NC0082949_Draft Permit_20191127

ROY COOPER
(�OI'PI]kAA .6?I
MICHAEL S. REGAN
LINDA CULPEPPER
*� a«01M'
NORTH CAROLINA
Environmental Quality
November 27, 2019
Mr. Kenneth Gamble, Town Manager
Town of Denton
PO Box 306
Denton,NC 27239-0306
Subject: Draft NPDES Permit NC0082949
Denton WTP
Grade I Physical Chemical WPCS
Davidson County
Dear Mr. Gray:
The Division has reviewed your request to renew the subject permit. 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:
1. Outfall map has been updated.
2. Language and the components list on the Supplement to Permit Cover Sheet has been updated.
3. Units of measure have been updated in Section A. (1).
4. Monitoring for flow has been reduced, and the associated footnote has been updated, in Section
A. (1)per the current water treatment plant strategy.
5. Monitoring for turbidity has been reduced to monthly in Section A. (1)per the current water
treatment plant strategy.
6. Monitoring for manganese has been reduced to quarterly in Section A. (1) as there is no longer a
water quality standard for manganese but it remains a pollutant of concern in WS-class waters.
7. The limit for aluminum has been removed and monitoring reduced to quarterly in Section A. (1)
per the current water treatment plant guidance.
8. Limits have been added for copper and monitoring increased to monthly in Section A. (1)based
on a reasonable potential to exceed water quality standards.
9. Monitoring for total hardness has been added in Section A. (1) per the current water treatment
plant guidance.
10. Monitoring for iron has been removed in Section A. (1) as there is no longer a water quality
standard for iron and the renewal application indicated iron does not have a possibility to be
discharged.
11. Monitoring for zinc has been removed in Section A. (1)per the reasonable potential analysis, and
as the renewal application indicated zinc does not have a possibility to be discharged.
North Carolina Department of Environmental Quality I Division of Water Resources
1617 Mail Service Center I Raleigh,North Carolina 27699-1617
919-707-9000

12. Former footnote#4 in Section A. (1)has been removed as monitoring in conjunction with
toxicity samples is no longer required.
The NC 2007-2014 Water Quality Standard(WQS)Triennial Review was approved by the NC
Environmental Management Committee(EMC)on November 13, 2014. The US EPA subsequently
approved the WQS revisions on April 6, 2016 with some exceptions. The NC Division of Water
Resources NPDES PermittingUnit is required to implement the new dissolved metal standards in all
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permits public noticed after April 6, 2016.
The new standards for most metals include acute standards. Further, the freshwater standards for several
metals are expressed as the dissolved form of the metals, and seven metals have hardness-dependent
equations. As a result,the NPDES Permitting Unit will need site-specific effluent hardness data and
instream hardness data,upstream of the discharge, for each facility monitoring these metals in order to
calculate permit limitations. Effluent hardness and instream hardness sampling,upstream of the
discharge,has been added to this permit at a monitoring frequency of quarterly. See Section A.(1)
Effluent Limitations and Monitoring Requirements.
With this notification,the Division will solicit public comment on this draft permit by publishing a
notice in newspapers having circulation in the general Davidson County area, per EPA requirements.
Please provide your comments,if any,to me 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 919-707-3619, or via e-mail [[e-mail]].
Sincerely,
Brianna Young
Compliance and Expedited Permitting Unit
cc: NPDES Files
Winston-Salem Regional Office
Wastewater Operator Certification Group
WSS/Aquatic Toxicology Branch
DWR/Public Water Supply

Permit NC0082949
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
Town of Denton
is hereby authorized to discharge treated wastewater from a facility known as
Denton Water Treatment Plant(WTP)
3049 Bringle Ferry Road
Davidson County
to receiving waters designated as an unnamed tributary (UT) to the Yadkin River, within the Yadkin
Pee-Dee River Basin, in accordance with effluent limitations, monitoring requirements, and other
applicable conditions set forth in Parts I, II, III, and IV hereof
The permit shall become effective
This permit and the authorization to discharge shall expire at midnight on January 31, 2024.
Signed this day
Linda Culpepper
Director, Division of Water Resources
By Authority of the Environmental Management Commission
Page 1 of 9

