NC0020737_Fact Sheet_20240222

Fact Sheet
NPDES Permit No. NCO02O737
Permit Writer/Email Contact:Nick Coco,[e-mail]
Date: January 16, 2024
Division/Branch:NC Division of Water Resources/NPDES Municipal Permitting
Fact Sheet Template: Version 09Jan2017
Permitting Action:
® Renewal
❑ Renewal with Expansion
❑ New Discharge
❑ Modification(Fact Sheet should be tailored to mod request)
Note: A complete application should include the following:
• For New Dischargers,EPA Form 2A or 2D requirements,Engineering Alternatives Analysis,Fee
• For Existing Dischargers (POTW),EPA Form 2A, 3 effluent pollutant scans,4 2nd species WET
tests.
• For Existing Dischargers (Non-POTW),EPA Form 2C with correct analytical requirements based
on industry category.
Complete applicable sections below. If not applicable, enter NA.
1. Basic Facility Information
Facility Information
Applicant/Facility Name: City of Kings Mountain/Pilot Creek Wastewater Treatment Plant(WWTP)
Applicant Address: P.O. Box 429,Kings Mountain,NC 28086
Facility Address: 200 Potts Creek Road,Kings Mountain,NC 28086
Permitted Flow: 6.0 MGD with interim operation tiers at 3.0 MGD and 4.0 MGD
Facility Type/Waste: MAJOR Municipal; 41.8%domestic and 58.2%industrial*
Facility Class: Grade IV Biological Water Pollution Control System
Treatment Units: Bar Screen,Activated Sludge/Aeration, Clarification, Chlorine
Disinfection,Aerobic Digestion, Sludge Dewatering
Pretreatment Program(Y/N) Y; LTMP
County: Cleveland
Region Mooresville
*Based on permitted flows(compared to 3.0 MGD flow tier)
Briefly describe the proposed permitting action and facility background: The City of Kings Mountain
applied for an NPDES permit renewal for the 6.0 MGD Pilot Creek WWTP and continuation of the
interim operation tiers of 3.0 MGD and 4.0 MGD on March 6, 2023. The facility is rated for 6.0 MGD.
The current permitted flow is 3.0 MGD and expanded flow tiers at 4.0 MGD and 6.0 MGD are permitted,
taking effect once the facility demonstrates a rolling average flow for any twelve(12)month period that
exceeds 2.7 MGD and 3.6 MGD,respectively. As review of the Town's discharge monitoring reports
(DMRs) during the period reviewed(February 2019 to June 2023)did not demonstrate a rolling average
flow for any 12-month period exceeding 2.7 MGD,the 3.0 MGD flow tier and conditions have been
maintained. This facility serves a population of approximately 11,200 residents as well as 8 significant
industrial users(SIU), including 7 categorical significant industrial users(CIUs),via an approved
pretreatment program. Treated domestic and industrial wastewater is discharged into Buffalo Creek, a
class C waterbody in the Broad River Basin. Outfall 001 is approximately 8.3 miles upstream of the
NC/SC state border and approximately 0.75 miles from the Pilot Creek WWTP.
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Sludge disposal: Sludge is transported to the Cleveland County Landfill for final disposal.
Inflow and Infiltration(I/L. In their application,the City noted an estimated average daily I/I flow of
approximately 313,000 gpd. The City has conducted collection system repairs and manhole rehabilitation
that has gradually reduced the I/I experienced at the facility from 2020 through 2022.
24-hour Staffing Waiver: 15A NCAC 02H .0124(4)requires mechanical facilities with a design capacity
equal to or greater than 5.0 MGD and continues operation 24 hours per day, seven days per week staffing
with each shift staffed by at least one certified wastewater operator unless the applicant can demonstrate
that this requirement is not necessary to ensure the reliability of unit processes. The City is currently
waived of the requirement for 24-hour staffing as part of an agreement with the Division. In their
application,the City provided a description of their operation process (attached) and requested
continuation of the 24-hour staffing waiver. Based on review of the supporting documentation,the waiver
has been continued. The Division may rescind this waiver if necessary.
2. Receiving Waterbody Information:
Receiving Waterbody Information
Outfalls/Receiving Stream(s): Outfall 001 -Buffalo Creek
Stream Segment: 9-53-(5)
Stream Classification: C
Drainage Area(mi2): 116
Summer 7Q10(cfs) 19
Winter 7Q10(cfs): 42
30Q2 (cfs): 54
Average Flow(cfs): 162
IWC (%effluent): 20.0 at 3.0 MGD,24.6 at 4.0 MGD and 33.0 at 6.0 MGD
2022 303(d) listed/parameter: Not listed
Subject to TMDL/parameter: Yes- State wide Mercury TMDL implementation.
Basin/HUC: Broad River/03050105
USGS Topo Quad: F13SW
3. Effluent Data Summary
Effluent data for Outfall 001 is summarized below for the period of February 2019 through June 2023.
Table 1. Effluent Data Summary Outfall 001
Parameter Units Average Max Min Permit Limit
Flow* MGD 1.6 5.894 0.456 MA 3.0
BOD summer mg/l 3.0 21.8 <2 WA 42.0
MA 28.0
BOD winter mg/1 3.3 31 <2 WA 45.0
MA 30.0
NH3N summer mg/1 0.3 12.74 <0.1 WA 7.8
MA 2.6
NH3N winter mg/1 0.5 15.3 <0.1 WA 26.7
MA 8.9
TSS mg/1 7.9 405.8 1.3 WA 45.0
MA 30.0
pH SU 6.8 7.7 6 6.0>pH<9.0
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eomean
(geometric)
Fecal coliform #/100 ml g 8.5
>2420 < 1 WA 400
MA 200
DO mg/l 8.4 13 5 DA>5.0
Temperature ° C 19.2 29 6.9 Monitor&
Report
Total Residual Chlorine µg/1 21.5 83 < 10 DM 28
TN mg/l 22.1 53.4 10.74 Monitor&
Report
TP mg/l 2.8 4.73 1.9 Monitor&
Report
Total Arsenic µg/1 62.8 210 6.8 Monitor&
Report
Total Cyanide µg/l 8.4 13 <5 Monitor&
Report
Total Molybdenum mg/I 1.9 6.4 .004 MA 10.2
DM 10.2
Total Selenium µg/l 7.1 <50 < 1 MA 25.4
DM 245.0
MA 10.2
Total Thallium µg/l 3.9 20 <0.5 DM 10.2
SOC MA 60.1
(exp. 8/31/2020)
Total Hardness mg/l 136 200 12 Monitor&
Report
MA-Monthly Average,WA-Weekly Average,DM-Daily Maximum,DA=Daily Average
*The maximum 12-month rolling average monthly flow reported during the period reviewed was 1.7
MGD. As the 12-month rolling average monthly flow did not exceed 2.7 MGD,the 4.0 MGD flow tier
has not been triggered and the 3.0 MGD flow tier and limitations continue to apply.
4. Instream Data Summary
Instream monitoring may be required in certain situations, for example: 1)to verify model predictions
when model results for instream DO are within 1 mg/1 of instream standard at full permitted flow;2)to
verify model predictions for outfall diffuser; 3)to provide data for future TMDL;4)based on other
instream concerns. Instream monitoring may be conducted by the Permittee, and there are also
Monitoring Coalitions established in several basins that conduct instream sampling for the Permittee(in
which case instream monitoring is waived in the permit as long as coalition membership is maintained).
Is this facility a member of a Monitoring Coalition with waived instream monitoring(YIN): NO
Name of Monitoring Coalition: NA
If applicable, summarize any instream data and what instream monitoring will be proposed for this
permit action: The current permit requires instream monitoring for temperature, dissolved oxygen and
conductivity upstream 100 yards above the outfall and downstream at NCSR 1103 (Pleasant Hill Church
Road), located approximately 2.4 miles downstream of the outfall. Instream monitoring is conducted three
times per week during the months of June,July,August and September then once per week during the
remaining months of the year. Total hardness sampling is conducted upstream of the discharge at a
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quarterly frequency. In addition to the required parameters,the City conducted instream pH monitoring.
Instream data have been summarized below in Table 2.
Table 2. Downstream Monitoring Data Summary
Upstream Downstream
Parameter Units
Average Max Min Average Max Min
Temperature ° C 20.3 28 7 18.8 27 6
DO mg/l 8.6 13 6.6 8.8 13.9 6.1
Conductivity µmhos/cm 69 203 27 122 468 47
pH S.U. 7.0 8.3 6.2 7.1 8.4 6.2
Total mg/1 27.4 170 16
Hardness
Students t-tests were run at a 95% confidence interval to analyze relationships between instream
samples.A statistically significant difference is determined when the t-test p-value result is<0.05.
Downstream temperature was not greater than 29 degrees Celsius [per 15A NCAC 02B .0211 (18)]
during the period reviewed. Downstream temperature was not greater than upstream temperature by more
than 2.8 degrees Celsius during the period reviewed. It was concluded that a statistically significant
difference exists between upstream and downstream temperature,with downstream temperature generally
being lower than upstream temperature. While temperatures vary upstream and downstream of the
discharge,no exceedance of the stream standard was observed. Monitoring has been maintained.
Average downstream DO was above 5 mg/L [per 15A NCAC 02B .0211 (6)] both upstream and
downstream of the discharge during the period reviewed. Instream DO was not observed at levels less
than 4.0 mg/L during the period reviewed. It was concluded that a statistically significant difference exists
between upstream and downstream DO. Review of instream DO showed variable differences between
upstream and downstream DO,with occurrences of higher or lower downstream DO concentrations.
While DO concentrations vary upstream and downstream of the discharge,no exceedance of the stream
standard was observed. Monitoring has been maintained.
It was concluded that a statistically significant difference exists between upstream and downstream
conductivity,with downstream conductivity being consistently reported at levels higher than the upstream
sample. Monitoring has been maintained.
pH was not observed out of the range of 6.0 s.u. and 9.0 s.u. [per 15A NCAC 02B .0211(4)] either
upstream or downstream during the period reviewed. It was concluded that a statistically significant
difference exists between upstream and downstream pH. Review of instream pH showed variable
differences between upstream and downstream pH,with occurrences of higher or lower downstream pH.
While DO concentrations vary upstream and downstream of the discharge,no exceedance of the stream
standard was observed. The City is encouraged to continue conducting ambient pH monitoring.
Fecal coliform is not currently monitored instream. As the receiving stream is neither class B nor
impaired for fecal coliform, and as the facility has reported no effluent fecal coliform limit violations
during the period reviewed(past 5 years),no changes were made.
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5. Compliance Summary
Summarize the compliance record with permit effluent limits (past 5 years): In 2018,the facility reported
1 ammonia limit violation resulting in enforcement. The facility reported 3 ammonia limit violations, 2
total residual chlorine limit violations and 3 total arsenic limit violations resulting in enforcement in 2019.
In 2022,the facility reported 1 TSS limit violation resulting in enforcement. The facility reported 1 TSS
limit violation resulting in enforcement in 2023.
Summarize the compliance record with aquatic toxicity test limits and any second species test results
(past 5 years): The facility passed 18 of 18 quarterly chronic toxicity tests, as well as all 4 second species
chronic toxicity tests from January 2019 to April 2023.
Summarize the results from the most recent compliance inspection: The last facility inspection conducted
in October 2023 reported that the facility was not compliant.Additional information regarding the
compliance issues may be found in the attached Inspection Report. The last pretreatment inspection
conducted in May 2022 reported that the facility was compliant.
6. Water Quality-Based Effluent Limitations (WQBELs)
Dilution and MixingZ ones
In accordance with 15A NCAC 2B.0206,the following streamflows are used for dilution considerations
for development of WQBELs: 1Q10 streamflow(acute Aquatic Life); 7Q10 streamflow(chronic Aquatic
Life;non-carcinogen HH); 30Q2 streamflow(aesthetics); annual average flow(carcinogen,HH).
If applicable, describe any other dilution factors considered(e.g., based on CORMIX model results):NA
If applicable, describe any mixing zones established in accordance with 15A NCAC 2B.0204(b): NA
Oxygen-Consuming Waste Limitations
Limitations for oxygen-consuming waste(e.g., BOD) are generally based on water quality modeling to
ensure protection of the instream dissolved oxygen(DO)water quality standard. Secondary TBEL limits
(e.g., BOD=30 mg/1 for Municipals)may be appropriate if deemed more stringent based on dilution and
model results.
If permit limits are more stringent than TBELs, describe how limits were developed: Limitations for
summer BOD are based on a Streeter Phelps model(Level B)conducted in 1989 for instream DO
protection. Limitations for winter BOD are based on Secondary Treatment Standard defined in 40 CFR
133.102. These limits are applied to all flow tiers. No changes were made.
Ammonia and Total Residual Chlorine Limitations
Limitations for ammonia are based on protection of aquatic life utilizing an ammonia chronic criterion of
1.0 mg/1(summer) and 1.8 mg/1(winter). Acute ammonia limits are derived from chronic criteria,
utilizing a multiplication factor of 3 for Municipals and a multiplication factor of 5 for Non-Municipals.
Limitations for Total Residual Chlorine(TRC) are based on the NC water quality standard for protection
of aquatic life(17 ug/1) and capped at 28 ug/l(acute impacts). Due to analytical issues,all TRC values
reported below 50 ug/1 are considered compliant with their permit limit.
Describe any proposed changes to ammonia and/or TRC limits for this permit renewal: The current
permit requires limits and monitoring for TRC. The TRC limits have been reviewed in the attached WLA
for toxicity and have been found to be protective.No changes were made.
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Limitations for ammonia are Instream Waste Concentration(IWC)-based calculations for toxicity at the
6.0 MGD flow tier. These limits are applied to all flow tiers. The ammonia limits have been reviewed in
the attached WLA for toxicity and have been found to be protective.No changes were made.
Reasonable Potential Analysis(RPA)for Toxicants
If applicable, conduct RPA analysis and complete information below.
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%2 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.
A reasonable potential analysis was conducted on effluent toxicant data collected between February 2019
and July 2023. 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:
o Total Arsenic
■ @ 4.0 MGD: MA 271.3 ug/L,DM 1,200.4 ug/L
■ @ 6.0 MGD: MA 184.2 ug/L,DM 913.6 ug/L
o Total Molybdenum
■ @ 6.0 MGD flow tier only: MA and DM of 6.1 mg/L
o Total Silver
■ @ 3.0 MGD: MA 0.31 ug/L,DM 4.60 ug/L
■ @ 4.0 MGD: MA 0.24 ug/L,DM 4.50 ug/L
■ @ 6.0 MGD: MA 0.18 ug/L,DM 4.42 ug/L
o Total Selenium
■ @ 3.0 MGD: MA 15.8 ug/L,DM 245.0 ug/L
■ @ 4.0 MGD: MA 12.6 ug/L,DM 197.7 ug/L
■ @ 6.0 MGD: MA 9.4 ug/L,DM 150.5 ug/L
o Total Thallium
■ @ 3.0 MGD: MA 10.2 ug/L,DM 10.2 ug/L
■ @ 4.0 MGD: MA 8.13 ug/L,DM 8.13 ug/L
■ @ 6.0 MGD: MA 6.1 ug/L,DM 6.1 ug/L
• Monitoring Only. The following parameters will receive a monitor-only requirement since they
did not demonstrate reasonable potential to exceed applicable water quality standards/criteria,
but the maximum predicted concentration was>50%of the allowable concentration: Total
Arsenic (@ 3.0 MGD flow tier only), Total Cadmium(@ all flow tiers), Total Chlorides (@ 6.0
MGD flow tier only), Total Cyanide(@ all flow tiers), Total Molybdenum(@ 3.0 MGD and 4.0
MGD flow tiers only)
• 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: Total Chromium, Total Copper, Total Lead, Total Nickel, Total Zinc
• POTW Effluent Pollutant Scan Review: Three effluent pollutant scans (2020,2021 and 2022)
were evaluated for additional pollutants of concern.
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o The following parameter(s)will receive a water quality-based effluent limit(WQBEL)
with monitoring, since as part of a limited data set,two samples exceeded the allowable
discharge concentration: None
o The following parameter(s)will receive a monitor-only requirement, since as part of a
limited data set, one sample exceeded the allowable discharge concentration: None
o 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: Total
Beryllium, Total Phenolic Compounds,Chloroform,Chlorodibromomethane,
Dichlorobromomethane
In the 2015 permit renewal, limits for thallium(1.43 µg/L monthly average and daily max)was included
in the permit due to high thallium concentrations in the effluent from Pilot Creek WWTP. A Special
Order of Consent(SOC) for total thallium(60.1 µg/L monthly average)was issued in July, 2016 and
renewed in March 2018. This SOC expired on August 31, 2020. Because the state of North Carolina did
not have water quality criteria for thallium, in the 2015 permit renewal,the EPA recommended criteria of
0.47 µg/L was used for the calculation of thallium limit. In 2018,the NC Division of Water resources
(DWR) conducted an assessment of thallium criteria and recommend surface water criteria for thallium as
2 µg/L in all surface waters of the state. In the 2018 permit renewal and during the current renewal
process,thallium limits were recalculated based on the updated criteria value of 2 µg/L.
As reasonable potential for an excursion above the chronic allowable discharge concentration was
demonstrated and the facility has a known source of total silver in its pretreatment program,the permit
total silver limits and monthly monitoring have been added to each flow tier. The City shall monitor for
total silver using a test method at least as sensitive as to be able to achieve a Practical Quantitation Level
of< 1 µg/L. Since 2021,the City had conducted monitoring using a PQL of<0.5 µg/L and is encouraged
to continue to use this level of sensitivity.
The 2020-2022 Surface Water Triennial Review proposed several amendments to the 15A NCAC 2B
.0200 rules,including changes to the freshwater dissolved selenium standard,which has been adopted
into rule. When the draft method was prepared for this facility's permit renewal, a procedure to
incorporate the new dissolved selenium standard was not developed. While a procedure is still in
development,the need for selenium requirements in the permit has been reevaluated. At least one
significant industrial user identified in the City's pretreatment program has a local limit in its industrial
user permit for total selenium. Considering there is at least one known source of selenium entering the
facility and the standard for selenium has changed, additional selenium requirements have been added to
the permit. The data available are for total selenium and the new standard is for dissolved selenium. At
present,no translator exists for dissolved to total selenium in freshwater. The EPA Form 2A NPDES
application requires selenium be reported for the application as "total recoverable,"which is reflected in
the Effluent Pollutant Scan special condition of the permit.Additionally,the acute criterion applied for
selenium is for total selenium,not dissolved. Until a translator is identified for dissolved to total selenium,
a translator of 1.0 is assumed and total selenium data will be collected and applied against the dissolved
and total selenium limits in the permit. The City reported effluent total selenium using an insufficiently
sensitive test method on 7 of the 46 samples conducted during the period reviewed. The City shall
monitor for total selenium using a test method at least as sensitive as to be able to achieve a Practical
Quantitation Level of<5 µg/L or lower.
If applicable, attach a spreadsheet of the RPA results as well as a copy of the Dissolved Metals
Implementation Fact Sheet for freshwater/saltwater to this Fact Sheet. Include a printout of the RPA
Dissolved to Total Metal Calculator sheet if this is a Municipality with a Pretreatment Program.
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Toxicity Testing Limitations
Permit limits and monitoring requirements for Whole Effluent Toxicity(WET)have been established in
accordance with Division guidance(per WET Memo, 8/2/1999). Per WET guidance, all NPDES permits
issued to Major facilities or any facility discharging"complex"wastewater(contains anything other than
domestic waste)will contain appropriate WET limits and monitoring requirements,with several
exceptions. The State has received prior EPA approval to use an Alternative WET Test Procedure in
NPDES permits,using single concentration screening tests,with multiple dilution follow-up upon a test
failure.
Describe proposed toxicity test requirement: This is a Major POTW, and a chronic WET limit will
continue on a quarterly frequency at an effluent concentration defined as follows:
Table 3. effluent concentration for chronic WET limit
Permitted flow 3.0 MGD 4.0 MGD 6.0 MGD
Effluent concentration 20.0% 24.6% 33.0%
Mercury Statewide TMDL Evaluation
There is a statewide TMDL for mercury approved by EPA in 2012. The TMDL target was to comply
with EPA's mercury fish tissue criteria(0.3 mg/kg) for human health protection. The TMDL established a
wasteload allocation for point sources of 37 kg/year(81 lb/year), and is applicable to municipals and
industrial facilities with known mercury discharges. Given the small contribution of mercury from point
sources(-2%of total load),the TMDL emphasizes mercury minimization plans (MMPs)for point source
control. Municipal facilities>2 MGD and discharging quantifiable levels of mercury(>1 ng/1)will
receive an MMP requirement. Industrials are evaluated on a case-by-case basis, depending if mercury is a
pollutant of concern. Effluent limits may also be added if annual average effluent concentrations exceed
the WQBEL value(based on the NC WQS of 12 ng/1) and/or if any individual value exceeds a TBEL
value of 47 ng/l.
Table 3. Mercury Effluent Data Summary
2019 2020 2021 2022 2023
#of Samples 3 4 4 5 3
Annual Average Conc. n /L 2.7 3.2 7.6 3.1 3
Maximum Conc.,n L 2.94 4.62 23.2 5.18 3.29
TBEL,n /L 47
WQBEL,n /L 1 61.0 @ 3.0 MGD,48.7 @ 4.0 MGD and 36.5 6.0 MGD
Describe proposed permit actions based on mercury evaluation: Since no annual average mercury
concentration exceeded the WQBEL, and no individual mercury sample exceeded the TBEL at any flow
tier,no mercury limit is required. However, since the facility is>2 MGD and reported quantifiable levels
of mercury(> 1 ng/1), the mercury minimization plan(MMP) condition has been maintained.
Other TMDL/Nutrient Management Strategy Considerations
If applicable, describe any other TMDLs/Nutrient Management Strategies and their implementation
within this permit: NA
Other WQBEL Considerations
If applicable, describe any other parameters of concern evaluated for WQBELs: As required by Session
Law 2018-5, Senate Bill 99, Section 13.1(r), every applicant shall submit documentation of any additional
pollutants for which there are certified methods with the permit application if their discharge is
anticipated via a Chemical Addendum to NPDES Application table. As an attachment to the permit
application,the City informed the Division that no monitoring for additional pollutants has been
conducted and therefore no additional pollutants of concern have been identified.
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If applicable, describe any special actions (HQW or ORW) this receiving stream and classification shall
comply with in order to protect the designated waterbody:NA
If applicable, describe any compliance schedules proposed for this permit renewal in accordance with
15A NCAC 2H.0107(c)(2)(B), 40CFR 122.47, and EPA May 2007 Memo: NA
If applicable, describe any water quality standards variances proposed in accordance with NCGS 143-
215.3(e) and 15A NCAC 2B.0226 for this permit renewal:NA
7. Technology-Based Effluent Limitations (TBELs)
Municipals (if not applicable,delete and skip to Industrials)
Are concentration limits in the permit at least as stringent as secondary treatment requirements (30 mg/l
BODS/TSS for Monthly Average, and 45 mg/l for BODS/TSS for Weekly Average). YES
If NO,provide a justification for alternative limitations (e.g., waste stabilization pond). NA
Are 85%removal requirements for BOD51TSS included in the permit? YES
If NO,provide a justification (e.g., waste stabilization pond). NA
8. Antidegradation Review (New/Expanding Discharge):
The objective of an antidegradation review is to ensure that a new or increased pollutant loading will not
degrade water quality. Permitting actions for new or expanding discharges require an antidegradation
review in accordance with 15A NCAC 213.0201. Each applicant for a new/expanding NPDES permit
must document an effort to consider non-discharge alternatives per 15A NCAC 2H.0105(c)(2). In all
cases, existing instream water uses and the level of water quality necessary to protect the existing use is
maintained and protected.
If applicable, describe the results of the antidegradation review, including the Engineering Alternatives
Analysis (EAA) and any water quality modeling results:NA
9. Antibacksliding Review:
Sections 402(o)(2) and 303(d)(4)of the CWA and federal regulations at 40 CFR 122.44(1)prohibit
backsliding of effluent limitations in NPDES permits. These provisions require effluent limitations in a
reissued permit to be as stringent as those in the previous permit,with some exceptions where limitations
may be relaxed(e.g.,based on new information,increases in production may warrant less stringent TBEL
limits, or WQBELs may be less stringent based on updated RPA or dilution).
Are any effluent limitations less stringent than previous permit(YES/NO): YES
If YES, confirm that antibacksliding provisions are not violated: Based on the reasonable potential
analysis predicting a maximum effluent total molybdenum concentration that is greater than half of the
allowable discharge concentration based on state water quality standards (i.e.no reasonable potential
shown),total molybdenum limits have been removed and monthly monitoring reduced to quarterly at the
3.0 MGD and 4.0 MGD flow tiers. The total molybdenum limits have been maintained at the 6.0 MGD
flow tier. Monitoring of the analyte at the 3.0 MGD and 4.0 MGD flow tier provides data to evaluate
molybdenum levels when the facility enters the 6.0 MGD operation tier.
10. Monitoring Requirements
Monitoring frequencies for NPDES permitting are established in accordance with the following
regulations and guidance: 1) State Regulation for Surface Water Monitoring, 15A NCAC 2B.0500;2)
NPDES Guidance,Monitoring Frequency for Toxic Substances(7/15/2010 Memo); 3)NPDES Guidance,
Reduced Monitoring Frequencies for Facilities with Superior Compliance(10/22/2012 Memo); 4)Best
Professional Judgement(BPJ). Per US EPA(Interim Guidance, 1996),monitoring requirements are not
considered effluent limitations under Section 402(o)of the Clean Water Act, and therefore anti-
backsliding prohibitions would not be triggered by reductions in monitoring frequencies.
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For instream monitoring,refer to Section 4.
The current permit does not require effluent conductivity monitoring. As the facility receives industrial
wastewater and in accordance with 15A NCAC 02B .0508, effluent conductivity monitoring has been
added to the permit at a frequency of daily at all flow tiers. The current permit also does not require
effluent temperature monitoring. In accordance with 15A NCAC 02B .0508, effluent temperature
monitoring has been added to the permit at a frequency of daily at all flow tiers.
To better identify the triggers for activation of expanded operational tiers, a requirement to report the
annual average daily flow for each calendar year has been added to the permit along with a special
condition for notification of the Central and Regional Offices.
To identify PFAS concentrations in waters classified as Water Supply(WS)waters,monitoring
requirements are to be implemented in permits with pretreatment programs that discharge to WS waters.
While there are no WS waters designated by the Division downstream of the discharge,the discharge
point is approximately 8.3 miles upstream of the border between North Carolina and South Carolina.
Since all waters in South Carolina are deemed suitable for drinking water uses with appropriate treatment,
and to ensure PFAS contamination does not cross State lines, and as the Pilot Creek WWTP has a
pretreatment program,monitoring of PFAS chemicals has been added to the permit. Currently,EPA
Method 1633 is in its 4th draft form and not yet published in the Federal Register as a final methodology.
As the Pilot Creek WWTP accepts influent wastewater from several industrial facilities that are potential
sources of PFAS via the approved pretreatment program, and since a finalized EPA method for sampling
and analyzing PFAS in wastewater is not currently available, effluent PFAS monitoring has been added to
the permit at a quarterly frequency using the Draft Method 1633.Upon evaluation of laboratory
availability and capability to perform the draft analytical method, it was determined that the sampling
may be conducted using the 3rd draft method 1633 or more recent. Sampling using the draft method shall
take effect the first full calendar quarter following 6 months after the effective date of the permit to
provide the City time to select a laboratory, develop a contract, and begin collecting samples. Effective 6
months after EPA has a final wastewater method in 40 CFR136 published in the Federal Register,the
City shall conduct effluent monitoring using the Final Method 1633 and is no longer required to conduct
effluent monitoring.
In addition to monitoring at the wastewater management facility, the City shall identify and monitor SIUs
suspected of discharging PFAS compounds [see A.(8.)(c)(i.)] within 6 months of the permit effective
date. The City shall update their Industrial Waste Survey- (IWS)to identify indirect dischargers of PFAS
contributing to concentrations experienced at the Pilot Creek WWTP. A summary of information learned
during this process will be provided as part of the 2024 Pretreatment Annual Report(PAR). Within 6
months of completion of the IWS, the City shall begin sampling of indirect dischargers identified as
potential PFAS sources. Sampling conducted at SIUs and indirect dischargers shall also be conducted at a
quarterly frequency. This is a summary of the PFAS requirements. For a detailed outline of the specific
PFAS requirements, see Special Condition A.(8.)PFAS Monitoring Requirements.
As the Pilot Creek WWTP accepts influent wastewater from several industrial facilities that are potential
sources of 1,4-dioxane via the approved pretreatment program, as no additional sampling has been
conducted for 1,4-dioxane at this facility as identified in the chemical addendum submitted by the City,
and as the facility discharges above the NC/SC state border line,monthly effluent monitoring for 1,4-
dioxane as well as a 1,4-dioxane reopener condition have been added to the permit.After a 24-month
sampling period,the Permittee may request the Division conduct a review of submitted data for
assessment and approval of a 1,4-dioxane monitoring frequency reduction from monthly to quarterly.
Page 10 of 15

