NC0083101_Permit Issuance_20170609

Water Resources
Environmental Quality
June 9, 2017
Ms. Clarissa Lipscomb, Director
City of Henderson
P.O. Box 1434
Henderson, NC 27536
ROY COOPER
Governor
MICHAEL S. REGAN
Secretory
S. JAY ZIMMERMAN
Director
Subject: Issuance of NPDES Permit NCO083101
Kerr Lake Regional WTP, PC-1
280 Regional Water Lane, Henderson 27536
Vance County
Dear Ms. Lipscomb:
The Division of Water Resources (the Division) hereby issues the attached NPDES permit for
the subject facility. This permit is issued pursuant to the requirements of North Carolina General
Statute 143-215.1 and the Memorandum of Agreement between North Carolina and the U.S.
Environmental Protection Agency dated October 15, 2007, or as subsequently amended.
The Division understands that you have made no significant changes to your facility since the
last permit renewal. We have made the following changes for the final permit:
1. Removed upstream Total Hardness sampling because stream flow conditions are zero
(7Q10/30Q2=0) at the point of discharge (Outfall 001).
We have made the following updates to your previous permit:
2. updated the facility map including correction to location of Outfa11001
o Latitude: 36e 26' 07"
o Longitude -78e 2 V 19"
3. added a 25 NTU daily average limit and a 25 NTU maximum average limit for Turbidity
[NCAC 02B .0211(21), for lakes and reservoirs not designated as trout waters]
4. removed Total Iron and Total Manganese monitoring
5. removed Total Copper monitoring since data did not demonstrate reasonable potential to
exceed applicable water quality standard/criteria
6. added Total Zinc monitoring because the use of Zinc Orthophosphate (CorrGuard 939)
7. added effluent quarterly monitoring for Total Hardness (see dissolved metals discussion)
8. added a daily maximum and monthly average limits of 1.8 mg/L for Total Fluoride since
data demonstrated a reasonable potential to exceed applicable water quality
standard/criteria
!`/'Nothing ComparesN
State of North Carolina I Environmental Quality
1617 Mail Service Center I Raleigh, North Carolina 27699-1617
919-707-9000

Ms. Lipscomb
June 9, 2017
Page 2 of 3
9. added Total Nitrogen and Total Phosphorous monitoring in accordance with WTP
permitting strategy for flows greater than 0.05 MGD
10. due to toxicity failures, a permit re -opener is added that allows for additional metals
testing, a toxicity identification evaluation, a toxicity reduction evaluation, and/or an
assessment of discharge treatment alternatives may be requested [Section A. (2)]
11. added electronic reporting of discharge monitoring reports (eDMR) in Section A. (4.).
In reply to comments received from the permittee:
• A correction was made to the WTP facility name on Supplement to Cover Sheet
• Upstream Hardness - Since this WTP discharges under zero flow conditions (the
unnamed tributary being effluent dominate), upstream monitoring is not relevant. The
final permit will be updated to remove upstream monitoring and require only effluent
total hardness monitoring. Any metals that are hardness dependent for future permit
renewals will use the default value of 25 mg/1 for upstream Total Hardness for reasonable
potential analysis (RPA) of hardness dependent metals.
Effective December 21, 2016, federal regulations require electronic submittal of all discharge
monitoring reports (DMRs) and specify that, if a state does not establish a system to receive such
submittals, then permittees must submit DMRs electronically to the Environmental Protection
Agency (EPA). The final NPDES Electronic Reporting Rule was adopted and became effective
on December 21, 2015.
The requirement to begin reporting discharge monitoring data electronically using the NC
DWR's Electronic Discharge Monitoring Report (eDMR) internet application has been added to
your final NPDES permit. [See Special Condition A. (4.)] For information on eDMR, registering
for eDMR and obtaining an eDMR user account, please visit the following web page:
h=://dgg.nc.gov/about/divisions/water-resources/edmr.
For more information on EPA's final NPDES Electronic Reporting Rule, please visit the
following web site:
http://www2.epa. ov�pliance/final-national-pollutant-discharge-elimination-s s�pdes-
electronic-reporting-rule.

Ms. Lipscomb
June 9, 2017
Page 3 of 3
If any parts, measurement frequencies, or sampling requirements contained in this permit are
unacceptable, you have the right to an adjudicatory hearing, upon written request submitted
within thirty (30) days after receiving this letter. Your request must take the form of a written
petition conforming to Chapter 150B of North Carolina General Statutes, and you must file it
with the Office of Administrative Hearings, 6714 Mail Service Center, Raleigh, North Carolina
27699-6714. Unless such a demand is made, this permit shall remain final and binding.
Please note that this permit is not transferable except after notice to the Division. The Division
may require modification or revocation and reissuance of the permit. This permit does not affect
the legal requirements to obtain other permits which may be required by the Division of Water
Resources or any other Federal, State, or Local governmental permits that may be required.
If you have questions, or if we can be of further service, please contact Derek Denard at
[[e-mail]] or call [phone].
Re ectfully,
S. Jay Zimmerman, Di ctor
Division of Water Resources, NCDEQ
Enclosure: NPDES Permit NCO083101 (Issuance Final)
hc: Central Files
NPDES Program Files
RRO Files/ Attn: Danny Smith
cc: WSS/Aquatic Toxicology Branch / Susan Meadows [[e-mail]]
WSS/Aquatic Toxicology Branch / Cindy Moore [[e-mail]]
Clarissa Lipscomb, Director, City of Henderson [[e-mail]]

NPDES Permit NCO083101
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
PDES
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
City of Henderson
is hereby authorized to discharge wastewater from a facility located at the
Kerr Lake Regional Water Treatment Plant (WTP)
280 Regional Water Lane, Henderson 27536
Vance County
to receiving waters designated as an unnamed tributary to Anderson Swamp Arm of Kerr Lake in the
Roanoke River Basin, in accordance with effluent limitations, monitoring requirements, and other
conditions set forth in Parts I,11, I11 and IV hereof.
This permit shall become effective July 1, 2017.
This permit and authorization to discharge shall expire at midnight on March 31, 2022.
Signed this day June 9, 2017.
may Zimmerman, P.G., Direr �.
Division of Water -Resources
By Authority of the Environmental Management Commission
Page 1 of 8

NPDES Permit NCO083101
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.
City of Henderson
is hereby authorized to:
1. continue to operate a wastewater treatment system utilizing conventional water treatment plant
technology [coagulation, flocculation, sedimentation, and filtration] with a maximum, monthly
average wastewater discharge of 6.671 MGD from media filter backwash and sedimentation basins
with a design potable flowrate of 10 MGD;
located at the Kerr Lake Regional WTP, 280 Regional Water Lane, Henderson, Vance County,
2. discharge from said treatment works via Outfall 001, at the location specified on the attached map
into an unnamed tributary to Anderson Swamp Arm of Kerr Lake [23-8-6-(1.5)], a waterbody
classified WS-III, B; CA located within Subbasin 03-02-06 [HUC: 030101021001 ] of the Roanoke
River Basin.
Page 2 of 8

