background sample should be taken at or near the mouth of Bunton Creek, in the estuary, outside
the influence of the discharge.
M6 — Along a northwest/southeast transect from the discharge point, approximately 50 feet northwest
of the discharge.
NOTE: The attached map is not to scale.
A. (5) SCHEDULE OF COMPLIANCE FOR ZINC (OUTFALL 001)
[G.S. 143-215.1(b), 40 CFR Part 122]
(a.) No later than August 1, 2025, the Permittee shall submit to the Division of Water Resources a
Corrective Action Plan summarizing the actions or strategy to be taken to achieve compliance
with the Total Zinc limits at Outfall 001. Specific dates for completion or implementation of each
action shall be included.
(b.) No later than August 1, 2026, submit a report to the Division summarizing actions taken in
accordance with the Corrective Action Plan.
(c.) No later than August 1, 2027, submit a report to the Division summarizing actions taken in
accordance with the Corrective Action Plan.
(d.) No later than August 1, 2028, submit a report to the Division summarizing actions taken in
accordance with the Corrective Action Plan.
(e.) Achieve compliance with Total Zinc limits specified in Section A. (1) no later than August 1,
2029.
Upon approval of the Corrective Action Plan by the Division, the report and actions become an
enforceable part of this permit. Any modifications to the schedule shall be requested to the Division at
least ninety (90) days before the deadline. Modifications to the schedule more than four months will
be subject to public notice.
The Corrective Action Plan and reports shall include the owner's name, NPDES permit number and
Permittee contact person, and shall be submitted to:
NCDEQ/Division of Water Resources
NPDES Compliance and Expedited Permitting
1617 Mail Service Center
Raleigh, NC 27699-1617
NCDEQ/Division of Water Resources
Washington Regional Office
943 Washington Square Mall
Washington, NC 27889
No later than 14 days following each interim date and the final date of compliance, the Permittee shall
notify the Division in writing of its compliance or noncompliance with the interim or final
requirements, or submit progress reports.
Page 6 of 9

NPDES Permit NCO086924
A. (6) 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. Reporting Requirements [Supersedes Section D. (2.) and Section E. (5.) (a)]
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:Hdeg.ne.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
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.
Monitoring results obtained during the previous month(s) shall be summarized for each month and
reported via the eDMR system no later than the last calendar day of the month following the
Page 7 of 9

NPDES Permit NCO086924
completed reporting period. 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 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:
https://www.federalre ister.gov/documents/2015/10/22/2015-24954/national-pollutant-discharge-
elimination-s sty em-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
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.
Page 8 of 9

NPDES Permit NC0086924
Information on eDMR and the application for a temporary electronic reporting waiver are found on
the following web page:
http://deg.nc.gov/about/divisions/water-resources/edmr
4. Sienatory Requirements [Supplements Section B. (11.) (b) and Supersedes Section B. (11.)
f"
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. (I 1.)(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:
httl://deg.nc.jzov/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:
V 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. 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.)1
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 9 of 9

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Tyrrell County Reverse Osmosis WTP
NPDES Permit NCO086924
Receiving Stream: Bull Bay
Stream Index: 30-14
River Basin: Pasquotank
Stream Class: SB
Longitude: 76' 21' 16" W
Latitude: 36' 56' 16" N
HUC: 030102050207
Subbasin: 03-01-53
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NPDES Permit NC0086924