11. Electronic Reporting Requirements
The US EPA NPDES Electronic Reporting Rule was finalized on December 21, 2015. Effective
December 21, 2016,NPDES regulated facilities are required to submit Discharge Monitoring Reports
(DMRs) electronically. While NPDES regulated facilities would initially be required to submit additional
NPDES reports electronically effective December 21, 2020, EPA extended this deadline from December
21,2020,to December 21,2025. The current compliance date, effective January 4,2021,was extended as
a final regulation change published in the November 2, 2020 Federal Register. This permit contains the
requirements for electronic reporting, consistent with Federal requirements.
12. Summary of Proposed Permitting Actions:
Table 4. Current Permit Conditions and Proposed Changes Outfall 001
Parameter Current Permit Proposed Change Basis for Condition/Change
Flow MA 3.0 MGD with expansion No change 15A NCAC 2B .0505
to 4.0 MGD and 6.0 MGD
Annual No requirement Report annually For tracking operational flow tier
Average Special Condition triggers
Flow A.(9.)Operational
Flow Tier Notice
BOD5 All flow tiers: No change Summer: WQBEL. 1989 Level B
Summer: Model,Based on protection of DO
MA 28 mg/1 standard.
WA 12 mg/1 Winter: TBEL. Secondary treatment
Winter: standards/40 CFR 133 / 15A NCAC
MA 30 mg/l 2B .0406.
WA 45 mg/1
Monitor and Report Daily Surface Water Monitoring, 15A
NCAC 2B. 0500
NH3-N All flow tiers: No change WQBEL. 2023 WLA for.6.0 MGD
Summer: flow tier—applied to all flow tiers;
MA 2.6 mg/1 Surface Water Monitoring, 15A
WA 7.8 mg/l NCAC 2B. 0500
Winter:
MA 8.9 mg/l
WA 26.7 mg/l
Monitor and report Dail
TSS All flow tiers: No change TBEL. Secondary treatment
MA 30 mg/l standards/40 CFR 133 / 15A NCAC
WA 45 mg/l 2B .0406; Surface Water
Monitor and report Daily Monitoring, 15A NCAC 2B. 0500
Fecal All flow tiers: No change WQBEL. State WQ standard, 15A
coliform MA 200/100ml NCAC 2B .0200; Surface Water
WA 400/100ml Monitoring, 15A NCAC 2B. 0500
Monitor and report Dail
Temperature No requirement All flow tiers: Based on instream temperature data
Monitor and Report review; Surface Water Monitoring,
Daily 15A NCAC 2B. 0508
DO All flow tiers: No change WQBEL. State WQ standard, 15A
>5 mg/1 NCAC 2B .0200; 15A NCAC 02B
Monitor and Report Daily .0500
Page 11 of 15

pH All flow tiers: No change WQBEL. State WQ standard, 15A
6—9 SU NCAC 2B .0200; 15A NCAC 02B
Monitor and Report Daily .0500
Total All flow tiers: No change WQBEL. 2023 WLA. Surface
Residual DM 28 ug/L Water Monitoring, 15A NCAC 2B.
Chlorine Monitor and Report Daily 0500—active if chlorination is used
TKN No requirement All flow tiers: For calculation of TN
Monitor and Report
Quarterly
NO2+NO3 No requirement All flow tiers: For calculation of TN
Monitor and Report
Quarterly
Total All flow tiers: No change Surface Water Monitoring, 15A
Nitrogen Monitor and Report Quarterly NCAC 2B. 0500
Total All flow tiers: No change Surface Water Monitoring, 15A
Phosphorus Monitor and Report Quarterly NCAC 2B. 0500
Conductivity All flow tiers: All flow tiers: Receives industrial waste; Surface
No requirement Monitor and Report Water Monitoring, 15A NCAC 2B.
Daily 0500
Total All flow tiers: No changes Hardness-dependent dissolved
Hardness Quarterly monitoring metals water quality standards
Upstream and in Effluent approved in 2016
Total 3.0 MGD and 4.0 MGD flow No change for 3.0 WQBEL—4.0 MGD and 6.0 MGD
Arsenic tiers: MGD. flow tiers. Based on RPA; RP
Monitor and Report Quarterly No change for 6.0 shown-apply Monthly Monitoring
6.0 MGD flow tier: MGD limits. with Limit.
MA 184.2 ug/L 4.0 MGD flow tier:
DM 913.6 ug/L MA 271.3 ug/L Effluent Monitoring—3.0 MGD.
Monitor and Report Monthly DM 1,200.4 ug/L Based on RPA;No RP ,Predicted
Monitor and Report Max >50%of Allowable Cw-
Monthly apply Quarterly Monitoring
Total No requirement All flow tiers: Surface Water Monitoring. Based
Cadmium Monitor and Report on RPA;No RP ,Predicted Max >
Quarterly 50%of Allowable Cw-apply
Quarterly Monitoring
Total All flow tiers: No change Surface Water Monitoring. Based
Cyanide Monitor and Report Quarterly on RPA;No RP ,Predicted Max >
50%of Allowable Cw-apply
Quarterly Monitoring
Chlorides No requirement for 3.0 MGD No change 3.0 MGD and 4.0 MGD flow tiers:
and 4.0 MGD flow tiers. Based on RPA;No RP, Predicted
6.0 MGD flow tier: Max<50%of Allowable Cw-No
Monitor and Report Quarterly Monitoring required
Surface Water Monitoring—6.0
MGD. Based on RPA;No RP ,
Predicted Max >50%of Allowable
Cw-apply Quarterly Monitoring
Page 12 of 15

Total 3.0 MGD flow tier: Remove limits at 3.0 Surface Water Monitoring-3.0
Molybdenum MA 10.2 mg/L MGD and 4.0 MGD MGD and 4.0 MGD. Based on
DM 10.2 mg/L flow tiers and reduce RPA;No RP , Predicted Max >_
4.0 MGD flow tier: monitoring from 50%of Allowable Cw-apply
MA 8.13 mg/L monthly to quarterly. Quarterly Monitoring
DM 8.13 mg/L WQBEL-6.0 MGD. Based on
6.0 MGD flow tier: No change at 6.0 RPA; RP shown-apply Monthly
MA 6.1 mg/L
DM 6.1 mg/L MGD flow tier. Monitoring with Limit.
All flow tiers:
Monitor and Report Monthly
Total 3.0 MGD flow tier: 3.0 MGD flow tier: WQBEL. Based on known source
Selenium MA 25.4 ug/L MA 15.8 ug/L of selenium in pretreatment
DM 245.0 ug/L DM 245.0 ug/L program and updated selenium
4.0 MGD flow tier: 4.0 MGD flow tier: standard- 15A NCAC 02B
MA 20.3 ug/L MA 12.6 ug/L .0211(11)(d)-Lotic Water Column
DM 197.7 ug/L DM 197.7 ug/L
6.0 MGD flow tier: 6.0 MGD flow tier:
MA 15.2 ug/L MA 9.4 ug/L
DM 150.5 ug/L DM 150.5 ug/L N6h'
All flow tiers: All flow tiers:
Monitor and Report Monthly Monitor and Report
Monthly
Total 3.0 MGD flow tier: No change WQBEL. Based on RPA;RP shown
Thallium MA 10.2 ug/L -apply Monthly Monitoring with
DM 10.2 ug/L Limit.
4.0 MGD flow tier:
MA 8.13 ug/L
DM 8.13 ug/L
6.0 MGD flow tier:
MA 6.1 ug/L
DM 6.1 ug/L
All flow tiers:
Monitor and Report Monthly
Total Silver No requirement 3.0 MGD flow tier: WQBEL. Based on known source
MA 0.31 ug/L of silver in pretreatment program
DM 4.60 ug/L and results of RPA: RP shown-
4.0 MGD flow tier: apply Monthly Monitoring with
MA 0.24 ug/L Limit.
DM 4.50 ug/L
6.0 MGD flow tier:
MA 0.18 ug/L
DM 4.42 ug/L
All flow tiers:
Monitor and Report
Monthly
1,4-Dioxane No requirement All flow tiers: Based on PT Program-industrial
Monitor and Report facilities linked to 1,4-dioxane;
Monthly and Discharge above NC/SC border
reopener condition;
24-month sampling
reassessment
Page 13 of 15

All flow tiers:
See Special Evaluation of PFAS contribution:
PFAS No requirement Condition A.(8.) pretreatment facility; Discharge
PFAS Monitoring above NC/SC border
Requirements and
Pretreatment
Toxicity Test 3.0 MGD flow tier: No change WQBEL. No toxics in toxic
Chronic limit, 20.0%effluent amounts. 15A NCAC 213.0200 and
4.0 MGD flow tier: 15A NCAC 213.0500
Chronic limit,24.6% effluent
6.0 MGD flow tier:
Chronic limit, 33.0%effluent
Effluent Three times per permit cycle No change; 40 CFR 122
Pollutant conducted in 2025,
Scan 2026,2027
Instream Monitor and Report for No change Surface Water Monitoring, 15A
Monitoring temperature, dissolved NCAC 2B. 0508; Instream
oxygen, and conductivity I monitoring review
3/week during June through
September and 1/week during
remainder of the year
Mercury MMP Special Condition No change; Condition Consistent with 2012 Statewide
Minimization maintained. Mercury TMDL Implementation
Plan(MMP) multiple detections during review
Electronic Electronic Reporting Special No change In accordance with EPA Electronic
Reporting Condition I I Reporting Rule 2015.
MGD—Million gallons per day,MA- Monthly Average,WA—Weekly Average,DM—Daily Max
13. Public Notice Schedule:
Permit to Public Notice: 12/1/2023
Per 15A NCAC 2H .0109 & .0111, The Division will receive comments for a period of 30 days following
the publication date of the public notice.Any request for a public hearing shall be submitted to the
Director within the 30 days comment period indicating the interest of the party filing such request and the
reasons why a hearing is warranted.
14. NPDES Division Contact
If you have any questions regarding any of the above information or on the attached permit,please
contact Nick Coco at(919) 707-3609 or via email at nick.cocokdeq.nc.gov.
15. Fact Sheet Addendum (if applicable):
The draft was submitted to the City of Kings Mountain,EPA Region IV, and the Division's Mooresville
Regional Office,Aquatic Toxicology Branch, Operator Certification Program,Pretreatment Coordinator
and South Carolina DHEC for review. Comments were received from the Southern Environmental Law
Center(SELC) on January 5,2024. The comments and Division responses are provided in the attached
addendum to the fact sheet. In addition to the comments, it was noted during the final review process that
a typographical error was made in the draft permit regarding the units for total molybdenum(drafted as
µg/L but should be mg/L). This has been corrected.
Page 14 of 15

Were there any changes made since the Draft Permit was public noticed(Yes/No):YES
If Yes, list changes and their basis below:
• As reasonable potential for an excursion above the chronic allowable discharge concentration was
demonstrated and the facility has a known source of total silver,the permit has been revised to
include total silver limits at all flow tiers accompanied by monthly monitoring [See A.(L),A.(2.)
and A.(3.)].
• As the Division has adopted new freshwater selenium standards and the facility has a known
source of total selenium,the permit has been revised to include total selenium limits at all flow
tiers accompanied by monthly monitoring [See A.(L),A.(2.)and A.(3.)].
• A typographical error has been corrected regarding the units for total molybdenum limits.
Based on these substantial changes,the revised draft permit has been submitted for a second public
notice.
16. Fact Sheet Attachments (if applicable):
• RPA Spreadsheet Summary
• NPDES Implementation of Instream Dissolved Metals Standards—Freshwater Standards
• NH3/TRC WLA Calculations
• BOD&TSS Removal Rate Calculations
• Mercury TMDL Calculations
• Additional information Requested
• Chemical Addendum
• WET Testing and Self-Monitoring Summary
• Public comments and responses
Page 15 of 15

LOCAL'100
StarNews I The Dispatch I Times-News PO Box 631697 Cincinnati,OH 45263-1697
Sun Journal I The Daily News I The Star
The Free Press I Gaston Gazette
Pulic Notice
PROOF OF PUBLICATION North Carolina
Environmental Management
Commission/NPDES Unit
Wren Thedford 1617 Mail Service Center
Nc Division Of Water uali Attn:Wren Thedford Raleigh, to 27699-1617
Q tY� Notice of Intent to Issue a
1617 Mail Service CTR NPDES Wastewater Permit
Raleigh NC 27699-1600 NCO020737 Pilot Creek
WWTP The North Carolina
Environmental Management
Commission proposes to
issue a NPDES wastewater
STATE OF NORTH CAROLINA, COUNTY OF CLEVELAND discharge permit to the
person(s) listed below. Writ-
ten comments regarding the
The Star, a newspaper printed and published in the city of Shelby, proposed permit will be
and of general circulation in the County of Cleveland,State of accepted 30 days after the
publish date of this notice.
North Carolina,and personal knowledge of the facts herein state The Director of the NC Divi-
and that the notice hereto annexed was Published in said sion of Water Resources
newspapers in the issue dated: hea hearing should�the a be lea
significant degree of public
12/O1/2023 interest. Please mail
comments and/or informa-
tion requests To DWR at the
and that the fees charged are legal. above address. Interested
persons may visit the DWR
Sworn to and subscribed before on 12/01/2023 at 512 N. Salisbury Street,
Raleigh, NC 27604 to review
the information on file. Addi-
tional information on NPDES
Permits and this notice may
be found on our website:
https://deq.nc.gov/public-
notices-hearings,or by call-
ing [phone].The City of
Kings Mountain [PO Box 429,
Kings Mountain, NC 280861
has requested renewal of
NPDES permit NCO020737 for
its Pilot Creek Wastewater
Treatment Plant, located in
Cleveland County. This
Legal Clerk permitted facility discharges
treated municipal and indus-
trial trial wastewater to Buffalo
Creek,a class C water in the
,State of WI,Count of Brown Broad River Basin.
Notary, Y Currently BOD, ammonia,
fecal coliform, dissolved
oxygen, pH, total residual
M expires chlorine, total arsenic, total
Y COmmlSlOn P molybdenum, and total thal-
lium are water quality
Publication Cost: $91.50 limited. This discharge may
Order No: 9570411 affect future allocations in
#of Copies: this segment of Buffalo
Customer No: 745425 1 Creek.
12/1/23 9570411
PO#: NCO020737
THIS IS NOT AN INVOICE!
Please do not use this form far pa ment remittance.
MARIAH VERHAGEN
Notary Public
State of Wisconsin
Page 1 of 1