NPDES Permit NCO083101
PART I
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
[I 5A 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 filter backwash from outfall 001. Such discharges shall be limited,
monitored and reported' by the Permittee as specified below:
Ek' M. iT _
CHARACTERISTIC
'ER CODESJ.
LIlVIITS:
M4NTrORING REQUI , WSl
�, o� x �.
Monthly
Avera e
g
Daily
M azimum
Measurement
Frequency :
_
: Ssmpee `
Type
Sample' :`
�.ocation
Flow (MGD)
50050
Continuous
Recording
Effluent
Total Suspended Solids (TSS) (mg/1)
C0530
30 mg/1
45 mg/1
Weekly
Grab
Effluent
Turbidity 2 (NM
00070
25 NTU
25 NTU
Weekly
Grab
Effluent
pH (su)
00400
Not<6.Oor>9.0
standard
Weekly
Grab
Effluent
Total Residual Chlorine 3 (µg/1)
50060
17 µg/1
Weekly
Grab
Effluent
Total Fluoride (mg/1)
009S1
1.8 mg/1
1.8 mg/1
Monthly
Grab.
Effluent
Hardness - Total as
[CaCO3 or (Ca + Mg)] 4 (mg/L)
00900
Monitor & Report
Quarterly
Grab
Effluent
Total Zinc (µg/1) 4
01092
Quarterly
Grab
Effluent
Total Aluminum (µg/1)
01105
Quarterly
Grab
Effluent
Total Nitrogen (mg/1) 5
C0600
Monitor & Report
Quarterly
Grab
Effluent
Total Phosphorus (mg/1)
C0665
Monitor & Report
Quarterly
Grab
Effluent
Chronic WET Testing
TGP3B
Quarterly
Grab
Effluent
Footnotes:
1. Effective December 21, 2016, begin submitting Discharge Monitoring Reports electronically using NC DWR's eDMR
application system. See Condition A. (4.).
2. Turbidity — Effluent turbidity shall not cause receiving -stream turbidity to exceed 25 NTU. If background turbidity
naturally exceeds 25 NTU, the effluent shall not cause background turbidity to increase. Any discharge exceeding this
permit limit will require sufficient instream sampling (upstream and/or downstream) to verify compliance (effluent vs.
background)." [NCAC 02B. 0211(21)]
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 test method (including
field certified), even if these values fall below 50 µg/L.
4. Effluent hardness sampling should be performed in conjunction with sampling for hardness dependent metals (Zinc).
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. Chronic WET testing (Ceriodaphnia dubia) 7-day pass/fail test at 90% in January, April, July and October. See condition
A. (3.).
Conditions:
• 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 visible in other than trace amounts.
Page 3 of 8

NPDES Permit NC0083101
A. (2.) 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 4 of 8

NPDES Permit NCO083101
A. (3.) CHRONIC TOXICITY PASS/FAIL MONITORING ONLY (QUARTERLY)
[I 5A NCAC 02B .0500 et seq.]
The permittee shall conduct guarterl 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
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 on the Effluent Discharge
Monitoring Form (MR-1) 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:
Attention: North Carolina Division of Water Resources
Water Sciences Section/Aquatic Toxicology Branch
1621 Mail Service Center
Raleigh, NC 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 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.
Page 5of8

NPDES Permit NCO083101
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 H 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. 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:
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).
Page 6 of 8

NPDES Permit NCO083101
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: httn://www2.epa.90v/compliance/final-national-pollutant-discharge-elimination-system-
npdes-electronic-reporting-rule.
Electronic submissions must start by the dates listed in the "Reporting Requirements" section above.
3. How to Request a Waiver from Electronic Reporting
The permittee may seek a temporary electronic reporting waiver from the Division. To obtain an electronic
reporting waiver, a permittee must first submit an electronic reporting waiver request to the Division.
Requests for temporary electronic reporting waivers must be submitted in writing to 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://deg.nc.gov/about/divisions/water-resources/edmr
4. Signatory 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 H,
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://deg.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:
Page 7 of 8

NPDES Permit NCO083101
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 qualifiedpersonnel 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. (631
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 8 of 8

ANA
W.
_ _ h
SatterwhiteN
Pmnt Anderson Swamp Arm of Kerr Lake �
1
Outfa11001�
[flows west]
INN
19
! _ Approximate _ �-
(, Facility Boundary
so Kn`
eyE
v
- _ f
a � - Regional Water Ln��-
^
0
U -ram
l - -
City of Henderson - Kerr Lake Regional WTP
N
NPDES Permit NCO083101
280 Regional Water Lane, Henderson 27536
Receiving Stream: UT to Anderson Swamp Arm of Kerr Lake
Stream Segment: 23-8-6-(1.5) Stream Class: WS-III,B;CA
36.435278° N,-78.355278° W
River Basin: Roanoke Sub -Basin M 03-02-06
SCALE
NC Grid: B25NE
County: Vance HUC: 030101021001
1:24,000
USGS Quad: Middleburg, NC

DEQ / DWR / NPDES
EXPEDITED FACT SHEET - NPDES PERMIT DEVELOPMENT
NPDES Permit NCO083101
Derek Denard, Compliance & Expedited Permitting Unit / 919-807-6307 02Jun2017
Facility Information
Applicant/Facility Name
City of Henderson
Kerr Lake Regional WTP
Applicant Address
PO Box 1434, Henderson, NC 27536
Facility Address
280 Regional Water Lane, Henderson, NC 27536
Permitted Flow (MGD)
Not limited
Type of Waste
Water Plants and Water Conditioning Discharge — filter backwash
— Conventional WTP System
Facility Class
PC-1
County
Vance
Permit Status
Renewal
Regional
Office
RRO
Stream Characteristics
UT to Anderson
Receiving Stream
Swamp Arm of Kerr
Stream Classification
WS-M,B;CA
Lake
Stream; Segment
[23-8-6-(1.5)]
Drainage basin
Roanoke
Summer 7Q10 (cfs)
0
Subbasin [iHuq
03-02-06
[030101021001]
Winter 7Q 10 (cfs)
0
Use Support
No Data
30Q2 (cfs)
0
303(d) Listed
Average Flow (cfs)
0
State Grid
B25NE
IWC (%)
100%
USGS Topo Quad
Middleburg, NC
FACILITY SUMMARY: This facility is a conventional technology *ater treatment plant [coagulation,
flocculation, sedimentation, and filtration] with discharge of wastewaters from media filter backwash and
sedimentation basins with a design potable flowrate of 10 MGD, a backwash or reject flow of 0.5 MGD and
a maximum monthly average wastewater discharge of 6.671 MGD. The facility consists of the following
water and wastewater treatment units:
• coagulation
• flocculation
• sedimentation basins
• in basin Sypder system for sludge removal
• filters
• settling pond
• thickeners
• chemicals - Potable Water Treatment
■ Alum / aluminum sulfate [primary coagulant]
■ Fluoride [fluoridation]
■ Zinc -orthophosphate (CorrGuard 939)
■ Caustic [pH adjustment]
■ Potassium Permanganate [oxidizer: iron & manganese removal, taste &
order control / removal of hydrogen sulfide]
■ Sodium Hypochlorite [disinfection]
■ Polymer (Sefloc F 1740) [thickening & settling]
Fact Sheet
Renewal 2017 -- NPDES Pennit NCO083101
Page l

