NC0089290_Draft Permit_20230502

ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
RICHARD E. ROGERS, JR.
Director
Ken Gamble, Town Manager
Town of Mocksville
771 Sanford Ave
Mocksville, NC 27028
Dear Permittee:
NORTH CAROLINA
Environmental Quality
May 2, 2023
Subject: Draft NPDES Permit NCO089290
Hugh A. Lagle WTP
Grade I Physical Chemical WPCS
Davie County
The Division has reviewed your request to renew the subject NPDES 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 Supplement to Cover Sheet page has been updated to include the estimated maximum, monthly
average flow, stream index, an updated components list, and the HUC.
➢ Appropriate units of measure have been added to the Effluent table in Section A. (1). Please make sure to
report monitoring results using the correct eDMR code and units.
➢ Iron has been removed from the Effluent table in Section A. (1) as there are no longer water quality
standards for Iron and the permit renewal application indicates that Iron sulfate or Ferrous sulfate does not
have the potential to be discharged.
➢ Ammonia Nitrogen has been removed from the Effluent table in Section A. (1) as chloramines are not
used for disinfection at the facility.
➢ The monitoring frequency for Turbidity has been reduced to Monthly and the eDMR parameter code has
been updated in Section A. (1) per current water treatment plant guidance.
➢ Limits for Total Copper have been added to the Effluent table in Section A. (1.) in conjunction with a
Compliance Schedule in Section A. (4) based on a reasonable potential to exceed water quality standards.
➢ Section A. (2) has been updated regarding the submission of aquatic toxicity test results.
➢ A Permit Re -Opener special condition for WET testing has been added (Section A. (3)) as the permittee
has failed over 25% of their toxicity tests over the past three years. The Division may request that
additional actions be taken to address toxicity issues if the permittee continues to fail their whole effluent
toxicity testing.
➢ Section A. (5) has been updated to reflect current federal requirements for Electronic Reporting of
Discharge Monitoring Reports (DMRs).
Please note that Bear Creek is listed as an impaired waterbody on the North Carolina 303(d) Impaired Waters
List. Addressing impaired waters is a high priority with the Division, and instream data will continue to be
evaluated. If there is noncompliance with permitted effluent limits and stream impairment can be attributed to
your facility, then mitigative measures may be required.
D E Q�� North Carolina Department of Environmental Quality I Division of Water Resources
�or512 North Salisbury Street 1 1617 Mail Service Center I Raleigh, North Carolina 27699-1617
NORTH CAROLINA _
���afEnwron��iouai\ /./ 919.707.9000

Page 2 of 2
NPDES Permit NC0089290
DRAFT Permit Renewal
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 latest version is available at https:/ibit.ly/3k5NFaL and can be viewed
online or downloaded as a PDF file.
With this notification, the Division will solicit public comment on this draft permit by publishing a notice in
newspapers having circulation in the general Davie 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 sydney.carpenter(a,ncdenr.gov.
Sincerely,
JJA�_ 0_�*
Sydney Carpenter
Environmental Specialist II
NPDES Compliance and Expedited Permitting
cc: NPDES File [Laserfiche]
Winston-Salem Regional Office [Laserfiche]
Public Water Supply
Operator Certification Program
Aquatic Toxicology Unit

NPDES Permit NCO089290
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
DES
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
Town of Mocksville
is hereby authorized to discharge wastewater from a facility located at the
Hugh A. Lagle WTP
771 Sanford Ave
Mocksville
Davie County
to receiving waters designated as an unnamed tributary to Bear Creek in subbasin 03-07-06 of the
Yadkin Pee -Dee 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
This permit and authorization to discharge shall expire at midnight on December 31, 2026.
Signed this day
Richard E. Rogers, Jr.
Director, Division of Water Resources
By Authority of the Environmental Management Commission
Page 1 of 9

