NC0083101_Final Fact_Sheet_20231018

DocuSign Envelope ID: DFDEA17E-2B45-40CF-9636-4C5B4CABF7CD
DEQ/DWR/NPDES
EXPEDITED FACT SHEET - NPDES PERMIT DEVELOPMENT
NPDES Permit NCO083101
Caroline Robinson, Compliance&Expedited Permitter Unit/919-707-9130 September 2023
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 RRO
Office
Stream Characteristics
UT to Anderson
Receiving Stream Swamp Arm of Kerr Stream Classification WS-III&B;CA
Lake
Stream Segment [23-8-6-(1.5)] Drainage basin Roanoke
Summer 7Q10(cfs) 0 Subbasin [HUC] 03-02-06
[030101021001]
Winter 7Q10(cfs) 0 Use Support
No
30Q2 (cfs) 0 303(d)Listed
Average Flow(cfs) 0
IWC(%) 1 100% USGS Topo Quad Middleburg,NC
FACILITY SUMMARY: This facility is a conventional technology water 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 F1740) [thickening&settling]
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System Upgrades 2023:
The permittee sent the following list of system improvements:
- Powdered activated carbon (PAC) slurry system;
- The installation of four(4) additional granular media gravity filters with activated carbon. Each
filter is 21' x 21', so the design filtration capacity is 20.3 mgd with all eight filters online at 4
gpm/sf;
- Filter building/pump station expansion, including a four(4) bay expansion with a crane bridge
extension, piping, electrical, plumbing, and HVAC improvements;
- Architectural improvements such as the addition of locker rooms/bathrooms, a training room,
kitchen, additional offices, and elevator;
- A new clearwell for additional disinfectant dosage-contact time ("CT") capacity and reliability;
- A new permanganate storage building;
- Miscellaneous chemical system expansion and upgrades. Chemical storage is sized for 30-day
storage at average flow and dose;
- Miscellaneous site and civil improvements and equipment;
- Instrumentation and controls necessary to integrate the new equipment and systems into the
plant's existing computerized supervisory control and data acquisition (SCADA) system; and
Electrical, instrumentation,HVAC and plumbing upgrades throughout the site
RENEWAL SUMMARY: This permit reflects discharge at Outfall 001.
DWR updated the following from the draft for the final permit:
• Section A(4.)has been updated to be consistent with current federal requirements for electronic
reporting.
• Section A(3.)was updated to include latest language for toxicity testing requirements.
• Review of data from the last permit cycle demonstrated no reasonable potential for the exceedance
of water quality limits for fluoride. Therefore, the limit for Fluoride has been removed, and
monitoring has been reduced to quarterly.
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"
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2014 Integrated Report
Ilk
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Figure 1. Outfall 001 Location with aerial orthophotography [NC DWR,2014 Integrated Report,ArcGIS Online].
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 of WET tests indicated
3 failures out of the last 12 quarters.
Compliance History: This permit cycle (5 yrs) One NOV in 2019 for monitoring violations. No
enforcements.
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.
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(TRC)—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.
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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 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 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.No RPA for limit exceedance was found while reviewing monitoring data from the last
permit cycle. Therefore,the limit for Fluoride has been removed,and monitoring is reduced to quarterly.
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.No RPA for limit exceedance was found while reviewing monitoring data
from the last permit cycle. Therefore, quarterly Total Zinc monitoring only is continued for this permit
renewal.
Total Hardness—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.
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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 3 failures out of 12 quarters.