SOUTHERN 48 Patton Avenue,Suite 304 Telephone [phone]
ENVIRONMENTAL Asheville,NC 28801 Facsimile 828-258-2024
LAW
CENTER
January 5, 2024
Via Mail and Electronic Submission
Nick Coco
Environmental Engineer
NCDEQ-DWR
Water Quality Permitting Section
1617 Mail Service Center
Raleigh,NC 27699-1617
Re: Comments on NPDES Wastewater Permit NCO020737 Pilot Creek WWTP
Dear Mr. Coco,
Thank you for the opportunity to comment on the draft NPDES Wastewater Permit
NCO020737 for the Pilot Creek Wastewater Treatment Plant(the"Draft Permit").We submit these
comments on behalf of the Southern Environmental Law Center ("SELC"), MountainTrue, and
the Broad Riverkeeper.
We appreciate the hard work that DEQ put into crafting the Draft Permit and creating the
opportunity for public comment. We especially appreciate DEQ's efforts to address PFAS
pollution by inserting testing and reduction requirements into the Draft Permit. As currently
constituted, the Draft Permit requires the City of Kings Mountain (the "City" or "Permiee") to
collect PFAS monitoring data from industrial users and update the permits for these industrial
users"to address PFAS discharges."' These data must be collected relatively quickly and must be
shared in publicly available pretreatment reports. Together, these provisions will go a long way
toward reducing PFAS pollution in the Buffalo Creek watershed.
Other portions of the Draft Permit, however, do not do enough to protect the existing uses
of Buffalo Creek, as well as downstream environmental justice communities. These shortcomings
must be addressed in a revised permit.
I. DEQ must account for background conditions.
Binding federal regulations require DEQ to determine if a discharge "will cause, have the
reasonable potential to cause,or contribute to an excursion above any State water quality standard,
including State narrative criteria for water quality."2 Put differently, DEQ must analyze "whether
a discharge, alone or in combination with other sources of pollutants to a waterbody. . . could lead
1 Draft Permit at 13.
2 40 C.F.R. § 122.44(d)(1)(i)(emphasis added);see also 15A N.C.Admin.Code 02B .0203 (requiring DEQ to
design"[w]ater quality based effluent limitations and management practices for direct or indirect discharges of
waste. . . such that the water quality standards and best usage of receiving waters and all downstream waters will
not be impaired").
Charlottesville Chapel Hill Atlanta Asheville Birmingham Charleston Nashville Richmond Washington,DC

to an excursion above an applicable water quality standard."3 To that end, DEQ must first
"determine the critical background concentration of the pollutant of concern in the receiving water
before the discharge . . . to ensure that any pollutant limitations derived are protective of the
designated uses" for those waters.4
Despite the clear requirement and need to analyze background conditions, DEQ's Draft
Permit declines to do so. Instead, it assumes that background concentrations of "all toxicants
except" ammonia are "zero."5 That is a questionable assumption. Directly upstream of the outfall
is another permitted facility using chlorine for water treatment.6 Also located upstream within the
upper Buffalo Creek watershed are more than fifty permitted residual solids disposal sites for
various towns and cities.' Many of these permits allow for land application of solid wastes
containing heavy metals and toxic pollutants, including arsenic, cadmium, copper, lead, mercury,
molybdenum, nickel, selenium, and zinc.$ At least some of this pollution is likely washing
downstream during residual application, irrigation, and storm events.
DEQ must redo its reasonable-potential analyses to account for background pollution
levels.9 DEQ has effectively acknowledged as much, noting that it is engaged in "on-going"
discussions with EPA about "how best to address background concentrations."10 One simple
solution would be to sample in-stream pollution levels just upstream of the outfall." If DEQ is
unsure about how to incorporate this information into its reasonable-potential analyses, EPA's
Permit Writers' Manual provides several suggested approaches for incorporating"background in-
stream pollutant concentration[s]" into a reasonable-potential determination.12
II. DEQ must analyze whether a temperature limit is appropriate.
North Carolina law provides that the temperature of Buffalo Creek, as class C mountain
waters, is "not to exceed 2.8 degrees C (5.04 degrees F) above the natural water temperature, and
in no case to exceed 29 degrees C (84.2 degrees F)."13 This standard has two parts—a delta limit
3 U.S.EPA,NPDES Permit Writers' Manual at 6-23 (2010) [hereinafter"Permit Writers'Manual"];see also 40
C.F.R. § 122.44(d)(1)(ii)(requiring DEQ to"account for existing controls on point and nonpoint sources of
pollution"in the waterbody when conducting a reasonable-potential analysis).
4 Permit Writers'Manual at 6-19.
5 Fact Sheet at 37.
6 NPDES Permit No.NC0079740(Dec. 7,2018),
https:Hedocs.deq nc.gov/WaterResources/DocView.aspx?id=777598&dbid=O&repo=WaterResources&searchid=95
9657c4-ffl 7-465b-a3b5-427e40486e50.
7 N.C.Dep't of Env't Quality,DWR Permits Map,https:Hdata-ncdenr.opendata.arcgis.com/apps/ncdenr::permits-
map/explore.
8 See, e.g.,NPDES Permit No.WQ0001793(Dec. 18,2020),
https:Hedocs.deq nc.gov/WaterResources/DocView.aspx?id=1401016&dbid=O&repo=WaterResources&searchid=ff
fl bc7f-2669-4b61-bb01-c56074daabfc.
9 Testing for in-stream hardness upstream of the discharge cannot fill this void, since only certain metals are
hardness dependent.
to Fact Sheet at 37.
11 We recommend sampling on Buffalo Creek downstream of the confluence with Muddy Fork and Potts Creek.
Sampling on Buffalo Creek above the confluence would inappropriately skew the result by omitting potential
pollutants contributed by Muddy Fork and Potts Creek.
12 Permit Writers' Manual at 6-23 to-31.
is 15A N.C.Admin Code 02B .0211(18).
2

and an absolute limit. The delta limit prohibits an increase attributable to a "direct or indirect"
discharger of more than 2.8 °C above the natural water temperature.14 It does not require the
discharger to release "heated" liquids specifically; rather, it broadly prohibits dischargers from
adding effluent that increases the "natural" water temperature of the stream above a certain
threshold.15 Likewise, the absolute limit provides that temperature shall "in no case" exceed
29 °C—regardless of whether thermal dischargers are present.16 Therefore, both of these limits
apply to the Pilot Creek discharge as DEQ impliedly concedes.17
Yet DEQ's Draft Permit includes no temperature limit. Instead, it only requires daily
monitoring and reporting.18 The Fact Sheet suggests this is because downstream temperatures were
never more than 2.8 °C above upstream temperatures 19 and downstream temperatures never
exceeded 29 °C during the study period. However, the Fact Sheet does not contain a reasonable-
potential analysis to support this argument. What's more, the values the Fact Sheet does report
suggest that the City may be bumping up against both limits;downstream temperatures were 1.5 °C
higher on average and the maximum downstream temperature topped 28 °C. Given these high
values, it seems likely that a predictive analysis of the Pilot Creek discharge would show it has
"the reasonable potential to cause, or contribute to an excursion above" the state temperature
standard.20 DEQ must conduct this analysis in a revised draft permit.
III. DEQ should reevaluate its approach to total residual chlorine.
North Carolina's acute limit for total residual chlorine is 17 ug/L.21 The Draft Permit
acknowledges this limit and sets a daily maximum limit of 28 ug/L across all flow levels to protect
against acute toxicity.22 Nevertheless,the Draft Permit goes on to say that DEQ"shall consider all
effluent total residual chlorine values reported below 50 ug/L to be in compliance with the
permit. ,23 Apparently, this is because of"analytical issues"with analyzing chlorine levels below
14 Id. 02B .0203 ("Water quality based effluent limitations and management practices for direct or indirect
discharges of waste or for other sources of water pollution shall be developed by the Division such that the water
quality standards and best usage of receiving waters and all downstream waters will not be impaired.").
15 For example,if the natural water temperature of a stream is 15°C,and a discharger adds"room temperature"
effluent(around 20°C)to that stream,the temperature of the receiving waters will increase.While the discharger
may not be deliberately heating the receiving waters,the result is the same.
16 15A N.C.Admin Code 02B .0205 ("The adopted water quality standards relate to the condition of waters as
affected by the discharge of sewage,industrial wastes,or other wastes including those from nonpoint sources and
other sources of water pollution.").
"See Fact Sheet at 4.
18 Draft Permit at 3,5,7.
19 This may be a product of DEQ's sample design.According to the Fact Sheet,the downstream sampling site is 2.4
miles downstream of the outfall.Fact Sheet at 3. That is an extremely generous mixing zone.
20 In its reasonable-potential analyses of metal toxicants,DEQ consistently predicted that the maximum likely
concentration value was higher than the maximum recorded value;it is hard to see why temperature should be
treated any differently.
21 15A N.C.Admin. Code 02B .0211(3).
22 Draft Permit at 3,5,7.
23 Id. at 4,6,8.
3

50 ug/L.24 Due to these issues, DEQ has been inserting similarly capacious language into NPDES
permits since at least 2008.
DEQ should assess if its 15-year-old assumptions are outdated. In the intervening years,
scientists have developed numerous technologies to better assess chlorine concentrations and
eliminate interference.25 DEQ has also hinted that analytical difficulties no longer prevent accurate
measurements of chlorine below 50 ug/L.26 In fact, DEQ's Fact Sheet for Pilot Creek lists thirty-
five different violations of the 28 ug/L standard over the past five years—indicating that analytical
difficulties may not prevent accurate measurements below 50 ug/L.27 If that is the case,it is unclear
why DEQ is continuing to allow exceedances of the permitted residual chlorine level. After all,
DEQ lacks the authority to issue NPDES permits that do not ensure compliance with water quality
standards, including the total residual chlorine standard.28
DEQ must either explain in a revised draft permit and fact sheet why its de facto 50 ug/L
limit remains necessary or enforce North Carolina's actual standard for total residual chlorine.
IV. DEQ must set a chronic permit limit for silver.
When DEQ determines "that a discharge causes, has the reasonable potential to cause, or
contributes to an in-stream excursion above the allowable ambient concentration of a State numeric
criteria within a State water quality standard for an individual pollutant, the permit must contain
effluent limits for that pollutant. ,29 DEQ has no authority to issue NPDES permits that do not
ensure compliance with water quality standards.30 Where draft permits fail to ensure compliance,
they must be revised.
DEQ must revise the Draft Permit to include a chronic limit for silver. The chronic standard
for silver in class C waters is 0.06 ug/L.31 Data submitted by the City show that the facility's
2'Fact Sheet at 5;see also N.C.Dep't of Env't&Nat.Res., Total Residual Chlorine SO ug/L Compliance Level
(May 1,2008),https://www.deq nc.gov/coastal-management/gis/data/esmp-data/2010/july/npdes/trccomplevel-
20090710-dwq-swp-npdes/download.
25 See, e.g.,Robert Wilson et al.,Continuous Chlorine Detection in Drinking Water and a Review of New Detection
Methods,63 Johnson Matthey Tech.Rev. 103 (2019);Peng Li, Concise Review on Residual Chlorine Measurement:
Interferences and Possible Solutions,323 J. of Cleaner Prod. (2021);Peng Li.et al.,Micro particles as Interfering
Substances in Coloimetric Residual Chlorine Measurement,207 Ecotoxicology&Env't Safety(2021);Vt.Dep't of
Env't Conservation, Chlorine Residual,
https://dec.vennont.gov/sites/dec/files/wsm/wastewater/docs/Section%209_Total%20Residual%2OChlorine.pdf
(describing low-range colorimetric analyses with a range of 2 to 500 ug/L)
"See Compliance Evaluation Inspection Report,NPDES Permit No.NCO020737(Mar.24,2022)(criticizing Pilot
Creek's failure to show its chlorine curve could meet the low chlorine limit of 10 ug/L)
27 Fact Sheet at 40-42.
28 See 33 U.S.C. § 1311(b)(1)(C)(requiring NPDES permits to include limitations"necessary to meet water quality
standards");40 C.F.R. § 122.44(d)(1)(same).
29 40 C.F.R. § 122.44(d)(1)(iii)(emphasis added);see also Permit Writers' Manual at 6-31 ("If a permit writer has
determined that a pollutant or pollutant parameter is discharged at a level that will cause,have reasonable potential
to cause,or contribute to an excursion above any state water quality standard,the permit writer must develop
WQBELs for that pollutant parameter.").
"See 33 U.S.C. § 1311(b)(1)(C)(requiring NPDES permits to include limitations"necessary to meet water quality
standards");40 C.F.R. § 122.44(d)(1)(same).
31 15A N.C.Admin. Code 02B .0211(11)(d).
4

effluent topped out at 1.8 ug/L on April 15, 2021—thirty times the state standard.32 Though this
effluent is diluted by the receiving waters,DEQ's reasonable-potential analysis suggests it will not
be diluted enough. Using that analysis, DEQ calculated that the City's effluent must contain no
more than 0.305 ug/L to meet the chronic standard; however, its analysis predicted a maximum
effluent value of 4.325 ug/L.
Because DEQ not only had evidence that the City's discharge causes excursions, but also
has the reasonable potential to cause future excursions, it should have imposed a chronic silver
limit. Instead, it purported to exercise its `BPJ' 33—best professional judgment34—and required
quarterly monitoring instead. However, DEQ lacks the discretion to ignore the City's data and the
agency's own reasonable-potential analysis.35 It is required, as a matter of law,to impose a chronic
silver limit.
V. DEQ must employ the current chronic standard for selenium.
Current water quality standards for class C waters include a multi-component chronic
standard for selenium.36 In the following order of preference,DEQ must assess compliance using:
(1) fish egg/ovary tissue; (2) fish whole body or muscle tissue; or (3) water column
concentrations.31 Water-column concentrations are further divided into lentic and lotic standards
of 1.5 ug/L and 3.1 ug/L, respectively, which much be assessed using a 30-day average.38
DEQ did not assess compliance with this updated standard in the Draft Permit. Instead, it
mistakenly used the old 5 ug/L chronic standard in its analysis.39 Accordingly, it must redo its
selenium analysis.
It is unclear if the Permittee's reported data comply with the current standard. Based on the
Fact Sheet, it seems that the City sampled for selenium using water-column concentrations.
However, the Fact Sheet does not explain whether these samples were 30-day averages as the
regulation requires. DEQ must follow-up with the Permittee to determine whether their samples
post-dating the June 1, 2022 amendment to the selenium standard comply with that standard.
If DEQ has no useable data with which to assess compliance with the new selenium
standard, DEQ should engage in the qualitative approach suggested by EPA in its Permit Writers'
Manual.40 In the Manual, EPA recommends crafting a water-quality-based effluent limit by
assessing, among other factors, whether (1) the permittee has a "history of compliance problems
and toxic impacts"; (2) "[p]oint and nonpoint source controls" in the watershed; (3) "[s]pecies
"Fact Sheet at 25.
33 Id. at 30.
34 In the Clean Water Act context,"best professional judgment"is a statutory and regulatory standard for crafting
certain technology-based effluent limitations,among other limits.See, e.g.,40 C.F.R. § 125.3(a)(2)(i)(B). It is not a
"magic"phrase that allows DEQ to avoid setting permit limits.
35 See 33 U.S.C. § 1311(b)(1)(C);40 C.F.R. § 122.44(d)(1)(iii).
" 15A N.C.Admin. Code 02B .0211(11)(d).
37 Id.
38 Id.
39 Fact Sheet at 15-17.
40 See Permit Writers'Manual at 6-30 to-3 1.
5

sensitivity data including in-stream data, adopted water quality criteria, or designated uses"; and
(4) "[d]ilution information such as critical receiving water flows or mixing zones. ,41 DEQ should
also consider environmental justice impacts, as explained below.
VI. DEQ must not backslide on permit limits for molybdenum and selenium.
The Clean Water Act("CWA")was expressly designed to"eliminat[e] the discharge of all
pollutants. ,42 To that end, the Act broadly prohibits dischargers seeking a renewed or reissued
permit from backsliding on their previous permit's effluent limits.43 Special circumstances must
be present for a permittee to qualify for an exemption from this anti-backsliding requirement.44
For effluent limitations based on state water quality standards, as is largely the case here,
relaxation of a permit requirement must be consistent with CWA Section 303(d)(4).45 That Section
provides that if water quality standards for the receiving waters are being attained, then the
"permitting standard may be revised only if such revision is subject to and consistent with the
[state's] antidegradation poliey."46
North Carolina's antidegradation policy requires DEQ to protect"existing uses"of a water
body.47 This includes both the "present and anticipated usage of waters," including "any uses not
specified by the [waterbody's] assigned classification. ,48 To ensure these uses are not degraded,
both the permittee and DEQ must follow a set of specific procedures.49
DEQ's Draft Permit relaxes permit standards for molybdenum and selenium.50 Because
the previous permit's effluent limitations for these pollutants were based on state water quality
standards, and water quality standards in Buffalo Creek are currently being attained, DEQ may
only relax the molybdenum and selenium standards "if such revision is subject to and consistent
with the [state's] antidegradation policy."51 Yet DEQ expressly declines to conduct an
antidegradation review in the Draft Permit.52 The failure to do so violates the CWA.
Backsliding on the previous permit's selenium limit is particularly inappropriate given the
circumstances here. DEQ suggests that a strict application of its reasonable-potential analysis
would require a permit limit for selenium. In other words, it predicts—based on all of the City's
data—that the Permittee is likely to violate the water quality standard for selenium. When that is
41 Id.
42 33 U.S.C. § 1311(b).
43Id. § 1342(o).
44 Id.
41 Id. § 1342(o)(1).
46Id. § 1313(d)(4).
41 15A N.C.Admin. Code 02B .0201(b).
48 Id. 02B .0201(c).
49 Id.
50 Fact Sheet at 9.
51 33 U.S.C. § 1313(d)(4).
52 Fact Sheet at 9.
6

the case, DEQ may not revise a permit to contain a less stringent standard.53 However, DEQ
sidesteps this requirement by identifying a sampling failure. Specifically, DEQ notes that the
Permittee conducted seven of its forty-six selenium samples using an insufficiently sensitive
sampling method,54 which skewed the resulting analysis. Instead of applying the precautionary
principle, DEQ exercises its "best professional judgment" and throws those seven data points out
entirely. With those data removed, DEQ then finds that, under its inappropriately circumscribed
analysis,no selenium exceedances are reasonably likely. In effect, DEQ rewards the Permittee for
conducting inadequate testing by removing permit limits for selenium. That is not an appropriate
use of the agency's"best professional judgment"—especially given the presence of environmental
justice communities in the watershed.
VII. DEQ should consider the environmental justice impacts of the Draft Permit.
Governor Cooper's Executive Order 292 requires cabinet agencies—including DEQ—to
incorporate environmental justice considerations into their decision-making and "consider public
health impacts in their permitting, policy actions, and agency programs to the furthest extent
permissible by law."55 According to the state's community mapping tool, two environmental
justice communities are located downstream of the outfall.56 Both of these communities have
significantly higher rates of cancer, heart disease, and child mortality than the state average.57
Because communities like these are often disproportionately affected by chemical and
nonchemical pollution, E.O. 292 requires DEQ to carefully assess whether its permitted limits are
acting as cumulative stressors. This means the agency must analyze background conditions, as
explained above, and err on the side of caution when setting permit limits. For example, even if
DEQ concludes that it is technically permitted to backslide on molybdenum and selenium limits
after conducting its required antidegradation analysis,58 DEQ should still think twice about
greenlighting such backsliding, knowing that two environmental justice communities may be
cumulatively impacted by any increased pollution.
VIII. Conclusion
DEQ must revise the Draft Permit and reissue it for public comment. Thank you for
consideration of this letter. Please contact or Alyson Merlin(828-258-2023; [e-mail]),
or Spencer Scheidt (828-258-2023; [e-mail]) if you have any questions regarding
these comments.
53 33 U.S.C. § 1342(o)(3)("In no event may such a permit to discharge into waters be renewed,reissued,or
modified to contain a less stringent effluent limitation if the implementation of such limitation would result in a
violation of a water quality standard. . . .")
54 Fact Sheet at 7.
55 Exec. Order 292(Oct.24,2023).
56 See N.C.Dep't of Env't Quality, Community Mapping System,
https://ncdenr.maps.arcgis.com/apps/webappviewer/index html?id=lebOfbe2bcfb4cccb3cc212af8aOb8c8.
57 Id.
56 See supra.
7

Sincerely,
Alyson Merlin,Associate Attorney
Southern Environmental Law Center
Spencer Scheidt,Associate Attorney
Southern Environmental Law Center
David Caldwell, Broad Riverkeeper
MountamTrue
8

Pilot Creek WWTP Fact Sheet Addendum NCO020737
Comments to the draft permit NC0020737, which was public noticed for 30-day comment period on
12/1/2023, were provided by the Southern Environmental Law Center (SELC) with several requests. No
comments were received from any other party. Individual comments by SELC and Division responses are
provided below.
1. Background Conditions
a. DEQ must redo its reasonable-potential analyses to account for background pollution
levels.
Response: The assumption that the background concentrations are zero is typical for all
NPDES permits written in North Carolina. When writing permits, the Division considers
stream impairments identified in the most recent 303(d) list and Integrated Report to
account for instream issues. Your comment is appreciated and noted, but the Division's
practice remains the same at this time.
2. Temperature
a. DEQ must analyze whether a temperature limit is appropriate.
Response: In the instream monitoring summary, the upstream and downstream data
were accidentally flipped, with the upstream data appearing in the downstream section
and vice versa. This has been corrected and the full dataset has been provided as an
attachment to the fact sheet. Thank you for bringing this to our attention. When
considering the data, lower temperatures were observed downstream of the facility. As
such, it was determined that additional temperature requirements are not necessary at
this time and no changes were made to temperature.
3. Total Residual Chlorine
a. DEQ should reevaluate its approach to total residual chlorine with regard to the
consideration of values reported below 50 µg/L as compliant with the permit limit.
Response:The current permitting requirements for TRC account for analytical variability.
These are typical for permits written in North Carolina and are not being revised at this
time. We appreciate the comment and will assess this in the future in collaboration with
the Water Sciences Section.
4. Total Silver Limits
a. DEQ must set a chronic permit limit for silver as the RPA shows that a data point did
exceed the chronic allowable discharge concentration. DEQ cannot disregard this data
point.
Response: While the City's sole reported value was less than the acute allowable
discharge concentration for total silver, review of the facility's industrial sources found
that at least one significant industrial user identified in the City's pretreatment program
has a local limit in its industrial user permit for total silver. As reasonable potential for an
excursion above the chronic allowable discharge concentration was demonstrated and
the facility has a known source of total silver,the permit has been revised to include total
silver limits at all flow tiers accompanied by monthly monitoring.

Pilot Creek WWTP Fact Sheet Addendum NCO020737
5. Selenium
a. DEQ must employ the current chronic standard for selenium.
Response:The 2020-2022 Surface Water Triennial Review proposed several amendments
to the 15A NCAC 2B .0200 rules, including changes to the freshwater dissolved selenium
standard, which has been adopted into rule. When the draft method was prepared for
this facility's permit renewal, a procedure to incorporate the new dissolved selenium
standard was not developed. While a procedure is still in development, the need for
selenium requirements in the permit has been reevaluated. In your comments, you'd
noted that the Division should not disregard the 7 samples reported using insufficiently
sensitive quantitation levels for total selenium. It is not the intent of the Division to
penalize permittees for laboratory issues. However,at least one significant industrial user
identified in the City's pretreatment program has a local limit in its industrial user permit
for total selenium. Considering there is at least one known source of selenium entering
the facility and the standard for selenium has changed, additional selenium requirements
have been added to the permit. The data available are for total selenium and the new
standard is for dissolved selenium. At present, no translator exists for dissolved to total
selenium in freshwater. The EPA Form 2A NPDES application requires selenium be
reported for the application as "total recoverable," which is reflected in the Effluent
Pollutant Scan special condition of the permit.Additionally,the acute criterion applied for
selenium is for total selenium, not dissolved. Until a translator is identified for dissolved
to total selenium, a translator of 1.0 is assumed and total selenium data will be collected
and applied against the dissolved and total selenium limits in the permit.
6. Anti-backsliding and Antidegradation
a. DEQ must not backslide on permit limits for molybdenum and selenium and must conduct
an antidegradation review.
Response: Review of the discharge for reasonable potential for excursions above water
quality standards was conducted during the preparation of this draft permit to examine
whether existing instream water uses and the level of water quality necessary to protect
the existing uses are being maintained. This review identified for the 3.0 MGD and 4.0
MGD flow tiers, quarterly monitoring for total molybdenum is sufficient in accordance
with reasonable potential analysis (RPA) practices. Limits for total molybdenum were
maintained at the 6.0 MGD flow tier. Monitoring for total molybdenum at the 3.0 MGD
and 4.0 MGD flow tiers allows for continual tracking of the analyte in the discharge while
the facility is not yet at an operating tier where a limit is deemed necessary.As such,this
is not considered backsliding or degradation. No changes were made from the draft
permit for total molybdenum.
7. Environmental Justice
a. DEQ should consider the environmental justice impacts of the Draft Permit and consider
background concentrations for the chemical and nonchemical pollution that
disproportionately affect these downstream communities.
Response: The permitting action is for a renewal of an existing permit and not an
expansion or a new permit for a greenfield wastewater plant. The Division understands
the environmental impacts of the discharger on the neighboring community and
continues to pursue protection of the waterbody's designated uses. The programmatic
practices implemented during the preparation of the draft permit are consistent with

Pilot Creek WWTP Fact Sheet Addendum NCO020737
state and federal environmental protection regulations and are designed to ensure
protection of the stream's designated uses.