RENEWAL SUMMARY: This permit reflects discharge at Outfall 001.
DWR updated the following from the draft for the final permit:
1. Removed upstream Total Hardness sampling because stream flow conditions are zero
(7Q10/30Q2=0) at the point of discharge (Outfall 001).
DWR updated the following from the previous permit:
2. updated the facility map including correction to location of Outfall 001
o Latitude: 36' 26' 07"
o Longitude -78° 21' 19"
3. added a 25 NTU daily average limit and a 25 NTU maximum average limit for Turbidity [NCAC
02B .0211(21), for lakes and reservoirs not designated as trout waters]
4. removed Total Iron and Total Manganese monitoring
5. removed Total Copper monitoring since data did not demonstrate reasonable potential to exceed
applicable water quality standard/criteria
6. added Total Zinc monitoring because the use of Zinc Orthophosphate (CorrGuard 939)
7. added effluent quarterly monitoring for Total Hardness (see dissolved metals discussion)
8. added a daily maximum and monthly average limits of 1.8 mg/L for Total Fluoride since data
demonstrated a reasonable potential to exceed applicable water quality standard/criteria
9. added Total Nitrogen and Total Phosphorous monitoring in accordance with WTP permitting
strategy for flows greater than 0.05 MGD
10. due to toxicity failures, a permit re -opener is added that allows for additional metals testing, a
toxicity identification evaluation, a toxicity reduction evaluation, and/or an assessment of discharge
treatment alternatives may be requested [Section A. (2)]
11. added electronic reporting of discharge monitoring reports (eDMR) in Section A. (4.).
OUTFALL 001: The outfall as identified in aerial orthophotography (Figure 1.) is located at the following
coordinates (nearest second) from the location indicated in the site plan (Figure 2):
o Latitude: 36° 26' 07"
o Longitude -78° 21' 19"
iline].
Fact Sheet
Renewal 2017 -- NPDES NCO083101
Page 2

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Site pion for recommended residuals management facilities
scw., r-tar
Figure 2. Site Plan indicating Outfall 001 location [from ATC/Permit File].
ELIGIBILITY FOR COVERAGE UNDER THE GENERAL PERMIT NCG590000: Kerr Lake
Regional WTP is not eligible for the general permit. A review of the last three years (Oct2013—Ju12016) of
WET tests indicated 4 failures out of 12 quarter which is a 66.7% pass rate [see attached summary].
Additionally, Total Fluoride is limited because the reasonable potential to exceed the water quality
standard.
PARAMETERS OF CONCERN (POCs) & DICUSSION OF CHANGES FOR RENEWAL: Any
changes to this permit are made in accordance with the current Water Treatment Plant Strategy (WTP). The
following POCs are included in the current WTP strategy for conventional water treatment plant technology
[coagulation, flocculation, sedimentation, and filtration]:
Flow — Continuous monitoring is required for facilities discharging >50,000 gpd. The Maximum monthly
flow is 6.671 MGD (Mar2014-1762017). The permit application indicated backwash or reject flow to be
approximately 0.5 MGD. Therefore, flow monitoring is continuous recording or totalizing device.
Total Suspended Solids (TSS) — In accordance with current WTP permitting strategy, facilities with flows
>0.5 MGD are required to monitor weekly for TSS with a daily maximum limit of 45 mg/L and a monthly
average limit of 30 mg(L.
Fact Sheet
Renewal 2017 -- NPDES NC0083101
Page 3

pH — In accordance with current WTP permitting strategy, facilities with flows >0.5 MGD are required to
monitor weekly with the following limitation: Not < 6.0 or > 9.0 standard units.
Total Residual Chlorine (I'RC) — TRC is limited and monitored only if the facility adds chlorine
derivatives to water that is eventually discharged. The application indicated the use of Sodium
Hypochlorite. TRC monitoring is required for this permit renewal. With an instream waste concentration
(IWC) of 100%, TRC has a daily maximum limit of 17µg/L. 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 test method (including field certified),
even if these values fall below 50 µg/L. In accordance with current WTP permitting strategy, facilities with
flows >0.5 MGD are required to monitor TRC weekly.
Turbidity — In accordance with current WTP permitting strategy and US EPA Region IV memo dated
02/25/09, turbidity monitoring and limitation is required for this renewal. North Carolina has established
standards for Turbidity in accord with receiving -stream classification, monitoring and permit limits are
deemed appropriate to evaluate effluent compliance for freshwater [NCAC 02B .0211(21)] . For lakes and
reservoirs not designated as trout waters, the standard is 25 NTU. Accordingly, the following footnote is
inserted:
Turbidity Effluent turbidity shall not cause receiving -stream turbidity to exceed 25 NTU. If
background turbidity naturally exceeds 25 NTU, the effluent shall not cause background turbidity
to increase. Any discharge exceeding this permit limit will require sufficient instream sampling
(upstream and/or downstream) to verify compliance (effluent vs. background). [NCAC 02B.
0220(21)]
The 25 NTU standard applies as both a Monthly Average and Daily Maximum for this renewal. US EPA
requires both a Monthly Average and a Daily Maximum for all parameters that are limited [40 CFR 122.45
(d.)]. In accordance with current WTP permitting strategy, facilities with flows >0.5 MGD are required to
monitor turbidity weekly.
Total Aluminum — The facility uses Alum / aluminum sulfate. Therefore, quarterly monitoring is required
for this permit renewal.
Total Iron — The previous permit required Total Iron monitoring with a daily limit of 1.0 mg/l. The NC
2007-2015 Water Quality Standard (WQS) Triennial Review was approved by the NC Environmental
Management Commission (EMC) on November 13, 2014. The US EPA subsequently approved the WQS
revisions on April 6, 2016, with some exceptions. The WQS for Total Iron was removed. Total Iron is no
longer a parameter of concern. Furthermore, Iron sulfate/ferrous sulfate is not in use at this facility.
Therefore, Total Iron monitoring is removed for the permit renewal.
Total Copper — For this permit renewal, Total Copper monitoring is removed since data did not
demonstrate reasonable potential to exceed applicable water quality standard/criteria. Please see RPA
discussion below and attached RPA spreadsheets below for further details.
Total Manganese — The NC 2007-2015 Water Quality Standard (WQS) Triennial Review was approved by
the NC Environmental Management Commission (EMC) on November 13, 2014. The US EPA
subsequently approved the WQS revisions on April 6, 2016, with some exceptions. The WQS for Total
Manganese was removed. Total Manganese is no longer a parameter of concern. Therefore, Total
Manganese monitoring is removed for the permit renewal.
Total Fluoride — In accordance with current WTP permitting strategy, Fluoride should be monitored if the
Permittee backwashes with fluoridated finish water. The renewal application indicates that Fluoride is in
use at this facility. Daily maximum and monthly average limits of 1.8 mg/L for Total Fluoride are added
Fact Shco
Renewal 2017 -- NPDES NCO083101
Pagc 4