DATA SUMMARY
MAXIMUM Monthly Average Flow for past 36 months(Qw) (as of Mar 2023): 0.020 MGD
DMR Daily Parameter Values for Mar2019-Feb2023 (4 years)
Parameter n Average Min Max
00070 -Turbidity 157 3.88 0.00 25.00
00400 - pH 157 6.49 6.00 7.20
00900 - Hardness, Total (as CaCO3) 11 92.73 24.00 260.00
00951 - Fluoride, Total (as F) 37 0.65 0.10 10.00
01092 -Zinc, Total (as Zn) 11 7.29 0.01 10.00
01105 -Aluminum, Total (as Al) 11 1.42 0.10 6.58
50050 - Flow, in conduit or thru treatment plant 819 0.01 0.00 0.25
50060 - Chlorine, Total Residual 157 5.02 0.00 17.00
C0530 - Solids, Total Suspended - 157 7.26 2.00 46.00
Concentration
C0600 - Nitrogen, Total - Concentration 12 4.89 0.10 50.00
C0665 - Phosphorus, Total (as P) - 11 0.10 0.00 0.44
Concentration
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 213.0206. 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 Mar 2019-
Feb2023. 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:
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• 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: Fluoride,Zinc
(both fluoride and zinc will still be required to remain in the permit,with quarterly monitoring only,
due to presence chemical additives used in the treatment process)
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 ualit Standards/A uatic Life Protection
Parameter Acute FW, µg/I Chronic FW, µg/I Acute SW, µg/I Chronic SW, µg/I
(Dissolved) (Dissolved) (Dissolved) (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 1.9 0.1
Zinc Calculation Calculation 90 81
Table 1 Notes:
1. FW=Freshwater, SW= Saltwater
2. �=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/1 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*{1.136672-[1n hardness](0.041838)} •e^{0.9151 [In hardness]-3.14851
Cadmium,Acute Trout waters WER*{l.136672-[1n hardness](0.041838)} •e^{0.9151[ln hardness]-3.623 61
Cadmium,Chronic WER*{1.101672-[ln hardness](0.041838)} •eA f 0.7998[ln hardness]-4.44511
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Chromium I1I,Acute WER*0.316 •e^{0.8190[ln hardness]+3.7256}
Chromium I1I,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[ln hardness]-1.702}
Lead,Acute WER*{1.46203-[ln hardness](0.145712)} • e"{1.273[ln hardness]-1.460}
Lead,Chronic WER*{1.46203-[ln 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[ln 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, 7Q10(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
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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.
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,mg/L)+(s7Q 10, cfs *Avg.Upstream Hardness,mg/L)
(Permitted Flow, cfs+s7Q10,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 = I
Ctotal 1 + { [Kp.] [ss('+a)] [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
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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=(s7Q 10+Qw) (Cwgs)—(s7Q 10) (Cb)
Qom'
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.
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Public Notice
AFFP North Carolina
Public Notice North Carolina Environmental Management
Comm iss ion/NPDES Unit
Affidavit of Publication 1617 flail Service Center
tlelgh, NC 27 9-1617
Notice of Intent to, Issue a, NP-
STATEOFNC} SS LEES Wastewater Permit
COUNTY OF } CO31 01 Derr LakeRegion-
all WTP The North Carolina En-
Kimberly Cook, being duly sworn, says:
viror mental Management Com-
mission proposes 'to issue a
That she is Billing Clerk of the The Daily Dispatch, a daily N DES wastewater discharge
newspaper of general circulation, printed and published in permit to theperson(s) listed
Henderson, County, NC;that the publication, a copy of
which is attached hereto, was published in the said hale. Written ltt�r� comments re-
which
on the following dates: garding the proposed permit
May 23, 2023 will be accepted until 30 days
after the publish date of this no-
tice, The Director of the NC Di-
vision of Water Resources
( ) may hold a public hear-
ing should there be a signific-
That said newspaper was regularly issued and circulated art degree of public interest.
on those dates. Please rail comments and/or
SIGNED: information requests to DWR at
Ll U the above, address. interested
Billing Clerk persons may visit the DWR at
Subscribed to and sworn to me this 23rd day of May 2023. 512 l ` Salisbury t r e e t,
Raleigh, NC 27604 to revise
the information on file. Addition-
al information on NPDES per-
mits,G and this notice may be
Barbara M Daniels, Notary Guilford, County, NC found on our w e b s i t e '
hops;//d9q�nc.gv/pblic-no-
My commission expires: March 06`
Q,92 M""'• tires-hearings*or by calling
City of Henderson applied to to-
new permit for the Kerr Lake
70061580 70679185 A ;'-
Vg LPL ,z`'eRegional Wacurit ,
Wren Thedford .,`�p discharging - filtery-ba>ck as.h
DEQ- Division of Water Resources�(61P,,,��ve wastewater t, Anderson
r
1617 Mail Service Center Swamp Arm of Kerr Lake,
Raleigh, NC 27699
Roanoke River Basin. Some
parameters are water quality
limited.