Instream Temperature Review NCO020737 Pilot Creek WWTP
Date Upstream Downstream Diff> 2.8? Date Upstream Downstrearr Diff> 2.8?
2/4/2019 8 7 0 8/23/2019 27 25 0
2/11/2019 9 9 0 8/26/2019 26 22 0
2/19/2019 7 9 0 8/28/2019 26 23 0
2/25/2019 9 8 0 8/30/2019 25 21 0
3/4/2019 13 14 0 9/3/2019 27 25 0
3/11/2019 10 10 0 9/4/2019 26 23 0
3/18/2019 11 9 0 9/6/2019 27 24 0
3/25/2019 11 11 0 9/9/2019 27 25 0
4/1/2019 13 11 0 9/11/2019 26 24 0
4/8/2019 13 14 0 9/13/2019 26 24 0
4/15/2019 18 17 0 9/16/2019 26 23 0
4/23/2019 16 15 0 9/18/2019 26 23 0
4/29/2019 19 17 0 9/20/2019 23 19 0
5/6/2019 17 17 0 9/23/2019 25 21 0
5/13/2019 20 19 0 9/25/2019 26 23 0
5/20/2019 19 20 0 9/27/2019 26 23 0
5/28/2019 20 20 0 9/30/2019 26 23 0
6/3/2019 21 20 0 10/3/2019 26 23 0
6/5/2019 21 21 0 10/10/2019 21 18 0
6/7/2019 21 21 0 10/17/2019 17 13 0
6/10/2019 23 23 0 10/21/2019 19 16 0
6/12/2019 23 22 0 10/28/2019 18 16 0
6/14/2019 23 20 0 11/4/2019 14 9 0
6/17/2019 23 22 0 11/14/2019 13 6 0
6/19/2019 25 22 0 11/19/2019 12 10 0
6/21/2019 27 22 0 11/25/2019 11 10 0
6/24/2019 23 22 0 12/3/2019 11 10 0
6/26/2019 25 23 0 12/9/2019 11 9 0
6/28/2019 23 22 0 12/17/2019 11 12 0
7/1/2019 22 23 0 12/27/2019 10 8 0
7/3/2019 23 23 0 12/30/2019 10 12 0
7/5/2019 23 23 0 1/6/2020 10 8 0
7/8/2019 24 23 0 1/13/2020 11 13 0
7/10/2019 24 24 0 1/21/2020 9 6 0
7/12/2019 24 23 0 1/27/2020 9 8 0
7/15/2019 24 24 0 2/3/2020 9 7 0
7/17/2019 26 24 0 2/10/2020 10 9 0
7/19/2019 25 24 0 2/18/2020 11 11 0
7/22/2019 24 24 0 2/24/2020 10 10 0
7/24/2019 26 22 0 3/2/2020 10 9 0
7/26/2019 25 22 0 3/9/2020 10 9 0
7/29/2019 24 22 0 3/16/2020 13 11 0
7/31/2019 26 23 0 3/23/2020 13 13 0
8/2/2019 26 23 0 3/31/2020 15 15 0
8/5/2019 25 23 0 4/6/2020 15 14 0
8/7/2019 26 24 0 4/15/2020 17 16 0
8/9/2019 26 23 0 4/20/2020 18 17 0
8/12/2019 26 24 0 4/27/2020 17 15 0
8/14/2019 26 24 0 5/6/2020 18 16 0
8/16/2019 25 24 0 5/11/2020 18 15 0
8/19/2019 25 23 0 5/18/2020 19 19 0
8/21/2019 26 24 0 5/26/2020 18 18 0
6/1/2020 20 18 0 10/5/2020 20 17 0

6/3/2020 19 19 0 10/12/2020 21 20 0
6/5/2020 19 19 0 10/19/2020 20 17 0
6/8/2020 19 21 0 10/26/2020 20 17 0
6/10/2020 19 21 0 11/2/2020 18 13 0
6/12/2020 19 21 0 11/9/2020 18 17 0
6/15/2020 20 19 0 11/16/2020 17 16 0
6/17/2020 21 18 0 11/23/2020 17 16 0
6/19/2020 20 19 0 11/30/2020 15 12 0
6/22/2020 23 22 0 12/7/2020 13 11 0
6/24/2020 21 21 0 12/15/2020 15 10 0
6/26/2020 22 22 0 12/21/2020 11 10 0
6/29/2020 22 23 0 12/28/2020 9 7 0
7/1/2020 21 22 0 1/4/2021 9 8 0
7/3/2020 22 22 0 1/11/2021 9 9 0
7/7/2020 23 23 0 1/12/2021 8 8 0
7/8/2020 24 23 0 1/19/2021 8 6 0
7/10/2020 23 23 0 1/25/2021 8 9 0
7/13/2020 23 23 0 2/1/2021 8 8 0
7/15/2020 24 23 0 2/8/2021 8 7 0
7/17/2020 24 24 0 2/16/2021 9 9 0
7/20/2020 25 23 0 2/22/2021 10 10 0
7/22/2020 24 22 0 3/1/2021 9 8 0
7/24/2020 26 25 0 3/8/2021 10 11 0
7/27/2020 25 24 0 3/15/2021 11 12 0
7/29/2020 25 25 0 3/22/2021 12 11 0
7/31/2020 26 25 0 3/29/2021 14 13 0
8/3/2020 27 26 0 4/5/2021 13 12 0
8/5/2020 26 23 0 4/12/2021 15 14 0
8/7/2020 26 24 0 4/21/2021 18 17 0
8/10/2020 26 26 0 4/26/2021 15 14 0
8/12/2020 27 26 0 5/3/2021 17 17 0
8/14/2020 27 27 0 5/10/2021 18 18 0
8/17/2020 26 24 0 5/18/2021 19 19 0
8/19/2020 26 25 0 5/24/2021 19 19 0
8/21/2020 28 27 0 6/1/2021 19 19 0
8/24/2020 26 25 0 6/2/2021 20 20 0
8/26/2020 26 24 0 6/4/2021 20 20 0
8/28/2020 26 24 0 6/8/2021 20 22 0
8/31/2020 26 24 0 6/9/2021 20 21 0
9/2/2020 27 25 0 6/11/2021 20 21 0
9/4/2020 27 25 0 6/14/2021 21 20 0
9/8/2020 28 23 0 6/16/2021 21 20 0
9/9/2020 28 24 0 6/17/2021 23 22 0
9/11/2020 26 23 0 6/21/2021 21 21 0
9/14/2020 27 26 0 6/23/2021 21 21 0
9/16/2020 26 24 0 6/25/2021 24 23 0
9/18/2020 25 25 0 6/28/2021 23 22 0
9/21/2020 23 20 0 6/30/2021 23 23 0
9/23/2020 23 20 0 7/2/2021 23 23 0
9/25/2020 21 18 0 7/6/2021 24 24 0
9/28/2020 22 21 0 7/7/2021 24 22 0
9/30/2020 21 19 0 7/9/2021 24 23 0
10/2/2020 21 18 0 7/12/2021 23 23 0
7/14/2021 24 24 0 2/22/2022 10 12 0
7/16/2021 26 25 0 3/2/2022 16 15 0

7/21/2021 25 25 0 3/11/2022 15 14 0
7/22/2021 25 25 0 3/16/2022 13 13 0
7/23/2021 26 26 0 3/24/2022 14 13 0
7/26/2021 25 25 0 3/30/2022 15 15 0
7/27/2021 27 25 0 4/7/2022 18 19 0
7/30/2021 25 25 0 4/11/2022 17 16 0
8/2/2021 26 25 0 4/20/2022 17 16 0
8/4/2021 26 22 0 4/26/2022 19 18 0
8/6/2021 25 24 0 5/2/2022 22 19 0
8/9/2021 26 23 0 5/10/2022 21 20 0
8/11/2021 26 23 0 5/17/2022 19 18 0
8/13/2021 26 23 0 5/24/2022 23 20 0
8/16/2021 25 24 0 5/31/2022 23 23 0
8/18/2021 25 24 0 6/1/2022 21 21 0
8/20/2021 26 24 0 6/3/2022 22 21 0
8/23/2021 26 24 0 6/6/2022 22 20 0
8/25/2021 27 25 0 6/8/2022 24 23 0
8/27/2021 27 25 0 6/9/2022 24 23 0
8/31/2021 27 25 0 6/13/2022 22 22 0
9/1/2021 27 25 0 6/15/2022 23 23 0
9/3/2021 26 21 0 6/17/2022 24 23 0
9/7/2021 26 24 0 6/20/2022 22 20 0
9/8/2021 26 24 0 6/21/2022 23 21 0
9/10/2021 28 23 0 6/24/2022 24 24 0
9/13/2021 26 23 0 6/27/2022 24 23 0
9/14/2021 26 23 0 6/29/2022 24 23 0
9/17/2021 27 23 0 7/1/2022 24 23 0
9/20/2021 26 23 0 7/5/2022 24 24 0
9/22/2021 26 23 0 7/6/2022 25 25 0
9/24/2021 25 22 0 7/8/2022 24 25 0
9/27/2021 23 19 0 7/11/2022 26 23 0
9/30/2021 23 21 0 7/13/2022 25 24 0
10/4/2021 22 22 0 7/15/2022 25 23 0
10/12/2021 24 21 0 7/18/2022 26 25 0
10/18/2021 20 16 0 7/20/2022 26 24 0
10/25/2021 22 19 0 7/22/2022 26 25 0
11/2/2021 19 16 0 7/25/2022 26 25 0
11/9/2021 18 15 0 7/27/2022 27 25 0
11/15/2021 14 10 0 7/29/2022 27 25 0
11/22/2021 14 12 0 8/1/2022 27 25 0
11/29/2021 13 9 0 8/3/2022 28 24 0
12/6/2021 12 11 0 8/5/2022 27 24 0
12/13/2021 13 9 0 8/8/2022 27 25 0
12/22/2021 12 8 0 8/10/2022 27 25 0
12/28/2021 13 14 0 8/12/2022 28 24 0
1/7/2022 12 13 0 8/15/2022 28 24 0
1/10/2022 11 9 0 8/17/2022 27 23 0
1/19/2022 14 9 0 8/19/2022 27 23 0
1/26/2022 13 10 0 8/22/2022 26 24 0
2/1/2022 12 10 0 8/23/2022 27 24 0
2/8/2022 9 11 0 8/26/2022 26 24 0
2/15/2022 9 8 0 8/29/2022 26 24 0
8/31/2022 27 24 0 6/12/2023 20 20 0
9/2/2022 24 24 0 6/14/2023 20 20 0
9/6/2022 26 26 0 6/16/2023 20 20 0

9/7/2022 27 24 0 6/19/2023 20 21 0
9/9/2022 26 24 0 6/22/2023 21 21 0
9/12/2022 26 23 0 6/23/2023 21 22 0
9/14/2022 25 22 0 6/26/2023 22 21 0
9/16/2022 25 21 0 6/28/2023 22 21 0
9/19/2022 25 21 0 6/30/2023 22 22 0
9/21/2022 25 21 0
9/23/2022 25 21 0
9/26/2022 23 20 0
9/28/2022 23 17 0
9/30/2022 21 20 0 t-Test: Two-Sample Assuming Equal Variances
10/5/2022 20 19 0
10/11/2022 20 17 0 Variable 1 Variable 2
10/17/2022 20 18 0 Mean 20.281984 18.81201
10/24/2022 18 14 0 Variance 33.794622 31.142578
10/31/2022 18 17 0 ObservationE 383 383
11/9/2022 17 14 0 Pooled Varia 32.4686
11/14/2022 17 13 0 Hypothesize( 0
11/23/2022 16 14 0 df 764
11/28/2022 14 12 0 t Stat 3.5699508
12/7/2022 14 12 0 P(T<=t)one- 0.0001897
12/14/2022 16 13 0 t Critical one- 1.6468505
12/21/2022 10 12 0 P(T<=t)two-1 0.0003794
12/28/2022 11 7 0 t Critical two- 1.9630739
1/5/2023 11 7 0
1/11/2023 11 8 0
1/18/2023 9 9 0
1/26/2023 11 9 0
2/1/2023 9 10 0
2/9/2023 9 11 0
2/15/2023 9 9 0
2/22/2023 12 12 0
3/2/2023 15 14 0
3/7/2023 13 12 0
3/15/2023 12 8 0
3/23/2023 12 11 0
3/29/2023 16 14 0
4/5/2023 17 16 0
4/12/2023 24 15 0
4/19/2023 17 15 0
4/26/2023 16 16 0
5/3/2023 16 15 0
5/11/2023 19 17 0
5/18/2023 18 18 0
5/26/2023 22 20 0
5/31/2023 21 20 0
6/1/2023 20 19 0
6/2/2023 19 18 0
6/6/2023 20 20 0
6/7/2023 20 19 0
6/9/2023 19 18 0

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 Pilot Creek WWTP Par01 Arsenic Aquactic Life C 150 FW 340 ug/L
WWTP/WTP Class IV Par02 Arsenic Human Health C 10 HH/WS N/A ug/L
Water Supply
NPDES Permit NCO020737 Par03 Beryllium Aquatic Life NC 6.5 FW 65 ug/L
Outfall 001 Par04 Cadmium Aquatic Life NC 1.6553 FW 5.9002 ug/L
Flow, Qw (MGD) 3.000 Par05 Chlorides Aquatic Life NC 230 FW mg/L
Receiving Stream Buffalo Creek Par06 Chlorinated Phenolic Compounds Water Supply NC 1 A ug/L
HUC Number 03050105 Par07 Total Phenolic Compounds Aquatic Life NC 300 A ug/L
Stream Class C Par08 Chromium III Aquatic Life NC 203.2383 FW 1652.9020 ug/L
❑ Apply WS Hardness WQC Par09 Chromium VI Aquatic Life NC 11 FW 16 pg/L
Lentic or Lotic Lotic Par10 Chromium, Total Aquatic Life NC N/A FW N/A pg/L
7Q10s (cfs) 19.000 Par11 Copper Aquatic Life NC 13.9299 FW 20.9380 ug/L
7Q10w (cfs) 42.00 Par12 Cyanide Aquatic Life NC 5 FW 22 10 ug/L
30Q2 (cfs) 54.00 Par13 Fluoride Aquatic Life NC 1,800 FW ug/L
QA(cfs) 162.00 Par14 Lead Aquatic Life NC 6.2005 FW 171.7251 ug/L
1Q10s (Cfs) 15.69 Par15 Mercury Aquatic Life NC 12 FW 0.5 ng/L
Effluent Hardness 135.69 mg/L (Avg) Par16 Molybdenum Human Health NC 2000 HH ug/L
------------- -------------------
Upstream Hardness 27.4 mg/L (Avg) I Par17 Nickel Aquatic Life NC 65.4387 FW 624.4496 pg/L
------------- --------------------
Combined Hardness Chronic 48.69 mg/L Par18 Nickel Water Supply NC 25.0000 WS N/A pg/L
------------- ----------------------
Combined Hardness Acute _________52.1_6 mg/L Par19 Selenium Aquatic Life NC 3.1 FW 56 ug/L
Data Source(s) Freshwater Dissolved Selenium Standard used per Par20 Silver Aquatic Life NC 0.06 FW 1.0500 ug/L
❑ CHECK TO APPLY MODEL the 2020-2022 Surface Water Triennial Review Par21 Zinc Aquatic Life NC 222.9429 FW 234.3962 ug/L
updates. Total selenium data used for analysis as no
dissolved selenium data are available. Par22 Thallium Human Health NC 2 HH pg/L
Par23 Chloroform Human Health C 2000 HH pg/L
Par24 Chlorodibromomethane Human Health C 21 HH pg/L
Par25 Dichlorobromomethane Human Health C 17 HH pg/L
20737 RPA updated, input
1/29/2024

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 Pilot Creek WWTP Par01 Arsenic Aquactic Life C 150 FW 340 ug/L
WWTP/WTP Class IV Par02 Arsenic Human Health C 10 HH/WS N/A ug/L
Water Supply
NPDES Permit NCO020737 Par03 Beryllium Aquatic Life NC 6.5 FW 65 ug/L
Outfall 001 Par04 Cadmium Aquatic Life NC 1.7905 FW 6.5241 ug/L
Flow, Qw (MGD) 4.000 Par05 Chlorides Aquatic Life NC 230 FW mg/L
Receiving Stream Buffalo Creek Par06 Chlorinated Phenolic Compounds Water Supply NC 1 A ug/L
HUC Number 03050105 Par07 Total Phenolic Compounds Aquatic Life NC 300 A ug/L
Stream Class C Par08 Chromium III Aquatic Life NC 221.3562 FW 1804.9120 ug/L
❑ Apply WS Hardness WQC Par09 Chromium VI Aquatic Life NC 11 FW 16 pg/L
Lentic or Lotic Lotic Par10 Chromium, Total Aquatic Life NC N/A FW N/A pg/L
7Q10s (cfs) 19.000 Par11 Copper Aquatic Life NC 15.2280 FW 23.1681 ug/L
7Q10w (cfs) 42.00 Par12 Cyanide Aquatic Life NC 5 FW 22 10 ug/L
30Q2 (cfs) 54.00 Par13 Fluoride Aquatic Life NC 1,800 FW ug/L
QA(cfs) 162.00 Par14 Lead Aquatic Life NC 6.9605 FW 193.4108 ug/L
1Q10s (Cfs) 15.69 Par15 Mercury Aquatic Life NC 12 FW 0.5 ng/L
Effluent Hardness 135.69 mg/L (Avg) Par16 Molybdenum Human Health NC 2000 HH ug/L
------------- -------------------
Upstream Hardness 27.4 mg/L (Avg) I Par17 Nickel Aquatic Life NC 71.4732 FW 683.8580 pg/L
------------- --------------------
Combined Hardness Chronic 54.04 mg/L Par18 Nickel Water Supply NC 25.0000 WS N/A pg/L
------------- ----------------------
Combined Hardness Acute _________58.07 mg/L Par19 Selenium Aquatic Life NC 3.1 FW 56 ug/L
Data Source(s) Freshwater Dissolved Selenium Standard used per Par20 Silver Aquatic Life NC 0.06 FW 1.2631 ug/L
❑ CHECK TO APPLY MODEL the 2020-2022 Surface Water Triennial Review Par21 Zinc Aquatic Life NC 243.5349 FW 256.7319 ug/L
updates. Total selenium data used for analysis as no
dissolved selenium data are available. Par22 Thallium Human Health NC 2 HH pg/L
Par23 Chloroform Human Health C 2000 HH pg/L
Par24 Chlorodibromomethane Human Health C 21 HH pg/L
Par25 Dichlorobromomethane Human Health C 17 HH pg/L
20737 RPA updated, input
1/29/2024

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 Pilot Creek WWTP Par01 Arsenic Aquactic Life C 150 FW 340 ug/L
WWTP/WTP Class IV Par02 Arsenic Human Health C 10 HH/WS N/A ug/L
Water Supply
NPDES Permit NCO020737 Par03 Beryllium Aquatic Life NC 6.5 FW 65 ug/L
Outfall 001 Par04 Cadmium Aquatic Life NC 2.0093 FW 7.5309 ug/L
Flow, Qw (MGD) 6.000 Par05 Chlorides Aquatic Life NC 230 FW mg/L
Receiving Stream Buffalo Creek Par06 Chlorinated Phenolic Compounds Water Supply NC 1 A ug/L
HUC Number 03050105 Par07 Total Phenolic Compounds Aquatic Life NC 300 A ug/L
Stream Class C Par08 Chromium III Aquatic Life NC 250.9357 FW 2046.5492 ug/L
❑ Apply WS Hardness WQC Par09 Chromium VI Aquatic Life NC 11 FW 16 pg/L
Lentic or Lotic Lotic Par10 Chromium, Total Aquatic Life NC N/A FW N/A pg/L
7Q10s (cfs) 19.000 Par11 Copper Aquatic Life NC 17.3570 FW 26.7710 ug/L
7Q10w (cfs) 42.00 Par12 Cyanide Aquatic Life NC 5 FW 22 10 ug/L
30Q2 (cfs) 54.00 Par13 Fluoride Aquatic Life NC 1,800 FW ug/L
QA(cfs) 162.00 Par14 Lead Aquatic Life NC 8.2445 FW 229.0830 ug/L
1Q10s (Cfs) 15.69 Par15 Mercury Aquatic Life NC 12 FW 0.5 ng/L
Effluent Hardness 135.69 mg/L (Avg) Par16 Molybdenum Human Health NC 2000 HH ug/L
Upstream Hardness 27.4 mg/L (Avg) I Par17 Nickel Aquatic Life NC 81.3598 FW 778.6298 pg/L
------------- --------------------
Combined Hardness Chronic 62.99 mg/L Par18 Nickel Water Supply NC 25.0000 WS N/A pg/L
------------- ----------------------
Combined Hardness Acute _________67.7 mg/L Par19 Selenium Aquatic Life NC 3.1 FW 56 ug/L
Data Source(s) Freshwater Dissolved Selenium Standard used per Par20 Silver Aquatic Life NC 0.06 FW 1.6444 ug/L
❑ CHECK TO APPLY MODEL the 2020-2022 Surface Water Triennial Review Par21 Zinc Aquatic Life NC 277.2772 FW 292.3691 ug/L
updates. Total selenium data used for analysis as no
dissolved selenium data are available. Par22 Thallium Human Health NC 2 HH pg/L
Par23 Chloroform Human Health C 2000 HH pg/L
Par24 Chlorodibromomethane Human Health C 21 HH pg/L
Par25 Dichlorobromomethane Human Health C 17 HH pg/L
20737 RPA updated, input
1/29/2024

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 10/17/2019 130 130 Std Dev. 43.7687 1 3/4/2019 22 22 Std Dev. 33.6552
2 1/16/2020 100 100 Mean 135.6875 2 4/23/2019 20 20 Mean 27.4000
3 4/16/2020 140 140 C.V. 0.3226 3 7/12/2019 26 26 C.V. 1.2283
4 7/16/2020 200 200 n 16 4 10/17/2019 22 22 n 20
5 10/15/2020 130 130 10th Per value 102.00 mg/L 5 1/13/2020 20 20 10th Per value 16.00 mg/L
6 1/14/2021 140 140 Average Value 135.69 mg/L 6 4/15/2020 18 18 Average Value 27.40 mg/L
7 1/21/2021 120 120 Max. Value 200.00 mg/L 7 7/15/2020 24 24 Max. Value 170.00 mg/L
8 4/15/2021 128 128 8 10/12/2020 20 20
9 7/15/2021 136 136 9 1/12/2021 18 18
10 10/14/2021 184 184 10 1/20/2021 20 20
11 1/13/2022 168 168 11 4/12/2021 20 20
12 4/14/2022 187 187 12 7/14/2021 16 16
13 7/14/2022 12 12 13 10/12/2021 16 16
14 10/13/2022 160 160 14 1/10/2022 16 16
15 1/12/2023 132 132 15 3/11/2022 20 20
16 4/13/2023 104 104 16 4/11/2022 20 20
17 17 7/13/2022 20 20
18 18 10/11/2022 170 170
19 19 1/11/2023 20 20
20 20 4/12/2023 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
20737 RPA updated, data
- 1 - 1/29/2024