since data demonstrated a reasonable potential to exceed applicable water quality standard/criteria. [Please
see RPA discussion below and attached RPA spreadsheets below for further details.] The US EPA requires
both a Monthly Average and a Daily Maximum for all parameters that are limited [40 CFR 122.45 (d.)].
Total Zinc — In accordance with current WTP permitting strategy, Zinc should be monitored if the
Permittee adds Zinc Orthophosphate as a corrosion inhibiter prior to backwashing. The application
indicated that CorrGuard 939, an acidic zinc -phosphate mixture, is in use. The Material Safety Data Sheet
for CorrGuard 939 (see attached) indicates this chemical is synonym with Zinc Orthophosphate and is
utilized as a corrosion inhibitor. The previous permit version did not require monitoring for Zinc. Therefore,
quarterly Total Zinc monitoring only is added for this permit renewal.
Total Hardiness — Effluent hardness sampling and instream hardness sampling, upstream of the discharge,
are inserted into all permits with facilities monitoring for hardness -dependent metals to ensure the accuracy
of the permit limits and to build a more robust hardness dataset. Effluent hardness sampling should be
performed in conjunction with sampling for hardness dependent metals (zinc). Since this WTP discharges
under zero flow conditions (the unnamed tributary being effluent dominate), upstream monitoring is not
relevant. The final permit will be updated to remove upstream monitoring and require only effluent total
hardness monitoring. Any metals that are hardness dependent for future permit renewals will use the default
value of 25 mg/l for upstream Total Hardness for reasonable potential analysis (RPA) of hardness
dependent metals.
Ammonia Nitrogen — In accordance with current WTP permitting strategy, ammonia nitrogen should be
monitored if the Permittee uses chloramines (adds ammonia to chlorinated water) for secondary disinfection
prior to backwashing. The renewal application indicates no usage of Ammonia nitrogen or Chloramines at
this facility. Therefore, Ammonia Nitrogen monitoring is not required for this permit renewal.
Total Nitrogen (TN) and Total Phosphorus (TP) — In accordance with current WTP permitting strategy
for membrane technology, facilities with flows greater than 0.05 MGD are required to monitor for TN and
TP. Therefore, quarterly monitoring for TN and TP is added for the permit renewal.
Chronic Whole Effluent Toxicity (WET) testing — Chronic WET testing (Ceriodaphnia dubia) [TGP3B]
is 7-day pass/fail test at 90% in January, April, July and October [See condition A. (3.).]. Chronic WET
testing with the test organism Ceriodaphnia dubia is recommended by the Aquatic Toxicology Branch for
freshwater with an instream waste concentration (IWC) > 0.25%. A review of the last three years
(Oct2013 Ju12016) of WET tests indicated 4 failures out of 12 quarter which is a 66.7% pass rate [see
attached summary]. Due to these test failures, a permit re -opener is inserted for the permit renewal [Section
A. (2.)]. The permit re -opener allows for additional metals testing, a toxicity identification evaluation, a
toxicity reduction evaluation, and/or an assessment of discharge treatment alternatives may be requested.
Fact Sheet
Renewal 2017 -- NPDES NC0083101
Page 5

DATA SUAEMARY
Monthly Average Flow for Mar2014-17eh2617 (3 vears)
Parameter
LvlMax
! Min
'Count
UoM
mgd
50050 - Flow, in conduit or thru treatment plant 6.671, 0.065
36
DAM Dailv Parameter Values for Mar2014—Feb2017 (3 vears
Parameter -T
Max
Min
i Average Count
PQL I UoM
0.5, 1 ntu
00070 - Turbidity
14.5 0.07 2.0 155
00400 - pH
7
6
157
su
00951 - Fluoride, Total (as F)
1800,
160
587`
11
500!ug/l
01042 - Copper, Total (as Cu)
5
5
5
12
5 ug/l
01045 - Iron, Total (as Fe)
79
50
59.7
12
50' ug/l
01055 - Manganese, Total (as Mn)
5500
340
1804
12
ug/I
01105 - Aluminum, Total (as Al)
636
100
286
11
100, ug/I
50050 - Flow, in conduit or thru treatment plant
154
0.001
0.431,
954
; mgd
50060 - Chlorine, Total Residual
29
3
14
157
15 ug/I
C0530 -Solids, Total Suspended -Concentration
57
2.&
4.9',
1531
2.5; mg/l
Compliance History: f Wr2012—Feb2017) (5 years) [see attached]
RPA — The need for toxicant limits is based upon a demonstration of reasonable potential to exceed water
quality standards, a statistical evaluation that is conducted during every permit renewal utilizing the most
recent effluent data for each outfall. The RPA is conducted in accordance with 40 CFR 122.44 (d) (i). The
NC RPA procedure utilizes the following: 1) 95% Confidence Level/95% Probability; 2) assumption of
zero background; 3) use of % detection limit for "less than" values; and 4) streamflows used for dilution
consideration based on 15A NCAC 2B.0206. Effective April 6, 2016, NC began implementation of
dissolved metals criteria in the RPA process in accordance with guidance titled NPDES Implementation of
Instream Dissolved Metals Standards, dated June 10, 2016 [see information next page].
A reasonable potential analysis was conducted on effluent toxicant data collected between Mar2014—
Feb2017. Pollutants of concern included toxicants with positive detections and associated water quality
standards/criteria. Based on this analysis, the following permitting actions are proposed for this permit:
• Effluent Limit with Monitoring. The following parameters will receive a water quality -based
effluent limit (WQBEL) since they demonstrated a reasonable potential to exceed applicable water
quality standards/criteria: Fluoride.
• No Limit or Monitoring: The following parameters will not receive a limit or monitoring, since they
did not demonstrate reasonable potential to exceed applicable water quality standards/criteria and
the maximum predicted concentration was <50% of the allowable concentration: Copper.
Fact Sheet
Renewal 2017 -- NPDES NCO083101
Page 6