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Whole Effluent Toxicity Testing and Self Monitoring Summary
Kannapolis WTP NC0006220/001 County: Rowan Region: MRO Basin: YAD12 Jan Apr Jul Oct SOC_JOC:
Ceri7dPF Begin: 12/1/2013 Chr Monit:90% NonComp: 7Q10: PF: 0.16 IWC: Freq: Q
J F M A M J J A S 0 N D
2019 Pass - - Pass - - Pass - - Pass - -
2020 Pass - - Pass - - Fail - - Fail - -
2021 Fail - - Pass - - Fail - - Pass - -
2022 Fall - - Pass - - Pass - - Fail - -
2023 Fail - - - - - - - - - - -
Kenly WWTP N00064891/001 County: Johnston Region: RRO Basin: NEU06 Mar Jun Sep Dec SOC_JOC:
Ceri7dPF Begin: 8/1/2018 chr lim:22% + NonComp: Single 7Q10: 3.41 PF: 0.63 IWC: 22 Freq: Q
J F M A M J J A S 0 N D
2019 - - Pass - - Pass - - Pass - - Pass
2020 - - Pass - - Pass - - Pass - - Pass
2021 - - Pass - - Pass - - Pass >88(P) - Pass
2022 - - Pass - - Pass - - Pass - - Pass
2023 - - Pass - - - - - - - - -
Kenric Road WTP NCO084204/001 County: Robeson Region: FRO Basin: LUM51 Jan Apr Jul Oct SOC_JOC:
Ceri7dPF Begin: 8/1/2014 Chr Cer PF Monit:90 NonComp: 7Q10: PF: IWC: Freq: Q
J F M A M J J A S 0 N D
2019 Fail - - Fail - - Fail - - Fail - -
2020 Fail - - Fail - - Pass - - Fail - -
2021 Fail - - Fail - - Fail - - Fail - -
2022 Fail - - Fail - - Pass - - Fail - -
2023 Pass - - Pass - - - - - - - -
Kerr Lake Regional WTP NCO083101/001 County: Vance Region: RRO Basin: ROA05 Jan Apr Jul Oct SOC_JOC:
Ceri7dPF Begin: 6/1/2012 Chr Monit:90% NonComp: 7Q10: PF: IWC: Freq: Q
J F M A M J J A S O N D
2019 Pass - - Pass - - Pass - - Pass - -
2020 Pass - - Pass - - Pass - - Pass - -
2021 Pass - - Pass - - Pass - - Fail - -
2022 Fail - - Fail - - Pass - - Pass - -
2023 Pass - - - - - - - - - - -
Kershaw WTP NCO088331/001 County: Pamlico Region: WARO Basin: NEU10 Mar Jun Sep Dec SOC_JOC:
Mysd24PF Begin: 11/1/2018 AcP/F Monit:90%M NonComp: 7Q10: NA PF: IWC: Freq: Q
J F M A M J J A S 0 N D
2019 - - Fail - - Pass - - Pass - - Pass
2020 - - Pass - - Pass - - Pass - - Pass
2021 - - Pass - - Pass - - Pass - - Pass
2022 - - Pass - - Pass - - Pass - - Pass
2023 - - Pass - - - - - - - - -
Leeend: P=Fathead minnow(Pimchales promelasl.H=No Flow(facilitv is active).s=Split test between Certified Labs Page 55 of 115

DocuSign Envelope ID: DFDEA17E-2B45-40CF-9636-4C5B4CABF7CD
Freshwater RPA- 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
REQUIRED DATA ENTRY
Table 1. Project Information Table 2. Parameters of Concern
❑CHECK IF HQW OR ORW WQS Name WQS Type Chronic Modifier Acute PQL Units
Facility Name Kerr Lake WTP Paro1 Arsenic Aquactic Life C 150 FW 340 ug/L
WWTP/WTP Class Grade I Physical Chemical Par02 Arsenic Human Health C 10 HH/WS N/A ug/L
Water Supply
NPDES Permit NCO083101 Par03 Beryllium Aquatic Life INC 6.5 FW 65 ug/L
Outfall 001 Par04 Cadmium Aquatic Life INC 1.5875 FW 10.1621 ug/L
Flow,Qw(MGD) 0.020 Paros Chlorides Aquatic Life NC 230 FW
Receiving Stream UT Anderson Swamp Arm Kerr Lake Par061# Chlorinated Phenolic Compounds Water supply INC 1 A ug/L
HUC Number 030101021001 Par07 Total Phenolic Compounds Aquatic Life INC 300 A ug/L
Stream Class WS-II I,B;CA Paros Chromium III Aquatic Life NC 344.4503 FW 2647.9994 ug/L