REASONABLE POTENTIAL ANALYSIS
Par01 & Par02
Use"PASTE SPECIAL
Arsenic Values"then"COPY"
Maximum data
points=58
Date Data BDL=1/2DL Results
1 2/7/2019 140 140 Std Dev. 62.1868
2 3/7/2019 45 45 Mean 62.8143
3 4/25/2019 48 48 C.V. 0.9900
4 5/16/2019 50 50 n 28
5 6/6/2019 81 81
6 7/18/2019 130 130 Mult Factor= 1.36
7 8/8/2019 200 200 Max. Value 210.0 ug/L
8 8/15/2019 210 210 Max. Pred Cw 285.6 ug/L
9 8/29/2019 190 190
10 9/5/2019 140 140
11 10/17/2019 84 84
12 11/7/2019 54 54
13 12/5/2019 81 81
14 1/16/2020 44 44
15 4/16/2020 51 51
16 7/16/2020 37 37
17 10/15/2020 20 20
18 1/14/2021 15 15
19 1/21/2021 12 12
20 4/15/2021 15 15
21 7/15/2021 14 14
22 10/14/2021 14 14
23 1/13/2022 6.8 6.8
24 4/14/2022 11 11
25 7/14/2022 14 14
26 10/13/2022 13 13
27 1/12/2023 13 13
28 4/13/2023 26 26
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
20737 RPA updated, data
-2 - 1/29/2024

REASONABLE POTENTIAL ANALYSIS
Par03 Par04
Use"PASTE SPECIAL Use"PASTE SPECIAL
Beryllium Values"then"COPY" Cadmium Values"then"COPY"
Maximum data .Maximum data
points=58 points=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 11/17/2021 < 0.5 0.25 Std Dev. 0.1443 1 4/25/2019 < 0.5 0.25 Std Dev. 0.5232
2 4/16/2020 < 1 0.5 Mean 0.3333 2 7/18/2019 < 0.5 0.25 Mean 0.7647
3 7/30/2022 < 0.5 0.25 C.V. (default) 0.6000 3 10/17/2019 < 0.5 0.25 C.V. 0.6842
4 n 3 4 1/16/2020 < 2.5 1.25 n 18
5 5 4/16/2020 0.5 0.5
6 Mult Factor= 3.00 6 7/16/2020 < 0.5 0.25 Mult Factor= 1.47
7 Max. Value 0.50 ug/L 7 10/15/2020 1.1 1.1 Max. Value 1.910 ug/L
8 Max. Pred Cw 1.50 ug/L 8 1/14/2021 < 2.5 1.25 Max. Pred Cw 2.808 ug/L
9 9 1/21/2021 < 2.5 1.25
10 10 4/15/2021 0.68 0.68
11 11 7/15/2021 1.5 1.5
12 12 10/14/2021 0.78 0.78
13 13 1/13/2022 0.89 0.89
14 14 4/14/2022 0.58 0.58
15 15 7/14/2022 0.2 0.2
16 16 10/13/2022 < 0.15 0.075
17 17 1/12/2023 0.8 0.8
18 18 4/13/2023 1.91 1.91
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
20737 RPA updated, data
-3- 1/29/2024

REASONABLE POTENTIAL ANALYSIS
Par05 Par07 use"PASTE
Use"PASTE SPECIAL-
Values"then"COPY". SPECIAL-Values"
Chlorides Maximum data points= Total Phenolic Compounds then"COPY".
58 Maximum data
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results points=58
1 4/25/2019 170 170 Std Dev. 65.4758 1 10/21/2023 31 31 Std Dev. 15.7824
2 7/18/2019 260 260 Mean 202.6 2 4/16/2020 < 5 2.5 Mean 12.8333
3 10/17/2019 220 220 C.V. 0.3232 3 8/1/2022 < 10 5 C.V. (default) 0.6000
4 1/16/2020 82 82 n 18 4 n 3
5 4/16/2020 170 170 5
6 7/16/2020 280 280 Mult Factor= 1.2 6 Mult Factor= 3.00
7 10/15/2020 170 170 Max. Value 302.0 mg/L 7 Max. Value 31.0 ug/L
8 1/14/2021 230 230 Max. Pred Cw 368.4 mg/L 8 Max. Pred Cw 93.0 ug/L
9 1/21/2021 130 130 9
10 4/15/2021 184 184 10
11 7/15/2021 247 247 11
12 10/14/2021 302 302 12
13 1/13/2022 250 250 13
14 4/14/2022 226 226 14
15 7/14/2022 100 100 15
16 10/13/2022 287 287 16
17 1/12/2023 218 218 17
18 4/13/2023 121 121 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
20737 RPA updated, data
-4- 1/29/2024

REASONABLE POTENTIAL ANALYSIS
Par10 Pal
Use"PASTE SPECIAL Use"PASTE SPECIAL
Chromium, Total Values"then"COPY" Copper Values"then"COPY"
Maximum data .Maximum data
points=58 points=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 4/25/2019 < 5 2.5 Std Dev. 4.3318 1 2/7/2019 3.4 3.4 Std Dev. 1.2628
2 7/18/2019 < 5 2.5 Mean 3.5294 2 3/7/2019 3.4 3.4 Mean 5.0038
3 1/16/2020 < 25 12.5 C.V. 1.2274 3 4/25/2019 3.8 3.8 C.V. 0.2524
4 4/16/2020 < 5 2.5 n 17 4 5/16/2019 6.1 6.1 n 26
5 7/16/2020 < 5 2.5 5 6/6/2019 5.9 5.9
6 10/15/2020 < 5 2.5 Mult Factor= 1.88 6 7/18/2019 6.1 6.1 Mult Factor= 1.11
7 1/14/2021 < 25 12.5 Max. Value 12.5 pg/L 7 8/8/2019 5.5 5.5 Max. Value 8.00 ug/L
8 1/21/2021 < 25 12.5 Max. Pred Cw 23.5 pg/L 8 9/5/2019 5.5 5.5 Max. Pred Cw 8.88 ug/L
9 4/15/2021 < 2 1 9 10/17/2019 4 4
10 7/15/2021 < 2 1 10 11/7/2019 4.7 4.7
11 10/14/2021 < 2 1 11 12/5/2019 2.5 2.5
12 1/13/2022 2 2 12 1/16/2020 < 10 5
13 4/14/2022 < 2 1 13 4/16/2020 4.1 4.1
14 7/14/2022 < 2 1 14 7/16/2020 3.9 3.9
15 10/13/2022 < 2 1 15 10/15/2020 4.1 4.1
16 1/12/2023 < 2 1 16 1/14/2021 < 10 5
17 4/13/2023 < 2 1 17 1/21/2021 < 10 5
18 18 4/15/2021 5 5
19 19 7/15/2021 4 4
20 20 10/14/2021 5 5
21 21 1/13/2022 7.1 7.1
22 22 4/14/2022 5 5
23 23 7/14/2022 8 8
24 24 10/13/2022 7 7
25 25 1/12/2023 5 5
26 26 4/13/2023 6 6
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
20737 RPA updated, data
- 5- 1/29/2024

REASONABLE POTENTIAL ANALYSIS
Par12 Par14
Use"PASTE SPECIAL Use"PASTE SPECIAL
Cyanide Values"then"COPY" Lead Values"then"COPY"
Maximum data .Maximum data
points=58 points=58
Date Data BDL=1/2DL Results Date BDL=1/2DL Results
1 2/7/2019 13 13 Std Dev. 2.0153 1 4/25/2019 < 2 1 Std Dev. 1.6139
2 3/7/2019 10 10 Mean 5.69 2 7/18/2019 < 2 1 Mean 2.6111
3 4/25/2019 < 10 5 C.V. 0.3540 3 10/17/2019 < 2 1 C.V. 0.6181
4 5/16/2019 < 10 5 n 26 4 1/16/2020 < 10 5 n 18
5 6/6/2019 10 10 5 4/16/2020 < 2 1
6 7/18/2019 < 10 5 Mult Factor= 1.15 6 7/16/2020 < 2 1 Mult Factor= 1.42
7 8/8/2019 < 10 5 Max. Value 13.0 ug/L 7 10/15/2020 < 2 1 Max. Value 6.000 ug/L
8 9/5/2019 < 10 5 Max. Pred Cw 15.0 ug/L 8 1/14/2021 < 10 5 Max. Pred Cw 8.520 ug/L
9 10/17/2019 < 10 5 9 1/21/2021 < 10 5
10 11/7/2019 < 10 5 10 4/15/2021 < 5 2.5
11 12/5/2019 < 10 5 11 7/15/2021 < 5 2.5
12 1/16/2020 < 10 5 12 10/14/2021 < 5 2.5
13 4/16/2020 < 10 5 13 1/13/2022 < 5 2.5
14 7/16/2020 < 10 5 14 4/14/2022 < 5 2.5
15 10/15/2020 < 10 5 15 7/14/2022 < 5 2.5
16 1/14/2021 < 10 5 16 10/13/2022 6 6
17 1/21/2021 < 10 5 17 1/12/2023 < 5 2.5
18 4/15/2021 < 5 5 18 4/13/2023 < 5 2.5
19 7/15/2021 < 5 5 19
20 10/14/2021 < 5 5 20
21 1/13/2022 < 5 5 21
22 4/14/2022 < 5 5 22
23 7/29/2022 < 5 5 23
24 10/13/2022 < 5 5 24
25 1/12/2023 < 5 5 25
26 4/13/2023 < 5 5 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
20737 RPA updated, data
-6- 1/29/2024

REASONABLE POTENTIAL ANALYSIS
Par16 Use"PASTE SPECIAL Par17 & Par18 use"PASTE
Values"then"COPY" SPECIAL-Values"
Molybdenum Maximum data Nickel then"COPY".
.
points=58 Maximum data
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results points=58
1 4/25/2019 630 630 Std Dev. 1363.3047 1 4/25/2019 22 22 Std Dev. 5.3058
2 7/18/2019 6200 6200 Mean 1975.8261 2 7/18/2019 30 30 Mean 17.3389
3 10/17/2019 2500 2500 C.V. 0.6900 3 10/17/2019 25 25 C.V. 0.3060
4 1/16/2020 430 430 n 46 4 1/16/2020 12 12 n 18
5 2/13/2020 6400 6400 5 4/16/2020 19 19
6 3/12/2020 3700 3700 Mult Factor= 1.07 6 7/16/2020 18 18 Mult Factor= 1.20
7 4/16/2020 1600 1600 Max. Value 6400.0 ug/L 7 10/15/2020 18 18 Max. Value 30.0 pg/L
8 5/7/2020 550 550 Max. Pred Cw 6848.0 ug/L 8 1/14/2021 15 15 Max. Pred Cw 36.0 pg/L
9 6/11/2020 520 520 9 1/21/2021 16 16
10 7/16/2020 1300 1300 10 4/15/2021 17 17
11 8/13/2020 910 910 11 7/15/2021 22 22
12 9/10/2020 2800 2800 12 10/14/2021 20 20
13 10/15/2020 2000 2000 13 1/13/2022 18 18
14 11/12/2020 1500 1500 14 4/14/2022 13 13
15 12/10/2020 1600 1600 15 7/14/2022 16 16
16 1/14/2021 2500 2500 16 10/13/2022 11.5 11.5
17 1/21/2021 1400 1400 17 1/12/2023 9.2 9.2
18 2/11/2021 1890 1890 18 4/13/2023 10.4 10.4
19 3/11/2021 470 470 19
20 4/15/2021 1850 1850 20
21 5/13/2021 2710 2710 21
22 6/10/2021 2950 2950 22
23 7/15/2021 3430 3430 23
24 8/12/2021 2260 2260 24
25 9/9/2021 638 638 25
26 10/14/2021 2520 2520 26
27 11/18/2021 2000 2000 27
28 12/9/2021 1640 1640 28
29 1/13/2022 1490 1490 29
30 2/8/2022 1108 1108 30
31 3/10/2022 4000 4000 31
32 4/14/2022 1360 1360 32
33 5/12/2022 3150 3150 33
34 6/9/2022 2470 2470 34
35 7/14/2022 626 626 35
36 8/11/2022 1180 1180 36
37 9/15/2022 335 335 37
38 10/13/2022 615 615 38
39 11/10/2022 2150 2150 39
40 12/8/2022 1370 1370 40
41 1/12/2023 3200 3200 41
42 2/9/2023 4010 4010 42
43 3/9/2023 1120 1120 43
44 4/13/2023 1310 1310 44
45 5/11/2023 656 656 45
46 6/8/2023 1840 1840 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
20737 RPA updated, data
-7- 1/29/2024

REASONABLE POTENTIAL ANALYSIS
Par19 Par20
Use"PASTE SPECIAL Use"PASTE SPECIAL
Selenium Values"then"COPY" Silver Values"then"COPY"
Maximum data .Maximum data
points=58 points=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 4/25/2019 < 5 2.5 Std Dev. 5.1258 1 4/25/2019 < 1 0.5 Std Dev. 0.8619
2 7/18/2019 < 5 2.5 Mean 3.4022 2 7/18/2019 < 1 0.5 Mean 0.7944
3 10/17/2019 < 5 2.5 C.V. 1.5066 3 10/17/2019 < 1 0.5 C.V. 1.0849
4 1/16/2020 < 25 12.5 n 46 4 1/16/2020 < 5 2.5 n 18
5 2/13/2020 < 25 12.5 5 4/16/2020 < 1 0.5
6 3/12/2020 < 25 12.5 Mult Factor= 1.13 6 7/16/2020 < 1 0.5 Mult Factor= 1.73
7 4/16/2020 < 5 2.5 Max. Value 25.0 ug/L 7 10/15/2020 < 1 0.5 Max. Value 2.500 ug/L
8 5/7/2020 < 5 2.5 Max. Pred Cw 28.3 ug/L 8 1/14/2021 < 5 2.5 Max. Pred Cw 4.325 ug/L
9 6/11/2020 < 5 2.5 9 1/21/2021 < 5 2.5
10 7/16/2020 < 5 2.5 10 4/15/2021 1.8 1.8
11 8/13/2020 < 5 2.5 11 7/15/2021 < 0.5 0.25
12 9/10/2020 < 25 12.5 12 10/14/2021 < 0.5 0.25
13 10/15/2020 < 5 2.5 13 1/13/2022 < 0.5 0.25
14 11/12/2020 < 5 2.5 14 4/14/2022 < 0.5 0.25
15 12/10/2020 < 50 25 15 7/14/2022 < 0.5 0.25
16 1/14/2021 < 25 12.5 16 10/13/2022 < 0.5 0.25
17 1/21/2021 < 25 12.5 17 1/12/2023 < 0.5 0.25
18 2/11/2021 < 1 0.5 18 4/13/2023 < 0.5 0.25
19 3/11/2021 < 10 5 19
20 4/15/2021 < 10 5 20
21 5/13/2021 1 1 21
22 6/10/2021 < 1 0.5 22
23 7/15/2021 < 1 0.5 23
24 8/12/2021 < 1 0.5 24
25 9/9/2021 < 10 5 25
26 10/14/2021 < 1 0.5 26
27 11/18/2021 < 1 0.5 27
28 12/9/2021 < 1 0.5 28
29 1/13/2022 < 1 0.5 29
30 2/8/2022 < 1 0.5 30
31 3/10/2022 < 1 0.5 31
32 4/14/2022 < 1 0.5 32
33 5/12/2022 < 1 0.5 33
34 6/9/2022 < 1 0.5 34
35 7/14/2022 < 1 0.5 35
36 8/11/2022 < 1 0.5 36
37 9/15/2022 < 1 0.5 37
38 10/13/2022 < 1 0.5 38
39 11/10/2022 < 1 0.5 39
40 12/8/2022 < 1 0.5 40
41 1/12/2023 < 1 0.5 41
42 2/9/2023 < 1 0.5 42
43 3/9/2023 < 1 0.5 43
44 4/13/2023 2 2 44
45 5/11/2023 < 1 0.5 45
46 6/8/2023 2 2 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
20737 RPA updated, data
-8- 1/29/2024

REASONABLE POTENTIAL ANALYSIS
Par21 Par22
Use"PASTE SPECIAL Use"PASTE SPECIAL
Zinc Values"then"COPY" Thallium Values"then"COPY"
Maximum data .Maximum data
points=58 points=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 2/7/2019 33 33 Std Dev. 12.3921 1 2/7/2019 6.6 6.6 Std Dev. 2.4227
2 3/7/2019 34 34 Mean 36.7308 2 3/7/2019 3.5 3.5 Mean 3.0309
3 4/25/2019 38 38 C.V. 0.3374 3 4/25/2019 4.1 4.1 C.V. 0.7993
4 5/16/2019 61 61 n 26 4 5/16/2019 6.4 6.4 n 55
5 6/6/2019 49 49 5 6/6/2019 8.5 8.5
6 7/18/2019 58 58 Mult Factor= 1.14 6 7/18/2019 7.3 7.3 Mult Factor= 1.02
7 8/8/2019 39 39 Max. Value 64.0 ug/L 7 8/8/2019 6.9 6.9 Max. Value 10.000000 pg/L
8 9/5/2019 53 53 Max. Pred Cw 73.0 ug/L 8 9/5/2019 4 4 Max. Pred Cw 10.200000 pg/L
9 10/17/2019 25 25 9 10/17/2019 < 2 1
10 11/7/2019 31 31 10 11/7/2019 < 2 1
11 12/5/2019 36 36 11 12/5/2019 < 2 1
12 1/16/2020 < 50 25 12 1/16/2020 < 10 5
13 4/16/2020 55 55 13 2/13/2020 < 10 5
14 7/16/2020 36 36 14 3/12/2020 < 10 5
15 10/15/2020 28 28 15 4/16/2020 2.3 2.3
16 1/14/2021 < 50 25 16 5/7/2020 2.2 2.2
17 1/21/2021 < 50 25 17 6/11/2020 3.2 3.2
18 4/15/2021 43 43 18 7/16/2020 2.7 2.7
19 7/15/2021 30 30 19 7/31/2020 2.8 2.8
20 10/14/2021 25 25 20 8/13/2020 4.7 4.7
21 1/13/2022 64 64 21 9/10/2020 < 10 5
22 4/14/2022 30 30 22 10/15/2020 < 2 1
23 7/14/2022 29 29 23 11/12/2020 < 2 1
24 10/13/2022 33 33 24 12/10/2020 < 20 10
25 1/12/2023 25 25 25 1/14/2021 < 10 5
26 4/13/2023 25 25 26 1/21/2021 < 10 5
27 27 2/11/2021 0.8 0.8
28 28 3/11/2021 2.2 2.2
29 29 4/15/2021 2.4 2.4
30 30 5/13/2021 2.1 2.1
31 31 6/10/2021 2.3 2.3
32 32 7/15/2021 2.4 2.4
33 33 8/12/2021 3 3
34 34 9/9/2021 2.5 2.5
35 35 10/14/2021 2.2 2.2
36 36 11/18/2021 1.1 1.1
37 37 12/9/2021 0.8 0.8
38 38 1/13/2022 3.9 3.9
39 39 2/8/2022 1.2 1.2
40 40 3/10/2022 6.2 6.2
41 41 4/14/2022 1.2 1.2
42 42 5/12/2022 < 5 2.5
43 43 6/9/2022 1.6 1.6
44 44 7/14/2022 2 2
45 45 8/11/2022 2 2
46 46 9/15/2022 < 0.5 0.25
47 47 10/13/2022 1.2 1.2
48 48 11/10/2022 1 1
49 49 12/8/2022 0.7 0.7
50 50 1/12/2023 < 0.5 0.25
51 51 2/9/2023 < 0.5 0.25
52 52 3/9/2023 0.6 0.6
53 53 4/13/2023 < 0.5 0.25
54 54 5/11/2023 0.6 0.6
55 55 6/8/2023 9 9
56 56
57 57
58 58
20737 RPA updated, data
-9- 1/29/2024

REASONABLE POTENTIAL ANALYSIS
Par23 Par24 use"PASTE
Use"PASTE SPECIAL SPECIAL-
Values"then"COPY" Values"then
Chloroform .Maximum data Chlorodibromomethane "COPY".
points=58 Maximum data
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results points=58
1 10/19/2021 15.3 15.3 Std Dev. 7.1218 1 10/19/2021 17.3 17.3 Std Dev. 5.0083
2 4/16/2020 5.1 5.1 Mean 7.3300 2 4/16/2020 7.3 7.3 Mean 12.467
3 7/29/2022 1.59 1.59 C.V. (default) 0.6000 3 7/29/2022 12.8 12.8 C.V. (default) 0.6000
4 n 3 4 n 3
5 5
6 Mult Factor= 3.00 6 Mult Factor= 3.00
7 Max. Value 15.300000 pg/L 7 Max. Value 17.30 pg/L
8 Max. Pred Cw 45.900000 pg/L 8 Max. Pred Cw 51.90 pg/L
9 9
10 10
11 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 58
20737 RPA updated, data
- 10 - 1/29/2024

REASONABLE POTENTIAL ANALYSIS
Par25
Use"PASTE SPECIAL
Dichlorobromomethane Values"then"COPY"
Maximum data
points=58
Date Data BDL=1/2DL Results
1 10/19/2021 15.1 15.1 Std Dev. 5.6945
2 4/16/2020 5.6 5.6 Mean 8.5367
3 7/29/2022 4.91 4.91 C.V. (default) 0.6000
4 n 3
5
6 Mult Factor= 3.00
7 Max. Value 15.100000 tag/L
8 Max. Pred Cw 45.300000 pg/L
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
20737 RPA updated, data
- 11 - 1/29/2024