NPDES Implementation of Instream Dissolved Metals Standards - Freshwater Standards
The NC 2007-2015 Water Quality Standard (WQS) Triennial Review was approved by the NC
Environmental Management Commission (EMC) on November 13, 2014. The US EPA subsequently
approved the WQS revisions on April 6, 2016, with some exceptions. Therefore, metal limits in draft
permits out to public notice after April 6, 2016 must be calculated to protect the new standards - as
approved.
Table 1. NC Dissolved Metals Water uality Standards/Aquatic Life Protection
Parameter
Acute FW, µg/I
(Dissolved)
Chronic FW, µg/I
(Dissolved)
Acute SW, µg/I
(Dissolved)
Chronic SW, µg/I
(Dissolved)
Arsenic
340
150
69
36
Beryllium
65
6.5
---
---
Cadmium
Calculation
Calculation
40
8.8
Chromium III
Calculation
Calculation
---
Chromium VI
16
11
1100
50
Copper
Calculation
Calculation
4.8
3.1
Lead
Calculation
Calculation
210
8.1
Nickel
Calculation
Calculation
74
8.2
Silver
Calculation
0.06
1 1.9
0.1
Zinc
Calculation
Calculation
1 90
81
Table 1 Notes:
1. FW= Freshwater, SW= Saltwater
2. C A&M = Hardness dependent standard
3. Only the aquatic life standards listed above are expressed in dissolved form. Aquatic life standards
for Mercury and selenium are still expressed as Total Recoverable Metals due to bioaccumulative
concerns (as are all human health standards for all metals). It is still necessary to evaluate total
recoverable aquatic life and human health standards listed in 15A NCAC 213.0200 (e.g., arsenic at
10 µg/l for human health protection; cyanide at 5 µg/L and fluoride at 1.8 mg/L for aquatic life
protection).
Table 2. Dissolved Freshwater Standards for Hardness -Dependent Metals
The Water Effects Ratio (WER) is equal to one unless determined otherwise under 15A
NCAC 02B .0211 Subparagraph (11)(d)
Metal
NC Dissolved Standard, µg/I
Cadmium, Acute
WER* (I. 136672-[In hardness](0.041838)) • e^{0.9151 [In hardness]-3.1485)
Cadmium, Acute Trout waters
WER*{1.136672-[In hardness](0.041838)) • e^(0.9151[ln hardness]-3.6236)
Cadmium, Chronic
WER*{1.101672-[In hardness](0.041838)) • e^(0.7998[In hardness]-4.4451)
Chromium III, Acute
WER*0.316 • e^(0.8190[ln hardness]+3.7256)
Chromium III, Chronic
WER*0.860 • e^{0.8190[ln hardness]+0.6848)
Copper, Acute
WER*0.960 • e^{0.9422[ln hardness]-1.700)
Copper, Chronic
WER*0.960 . e^(0.8545[In hardness]-1.702)
Lead, Acute
WER*{1.46203-[In hardness](0.145712)) • e^(1.273[ln hardness]-1.460)
Fact Sheet
Renewal 2017 -- NPDES NC0083101
Page 7

Lead, Chronic
WER*{1.46203-[In hardness](0.145712)) • e^{1.273[ln hardness]-4.705}
Nickel, Acute
WER*0.998 • e^{0.8460[ln hardness]+2.255)
Nickel, Chronic
WER*0.997 • e^(0.8460[ln hardness]+0.0584)
Silver, Acute
WER*0.85 • e^(1.72[In hardness]-6.59)
Silver, Chronic
Not applicable
Zinc, Acute
WER*0.978 • e^(0.8473[ln hardness]+0.884)
Zinc, Chronic
WER*0.986 • e^(0.8473[ln hardness]+0.884)
General Information on the Reasonable Potential Analysis (RPA)
The RPA process itself did not change as the result of the new metals standards. However, application of
the dissolved and hardness -dependent standards requires additional consideration in order to establish the
numeric standard for each metal of concern of each individual discharge.
The hardness -based standards require some knowledge of the effluent and instream (upstream) hardness
and so must be calculated case -by -case for each discharge.
Metals limits must be expressed as `total recoverable' metals in accordance with 40 CFR 122.45(c). The
discharge -specific standards must be converted to the equivalent total values for use in the RPA
calculations. We will generally rely on default translator values developed for each metal (more on that
below), but it is also possible to consider case -specific translators developed in accordance with established
methodology.
RPA Permitting Guidance/WQBELs for Hardness -Dependent Metals - Freshwater
The RPA is designed to predict the maximum likely effluent concentrations for each metal of concern,
based on recent effluent data, and calculate the allowable effluent concentrations, based on applicable
standards and the critical low -flow values for the receiving stream.
If the maximum predicted value is greater than the maximum allowed value (chronic or acute), the
discharge has reasonable potential to exceed the standard, which warrants a permit limit in most cases. If
monitoring for a particular pollutant indicates that the pollutant is not present (i.e. consistently below
detection level), then the Division may remove the monitoring requirement in the reissued permit.
1. To perform a RPA on the Freshwater hardness -dependent metals the Permit Writer compiles the
following information:
• Critical low flow of the receiving stream, 7Q 10 (the spreadsheet automatically calculates
the 1 Q 10 using the formula 1 Q 10 = 0.843 (s7Q 10, cfs) 0.993
• Effluent hardness and upstream hardness, site -specific data is preferred
• Permitted flow
• Receiving stream classification
2. In order to establish the numeric standard for each hardness -dependent metal of concern and for
each individual discharge, the Permit Writer must first determine what effluent and instream
(upstream) hardness values to use in the equations.
The permit writer reviews DMR's, Effluent Pollutant Scans, and Toxicity Test results for any
hardness data and contacts the Permittee to see if any additional data is available for instream
hardness values, upstream of the discharge.
Fact Shco
Rcnewal 2017 -- NPDES NCO083101
Page 8

If no hardness data is available, the permit writer may choose to do an initial evaluation using a
default hardness of 25 mg/L (CaCO3 or (Ca + Mg)). Minimum and maximum limits on the
hardness value used for water quality calculations are 25 mg/L and 400 mg/L, respectively.
If the use of a default hardness value results in a hardness -dependent metal showing reasonable
potential, the permit writer contacts the Permittee and requests 5 site -specific effluent and upstream
hardness samples over a period of one week. The RPA is rerun using the new data.
The overall hardness value used in the water quality calculations is calculated as follows:
Combined Hardness (chronic)
_ (Permitted Flow, cfs *Avg. Effluent Hardness, in")+(s7O10. cfs *Avg. Upstream Hardness, in")
(Permitted Flow, cfs + s7Q 10, cfs)
The Combined Hardness for acute is the same but the calculation uses the IQ 10 flow.
3. The permit writer converts the numeric standard for each metal of concern to a total recoverable
metal, using the EPA Default Partition Coefficients (DPCs) or site -specific translators, if any have
been developed using federally approved methodology.
EPA default partition coefficients or the "Fraction Dissolved" converts the value for
dissolved metal at laboratory conditions to total recoverable metal at in -stream ambient
conditions. This factor is calculated using the linear partition coefficients found in The
Metals Translator. Guidance for Calculating a Total Recoverable Permit Limit from a
Dissolved Criterion (EPA 823-B-96-007, June 1996) and the equation:
Cdiss 1
Ctotal 1 + { [Kpo] [Ss(t+e)] [10-6] }
Where:
ss = in -stream suspended solids concentration [mg/1], minimum of 10 mg/L used, and
Kpo and a = constants that express the equilibrium relationship between dissolved and
adsorbed forms of metals. A list of constants used for each hardness -dependent metal can
also be found in the RPA program under a sheet labeled DPCs.
4. The numeric standard for each metal of concern is divided by the default partition coefficient (or
site -specific translator) to obtain a Total Recoverable Metal at ambient conditions.
In some cases, where an EPA default partition coefficient translator does not exist (ie. silver), the
dissolved numeric standard for each metal of concern is divided by the EPA conversion factor to
obtain a Total Recoverable Metal at ambient conditions. This method presumes that the metal is
dissolved to the same extent as it was during EPA's criteria development for metals. For more
information on conversion factors see the June, 1996 EPA Translator Guidance Document.
5. The RPA spreadsheet uses a mass balance equation to determine the total allowable concentration
(permit limits) for each pollutant using the following equation:
Ca = (s70 10 + Ow) (Cwgs)- s7O 10) (Cb)
Fact Sheet
Renewal 2017 -- NPDES NC0083101
Page 9