NPDES Permit NCO089290
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby revoked,
and as of this 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.
Town of Mocksville
is hereby authorized to:
1. Continue to operate a conventional water treatment plant with discharge from filter backwash
wastewater, sediment basin flush, and untreated raw water. The facility currently has a design
potable flowrate of 2.0 MGD and a maximum, monthly average wastewater discharge of
approximately 0.2604 MGD. This facility is located at the Hugh A. Lagle WTP, 771 Sanford
Avenue in Mocksville in Davie County. Water and wastewater treatment consists of.
• Flash mixer
• Flocculation
• Sedimentation
• Filtration
• Disinfection
• Two 250,000-gallon equalization storage tanks
• Dechlorination
• Flow meter
Chemical usage consists of
• Poly aluminum chloride
• Sodium hydroxide
• Poly-ortho phosphate blend
• Chlorine (gas)
• Fluoride
2. Discharge from said treatment works via Outfall 001 at the location specified on the attached
map into an unnamed tributary to Bear Creek [Stream Segment: 12-108-18-(3)], a waterbody
currently classified WS-IV in subbasin 03-07-06 [HUC: 030401010301] of the Yadkin Pee -Dee
River Basin.
Page 2 of 9

NPDES Permit NCO089290
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]
Beginning with the effective date of this permit and lasting until expiration, the Permittee is
authorized to discharge treated wastewater 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
Location
Flow (MGD) [50050]
Monitor & Report
Continuous
Recording
Effluent
PH (00400]
> 6.0 and < 9.0 standard
— units
2/Month
Grab
Effluent
Total Suspended Solids (mg/L) [C0530]
30.0 mg/L
45.0 mg/L
2/Month
Grab
Effluent
Total Residual Chlorine (pg/L) 2 [500601
17 pg/L
2/Month
Grab
Effluent
Turbidity (NTU) [00070]
Monitor & Report
Monthly
Grab
Effluent
Total Copper (pg/L) 3 [01042]
8.41 pg/L
11.25 pg/L
Monthly
Grab
Effluent
Total Aluminum (pg/L) [011051
Monitor & Report
Quarterly
Grab
Effluent
Total Fluoride (fag/L) [009511
Monitor & Report
Quarterly
Grab
Effluent
Total Zinc (pg/L) [01092]
Monitor & Report
Quarterly
Grab
Effluent
Total Manganese (pg/L) [010551
Monitor & Report
Quarterly
Grab
Effluent
Total Nitrogen (mg/L) [C0600]
Monitor & Report
Quarterly
Grab
Effluent
Total Phosphorus (mg/L) [C0665]
Monitor & Report
Quarterly
Grab
Effluent
Hardness — Total as
[CaCO3 or (Ca + Mg)] 4 (mg/L) [00900]
Monitor & Report
Quarterly
Grab
Effluent
Hardness — Total as
[CaCO3 or (Ca + Mg)] 5 (mg/L) [009001
Monitor & Report
Quarterly
Grab
Upstream
Whole Effluent Toxicity Monitoring 6 [TGP3B]
Pass/Fail
Quarterly
Grab
Effluent
Footnote,, -
The permittee shall submit discharge monitoring reports electronically using the NC DWR's eDMR
application system [see Section A. (5)].
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.
See Section A. (4) for a compliance schedule.
Page 3 of 9