Pilot Creek WWTP > Outfall 001
NCO020737 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 3 MGD
MAXIMUM DATA POINTS = 58
Qw (MGD) = 3.0000 WWTP/WTP Class: IV COMBINED HARDNESS (mg/L)
1Q10S (cfs) = 15.69 IWC% @ 1Q10S = 22.86135693 Acute = 52.16 mg/L
7Q10S (cfs) = 19.00 IWC% @ 7QIOS = 19.66173362 Chronic=48.69 mg/L
7Q10W (cfs) = 42.00 IWC% @ 7Q10W= 9.967845659
30Q2 (cfs) = 54.00 IWC% @ 30Q2 = 7.928388747
Avg. Stream Flow, QA(cfs) = 162.00 IW%C @ QA= 2.790279028
Receiving Stream: Buffalo Creek HUC 03050105 Stream Class: C
PARAMETER NC STANDARDS OR EPA CRITERIA J co REASONABLE POTENTIAL RESULTS RECOMMENDED ACTION
TYPE Aplied Chronic Standa d Acute D n #Det. Max Pred Cw Allowable Cw
Acute (FW): 1,487.2
Arsenic C 150 FW(7Q10s) 340 ug/L
28 28 285.E Chronic (FW)----762.9--- ---------------------------
No value >Allowable Cw
_ ___ ____ _ _ _ _ _ _ _ _ _ _ _ ____
Arsenic C 10 HH/WS(Qavg) ug/L Chronic (HH) 358.4 RP for Limited Dataset (n<8 samples)-apply
No value >Allowable Cw Quarterly Monitoring
Acute: 284.32
Beryllium NC 6.5 FW(7Q10s) 65 ug/L 3 0 1.50
Note: n< 9 C.V. (default) Chronic: 33.06 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set NO DETECTS Max MDL= 1 Monitoring required
Acute: 25.808
Cadmium NC 1.6553 FW(7Q10s) 5.9002 ug/L 18 10 2.808
Chronic: 8.419 No RP, Predicted Max< 50% of Allowable Cw- No
No value >Allowable Cw Monitoring required
Acute: NO WQS
Chlorides NC 230 FW(7QI Os) mg/L 18 18 368.4
Chronic: 1,169.8 No RP, Predicted Max< 50% of Allowable Cw- No
No value >Allowable Cw Monitoring required
Acute: NO WQS
Total Phenolic Compounds NC 300 A(30Q2) ug/L 3 1 93.0
Note: n< 9 C.V. (default) Chronic: 3,783.9 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: 7,230.1
Chromium III NC 203.2383 FW(7Q10s) 1652.9020 µg/L 0 0 N/A - _ _ ---- _-_
-Ch -- ---------------------------Chronic: 1
Acute: 70.0
Chromium VI NC I FW(7Q10s) 16 µg/L 0 0 N/A
--Chronic: ----- 55.9 --- ---------------------------
Tot Cr value(s) > 5 but< Cr VI Allowable Cw
Chromium, Total NC µg/L 17 1 23.5 Max reported value 12.5 a: No monitoring required if all Total Chromium
samples are < 5 pg/L or Pred. max for Total Cr is <
allowable Cw for Cr VI.
Acute: 91.59
Copper NC 13.9299 FW(7Q10s) 20.9380 ug/L 26 23 8.88
Chronic: 70.85 No RP, Predicted Max< 50% of Allowable Cw- No
No value>Allowable Cw Monitoring required
20737 RPA updated, rpa
Page 1 of 2 1/29/2024

Pilot Creek WWTP Outfall 001
NCO020737 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 3 MGD
Acute: 96.2
Cyanide NC 5 FW(7Q10s) 22 10 ug/L 26 3 15.0 _
Chronic: 25.4 No RP , Predicted Max >_ 50% of Allowable Cw
No value >Allowable Cw apply Quarterly Monitoring
Acute: 751.159
Lead NC 6.2005 FW(7Q10s) 171.7251 ug/L 18 1 8.520
Chronic: 31.536 No RP, Predicted Max< 50% of Allowable Cw- No
No value >Allowable Cw Monitoring required
Acute: NO WQS
Molybdenum NC 2000 HH(7Q10s) ug/L 46 46 6,848.0 ___ _ ____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Chronic: 10,172.0 No RP , Predicted Max >_ 50% of Allowable Cw
No value >Allowable Cw apply Quarterly Monitoring
Acute (FW): 2,731.5
Nickel NC 65.4387 FW(7Q10s) 624.4496 µg/L _ _ _ _____ ____ _ _ _ _ _ _ _ _ _ _ _ _ _
18 18 36.0 Chronic (FW) 332.8 No RP, Predicted Max< 50% of Allowable Cw- No
No value >_Allowable_Cw Monitoring required
--- -----------------------------
Nickel NC 25.0000 WS(7Q10s) µg/L Chronic (WS) 127.2
No value >Allowable Cw
Acute: 245.0
Selenium NC 3.1 FW(7Q10s) 56 ug/L 46 3 28.3
Chronic: 15.8 RP shown - apply Monthly Monitoring with Limit
1 values >Allowable Cw
Acute: 4.593
Silver NC 0.06 FW(7Q10s) 1.0500 ug/L 18 1 4.325
Chronic: 0.305 RP shown - apply Monthly Monitoring with Limit
10 values >Allowable Cw
Acute: 1,025.3
Zinc NC 222.9429 FW(7Q10s) 234.3962 ug/L 26 23 73.0
Chronic: 1,133.9 No RP, Predicted Max< 50% of Allowable Cw- No
No value >Allowable Cw Monitoring required
Acute: NO WQS
Thallium NC 2 HH(7Q10s) µg/L 55 38 10.20000
--Chronic: --- 10.17204 - ---------------------------
RP shown - apply Monthly Monitoring with Limit
No value >Allowable Cw
Acute: NO WQS
Chloroform C 2000 HH(Qavg) µg/L 3 3 45.90000
Note: n<9 C.V. (default) Chronic: 71677.41935 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: NO WQS
Chlorodibromomethane C 21 HH(Qavg) µg/L 3 3 51.90000
Note: n<9 C.V. (default) Chronic: 752.61290 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: NO WQS
Dichlorobromomethane C 17 HH(Qavg) µg/L 3 3 45.30000
Note: n<9 C.V. (default) Chronic: 609.25806 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value>Allowable Cw Monitoring required
20737 RPA updated, rpa
Page 2 of 2 1/29/2024

Pilot Creek WWTP > Outfall 001
NCO020737 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 4 MGD
MAXIMUM DATA POINTS = 58
Qw (MGD) = 4.0000 WWTP/WTP Class: IV COMBINED HARDNESS (mg/L)
1Q10S (cfs) = 15.69 IWC% @ 1Q10S = 28.32343536 Acute = 58.07 mg/L
7Q10S (cfs) = 19.00 IWC% @ 7Q10S = 24.6031746 Chronic= 54.04 mg/L
7Q10W (cfs) = 42.00 IWC% @ 7Q10W= 12.86307054
30Q2 (cfs) = 54.00 IWC% @ 30Q2 = 10.29900332
Avg. Stream Flow, QA(cfs) = 162.00 IW%C @ QA= 3.68608799
Receiving Stream: Buffalo Creek HUC 03050105 Stream Class: C
PARAMETER NC STANDARDS OR EPA CRITERIA J co REASONABLE POTENTIAL RESULTS RECOMMENDED ACTION
TYPE Aplied Chronic Standa d Acute D n #Det. Max Pred Cw Allowable Cw
Acute (FW): 1,200.4
Arsenic C 150 FW(7Q10s) 340 ug/L
28 28 285.E Chronic (FW)----609.7--- ---------------------------
No value >AllowableCw
_ _ ____ ____ ___________________________
Arsenic C 10 HH/WS(Qavg) ug/L Chronic (HH) 271.3
RP shown - apply Monthly Monitoring with Limit
No value >Allowable Cw
Acute: 229.49
Beryllium NC 6.5 FW(7Q10s) 65 ug/L 3 0 1.50
Note: n< 9 C.V. (default) Chronic: 26.42 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set NO DETECTS Max MDL= 1 Monitoring required
Acute: 23.034
Cadmium NC 1.7905 FW(7Q10s) 6.5241 ug/L 18 10 2.808
Chronic: 7.278 No RP, Predicted Max< 50% of Allowable Cw- No
No value >Allowable Cw Monitoring required
Acute: NO WQS
Chlorides NC 230 FW(7Q10s) mg/L 18 18 368.4
Chronic: 934.8 No RP, Predicted Max< 50% of Allowable Cw- No
No value >Allowable Cw Monitoring required
Acute: NO WQS
Total Phenolic Compounds NC 300 A(30Q2) ug/L 3 1 93.0
Note: n<9 C.V. (default) Chronic: 2,912.9 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: 6,372.5
Chromium III NC 221.3562 FW(7Q10s) 1804.9120 µg/L 0 0 N/A - _ _ ------_ _
- --- ---------------------------
Chronic:
Acute: 56.5
Chromium VI NC 11 FW(7Q10s) 16 µg/L 0 0 N/A
--Chronic: ----- 44.7 --- ---------------------------
Tot Cr value(s) > 5 but< Cr VI Allowable Cw
Chromium, Total NC µg/L 17 1 23.5 Max reported value 12.5 a: No monitoring required if all Total Chromium
samples are < 5 pg/L or Pred. max for Total Cr is <
allowable Cw for Cr VI.
Acute: 81.80
Copper NC 15.2280 FW(7Q10s) 23.1681 ug/L 26 23 8.88
Chronic: 61.89 No RP, Predicted Max< 50% of Allowable Cw- No
No value>Allowable Cw Monitoring required
20737 RPA updated, rpa
Page 1 of 2 1/29/2024

Pilot Creek WWTP > Outfall 001
NCO020737 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 4 MGD
Acute: 77.7
Cyanide NC 5 FW(7Q10s) 22 10 ug/L 26 3 15.0 _
Chronic: 20.3 No RP , Predicted Max >_ 50% of Allowable Cw
No value >Allowable Cw apply Quarterly Monitoring
Acute: 682.865
Lead NC 6.9605 FW(7Q10s) 193.4108 ug/L 18 1 8.520
Chronic: 28.291 No RP, Predicted Max< 50% of Allowable Cw- No
No value >Allowable Cw Monitoring required
Acute: NO WQS
Molybdenum NC 2000 HH(7Q10s) ug/L 46 46 6,848.0 ___ _ ____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Chronic: 8,129.0 No RP , Predicted Max >_ 50% of Allowable Cw
No value >Allowable Cw apply Quarterly Monitoring
Acute (FW): 2,414.5
Nickel NC 71.4732 FW(7Q10s) 683.8580 µg/L _ _ _ _____ ____ _ _ _ _ _ _ _ _ _ _ _ _ _
18 18 36.0 Chronic (FW) 290.5 No RP, Predicted Max< 50% of Allowable Cw- No
No value >_Allowable_Cw Monitoring required
--- -----------------------------
Nickel NC 25.0000 WS(7Q10s) µg/L Chronic (WS) 101.6
No value >Allowable Cw
Acute: 197.7
Selenium NC 3.1 FW(7Q10s) 56 ug/L 46 3 28.3
Chronic: 12.6 RP shown - apply Monthly Monitoring with Limit
1 values >Allowable Cw
Acute: 4.459
Silver NC 0.06 FW(7Q10s) 1.2631 ug/L 18 1 4.325
--Chronic: -----0.244--- ---------------------------
RP shown - apply Monthly Monitoring with Limit
18 values >Allowable Cw
Acute: 906.4
Zinc NC 243.5349 FW(7Q10s) 256.7319 ug/L 26 23 73.0
Chronic: 989.9 No RP, Predicted Max< 50% of Allowable Cw- No
No value >Allowable Cw Monitoring required
Acute: NO WQS
Thallium NC 2 HH(7Q10s) µg/L 55 38 10.20000
--Chronic: ----8.12903-- ---------------------------
RP shown - apply Monthly Monitoring with Limit
3 values >Allowable Cw
Acute: NO WQS
Chloroform C 2000 HH(Qavg) µg/L 3 3 45.90000
Note: n<9 C.V. (default) Chronic: 54258.06452 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: NO WQS
Chlorodibromomethane C 21 HH(Qavg) µg/L 3 3 51.90000
Note: n<9 C.V. (default) Chronic: 569.70968 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: NO WQS
Dichlorobromomethane C 17 HH(Qavg) µg/L 3 3 45.30000 ___ _ ____ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _
Note: n<9 C.V. (default) Chronic: 461.19355 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value>Allowable Cw Monitoring required
20737 RPA updated, rpa
Page 2 of 2 1/29/2024

Pilot Creek WWTP > Outfall 001
NCO020737 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 6 MGD
MAXIMUM DATA POINTS = 58
Qw (MGD) = 6.0000 WWTP/WTP Class: IV COMBINED HARDNESS (mg/L)
1Q10S (cfs) = 15.69 IWC% @ 1Q10S = 37.21488595 Acute = 67.7 mg/L
7Q10S (cfs) = 19.00 IWC% @ 7Q10S = 32.86219081 Chronic= 62.99 mg/L
7Q10W (cfs) = 42.00 IWC% @ 7Q10W= 18.12865497
30Q2 (cfs) = 54.00 IWC% @ 30Q2 = 14.69194313
Avg. Stream Flow, QA(cfs) = 162.00 IW%C @ QA= 5.429071804
Receiving Stream: Buffalo Creek HUC 03050105 Stream Class: C
PARAMETER NC STANDARDS OR EPA CRITERIA J co REASONABLE POTENTIAL RESULTS RECOMMENDED ACTION
TYPE Aplied Chronic Standa d Acute D n #Det. Max Pred Cw Allowable Cw
Acute (FW): 913.6
Arsenic C 150 FW(7Q10s) 340 ug/L
28 28 285.E Chronic (FW)----456.5--- ---------------------------
No value >AllowableCw
_ _ ____ ____ ___________________________
Arsenic C 10 HH/WS(Qavg) ug/L Chronic (HH) 184.2
RP shown - apply Monthly Monitoring with Limit
3 values >Allowable Cw
Acute: 174.66
Beryllium NC 6.5 FW(7Q10s) 65 ug/L 3 0 1.50
Note: n< 9 C.V. (default) Chronic: 19.78 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set NO DETECTS Max MDL= 1 Monitoring required
Acute: 20.236
Cadmium NC 2.0093 FW(7Q10s) 7.5309 ug/L 18 10 2.808
Chronic: 6.114 No RP, Predicted Max< 50% of Allowable Cw- No
No value >Allowable Cw Monitoring required
Acute: NO WQS
Chlorides NC 230 FW(7Q10s) mg/L 18 18 368.4 _
Chronic: 699.9 No RP , Predicted Max >_ 50% of Allowable Cw
No value >Allowable Cw apply Quarterly Monitoring
Acute: NO WQS
Total Phenolic Compounds NC 300 A(30Q2) ug/L 3 1 93.0
Note: n<9 C.V. (default) Chronic: 2,041.9 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: 5,499.3
Chromium III NC 250.9357 FW(7Q10s) 2046.5492 µg/L 0 0 N/A - _ _ ---- _ _
- --- ---------------------------
Chronic: -763.E
Acute: 43.0
Chromium VI NC 11 FW(7QIOs) 16 µg/L 0 0 N/A
--Chronic: ----- 33.5 --- ---------------------------
Tot Cr value(s) > 5 but< Cr VI Allowable Cw
Chromium, Total NC µg/L 17 1 23.5 Max reported value 12.5 a: No monitoring required if all Total Chromium
samples are < 5 pg/L or Pred. max for Total Cr is <
allowable Cw for Cr VI.
Acute: 71.94
Copper NC 17.3570 FW(7Ql Os) 26.7710 ug/L 26 23 8.88
Chronic: 52.82 No RP, Predicted Max< 50% of Allowable Cw- No
No value>Allowable Cw Monitoring required
20737 RPA updated, rpa
Page 1 of 2 1/29/2024

Pilot Creek WWTP > Outfall 001
NCO020737 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 6 MGD
Acute: 59.1
Cyanide NC 5 FW(7Q10s) 22 10 ug/L 26 3 15.0 _
Chronic: 15.2 No RP , Predicted Max >_ 50% of Allowable Cw
No value >Allowable Cw apply Quarterly Monitoring
Acute: 615.568
Lead NC 8.2445 FW(7Q10s) 229.0830 ug/L 18 1 8.520
Chronic: 25.088 No RP, Predicted Max< 50% of Allowable Cw- No
No value >Allowable Cw Monitoring required
Acute: NO WQS
Molybdenum NC 2000 HH(7Q10s) ug/L 46 46 6,848.0 ------------------- -----------------------------
Chronic: 6,086.0 RP shown - apply Monthly Monitoring with Limit
2 values >Allowable Cw
Acute (FW): 2,092.3
Nickel NC 81.3598 FW(7Q10s) 778.6298 µg/L _ _ _ _____ ____ _ _ _ _ _ _ _ _ _ _ _ _ _
18 18 36.0 Chronic (FW) 247.6 No RP, Predicted Max< 50% of Allowable Cw- No
No value >_Allowable_Cw Monitoring required
--- -----------------------------
Nickel NC 25.0000 WS(7Q10s) µg/L Chronic (WS) 76.1
No value >Allowable Cw
Acute: 150.5
Selenium NC 3.1 FW(7Q10s) 56 ug/L 46 3 28.3
--Chronic: ----- 9.4 --- ---------------------------
RP shown - apply Monthly Monitoring with Limit
7 values >Allowable Cw
Acute: 4.419
Silver NC 0.06 FW(7Q10s) 1.6444 ug/L 18 1 4.325
--Chronic: -----0.183--- ---------------------------
RP shown - apply Monthly Monitoring with Limit
18 values >Allowable Cw
Acute: 785.6
Zinc NC 277.2772 FW(7Q10s) 292.3691 ug/L 26 23 73.0
Chronic: 843.8 No RP, Predicted Max< 50% of Allowable Cw- No
No value >Allowable Cw Monitoring required
Acute: NO WQS
Thallium NC 2 HH(7Q10s) µg/L 55 38 10.20000
--Chronic: ----6.08602-- ---------------------------
RP shown - apply Monthly Monitoring with Limit
8 values >Allowable Cw
Acute: NO WQS
Chloroform C 2000 HH(Qavg) µg/L 3 3 45.90000
Note: n<9 C.V. (default) Chronic: 36838.70968 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: NO WQS
Chlorodibromomethane C 21 HH(Qavg) µg/L 3 3 51.90000
Note: n<9 C.V. (default) Chronic: 386.80645 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: NO WQS
Dichlorobromomethane C 17 HH(Qavg) µg/L 3 3 45.30000 ___ _ ____ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _
Note: n<9 C.V. (default) Chronic: 313.12903 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value>Allowable Cw Monitoring required
20737 RPA updated, rpa
Page 2 of 2 1/29/2024

Permit No. NCO020737
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 Q ality Standards/A uatic Life Protection
Parameter Acute FW, µg/l Chronic FW, µg/l Acute SW, µg/1 Chronic SW, µg/1
(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. Calculation=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
2B.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-[ln hardness](0.041838)} e^{0.9789 [ln hardness]-3.443}
Cadmium,Acute Trout waters WER*{1.136672-[ln hardness](0.041838)} e^{0.9789[ln hardness]-3.866}
Cadmium,Chronic WER*{1.101672-[ln hardness](0.041838)} •e^{0.7977[ln hardness]-3.909}
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[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}
Page 1 of 4

Permit No. NCO020737
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/WOBELs 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
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.
Page 2 of 4

Permit No. NCO020737
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)+s7Q10, 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 - 1
Ctotal I + { [Kpo] [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
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)
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
Page 3 of 4

Permit No. NC0020737
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.
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) 135.69 Average from 312019 to 412023
[Total as, CaCO3 or(Ca+Mg)] samples
Average Upstream Hardness (mg/L) 27.4 Average from 312019 to 412023
[Total as, CaCO3 or(Ca+Mg)] samples
7Q10 summer(cfs) 19.0 Historical;Previous Fact Sheet
1Q10(cfs) 15.69 Calculated in RPA
Permitted Flow(MGD) 6.0 MGD NPDES Files
with
operation
tiers at 3.0
MGD and 4.0
MGD
Date: Janua /29/2024
Permit Writer: Nick Coco
Page 4 of 4

NH3/TRC WLA Calculations
Facility: Pilot Creek WWTP
PermitNo. NC0020737
Prepared By: Nick Coco
Enter Design Flow (MGD): 6
Enter s7Q10 (cfs): 19
Enter w7Q10 (cfs): 42
Total Residual Chlorine (TRC) Ammonia (Summer)
Daily Maximum Limit(ug/1) Monthly Average Limit (mg NH3-N/1)
s7Q10 (CFS) 19 s7Q10 (CFS) 19
DESIGN FLOW (MGD) 6 DESIGN FLOW (MGD) 6
DESIGN FLOW (CFS) 9.3 DESIGN FLOW (CFS) 9.3
STREAM STD (UG/L) 17.0 STREAM STD (MG/L) 1.0
Upstream Bkgd (ug/1) 0 Upstream Bkgd (mg/1) 0.22
IWC (%) 32.86 IWC (%) 32.86
Allowable Conc. (ug/1) 52 Allowable Conc. (mg/1) 2.6
Cap at 28 ug/L.Consistent with current limit.Maintain Limit. Consistent with current limit.Maintain limit.
Applied to all flow tiers. Applied to all flow tiers.
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/1)
Fecal Coliform w7Q10 (CFS) 42
Monthly Average Limit: 200/100m1 DESIGN FLOW (MGD) 6
(If DF >331; Monitor) DESIGN FLOW (CFS) 9.3
(If DF<331; Limit) STREAM STD (MG/L) 1.8
Dilution Factor(DF) 3.04 Upstream Bkgd (mg/1) 0.22
IWC (%) 18.13
Allowable Conc. (mg/1) 8.9
Consistent with current limit.Maintain limit.
Applied to all flow tiers.
Total Residual Chlorine
1. Cap Daily Max limit at 28 ug/I to protect for acute toxicity
Ammonia (as NH3-N)
1. If Allowable Conc > 35 mg/l, Monitor Only
2. Monthly Avg limit x 3 = Weekly Avg limit (Municipals)
3. Monthly Avg limit x 5 = Daily Max limit (Non-Munis)
If the allowable ammonia concentration is > 35 mg/L, no limit shall be imposed
Fecal Coliform
1. Monthly Avg limit x 2 = 400/100 ml = Weekly Avg limit (Municipals) = Daily Max limit (Non-Muni)