Qw
Where: Ca = allowable effluent concentration (µg/L or mg/L)
Cwqs = NC Water Quality Standard or federal criteria (µg/L or mg/L)
Cb = background concentration: assume zero for all toxicants except NH3* (µg/L or mg/L)
Qw = permitted effluent flow (cfs, match s7Q 10)
s7Q 10 = summer low flow used to protect aquatic life from chronic toxicity and human health
through the consumption of water, fish, and shellfish from noncarcinogens (cfs)
* Discussions are on -going with EPA on how best to address background concentrations
Flows other than s7Q 10 may be incorporated as applicable:
IQ 10 = used in the equation to protect aquatic life from acute toxicity
QA = used in the equation to protect human health through the consumption of water, fish,
and shellfish from carcinogens
30Q2 = used in the equation to protect aesthetic quality
6. The permit writer enters the most recent 2-3 years of effluent data for each pollutant of concern.
Data entered must have been taken within four and one-half years prior to the date of the permit
application (40 CFR 122.21). The RPA spreadsheet estimates the 95th percentile upper
concentration of each pollutant. The Predicted Max concentrations are compared to the Total
allowable concentrations to determine if a permit limit is necessary. If the predicted max exceeds
the acute or chronic Total allowable concentrations, the discharge is considered to show reasonable
potential to violate the water quality standard, and a permit limit (Total allowable concentration) is
included in the permit in accordance with the U.S. EPA Technical Support Document for Water
Quality -Based Toxics Control published in 1991.
7. When appropriate, permit writers develop facility specific compliance schedules in accordance with
the EPA Headquarters Memo dated May 10, 2007 from James Hanlon to Alexis Strauss on 40 CFR
122.47 Compliance Schedule Requirements.
8. The Total Chromium NC WQS was removed and replaced with trivalent chromium and hexavalent
chromium Water Quality Standards. As a cost savings measure, total chromium data results may be
used as a conservative surrogate in cases where there are no analytical results based on chromium
III or VI. In these cases, the projected maximum concentration (95th %) for total chromium will be
compared against water quality standards for chromium III and chromium VI.
9. Effluent hardness sampling and instream hardness sampling, upstream of the discharge, are inserted
into all permits with facilities monitoring for hardness -dependent metals to ensure the accuracy of
the permit limits and to build a more robust hardness dataset.
Fact Shect
Renewal 2017 -- NPDES NCO083101
Page 10

10. Hardness and flow values used in the Reasonable Potential Analysis for this permit included:
Parameter
Value
Comments (Data Source)
Average Effluent Hardness (mg/L)
[Total as, CaCO3 or (Ca+Mg)]
25
default hardness
Average Upstream Hardness (mg/L)
[Total as, CaCO3 or (Ca+Mg)]
25
default hardness
7Q 10 summer (cfs)
0
Not available; Lake/Reservoir
1 Q 10 (cfs)
0
Not available; Lake/Reservoir
Maximum Monthly Average (MGD)
6.671 MGD
Mar2014—Feb2017 DMR Data BIMS
Date: April 10, 2017
Permit Writer: Derek Denard
Fact Shcet
Renewal 2017 -- NPDES NCO083101
Page 1 1

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
REQUIRED DATA ENTRY CHECK WQS
Table 1. Proiect Information
❑CHECK IF HOW OR ORIN WQS
Facility Name
City of Henderson - Kerr Lake Regional WTP
WWTP/WTP Class
PC-1
NPDES Permit
NC0083101
Outfall
001
Flow, Qw (MGD)
6,671
Receiving Stream
UT to Anderson Swamp Arm of Kerr Lake
HUC Number
030101021001
Stream Class
WS-III,B;CA
0.00
QApply WS Hardness WQC
7Q10s (cfs)
7Q10w (cfs)
0.00
30Q2 (cfs)
0.00
CIA (cfs)
0.00
.00
1 Q10s (cfs)
Effluent Hardness
25 mg/L(Avg)
Upstream Hardness
_
25 mg/L (Avg)
_ _ _ _ _ . _ _ _ _ _ _I
._ _ _
Combined Hardness Chronic
25 m /L
9
Combined Hardness Acute
25 mg/L
BIMS DMR Data Jan2014 to Dec2016
Data Source(s)
❑CHECK TO APPLY MODEL
Follow directions for data entry. In some rases a
comment menu list the available choices or a
dropdown menu will provide a list you may select
from. Error message occur if data entry does not
meet input criteria.
Partt
Par02
Par03
Par04
Par05
Par0611111
Par07
Pares
Par09
Porte
Partt
� Par12
r.
Par13
Par14
Paris
Par16
Par17
Parts
Part
Pa20
Par21
Par22
Par23
Par24
Pa25
Table 2. Parameters of Concern
Name wos Type Chronic Modifier Acute PQL Units
Copper
Aquatic Life
NC
7.8806
FW
10.4720
ug/L
Fluoride
Aquatic Life
NC
1,800
FW
ug/L
Aluminum
Water Supply
NC
6500
WS
pg/L
Aluminum
Human Health
NC
e000
HH
pg/L
NC0083101 9595 Final FW RPA w_upstream sag data column_diss to totalmetals_nodetects_limiteddefaulls 2016_822, input
4/10/2017

REASONABLE POTENTIAL ANALYSIS
H7
H2
Use *PASTE SPECIAL
Use'PASTE SPECIAL
Effluent Hardness
values' then 'COPY"
Upstream Hardness
�a1u05• than -COPY"
. Maximum data
. Maximum data
points - 58
points = 58
Date Data BDL=1/2DL Results
_
Date Data BDL=112DL Results
1
25 25 Std Dev.
N/A
1
25 25 Std Dev.
N/A
2
Mean
25.0000
2
Mean
25.0000
3
C.V.
0.0000
3
C.V.
0.0000
4
n
1
4
n
1
5
10th Per value
25.00 mg/L
5
101h Per value
25.00 mg/L
6
Average Value
25.00 rnW1
6
Average Value
25.00 mg/L
7
Max. Value
25.00 mg/L
7
Max. Value
25.00 mg/L
8
8
9
9
10
10
I
11
12
12
13
13
14
14
15
15
16
16
17
17
18
18
19
19
20
20
21
21
22
22
23
23
24
24
25
25
26
26
27
27
28
28
29
29
.
30
30
31
31
32
32
33
33
34
34
35
35
36
36
37
37
38
38
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
51
52
52
53
53
54
54
55
55
56
56
57
57
58
1 58
NCO083101 9595 Final FW RPA w_upsseam avg data column_diss to totalmetals_nodetects_limileddefaults 2016_822, data
-1 - 4/10/2017