Permit NC0082949
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 described herein.
Town of Denton
is hereby authorized to:
1. Continue to operate a conventional water treatment plant with a discharge of wastewaters from
sedimentation basins and filter backwash. This water treatment plant currently has a design potable
flowrate of 2.2 MGD and a maximum,monthly average wastewater discharge of approximately
0.0342 MGD. This facility is located at the Denton WTP, 3049 Bringle Ferry Road in Denton in
Davidson County. Water and wastewater treatment consists of:
• Flash mixer
• Flocculation basin
• Two (2) sedimentation basins
• Four(4) sand filters
• Two (2) 500,000 gallon clearwells
• 200,000 gallon lined backwash/sludge holding basin
• 100,000 gallon polishing basin
• Chemicals utilized in potable water treatment include:
o Potassium permanganate
o Powder activated carbon
o Alum
o Caustic soda
o Chlorine , ,r
o Fluoride
o Corrosion inhibitory hopolyphosphate blend)
2. Discharge from said treatment works via Outfall 001 at a location specified on the attached map into
an unnamed tributary(UT)to the Yadkin River [Stream Segment: 12-(124.5)], a waterbody currently
classified WS-IV, B; CA [HUC: 0304010306] within subbasin 03-07-08 of the Yadkin Pee-Dee
River Basin.
Page 2 of 9

Permit NC0082949
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 .0302]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge filter backwash via Outfall 001. Such discharges shall be limited
and monitored' by the Permittee as specified below:
EFFLUENT CHARACTERISTIC LIMITS MONITORING REQUIREMENTS
Monthly Daily Measurement Sample Sample
Parameter Code Average Maximum Frequency Type Location
Flow(MGD)2 50050 2/Month Instantaneous or Effluent
Estimate 2
Total Suspended Solids C0530 30 mg/L 45 mg/L 2/Month Grab Effluent
pH 00400 >6.0 and<9.0 standard units 2/Month Grab Effluent
Total Residual Chlorine 3 50060 17 pg/L 2/Month Grab Effluent
o
Turbidity(NTU) 00070 Monthly Grab Effluent
Total Aluminum(pg/L) 01105 Monitor&Report Quarterly Grab Effluent
Total Copper 4 01042 7.88 pg/L 10.47 pg/L Monthly Grab Effluent
Total Fluoride Quarterly Grab Effluent
Total Manganese(pg/L) 01055 Monitor&Report Quarterly Grab Effluent
Hardness—Total as
[CaCO3 or(Ca+Mg)]5 00900 Monitor&Report Quarterly Grab Effluent
(mg/L)
Hardness—Total as
[CaCO3 or(Ca+Mg)]6 00900 Monitor&Report Quarterly Grab Upstream
(mg/L)
Chronic WET Testing 7 TGP3B Monitor&Report Quarterly Grab Effluent
Footnotes:
1. The permittee shall submit discharge monitoring reports electronically using the Division's eDMR system
[see Section A. (4)].
2. For instantaneous flow monitoring, the duration of the discharge should be noted in log books and a total
daily discharge reported on the DMR.
3. 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. (3) for compliance schedule.
5. Effluent hardness sampling should be performed in conjunction with testing for hardness dependent metals
(cadmium, copper, lead,nickel, silver, and zinc).
6. 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
Page 3 of 9

Pennit NC0082949
•
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.
7. Whole Effluent Toxicity(WET)testing of Ceriodaphnia dubia shall be performed as 7-day pass/fail test at
90% effluent concentration,during February,May,August,and November[see Section A.(2)].
Samples shall be taken at the outfall but prior to mixing with the receiving waters.
There shall be no discharge of floating solids or foam in other than trace amounts.
Page 4 of 9

Permit NC0082949
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 February, May, August and November. 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, [e-mail].
Completed Aquatic Toxicity Test Forms shall be filed with the Environmental 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 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
Environmental 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.
Page 5 of 9

Permit NC0082949
If the Permittee monitors any pollutant more frequently than required by this permit,the results of such
monitoring shall be included in the calculation&reporting of the data submitted on the DMR& all AT
Forms submitted.
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) 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.
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 127 Cardinal Drive Ext.
Raleigh,NC 27699-1617 Wilmington,NC 28405
A. (4) ELECTRONIC REPORTING - DISCHARGE MONITORING REPORTS
[G.S. 143-215.1 (b)]
Federal regulations require electronic submittal of all discharge monitoring reports (DMRs) and ro am
P l�'
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):
Page 6 of 9

Permit NC0082949
• 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://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 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, 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
Page 7 of 9

Permit NC0082949
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.federalregister.gov/documents/2015/10/22/2015-
24954/national-pollutant-di scharge-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
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. Signatory Requirements [Supplements Section B. (11.) (b) and Supersedes Section B. (11.) (d)1
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
Page 8 of 9

Permit NC0082949
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."
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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Receiving Stream: UT to Yadkin River Stream Class: WS-IV, B; CA scale not shown +1�► ►�
Stream Segment: 12-(124.5) Sub-Basin#: 03-07-08 �i�1�
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County: Davidson 35.59667°,-80.22278°