MONITORING REPORT(MR)VIOLATIONS for: Report Date: 08/31/22 Page 1 of 15
Permit: NCO020737 MRS Betweei 8 - 2018 and 8 - 2023 Region: % Violation Category:Limit Violation Program Category:
Facility Name:% Param Nam(% County: % Subbasin:% Violation Action:%
Major Minor: %
PERMIT: NCO020737 FACILITY: City of Kings Mountain-Pilot Creek WWTP COUNTY: Cleveland REGION: Mooresville
Limit Violation
MONITORING VIOLATION UNIT OF CALCULATED %
REPORT OUTFALL LOCATION PARAMETER DATE FREQUENCY MEASURE LIMIT VALUE Over VIOLATION TYPE VIOLATION ACTION
08-2019 001 Effluent Arsenic,Total(as As) 08/08/19 Monthly ug/I 184.2 200 8.6 Daily Maximum Proceed to
Exceeded Enforcement Case
08-2019 001 Effluent Arsenic,Total(as As) 08/15/19 Monthly ug/I 184.2 210 14.0 Daily Maximum Proceed to
Exceeded Enforcement Case
08-2019 001 Effluent Arsenic,Total(as As) 08/29/19 Monthly ug/I 184.2 190 3.1 Daily Maximum No Action, BPJ
Exceeded
08-2019 001 Effluent Arsenic,Total(as As) 08/31/19 Monthly ug/I 152.2 200 31.4 Monthly Average No Action, BPJ
Exceeded
08-2019 001 Effluent Arsenic,Total(as As) 08/31/19 Monthly ug/I 152.2 205 34.7 Monthly Average Proceed to
Exceeded Enforcement Case
08-2018 001 Effluent Chlorine,Total Residual 08/02/18 5 X week ug/I 28 29 3.6 Daily Maximum No Action, BPJ
Exceeded
08-2018 001 Effluent Chlorine,Total Residual 08/22/18 5 X week ug/I 28 31 10.7 Daily Maximum No Action, BPJ
Exceeded
08-2018 001 Effluent Chlorine,Total Residual 08/24/18 5 X week ug/I 28 29 3.6 Daily Maximum No Action, BPJ
Exceeded
09-2018 001 Effluent Chlorine,Total Residual 09/04/18 5 X week ug/I 28 31 10.7 Daily Maximum No Action, BPJ
Exceeded
09-2018 001 Effluent Chlorine,Total Residual 09/06/18 5 X week ug/I 28 31 10.7 Daily Maximum No Action, BPJ
Exceeded
09-2018 001 Effluent Chlorine,Total Residual 09/21/18 5Xweek ug/I 28 34 21.4 Daily Maximum No Action, BPJ
Exceeded
10-2018 001 Effluent Chlorine,Total Residual 10/17/18 5 X week ug/I 28 29 3.6 Daily Maximum No Action, BPJ
Exceeded
11-2018 001 Effluent Chlorine,Total Residual 11/01/18 5 X week ug/I 28 32 14.3 Daily Maximum No Action, BPJ
Exceeded
11-2018 001 Effluent Chlorine,Total Residual 11/19/18 5 X week ug/I 28 29 3.6 Daily Maximum No Action, BPJ
Exceeded
12-2018 001 Effluent Chlorine,Total Residual 12/03/18 5 X week ug/I 28 29 3.6 Daily Maximum No Action, BPJ
Exceeded
12-2018 001 Effluent Chlorine,Total Residual 12/04/18 5 X week ug/I 28 32 14.3 Daily Maximum No Action, BPJ
Exceeded

MONITORING REPORT(MR) VIOLATIONS for: Report Date: 08/31/22 Page 2 of 15
Permit: NCO020737 MRS Betweel 8 - 2018 and 8 - 2023 Region: % Violation Category:Limit Violation Program Category:
Facility Name:% Param Nam(% County: % Subbasin:% Violation Action:%
Major Minor: %
PERMIT: NCO020737 FACILITY: City of Kings Mountain-Pilot Creek WWTP COUNTY: Cleveland REGION: Mooresville
Limit Violation
MONITORING VIOLATION UNIT OF CALCULATED %
REPORT OUTFALL LOCATION PARAMETER DATE FREQUENCY MEASURE LIMIT VALUE Over VIOLATION TYPE VIOLATION ACTION
12-2018 001 Effluent Chlorine,Total Residual 12/07/18 5 X week ug/I 28 29 3.6 Daily Maximum No Action, BPJ
Exceeded
01-2019 001 Effluent Chlorine,Total Residual 01/14/19 5 X week ug/I 28 31 10.7 Daily Maximum No Action, BPJ
Exceeded
01-2019 001 Effluent Chlorine,Total Residual 01/16/19 5 X week ug/I 28 32 14.3 Daily Maximum No Action, BPJ
Exceeded
02-2019 001 Effluent Chlorine,Total Residual 02/22/19 5 X week ug/I 28 37 32.1 Daily Maximum No Action, BPJ
Exceeded
03-2019 001 Effluent Chlorine,Total Residual 03/06/19 5 X week ug/I 28 30 7.1 Daily Maximum No Action, BPJ
Exceeded
04-2019 001 Effluent Chlorine,Total Residual 04/05/19 5 X week ug/I 28 42 50 Daily Maximum No Action, BPJ
Exceeded
04-2019 001 Effluent Chlorine,Total Residual 04/09/19 5 X week ug/I 28 47 67.9 Daily Maximum No Action, BPJ
Exceeded
05-2019 001 Effluent Chlorine,Total Residual 05/09/19 5 X week ug/I 28 39 39.3 Daily Maximum No Action, BPJ
Exceeded
05-2019 001 Effluent Chlorine,Total Residual 05/14/19 5 X week ug/I 28 37 32.1 Daily Maximum No Action, BPJ
Exceeded
06-2019 001 Effluent Chlorine,Total Residual 06/10/19 5 X week ug/I 28 33 17.9 Daily Maximum No Action, BPJ
Exceeded
07-2019 001 Effluent Chlorine,Total Residual 07/03/19 5 X week ug/I 28 33 17.9 Daily Maximum No Action, BPJ
Exceeded
10-2019 001 Effluent Chlorine,Total Residual 10/16/19 5 X week ug/I 28 33 17.9 Daily Maximum No Action, BPJ
Exceeded
10-2019 001 Effluent Chlorine,Total Residual 10/21/19 5 X week ug/I 28 56 100 Daily Maximum Proceed to
Exceeded Enforcement Case
10-2019 001 Effluent Chlorine,Total Residual 10/22/19 5 X week ug/I 28 83 196.4 Daily Maximum Proceed to
Exceeded Enforcement Case
10-2019 001 Effluent Chlorine,Total Residual 10/23/19 5 X week ug/I 28 44 57.1 Daily Maximum No Action, BPJ
Exceeded
10-2019 001 Effluent Chlorine,Total Residual 10/24/19 5 X week ug/I 28 35 25 Daily Maximum No Action, BPJ
Exceeded

MONITORING REPORT(MR) VIOLATIONS for: Report Date: 08/31/22 Page 15 of 15
Permit: NCO020737 MRS Betweel 8 - 2018 and 8 - 2023 Region: % Violation Category:Limit Violation Program Category:
Facility Name:% Param Nam(% County: % Subbasin:% Violation Action:%
Major Minor: %
PERMIT: NCO020737 FACILITY: City of Kings Mountain-Pilot Creek WWTP COUNTY: Cleveland REGION: Mooresville
Limit Violation
MONITORING VIOLATION UNIT OF CALCULATED %
REPORT OUTFALL LOCATION PARAMETER DATE FREQUENCY MEASURE LIMIT VALUE Over VIOLATION TYPE VIOLATION ACTION
07-2023 001 Effluent Chlorine,Total Residual 07/18/23 5 X week ug/I 28 48 71.4 Daily Maximum No Action, BPJ
Exceeded
07-2023 001 Effluent Chlorine,Total Residual 07/19/23 5 X week ug/I 28 46 64.3 Daily Maximum No Action, BPJ
Exceeded
07-2023 001 Effluent Chlorine,Total Residual 07/20/23 5 X week ug/I 28 40 42.9 Daily Maximum No Action, BPJ
Exceeded
07-2023 001 Effluent Chlorine,Total Residual 07/21/23 5Xweek ug/I 28 34 21.4 Daily Maximum No Action, BPJ
Exceeded
07-2023 001 Effluent Chlorine,Total Residual 07/25/23 5 X week ug/I 28 32 14.3 Daily Maximum No Action, BPJ
Exceeded
07-2023 001 Effluent Chlorine,Total Residual 07/26/23 5 X week ug/I 28 30 7.1 Daily Maximum No Action, BPJ
Exceeded
07-2023 001 Effluent Chlorine,Total Residual 07/27/23 5 X week ug/I 28 42 50 Daily Maximum No Action, BPJ
Exceeded
07-2023 001 Effluent Chlorine,Total Residual 07/28/23 5 X week ug/I 28 47 67.9 Daily Maximum No Action, BPJ
Exceeded
09-2018 001 Effluent Nitrogen,Ammonia Total(as 09/30/18 5 X week mg/I 2.6 3.58 37.7 Monthly Average Proceed to
N)-Concentration Exceeded Enforcement Case
10-2019 001 Effluent Nitrogen,Ammonia Total(as 10/26/19 5 X week mg/I 7.8 9.82 25.8 Weekly Average Proceed to
N)-Concentration Exceeded Enforcement Case
10-2019 001 Effluent Nitrogen,Ammonia Total(as 10/31/19 5 X week mg/I 2.6 4.27 64.2 Monthly Average Proceed to
N)-Concentration Exceeded Enforcement Case
11-2019 001 Effluent Nitrogen,Ammonia Total(as 11/30/19 5 X week mg/I 8.9 10.51 18.1 Monthly Average Proceed to NOV
N)-Concentration Exceeded
04-2022 001 Effluent Solids,Total Suspended- 04/09/22 5 X week mg/I 45 85.44 89.9 Weekly Average Proceed to NOV
Concentration Exceeded
02-2023 001 Effluent Solids,Total Suspended- 02/18/23 5 X week mg/I 45 51.7 14.9 Weekly Average Proceed to NOV
Concentration Exceeded

Whole Effluent Toxicity Testing and Self Monitoring Summary
Kinder Morgan Southeast Terminals LLC NCO042501/001 County: Guilford Region: WSRO Basin: CPF08 Jan Apr Jul Oct SOC JOC:
Fthd24PF Begin: 4/1/2022 Acu Fthd 24hr PF Lim NonComp: 70,10: 0.0 PF: VAR IWC: 100 Freq: Q
J F M A M J J A S O N D
2019 Pass - - - - - - - - - - -
2019 >100 - - - - - - - - - - -
2019 >100 - - - - - - - - - - -
2020 Pass - - - - - - - - - - -
2020 >100 - - - - - - - - - - -
2021 >100 - - - - - - - - - - -
2021 Pass - - - - - - - - - - -
2021 >100 - - - - - - - - - - -
2022 - Pass - Pass - - Pass - - Pass - -
2022 >100 - - - - - - - - - - -
2022 >100 - - - - - - - - - - -
2023 - >100 - - - - - - - - - -
2023 H Pass - Pass - - - - - - - -
2023 - >100 - - - - - - - - - -
Kings Mountain,City of-Ellison WTP NCO079740/001 County: Cleveland Region: MRO Basin: BRD05 Jan Apr Jul Oct SOC JOC:
Ceri7dPF Begin: 1/1/2019 Chr Monit: 3.45% 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 - - Fail - - Pass - -
2021 Pass - - Pass - - Pass - - Pass - -
2022 Pass - - Pass - - Pass - - Pass - -
2023 Pass - - Pass - - - - - - - -
Kings Mtn.-Pilot Cr.WWTP NCO020737/001 County: Cleveland Region: MRO Basin: BRD05 Jan Apr Jul Oct SOC JOC:
Ceri7dPF Begin: 6/1/2015 chr lim:33% NonComp: Single 7Q10: 19.0 PF: 6.0 IWC: 33 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>100(P) - - Pass - -
2022 Pass - - Pass - - Pass>100(P) - - Pass >100 Pass -
2023 Pass>100 - - Pass - - - - - - - -
Kinston-Regional WRF NCO024236/001 County: Lenoir Region: WARO Basin: NEU05 Jan Apr Jul Oct SOC JOC:
Ceri7dPF Begin: 11/1/2018 Chr Lim:6.1 NonComp: Single 7Q10: 0 PF: 11.85 IWC: 100 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 - - Pass - -
2022 Pass - >12(P) Pass >10(P) >12(P) Pass - >12 Pass - -
2023 Pass - - Pass - - - - - - - -
Leeend: P=Fathead minnow(Pimohales oromelas).H=No Flow(facilitv is active).s=Solit test between Certified Labs Page 58 of 115

United States Environmental Protection Agency Form Approved.
EPA Washington,D.C.20460 OMB No.2040-0057
Water Compliance Inspection Report Approval expires 8-31-98
Section A: National Data System Coding (i.e., PCS)
Transaction Code NPDES yr/mo/day Inspection Type Inspector Fac Type
1 IN 1 2 u 3 I NCO020737 111 121 22/03/22 I17 18 LC]I 19 I G I 201 I
21111I I I I I I I II I I I I I I I I I I I I I I I I I I I I I I I II I I I I I r6
Inspection Work Days Facility Self-Monitoring Evaluation Rating B1 QA ----------------------Reserved-------------------
67 1.0 70L 711„ I 72 73 LJ74 79 I I I I 80
Section B: Facility Data
Name and Location of Facility Inspected(For Industrial Users discharging to POTW,also include Entry Time/Date Permit Effective Date
POTW name and NPDES permit Number) 09:50AM 22/03/22 20/02/01
Pilot Creek WWTP
200 Potts Creek Rd Exit Time/Date Permit Expiration Date
Kings Mountain NC 28086 12:30PM 22/03/22 23/08/31
Name(s)of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s) Other Facility Data
Kendrene Richelle Putnam/ORC/704-739-7131/
Name,Address of Responsible Official/Title/Phone and Fax Number
Contacted
Richelle Meek,PO Box 429 Kings Mtn NC 280860429/ORC/704-739-7131/
No
Section C:Areas Evaluated During Inspection (Check only those areas evaluated)
Permit 0 Flow Measurement Operations&Maintenar Records/Reports
Self-Monitoring Progran 0 Sludge Handling Dispo: Facility Site Review Effluent/Receiving Wate
Laboratory
Section D: Summary of Finding/Comments(Attach additional sheets of narrative and checklists as necessary)
(See attachment summary)
Name(s)and Signature(s)of Inspector(s) Agency/Office/Phone and Fax Numbers Date
Michael J Meilinger DWR/MRO WQ/704-235-2183/
Ori A Tuvia DWR/MRO WQ/704-663-1699/
Signature of Management Q A Reviewer Agency/Office/Phone and Fax Numbers Date
W. Corey Basinger DWR/Division of Water Quality/704-235-2194/
EPA Form 3560-3(Rev 9-94)Previous editions are obsolete.
Page# 1

NPDES yr/mo/day Inspection Type 1
31 NCO020737 I11 12I 22/03/22 117 18 i c i
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
Page# 2

Permit: NCO020737 Owner-Facility: Pilot Creek WWTP
Inspection Date: 03/22/2022 Inspection Type: Compliance Evaluation
Permit Yes No NA NE
(If the present permit expires in 6 months or less). Has the permittee submitted a new ❑ ❑ ■ ❑
application?
Is the facility as described in the permit? ■ ❑ ❑ ❑
#Are there any special conditions for the permit? ■ ❑ ❑ ❑
Is access to the plant site restricted to the general public? ■ ❑ ❑ ❑
Is the inspector granted access to all areas for inspection? ■ ❑ ❑ ❑
Comment: New tiered permit was issued and became effective on 2/1/2020. The new permit has
removed the Arsenic limit for the tiers under 6 MGD. The City implements an approved
Industrial Pretreatment Program.
Record Keeping Yes No NA NE
Are records kept and maintained as required by the permit? ■ ❑ ❑ ❑
Is all required information readily available, complete and current? ■ ❑ ❑ ❑
Are all records maintained for 3 years (lab. reg. required 5 years)? ■ ❑ ❑ ❑
Are analytical results consistent with data reported on DMRs? ■ ❑ ❑ ❑
Is the chain-of-custody complete? ■ ❑ ❑ ❑
Dates, times and location of sampling ■
Name of individual performing the sampling ■
Results of analysis and calibration ■
Dates of analysis ■
Name of person performing analyses ■
Transported COCs ■
Are DMRs complete: do they include all permit parameters? ■ ❑ ❑ ❑
Has the facility submitted its annual compliance report to users and DWQ? ■ ❑ ❑ ❑
(If the facility is = or> 5 MGD permitted flow) Do they operate 24/7 with a certified ❑ ❑ ■ ❑
operator on each shift?
Is the ORC visitation log available and current? ■ ❑ ❑ ❑
Is the ORC certified at grade equal to or higher than the facility classification? ■ ❑ ❑ ❑
Is the backup operator certified at one grade less or greater than the facility ■ ❑ ❑ ❑
classification?
Is a copy of the current NPDES permit available on site? ■ ❑ ❑ ❑
Facility has copy of previous year's Annual Report on file for review? ❑ ❑ ❑ ■
Page# 3

Permit: NCO020737 Owner-Facility: Pilot Creek WWTP
Inspection Date: 03/22/2022 Inspection Type: Compliance Evaluation
Record Keeping Yes No NA NE
Comment: The records reviewed durinq the inspection were organized and well maintained.
DMRs, COCs, ORC visitation log, Bench sheets, and calibration logs were reviewed for
the period October 2021 through December 2021.
Chlorine curve was late to be renewed for the year of 2021 and the new chlorine curve
did not pass the low chlorine limit (10 ug/L)the higher level passed 50 ug/L, is too high
since the permit limit is 28 ug/L.
Laboratory Yes No NA NE
Are field parameters performed by certified personnel or laboratory? ■ ❑ ❑ ❑
Are all other parameters(excluding field parameters) performed by a certified lab? 0 ❑ ❑ ❑
# Is the facility using a contract lab? 0 ❑ ❑ ❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 ■ ❑ ❑ ❑
degrees Celsius)?
Incubator (Fecal Coliform) set to 44.5 degrees Celsius+/- 0.2 degrees? ❑ ❑ ❑ ■
Incubator (BOD) set to 20.0 degrees Celsius +/- 1.0 degrees? ❑ ❑ ❑ ■
Comment: Influent and effluent analyses are performed under the City's certified laboratory#222.
Pace Labs (metals, priority pollutants, total phosphorus, total nitrogen, oil & grease,
Thallium), and ETT, Inc.(toxicity) have also been contracted to provide analytical
support
Influent Sampling Yes No NA NE
# Is composite sampling flow proportional? 0 ❑ ❑ ❑
Is sample collected above side streams? 0 ❑ ❑ ❑
Is proper volume collected? ■ ❑ ❑ ❑
Is the tubing clean? ■ ❑ ❑ ❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 0 ❑ ❑ ❑
degrees Celsius)?
Is sampling performed according to the permit? 0 ❑ ❑ ❑
Comment: The subject permit requires influent composite BOD and TSS samples. The facility staff
perform and document monthly aliquot verifications. Influent PH levels are continuously
monitored by an in-line monitoring system.
Effluent Sampling Yes No NA NE
Is composite sampling flow proportional? 0 ❑ ❑ ❑
Is sample collected below all treatment units? 0 ❑ ❑ ❑
Is proper volume collected? 0 ❑ ❑ ❑
Is the tubing clean? 0 ❑ ❑ ❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 0 ❑ ❑ ❑
degrees Celsius)?
Page# 4

Permit: NCO020737 Owner-Facility: Pilot Creek WWTP
Inspection Date: 03/22/2022 Inspection Type: Compliance Evaluation
Effluent Sampling Yes No NA NE
Is the facility sampling performed as required by the permit (frequency, sampling type ❑ ❑ ❑
representative)?
Comment: The subject permit requires composite and grab effluent samples. The facility staff
perform and document monthly aliquot verifications. Samples taken are time
proportional.
Upstream / Downstream Sampling Yes No NA NE
Is the facility sampling performed as required by the permit (frequency, sampling type, ■ ❑ ❑ ❑
and sampling location)?
Comment:
Operations & Maintenance Yes No NA NE
Is the plant generally clean with acceptable housekeeping? 0 ❑ ❑ ❑
Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable 0 ❑ ❑ ❑
Solids, pH, DO, Sludge Judge, and other that are applicable?
Comment: The facility staff incorporate a comprehensive process control program with all
measurements being properly documented and maintained on-site. Overall the waste
treatment unit is continually improving. The facility has purchased a SCADA system
and is in the process of improving it, the facility has a done good lob reducing the dead
spot areas in the aeration basins, and in addition greatly improved the condition of the
clarifiers.
However, the following items need to be adressed:
1. At the time of the inspection it was observed that the clarifier#3 weir was uneven.
2. Chlorine curve was late to be renewed for the year of 2021 and the new chlorine
curve did not pass the low chlorine limit (10 ug/L)the higher level passed 50 ug/L, is
above the permit limit 28 ug/L
Pump Station - Influent Yes No NA NE
Is the pump wet well free of bypass lines or structures? 0 ❑ ❑ ❑
Is the wet well free of excessive grease? 0 ❑ ❑ ❑
Are all pumps present? 0 ❑ ❑ ❑
Are all pumps operable? 0 ❑ ❑ ❑
Are float controls operable? 0 ❑ ❑ ❑
Is SCADA telemetry available and operational? 0 ❑ ❑ ❑
Is audible and visual alarm available and operational? ❑ ❑ ❑
Comment: Both screw pumps were operational and in service.
Bar Screens Yes No NA NE
Type of bar screen
Page# 5

Permit: NC0020737 Owner-Facility: Pilot Creek WWTP
Inspection Date: 03/22/2022 Inspection Type: Compliance Evaluation
Bar Screens Yes No NA NE
a.Manual ❑
b.Mechanical
Are the bars adequately screening debris? 0 ❑ ❑ ❑
Is the screen free of excessive debris? 0 ❑ ❑ ❑
Is disposal of screening in compliance? 0 ❑ ❑ ❑
Is the unit in good condition? ❑ ❑ ❑
Comment: Screenings are disposed at the Cleveland County Landfill.
Flow Measurement - Influent Yes No NA NE
# Is flow meter used for reporting? 0 ❑ ❑ ❑
Is flow meter calibrated annually? 0 ❑ ❑ ❑
Is the flow meter operational? 0 ❑ ❑ ❑
(If units are separated) Does the chart recorder match the flow meter? ❑ ❑ ❑
Comment: The influent flow meter is calibrated annually.
Chemical Feed Yes No NA NE
Is containment adequate? 0 ❑ ❑ ❑
Is storage adequate? ■ ❑ ❑ ❑
Are backup pumps available? ■ ❑ ❑ ❑
Is the site free of excessive leaking? 0 ❑ ❑ ❑
Comment:
Secondary Clarifier Yes No NA NE
Is the clarifier free of black and odorous wastewater? 0 ❑ ❑ ❑
Is the site free of excessive buildup of solids in center well of circular clarifier? 0 ❑ ❑ ❑
Are weirs level? 0 ❑ ❑ ❑
Is the site free of weir blockage? ■ ❑ ❑ ❑
Is the site free of evidence of short-circuiting? 0 ❑ ❑ ❑
Is scum removal adequate? 0 ❑ ❑ ❑
Is the site free of excessive floating sludge? 0 ❑ ❑ ❑
Is the drive unit operational? 0 ❑ ❑ ❑
Is the return rate acceptable (low turbulence)? 0 ❑ ❑ ❑
Is the overflow clear of excessive solids/pin floc? 0 ❑ ❑ ❑
Page# 6