❑Apply WS Hardness WQC Paros Chromium VI Aquatic Life NC 11 FW 16 pg/L
7Q10s(cfs) 0.00 1 Chromium,Total Aquatic Life INC N/A FW N/A pg/L
7Q1Ow(cfs) 0.00 1 Copper Aquatic Life INC 24.1546 FW 36.0075 ug/L
311(cfs) Par12 Cyanide Aquatic Life INC 5 FW 22 10 ug/L
QA(cfs) Par13 Fluoride Aquatic Life INC 1,800 FW ug/L
1Q10s(cfs) 1. 0.00 1 Lead Aquatic Life INC 12.6035 FW 323.4275 ug/L
Effluent Hardness 92.73 mg/L(Avg) Parts Mercury Aquatic Life INC 12 FW 0.5 ng/L
------------ --------------------
Upstream Hardness 25 mg/L(Avg) I Parts Molybdenum Human Health INC 2000 HH ug/L
------------ -------------------
Combined Hardness Chronic 92.73 mg/L I Par17 Nickel Aquatic Life INC 112.8519 FW 1016.0511 pg/L
------------ -------------------
Combined Hardness Acute 92.73 mg/L I Par18 Nickel Water Supply INC 25.0000 WS N/A pg/L
Data Source(s) Par19 Selenium Aquatic Life INC 5 FW 56 ug/L
❑CHECK TO APPLY MODEL Par20 Silver Aquatic Life NC 0.06 FW 2.8250 ug/L
Par21 Zinc Aquatic Life NC 384.7970 FW 381.6749 ug/L
Par22
Par23
Par24
NCO083101 Final FW RPA 2023, input
5/8/2023

DocuSign Envelope ID: DFDEA17E-2B45-40CF-9636-4C5B4CABF7CD
REASONABLE POTENTIAL ANALYSIS
H1 H2 Use"PASTE SPECIAL Use"PASTE SPECIAL
Effluent Hardness Values"then"COPY" Upstream Hardness Values"then"COPY"
.Maximum data .Maximum data
points=58 points=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 Std Dev. 99.9499 1 25 25 Std Dev. N/A
2 Mean 92.7273 2 Mean 25.0000
3 C.V. 1.0779 3 C.V. 0.0000
4 4/14/2020 26.8 26.8 n 11 4 n 1
5 7/28/2020 31.2 31.2 10th Per value 26.80 mg/L 5 10th Per value 25.00 mg/L
6 10/6/2020 246 246 Average Value 92.73 mg/L 6 Average Value 25.00 mg/L
7 1/19/2021 27 27 Max.Value 260.00 mg/L 7 Max.Value 25.00 mg/L
8 4/6/2021 237 237 8
9 7/6/2021 260 260 9
10 10/12/2021 36 36 10
11 1/11/2022 24 24 11
12 4/5/2022 36 36 12
13 7/5/2022 48 48 13
14 10/4/2022 48 48 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 58
NCO083101 Final FW RPA 2023,data
-3- 5/8/2023

DocuSign Envelope ID: DFDEA17E-2B45-40CF-9636-4C5B4CABF7CD
REASONABLE POTENTIAL ANALYSIS
Par13 Par21
Use"PASTE SPECIAL Use"PASTE SPECIAL
Fluoride Values"then"COPY" Zinc Values"then"COPY"
.Maximum data .Maximum data
points=58 points=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 3/10/2020 0.1 0.1 Std Dev. 1.1309 1 Std Dev. 9.4166
2 4/14/2020 0.1 0.1 Mean 0.3357 2 Mean 8.5455
3 5/5/2020 0.1 0.1 C.V. 3.3690 3 C.V. 1.1019
4 6/2/2020 < 0.1 0.05 n 37 4 4/14/2020 < 10 5 n 11
5 7/7/2020 < 0.1 0.05 5 7/28/2020 < 10 5
6 8/4/2020 < 0.1 0.05 Mult Factor= 1.43 6 10/6/2020 < 10 5 Mult Factor= 2.30
7 9/1/2020 < 0.1 0.05 Max.Value 5.0 ug/L 7 1/19/2021 < 10 5 Max.Value 36.0 ug/L
8 10/6/2020 < 10 5 Max.Fred Cw 7.2 ug/L 8 4/6/2021 < 10 5 Max.Fred Cw 82.8 ug/L
9 11/3/2020 < 10 5 9 7/6/2021 < 10 5
10 12/1/2020 < 0.1 0.05 10 10/12/2021 < 10 5
11 1/19/2021 < 0.1 0.05 11 1/11/2022 < 10 5
12 2/2/2021 < 0.1 0.05 12 4/5/2022 13 13
13 3/9/2021 < 0.1 0.05 13 7/5/2022 < 10 5
14 4/6/2021 < 0.1 0.05 14 10/4/2022 36 36
15 5/25/2021 < 0.1 0.05 15
16 6/1/2021 < 0.1 0.05 16
17 7/6/2021 < 0.1 0.05 17
18 8/3/2021 < 0.1 0.05 18
19 9/7/2021 < 0.1 0.05 19
20 10/5/2021 < 0.1 0.05 20
21 10/12/2021 < 0.1 0.05 21