REASONABLE POTENTIAL ANALYSIS
Pal
Par13
Use'PASTE SPECIAL
TE SPECIAL
Copper
valvee then 'COPY'
Fluoride
EVW.Wff�enlcop
Y"Mazlmum
tlata
mum datepoint;
= 58
nts = 5a
Date
Data
BDL=1/2DL
Results
Date
Data
BDL=112DL
Results
1
4/1/2014
<
5
2.5
Std Dev.
0.0000
1
4/1/2014
<
500
250
Std Dev.
469.8162
2
7/15/2014
<
5
2.5
Mean
2.5000
2
711MO14
1800
1800
Mean
405.4545
3
10/7/2014
<
5
2.5
C.V.
0.0000
3
10/712014
<
500
250
C.V.
1.1687
4
1113/2015
<
5
2.5
n
12
4
1/1312015
<
500
250
n
11
5
4/7/2015
<
5
2.5
5
4/7/2015
<
500
250
6
7/14/2015
<
5
2.5
Mult Factor =
1.00
6
7/14/2015
160
160
Mull Factor =
2.37
7
10/6/2015
<
5
2.5
Max. Value
2.50 ug/L
7
10/6/2015
<
500
250
Max. Value
1800.0 ug/L
8
1/12/2016
<
5
2.5
Max. Prod Cw
O DETECTS ug/L
8
1/12/2016
500
500
Max. Pred Cw
4266.0 ug/L
9
4/5/2016
<
5
2.5
9
4/5/2016
<
500
250
10
7/19/2016
<
5
2.5
10
7/19/2016
<
500
250
11
11/29/2016
<
5
2.5
11
1/3/2017
<
500
250
12
102017
<
5
2.5
12
13
13
14
14
15
15
16
16
17
17
18
18
19
19
20
20
21
21
22
22
23
23
24
24
25
25
26
26
27
27
28
28
29
29
30
30
31
31
32
32
33
33
34
34
35
35
36
36
37
37
38
3B
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
51
52
52
53
53
54
54
55
55
56
56
57
57
58
1 58
NC0083101 9595 Final FW RPA w_upstream avg data column_diss to totalmetals_nodetects_limiteddefaulls 2016_822, data
-2- 4/10/2017

REASONABLE POTENTIAL ANALYSIS
Pa22
Par23
Use -PASTE SPECIAL
Use 'PASTE SPECIAL
Aluminum
values' then 'COPY'
Aluminum
values. Men 'COPY'
. Maximum data
. Maximum data
points = 58
points = 58
Date Data
BDL=112DL
Results
Date
Data
BDL=112DL
Results
1
4/1/2014
370
370
Std Dev.
191.8153
1
411/2014
370
370
Std Dev.
191.8153
2
7115/2014 <
100
50
Mean
276.9091
2
7/15/2014
< 100
50
Mean
276,9091
3
10/7/2014
280
280
C.V.
0.6927
3
10/7/2014
280
280
C.V.
0.6927
4
1/13/2015
150
150
n
11
4
1/13/2015
150
150
n
11
5
417/2015
180
180
5
4/7/2015
180
180
6
7/14/2015
230
230
Mult Factor =
1.79
6
7/14/2015
230
230
Mull Factor =
1.79
7
10/6/2015 <
100
50
Max. Value
636.0 pg/L
7
10/6/2015
< 100
50
Max. Value
636.0 pg/L
8
1/12/2016
580
580
Max. Fred Cw
1138.4 pg/L
8
1/12/2016
580
580
Max. Fred Cw
1138.4 pg/L
9
4l5/2016
320
320
9
4/5/2016
320
320
10
7/19/2016
200
200
10
7/19/2016
200
200
11
1/3/2017
636
636
11
1/312017
636
636
12
12
13
13
14
14
15
15
16
16
17
17
18
18
19
19
20
20
21
21
22
22
23
23
24
24
25
25
26
26
27
27
28
28
29
29
30
30
31
31
32
32
33
33
34
34
35
35
36
36
37
37
38
38
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
51
52
52
53
53
54
54
55
55
56
56
57
57
58
1 58
NCO083101 9595 Final FW RPA w_upstream avg data column_diss to totalmetals_nodetects_limiteddeNults 2016_822. data
-3- 4/10/2017

City of Henderson - Kerr Lake Regional V TP a
NCO083101 Freshwater RPA - 95% Probability/95 Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Qw ( MOD) = 6.67
W WTP/WTP Class: PC-1
IQIOS (cfs)= 0.00
IWC% @ IQIOS = 100
7Q10S(cfs)= 0.00
IWC%@7QIOS= 100
7QIOW(efs)= 0.00
IWC%@7QIOW= 100
30Q2(cfs)= 0.00
IWC%@30Q2= 100
Avg. Stream Flow, QA (ca) = 0.00
IW%C @ QA = 100
Receiving Stream: UT to Anderson Swamp Arm of Kerr Lake HUC 03010102100 Stream Class: WS-III,B;CA
Outfall 001
Qw = 6.671 MGD
Acute = 25 mg/L
Chronic = 25 mg/L
YOU HAVE DESIGNATED THIS RECEIVING
STREAM AS WATER SUPPLY
Effluent Hard: 0 value> 100 mg/L
Effluent Hard Avg = 25 mg/L
PARAMETER
NC STANDARDS OR EPA CRITERIA
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
TYPE
C
Chronic Stand Acute
n # Det. Max Pmd Cw Allowable Cw
(t)
Acute: 10.47
No aetecls
Copper
NC
7.8806 FW 10.4720
ug/L
12 0
NODETEC7S
_ _
Chronic: 7.88
No detects
Max MDL= 5
Acute: NO WQS
Fluoride
NC
1800 FW
ug/L
11 3
4,266.0
_ _ _ _ _ __
___________ _______ _____
Chronic: le'Cw-
RP shown- apply Monthly Monitoring with Limit
No value > Allowable Cw
Acute: NO WQS
Aluminum
NC
6500 WS
µg/L
II 9
1,138.44
_ _ _ _
___________________-_-____
Chronic: 6500.0
No RP, Predicted Max <50%ofAllowableCw-
No value> Allowable Cw
Maintain Monitoring; Alum aluminum sulfate in use
Acute: NO WQS
Aluminum
NC
8000 HH
µg/L
II
1,138.4
_Chronic:
8000.0
L
No RPPredicted Max 150%of Allowable Cw -
value > Allowable C'w
Maintain Monitoring; Alum aluminum sulfate in use
NCO083101 9595 Final FW RPA w_upstream avg data column dim to totalmetals_rwdetects_Iimiteddefaults 2016_b22, rpa
Page 1 of 1 4/10/2017