NPDES Permit NCO089290
4. Effluent hardness sampling should be performed in conjunction with testing for hardness dependent
metals (copper and zinc).
5. The Permittee shall sample instream hardness, upstream of the facility's discharge. The sample shall be
representative of the hardness in the receiving stream. If the Permittee is a member of the Monitoring
Coalition Program, sampling for instream hardness may be waived as long as the Monitoring coalition
agrees to sample hardness at the nearest upstream location, at a minimum frequency of quarterly, and the
Permittee has obtained approval from DWR-NPDES Permitting Unit that the upstream station being
monitored by the Coalition is representative of the receiving stream for this discharge. The Permittee is
responsible for submitting instream hardness test results with its permit renewal application package. If
Coalition membership is cancelled or the Coalition terminates instream hardness sampling at the
approved station, the Permittee will immediately notify the Division and resume sampling for instream
hardness, upstream of its discharge.
6. Chronic WET Pass/Fail (Ceriodaphnia dubia) at 90% effluent during the months of March, June,
September, and December [see Section A. (2)].
THERE SHALL BE NO DISCHARGE OF FLOATING SOLIDS OR VISIBLE FOAM IN
OTHER THAN TRACE AMOUNTS.
A. (2) CHRONIC TOXICITY PASS/FAIL MONITORING (QUARTERLY)
[15A NCAC 02B .0500 et seq.]
The permittee shall conduct quarterly chronic toxicity tests using test procedures outlined in the
"North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," (Revised December 2010, or
subsequent versions).
The effluent concentration defined as treatment two in the procedure document is 90%. The testing
shall be performed as a Ceriodaphnia dubia 7-day pass/fail test. The tests will be performed during
the months of March, June, September, and December. 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 TGP3B. Additionally, DWR Form AT-1 (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, ATForms.ATB(&,,ncdenr.gov.
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 NCO089290
Test data shall be complete and accurate and include all supporting chemical/physical
measurements performed in association with the toxicity tests, as well as all dose/response data.
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 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) 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.
A. (4) SCHEDULE OF COMPLIANCE (OUTFALL 001)
[G.S. 143-215.1(b)]
1. Within one year from the effective date of the permit 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 Copper limits at Outfall 001. Specific dates for completion or
implementation of each action shall be included.
2. Within two years from the effective date of the permit submit a report to the Division
summarizing actions taken in accordance with the Corrective Action Plan.
3. Within three years from the effective date of the permit submit a report to the Division
summarizing actions taken in accordance with the Corrective Action Plan.
4. Within four years from the effective date of the permit submit a report to the Division
summarizing actions taken in accordance with the Corrective Action Plan.
Page 5 of 9

NPDES Permit NCO089290
5. Achieve compliance with Total Copper limits specified in Section A. (1) within five years of the
permit effective date.
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 in excess of 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:
(1) NCDEQ / Division of Water Resources (2) NCDEQ / Division of Water Resources
NPDES Compliance and Expedited Permitting Winston-Salem Regional Office
1617 Mail Service Center 450 West Hanes Mill Road, Suite 300
Raleigh, NC 27699-1617 Winston-Salem, NC 27105
A. (5) ELECTRONIC REPORTING - 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.)
• Section D. (2.)
• Section D. (6.)
• Section E. (5.)
Signatory Requirements
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. The eDMR system
may be accessed at: hgps:Hdeg.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
may be granted and discharge monitoring data may be submitted on paper DMR forms (MR 1,
Page 6 of 9

NPDES Permit NC0089290
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
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 ig ster.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
Page 7 of 9

NPDES Permit NC0089290
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.
Information on eDMR and the application for a temporary electronic reporting waiver are found
on the following web page:
http://deq.ne.gov/about/divisions/water-resources/edmr
4. Signatory Requirements [Supplements Section B. (11.) (b) and Supersedes Section B. (11.)
All eDMRs submitted to the permit issuing authority shall be signed by a person described in
Part II, Section B. (I 1.)(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:
hqp://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. I am aware that there are significant penalties for submitting false information,
including the possibility of fines and imprisonment for knowing violations. "
Page 8 of 9

NPDES Permit NCO089290
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 9 of 9

A
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Facility Location
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Discharge Point
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Mocksville WTP
NPDES Permit NCO089290
Receiving Stream: UT to Bear Creek Stream Index: 12-108-18-(3)
Lon.it� 800 34' 40" W River Basin: Yadkin Pee -Dee
Latitude: 350 53' 28" N Sub -Basin: 03-07-06
HUC: 030401020602 Stream Class: WS-IV
N
SCALE
1:12,000
Facility
Location
Davie County