22 11/2/2021 < 0.2 0.1 22
23 12/14/2021 < 0.1 0.05 23
24 1/11/2022 < 0.1 0.05 24
25 2/1/2022 < 0.1 0.05 25
26 3/1/2022 < 0.1 0.05 26
27 4/5/2022 < 0.1 0.05 27
28 5/3/2022 < 0.1 0.05 28
29 6/7/2022 < 0.1 0.05 29
30 7/5/2022 < 0.2 0.1 30
31 8/2/2022 < 0.1 0.05 31
32 9/6/2022 0.17 0.17 32
33 10/4/2022 < 0.1 0.05 33
34 11/1/2022 0.1 0.1 34
35 12/6/2022 0.1 0.1 35
36 1/3/2023 0.2 0.2 36
37 2/28/2023 0.1 0.1 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 58
NCO083101 Final FW RPA 2023,data
-4- 5/8/2023

DocuSign Envelope ID: DFDEA17E-2B45-40CF-9636-4C5B4CABF7CD
Kerr Lake WTP - Outfall 001
NCO083101 Freshwater RPA- 95% Probability/95% Confidence Using Metal Translators Qw = 0.02 MGD
MAXIMUM DATA POINTS = 58
Qw(MGD)= 0.0200 WWTP/WTP Class: Grade I Physical Chemical COMBINED HARDNESS(m¢/L)
1Q10S(cfs)= 0.00 1WC% @ 1Q10S = 100 Acute=92.73 mg/L
7Q10S(cfs)= 0.00 1WC% @ 7Q10S= 100 Chronic=92.73 mg/L
7Q10W(cfs)= 0.00 IWC%@ 7Q10W= 100
30Q2(cfs)= NO 30Q2 DATA 1WC%@ 30Q2= N/A
Avg.Stream Flow,QA(cfs)= NO QA DATA IW%C @ QA= N/A
Receiving Stream: UT Anderson Swamp Arm Kerr Lake HUC 030101021001 Stream Class: WS-III,B;CA
PARAMETER NC STANDARDS OR EPA CRITERIA J U) REASONABLE POTENTIAL RESULTS RECOMMENDED ACTION
TYPE Chronic Applied Acute o. D n #Det. Max Pred Cw Allowable Cw
Standa
Acute: NO WQS
Fluoride NC 1800 FW ug/L 37 8 7.2
Chronic:----1,800.0— ---------------------------
No value>Allowable Cw
Acute: 381.7
Zinc NC 384.7970 FW 381.6749 ug/L 11 2 82.8 _ _ _ _ ___ _ _ _ _ _ _ _ _ _ _ _ _
Chronic: 384.8 No RP,Predicted Max >_50%of Allowable Cw
No value>Allowable Cw apply Quarterly Monitoring
NCO083101 Final FW RPA 2023,rpa
Page 5 of 5 5/8/2023

From: Lii)scomb,Clarissa
To: Robinson.Caroline
Subject: [External] RE: NPDES Permit Issuance NCO083101
Date: Monday,November 6,2023 12:56:21 PM
Attachments: imaoe001.ona
CAUTION: External email. Do not click links or open attachments unless verified. Report suspicious emails with the
Report Message button located on your Outlook menu bar on the Home tab.
I have received.
From: Robinson, Caroline<[e-mail]>
Sent:Thursday, November 2, 2023 9:24 AM
To: Blackmon, Terrell <[e-mail]>; Blackmon, Terrell
<Terrel I Blackmon @ henderson.nc.gov>
Cc: Lipscomb, Clarissa <[e-mail]>;Thomas, Clark
<[e-mail]>
Subject: NPDES Permit Issuance NCO083101
Good Morning!
I've attached a PDF of the permit issuance and fact sheet for NCO083101/Kerr Lake
Regional WTP. Please respond to this email to confirm you have downloaded a copy for
your records.
Let me know if you have any questions or if you need a hard copy of the permit mailed to
you!
Thanks,
Caroline
Caroline Robinson (she/her/hers)
Environmental Specialist II, Division of Water Resources
North Carolina Department of Environmental Quality
Office: [phone] / Cell: [phone]
caroline.robinson(@deq.nc.gov

ki ;NORTH CAROLINA
Department of Environmental Quality
Email correspondence to and from this address is subject to the North
Carolina Public Records Law and may be disclosed to third parties.
Email correspondence to and from this address may be subject to the North Carolina Public Records Law and may be disclosed to third
parties by an authorized state official.