Date: 4/10/2017
FACILITY: City of Henderson - Kerr Lake Regional WTP
NPDES PERMIT: NCO083101 Dissolved to Total Metal Calculator
In accordance with Federal Regulations, permit limitations must be written as Total Metals per 40 CFR 122.45(c)
Receiving Receiving Rec. Stream
NPDES Total Suspendetl
Combined
Upstream Hard Avg (mg/L) = 25
EFF Hard Avg (mg/L) = 25
PARAMETER
Dlssalved
Metals
US EPA
Translators -using
Default Partition
Coefficients
streams
Maamum Allvaable muem encenlraapn
(MAEC)asaTdal Betal
=a1svwxj Moral. Tend"
COMMENTS(idenbfy parameters to PERCS Branch to maintain in facilitys LTMP/STMP):
Chronic
Acute
Chronic
Awte
u
u
Cadmium (d) _
cd-Trout stream
Chromium III (d)(h)
Chromium VI (d) _
Chromium, Total (t)
Copper d h)
0.15
0.15
24
0.82
0.252
_ _ _ 0.252
0.202
0.59
0.59
3.24
0.51
183
2.01
905.08
_
117.73
11
16
1.000
_
11.00
16.00
_
WA
WA
2.7
3.6
14
145
_
0.348
0.184
0.432
_
7.88
2.94
37.23
10.47
Lead d h
0.54
75.49
_
Nickel d h)
16
335.21
NI - Ws streams (t) _
Silver(d)(h,acute)
Zinc d)(h)
_
25 WA
0.06� 0.30
126.73 125.71
0.06
36
0.30
1.000
36
_
0.288
Be Ilium
6.5
65
1.000
6.5
65
Arsenic d
150
340
1.000
150
340
(d) = dissolved metal standard. See 15A NCAC 02B .0211 for more information.
(h) = hardness -dependent dissolved metal standard. See 15A NCAC 02B.0211 for more information.
(y = based upon measurement of total recoveable metal. See 15A NCAC 026.0211 for more information.
The Human Health standard for Nickel in Water Supply Streams is 25 mg/L which k Total Recoverable metal standard.
The Human Health standard for Arsenic Is 10 pg/L which is Total Recoverable metal standard.
Combined
InsVeam
InsUeam
Effluent
Stream
Stream
Solids
Hardness
Hardness
Wastewater
Wastewater
Upstream
Hardness
summer
summer 7O10
7D70
Flow Limit
Fixed Value-
chronic
Acute
Concentration
Concentration
Hardness
Average
7010 IDES)
(MGD)
GD
GD
(mgA)
(mglL)
(mglL)
Chronic)
(Awls)
Avera m
�( �)
(mg/L)
0.0000
0.0000
0.0000
6.6710
10
25.000
25.000
t00.0000
700.0000
25
25

Denard, Derek
From: Denard, Derek
Sent: Friday, June 02, 2017 4:07 PM
To: Hardy, Allen
Subject: Review of Discharge to Surface Waters Designated Water Supply (WS) - Permit Renewal
NPDES NC0083101 - City of Henderson — Kerr Lake Regional WTP
Attachments: NC0083101 DRAFT & Factsheet 2017.pdf; NC0083101 PWSS memo request
2017.doc.docx
Importance: Low
Allen,
Have you had a change to take a look at this NPDES discharge to a water supply stream? The permit is scheduled to be
finalized next week. My original message is below. Thank you.
Thanks,
Derek C Denard
Environmental Specialist
Compliance & Expedited Permitting Unit
N.C. Division of Water Resources
N.C. Department of Environmental Quality
919 807 6307 office
derek.denardCa)ncdenr.gov
N. C. Division of Water Resources
Water Quality Permitting Section - NPDES
1617 Mail Service Center
Raleigh, NC 27699-1617
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Denard, Derek
Sent: Wednesday, April 19, 2017 1:07 PM
To: Hardy, Allen <[e-mail]>
Subject: Review of Discharge to Surface Waters Designated Water Supply (WS) - Permit Renewal NPDES N00083101 -
City of Henderson — Kerr Lake Regional WTP
Allen,
Please find the attached memo request for the renewal of NPDES permit NC0083101 for the City of Henderson — Kerr
Lake Regional WTP. Please provide your comments by May 26, 2017 [email OK).
Thanks,

Derek C Denard
Environmental Specialist
Compliance & Expedited Permitting Unit
N.C. Division of Water Resources
N.C. Department of Environmental Quality
919 807 6307 office
derek. denard [7ancdenr. aov
N. C. Division of Water Resources
Water Quality Permitting Section - NPDES
1617 Mail Service Center
Raleigh, NC 27699-1617
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.

l e U 011 [7 e,
Denard, Derek
From: Denard, Derek
Sent: Friday, May 12, 2017 2:56 PM
To: 'Lipscomb, Clarissa'
Subject: RE: NPDES Permit NC0083101
Ms. Lipscomb,
I will make that correction to the Supplement to Cover Sheet for the WTP reference. My apologies I was working from an
earlier example as a template. Thanks for catching my error.
Since this WTP discharges under zero flow conditions (the unnamed tributary being effluent dominate), upstream
monitoring is not relevant. The final permit will be updated to remove upstream monitoring and require only effluent
total hardness monitoring. Any metals that are hardness dependent for future permit renewals will use the default value
of 25 mg/I for upstream Total Hardness for reasonable potential analysis (RPA) of hardness dependent metals.
If you have any questions, please let me know.
Sincerely,
Derek C Denard
Environmental Specialist
Compliance & Expedited Permitting Unit
N.C. Division of Water Resources
N.C. Department of Environmental Quality
919 807 6307 office
derek.denard -ncdenr.gov
N. C. Division of Water Resources
Water Quality Permitting Section - NPDES
1617 Mail Service Center
Raleigh, NC 27699-1617
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.
From: Lipscomb, Clarissa [mailto:[e-mail]]
Sent: Friday, May 12, 20171:20 PM
To: Denard, Derek <[e-mail]>
Subject: NPDES Permit NC0083101
Mr. Denard,
I have two questions concerning the renewal of NPDES Permit NC0083101.
1. On page 2, the name of the plant is listed wrong ... should be Kerr Lake Regional WTP, not R A Thomas WTP.

2. On the monitoring requirements, testing the Effluent for Hardness I understand. Since we essentially are the
stream though, where would we be testing for Hardness upstream?
Thank you for your help.
Clarissa (Christy) M. Lipscomb, Director/ORC
Kerr Lake Regional Water System
P. O. Box 1434
280 Regional Water Lane
Henderson, NC 27536
Phone:[phone]
Fax:[phone]
[e-mail]
"When the well is dry,we know the worth of water." Ben Franklin

Adw�ll I�(zn in +ne
Zb,'tD -D,5�th on
Public Notice
North Carolina
Environmental Management
Commission/NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
Notice of Intent to Issue a
NPDES Wastewater Permit
The North Carolina Environ-
mental Management Commis-
sion proposes to issue a NP-
DES wastewater discharge
permit to the person(s) listed
below. Written comments re-
garding the proposed permit
will be accepted until 30 days
after the publish date of this
notice. The Director of the NC
Division of Water Resources
(DWR) may hold a public hear-
ing should there be a signific-
ant degree of public interest.
Please mail comments and/or
information requests to DWR
at the above address. Inter-
ested persons may visit the
DWR at 512 N. Salisbury
Street, Raleigh, NC to review
information on file. Additional
information on NPDES per-
mits and this notice may be
found on our website:
h tt p: //d e q. n c. g o v/a b o u t/d i v i-
sions/water-resources/wa ter -
resources -pert Its/wastewater-
branch/npdes-wastewater/pub
Iic-notices,or by calling (919)
807-6397.
City of Henderson applied to
renew NPDES permit for the
Kerr Lake Regional WTP
[NC0083101], 280 Regional
Water Lane, Henderson, / N
Vance County, discharging fit-
ter -backwash wastewater to
Anderson Swamp Arm of Kerr
Lake, Roanoke River Basin.
Apr. 25, 2017