Permit: NCO020737 Owner-Facility: Pilot Creek WWTP
Inspection Date: 03/22/2022 Inspection Type: Compliance Evaluation
Secondary Clarifier Yes No NA NE
Is the sludge blanket level acceptable? (Approximately '/4 of the sidewall depth) 0 ❑ ❑ ❑
Comment: 3 (1,3,4) clarifiers were in service. At the time of the inspection it was observed that the
clarifier#3 weir was uneven.
Pumps-RAS-WAS Yes No NA NE
Are pumps in place? ■ ❑ ❑ ❑
Are pumps operational? 0 ❑ ❑ ❑
Are there adequate spare parts and supplies on site? ❑ ❑ 0 ❑
Comment:
Disinfection-Gas Yes No NA NE
Are cylinders secured adequately? 0 ❑ ❑ ❑
Are cylinders protected from direct sunlight? 0 ❑ ❑ ❑
Is there adequate reserve supply of disinfectant? ■ ❑ ❑ ❑
Is the level of chlorine residual acceptable? 0 ❑ ❑ ❑
Is the contact chamber free of growth, or sludge buildup? 0 ❑ ❑ ❑
Is there chlorine residual prior to de-chlorination? 0 ❑ ❑ ❑
Does the Stationary Source have more than 2500 Ibs of Chlorine (CAS No. 0 ❑ ❑ ❑
7782-50-5)?
If yes, then is there a Risk Management Plan on site? 0 ❑ ❑ ❑
If yes, then what is the EPA twelve digit ID Number? (1000- - )
If yes, then when was the RMP last updated?
Comment:
De-chlorination Yes No NA NE
Type of system ? Gas
Is the feed ratio proportional to chlorine amount (1 to 1)? ❑ ❑ ❑
Is storage appropriate for cylinders? ■ ❑ ❑ ❑
# Is de-chlorination substance stored away from chlorine containers? ❑ ❑ 0 ❑
Comment:
Are the tablets the proper size and type? ❑ ❑ ■ ❑
Are tablet de-chlorinators operational? ❑ ❑ 0 ❑
Number of tubes in use?
Page# 7

Permit: NC0020737 Owner-Facility: Pilot Creek WWTP
Inspection Date: 03/22/2022 Inspection Type: Compliance Evaluation
De-chlorination Yes No NA NE
Comment:
Flow Measurement - Effluent Yes No NA NE
# Is flow meter used for reporting? 0 ❑ ❑ ❑
Is flow meter calibrated annually? 0 ❑ ❑ ❑
Is the flow meter operational? 0 ❑ ❑ ❑
(If units are separated) Does the chart recorder match the flow meter? 0 ❑ ❑ ❑
Comment: The flow meters (end of each chlorine contact chamber) are calibrated annually
Effluent Pipe Yes No NA NE
Is right of way to the outfall properly maintained? ❑ ❑ ❑
Are the receiving water free of foam other than trace amounts and other debris? ❑ ❑ ❑ ■
If effluent (diffuser pipes are required) are they operating properly? ❑ ❑ ❑
Comment: Did not examine the outfall
Aerobic Digester Yes No NA NE
Is the capacity adequate? 0 ❑ ❑ ❑
Is the mixing adequate? 0 ❑ ❑ ❑
Is the site free of excessive foaming in the tank? ■ ❑ ❑ ❑
# Is the odor acceptable? ■ ❑ ❑ ❑
# Is tankage available for properly waste sludge? 0 ❑ ❑ ❑
Comment:
Solids Handling Equipment Yes No NA NE
Is the equipment operational? 0 ❑ ❑ ❑
Is the chemical feed equipment operational? 0 ❑ ❑ ❑
Is storage adequate? ❑ ❑ 0 ❑
Is the site free of high level of solids in filtrate from filter presses or vacuum filters? 0 ❑ ❑ ❑
Is the site free of sludge buildup on belts and/or rollers of filter press? 0 ❑ ❑ ❑
Is the site free of excessive moisture in belt filter press sludge cake? 0 ❑ ❑ ❑
The facility has an approved sludge management plan? ❑ ❑ ❑
Comment: Belt press appeared to be running properly at the time of the inspection
Page# 8

Permit: NC0020737 Owner-Facility: Pilot Creek WWTP
Inspection Date: 03/22/2022 Inspection Type: Compliance Evaluation
Standby Power Yes No NA NE
Is automatically activated standby power available? 0 ❑ ❑ ❑
Is the generator tested by interrupting primary power source? 0 ❑ ❑ ❑
Is the generator tested under load? 0 ❑ ❑ ❑
Was generator tested & operational during the inspection? ❑ ❑ ❑
Do the generator(s) have adequate capacity to operate the entire wastewater site? 0 ❑ ❑ ❑
Is there an emergency agreement with a fuel vendor for extended run on back-up 0 ❑ ❑ ❑
power?
Is the generator fuel level monitored? ❑ ❑ ❑
Comment: The facility is equipped with two backup generators. The smaller generator powers the
blowers for aeration basin #3 and the larger generator powers the rest of the plant.
Page# 9

NCO020737 Pilot Creek WWTP 8/31/2023
BOD monthly removal rate TSS monthly removal rate
Month RR(%) Month RR(%) Month RR(%) Month RR(%)
February-19 97.90 August-21 97.87 February-19 95.57 August-21 96.35
March-19 98.28 September-21 98.25 March-19 96.41 September-21 96.70
April-19 98.34 October-21 97.98 April-19 96.92 October-21 96.50
May-19 98.20 November-21 97.13 May-19 96.44 November-21 96.09
June-19 97.83 December-21 97.75 June-19 96.90 December-21 96.09
July-19 98.26 January-22 98.05 July-19 97.39 January-22 94.37
August-19 98.39 February-22 98.20 August-19 97.73 February-22 94.04
September-19 98.31 March-22 98.54 September-19 97.60 March-22 95.90
October-19 96.63 April-22 98.22 October-19 96.02 April-22 86.42
November-19 96.26 May-22 96.92 November-19 95.48 May-22 96.96
December-19 97.31 June-22 97.73 December-19 95.48 June-22 96.46
January-20 97.88 July-22 98.20 January-20 94.60 July-22 97.10
February-20 96.04 August-22 98.03 February-20 93.37 August-22 96.40
March-20 97.27 September-22 98.74 March-20 94.22 September-22 97.48
April-20 97.96 October-22 98.86 April-20 91.49 October-22 97.35
May-20 96.88 November-22 98.34 May-20 92.00 November-22 96.74
June-20 97.79 December-22 98.26 June-20 95.69 December-22 95.04
July-20 97.69 January-23 98.29 July-20 96.97 January-23 94.58
August-20 97.69 February-23 97.99 August-20 97.94 February-23 89.17
September-20 98.41 March-23 99.36 September-20 97.94 March-23 90.50
October-20 97.90 April-23 98.13 October-20 97.38 April-23 92.96
November-20 98.13 May-23 98.12 November-20 96.05 May-23 96.61
December-20 97.56 June-23 98.19 December-20 95.39 June-23 94.78
January-21 98.23 July-23 January-21 96.01 July-23
February-21 97.59 August-23 February-21 94.27 August-23
March-21 97.05 September-23 March-21 93.28 September-23
April-21 98.08 October-23 April-21 96.18 October-23
May-21 97.47 November-23 May-21 96.06 November-23
June-21 97.98 December-23 June-21 96.31 December-23
July-21 97.89 January-24 July-21 95.35 January-24
Overall BOD removal rate 97.89 Overall TSS removal rate 95.43

United States Environmental Protection Agency Form Approved.
EPA Washington,D.C.20460 OMB No.2040-0057
Water Compliance Inspection Report Approval expires 8-31-98
Section A: National Data System Coding (i.e., PCS)
Transaction Code NPDES yr/mo/day Inspection Type Inspector Fac Type
1 IN 1 2 u 3 I NCO020737 I11 121 23/10/26 I17 18I� I 19 I G I 201 I
211IIIII 111111III II III III1 I I IIIII IIIIIIIII II r6
Inspection Work Days Facility Self-Monitoring Evaluation Rating B1 QA ----------------------Reserved-------------------
67 70LJ 71 [L I 72 L-] 73 1 74 79 I I I I 80
Section B: Facility Data
Name and Location of Facility Inspected(For Industrial Users discharging to POTW,also include Entry Time/Date Permit Effective Date
POTW name and NPDES permit Number) 09:25AM 23/10/26 20/02/01
Pilot Creek WWTP
200 Potts Creek Rd Exit Time/Date Permit Expiration Date
Kings Mountain NC 28086 03:OOPM 23/10/26 23/08/31
Name(s)of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s) Other Facility Data
Rickey Lee Bailey/ORC/704-739-7131/
Name,Address of Responsible Official/Title/Phone and Fax Number
Contacted
Ricky Duncan,PO Box 429 Kings Mtn NC 280860429//704-734-4525/7047302152
No
Section C:Areas Evaluated During Inspection (Check only those areas evaluated)
Permit 0 Flow Measurement Operations&Maintenar Records/Reports
Self-Monitoring Progran 0 Sludge Handling Dispo: Facility Site Review Effluent/Receiving Wate
Laboratory
Section D: Summary of Finding/Comments(Attach additional sheets of narrative and checklists as necessary)
(See attachment summary)
Name(s)and Signature(s)of Inspector(s) Agency/Office/Phone and Fax Numbers Date
Wes Bell DWR/MRO WQ/704-235-2192/
Signature of Management Q A Reviewer Agency/Office/Phone and Fax Numbers Date
Andrew Pitner DWR/MRO WQ/704-663-1699 Ext.2180/
EPA Form 3560-3(Rev 9-94)Previous editions are obsolete.
Page# 1

NPDES yr/mo/day Inspection Type (Cont.) 1
31 NCO020737 I11 12I 23/10/26 117 18 i c i
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
On-site Representatives:
The following City staff were in attendance during the inspection: Mr. Donnie Spencer, Mr. Lee Bailey
and Mr. Kevin Hodges.
Record Keeping Section cont'd:
Several eDMRs will be revised and resubmitted to correct transcription errors in the following months:
- October 2022 (correct units of measurement for influent selenium and thallium);
-April 2023 [correct units of measurement for effluent selenium, thallium, and oil & grease (and
influent), zinc (and influent), correct">" symbol to "<" for influent oil &grease, and remove one
effluent mercury value— 11th or 13th];
- May 2023 (correct units of measurement for effluent thallium);
- July 2023 [add effluent tox value and correct units of measurement for effluent arsenic (and result)
and cyanide].
Effluent temperature values should also be added on all eDMRs starting in May 2023. The facility
staff must ensure all units of measurement, sample types, etc. are correctly reported on all future
eDMRs.
Page# 2

Permit: NCO020737 Owner-Facility: Pilot Creek WWTP
Inspection Date: 10/26/2023 Inspection Type: Compliance Evaluation
Permit Yes No NA NE
(If the present permit expires in 6 months or less). Has the permittee submitted a new ■ ❑ ❑ ❑
application?
Is the facility as described in the permit? ■ ❑ ❑ ❑
#Are there any special conditions for the permit? ■ ❑ ❑ ❑
Is access to the plant site restricted to the general public? ■ ❑ ❑ ❑
Is the inspector granted access to all areas for inspection? ■ ❑ ❑ ❑
Comment: The Division received the City's permit renewal package on 3/7/2023.
The City implements a Division-approved Industrial Pretreatment Program.
The last compliance evaluation inspection at this facility was performed by DWR staff
on 3/22/2022.
Record Keeping Yes No NA NE
Are records kept and maintained as required by the permit? ■ ❑ ❑ ❑
Is all required information readily available, complete and current? ■ ❑ ❑ ❑
Are all records maintained for 3 years (lab. reg. required 5 years)? ■ ❑ ❑ ❑
Are analytical results consistent with data reported on DMRs? ■ ❑ ❑ ❑
Is the chain-of-custody complete? ■ ❑ ❑ ❑
Dates, times and location of sampling ■
Name of individual performing the sampling ■
Results of analysis and calibration ■
Dates of analysis ■
Name of person performing analyses ■
Transported COCs ■
Are DMRs complete: do they include all permit parameters? ■ ❑ ❑ ❑
Has the facility submitted its annual compliance report to users and DWQ? ■ ❑ ❑ ❑
(If the facility is = or> 5 MGD permitted flow) Do they operate 24/7 with a certified ❑ ❑ ■ ❑
operator on each shift?
Is the ORC visitation log available and current? ■ ❑ ❑ ❑
Is the ORC certified at grade equal to or higher than the facility classification? ■ ❑ ❑ ❑
Is the backup operator certified at one grade less or greater than the facility ■ ❑ ❑ ❑
classification?
Is a copy of the current NPDES permit available on site? ■ ❑ ❑ ❑
Facility has copy of previous year's Annual Report on file for review? ■ ❑ ❑ ❑
Page# 3

Permit: NCO020737 Owner-Facility: Pilot Creek WWTP
Inspection Date: 10/26/2023 Inspection Type: Compliance Evaluation
Record Keeping Yes No NA NE
Comment: The records reviewed durinq the inspection were organized and well maintained.
Discharge Monitoring Reports (eDMRs)were reviewed for the period September 2022
through August 2023. A weekly average TSS effluent violation was reported in
February 2023. The Division has previously addressed this limit violation through the
issuance of a Notice of Violation (NOV).
See Summary Section for additional comments.
Laboratory Yes No NA NE
Are field parameters performed by certified personnel or laboratory? ■ ❑ ❑ ❑
Are all other parameters(excluding field parameters) performed by a certified lab? 0 ❑ ❑ ❑
# Is the facility using a contract lab? 0 ❑ ❑ ❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 ■ ❑ ❑ ❑
degrees Celsius)?
Incubator (Fecal Coliform) set to 44.5 degrees Celsius+/- 0.2 degrees? ❑ ❑ ❑ ■
Incubator (BOD) set to 20.0 degrees Celsius +/- 1.0 degrees? ❑ ❑ ❑ ■
Comment: Influent and effluent analyses (including filed) are performed under the City's
laboratory certification #222. Meritech, Inc. has also been contracted to provide
analytical support.
The 10.0 S.U. pH buffer had expired and should be discarded. The lab has an
additional 10.0 S.U. standard (not expired) that can be used for all future pH meter
calibrations.
Influent Sampling Yes No NA NE
# Is composite sampling flow proportional? ❑ 0 ❑ ❑
Is sample collected above side streams? ❑ 0 ❑ ❑
Is proper volume collected? ■ ❑ ❑ ❑
Is the tubing clean? ■ ❑ ❑ ❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 0 ❑ ❑ ❑
degrees Celsius)?
Is sampling performed according to the permit? ❑ 0 ❑ ❑
Comment: The subject permit requires influent composite BOD and TSS samples. The facility
staff were collecting time-based (constant time/constant volume) composite influent
samples. Please be advised that flow proportional influent composite samples must be
collected as required by the by the subject Permit (Part ll, Section A. Composite
Sample). The Division may grant a variance to collect time-based composite samples
only if the daily flow rates do not vary by more than 15%. A variance request has not
been submitted and/or received by the Division.
Effluent Sampling Yes No NA NE
Is composite sampling flow proportional? ❑ 0 ❑ ❑
Is sample collected below all treatment units? 0 ❑ ❑ ❑
Page# 4

Permit: NCO020737 Owner-Facility: Pilot Creek WWTP
Inspection Date: 10/26/2023 Inspection Type: Compliance Evaluation
Effluent Sampling Yes No NA NE
Is proper volume collected? 0 ❑ ❑ ❑
Is the tubing clean? ■ ❑ ❑ ❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 0 ❑ ❑ ❑
degrees Celsius)?
Is the facility sampling performed as required by the permit (frequency, sampling type ❑ ❑ ❑
representative)?
Comment: The subject permit requires composite and grab effluent samples. The facility staff
were collecting time-based (constant time/constant volume) composite effluent
samples. Please be advised that flow proportional effluent composite samples must be
collected as required by the by the subject Permit (Part II, Section A. Composite
Sample). The Division may grant a variance to collect time-based composite samples
only if the daily flow rates do not vary by more than 15%. A variance request has not
been submitted and/or received by the Division.
In addition, facility staff had used the values from the in-line dissolved oxygen (DO)
monitoring system (continuous) to report the daily DO effluent values on the May and
June 2023 eDMRs instead of using a calibrated hand held meter. Please be advised
that daily grab samples must be collected and analyzed as required by the subject
Permit (Part I, A(1) Effluent Limitations & Monitoring Requirements).
Upstream / Downstream Sampling Yes No NA NE
Is the facility sampling performed as required by the permit (frequency, sampling type, 0 ❑ ❑ ❑
and sampling location)?
Comment:
Operations & Maintenance Yes No NA NE
Is the plant generally clean with acceptable housekeeping? 0 ❑ ❑ ❑
Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable ❑ ❑ ❑
Solids, pH, DO, Sludge Judge, and other that are applicable?
Comment: The wastewater treatment facility appeared to be adequately treating wastewater at the
time of the inspection. Process control measurements were being performed with the
documentation being maintained on-site. The facility is equipped with a SCADA system
and the wastewater treatment plant is visited seven days per week with staff on call for
any alarm/emergency conditions.
Pump Station - Influent Yes No NA NE
Is the pump wet well free of bypass lines or structures? 0 ❑ ❑ ❑
Is the wet well free of excessive grease? 0 ❑ ❑ ❑
Are all pumps present? 0 ❑ ❑ ❑
Are all pumps operable? 0 ❑ ❑ ❑
Are float controls operable? 0 ❑ ❑ ❑
Page# 5

Permit: NCO020737 Owner-Facility: Pilot Creek WWTP
Inspection Date: 10/26/2023 Inspection Type: Compliance Evaluation
Pump Station - Influent Yes No NA NE
Is SCADA telemetry available and operational? 0 ❑ ❑ ❑
Is audible and visual alarm available and operational? ❑ ❑ 0 ❑
Comment: The telemetry type alarm system properly operated during the on-site test on the high
water alarm.
Bar Screens Yes No NA NE
Type of bar screen
a.Manual ❑
b.Mechanical
Are the bars adequately screening debris? 0 ❑ ❑ ❑
Is the screen free of excessive debris? ■ ❑ ❑ ❑
Is disposal of screening in compliance? 0 ❑ ❑ ❑
Is the unit in good condition? ❑ ❑ ❑
Comment: Screenings are disposed at a permitted landfill.
Chemical Feed Yes No NA NE
Is containment adequate? 0 ❑ ❑ ❑
Is storage adequate? ■ ❑ ❑ ❑
Are backup pumps available? ■ ❑ ❑ ❑
Is the site free of excessive leaking? ■ ❑ ❑ ❑
Comment: Sodium hydroxide is added to the influent (prior to aeration basins) to maintain
appropriate alkalinity/pH levels.
Aeration Basins Yes No NA NE
Mode of operation Ext. Air
Type of aeration system Diffused
Is the basin free of dead spots? ❑ 0 ❑ ❑
Are surface aerators and mixers operational? ❑ ❑ ■ ❑
Are the diffusers operational? 0 ❑ ❑ ❑
Is the foam the proper color for the treatment process? 0 ❑ ❑ ❑
Does the foam cover less than 25% of the basin's surface? 0 ❑ ❑ ❑
Is the DO level acceptable? 0 ❑ ❑ ❑
Is the DO level acceptable?(1.0 to 3.0 mg/1) 0 ❑ ❑ ❑
Page# 6

Permit: NCO020737 Owner-Facility: Pilot Creek WWTP
Inspection Date: 10/26/2023 Inspection Type: Compliance Evaluation
Aeration Basins Yes No NA NE
Comment: All three aeration basins were operational and in service. Wastewater staff have
initiated adjustments to the influent flow and air distribution sysems within the aeration
basins due to operational issues associated with the blowers. Dead spots were
observed due to the lack of proper aeration/mixing. The City has purchased three new
blowers with the first blower to be received on-site by December 2023.
Secondary Clarifier Yes No NA NE
Is the clarifier free of black and odorous wastewater? 0 ❑ ❑ ❑
Is the site free of excessive buildup of solids in center well of circular clarifier? 0 ❑ ❑ ❑
Are weirs level? ❑ 0 ❑ ❑
Is the site free of weir blockage? 0 ❑ ❑ ❑
Is the site free of evidence of short-circuiting? ■ ❑ ❑ ❑
Is scum removal adequate? 0 ❑ ❑ ❑
Is the site free of excessive floating sludge? 0 ❑ ❑ ❑
Is the drive unit operational? 0 ❑ ❑ ❑
Is the return rate acceptable (low turbulence)? 0 ❑ ❑ ❑
Is the overflow clear of excessive solids/pin floc? 0 ❑ ❑ ❑
Is the sludge blanket level acceptable? (Approximately '/4 of the sidewall depth) 0 ❑ ❑ ❑
Comment: All three secondary clarifiers (1,3,4)were operational and in service. Note: Afourth
clarifier was taken out of service several years ago. The weirs for clarifier#3 were
unlevel; however, no evidence of short-circuiting was observed. Plans should be made
to level the weirs in the tuture. The sludge blanket level in clarifier#4 was greater than
a quarter of the sidewall depth; however, wastewater staff have been wasting and
reducing the MLSS level in aeration basin #4.
Pumps-RAS-WAS Yes No NA NE
Are pumps in place? 0 ❑ ❑ ❑
Are pumps operational? ■ ❑ ❑ ❑
Are there adequate spare parts and supplies on site? ❑ ❑ ❑ ■
Comment:
Disinfection-Gas Yes No NA NE
Are cylinders secured adequately? ■ ❑ ❑ ❑
Are cylinders protected from direct sunlight? 0 ❑ ❑ ❑
Is there adequate reserve supply of disinfectant? 0 ❑ ❑ ❑
Is the level of chlorine residual acceptable? 0 ❑ ❑ ❑
Is the contact chamber free of growth, or sludge buildup? ■ ❑ ❑ ❑
Page# 7

Permit: NCO020737 Owner-Facility: Pilot Creek WWTP
Inspection Date: 10/26/2023 Inspection Type: Compliance Evaluation
Disinfection-Gas Yes No NA NE
Is there chlorine residual prior to de-chlorination? 0 ❑ ❑ ❑
Does the Stationary Source have more than 2500 Ibs of Chlorine (CAS No. ❑ ❑ ❑
7782-50-5)?
If yes, then is there a Risk Management Plan on site? ❑ ❑ ❑
If yes, then what is the EPA twelve digit ID Number? (1000- - )
If yes, then when was the RMP last updated?
Comment:
Flow Measurement - Effluent Yes No NA NE
# Is flow meter used for reporting? 0 ❑ ❑ ❑
Is flow meter calibrated annually? 0 ❑ ❑ ❑
Is the flow meter operational? 0 ❑ ❑ ❑
(If units are separated) Does the chart recorder match the flow meter? ❑ ❑ ❑
Comment: The facility is equipped with a flow meter(and V-notch weir) at the outlets of the three
chlorine contact chambers. All flows from the three flow meters are totalized
(automated system) and reported on the eDMRs. All flow meters are calibrated
annually (at a minimum) and were last calibrated on 3/8/2023 by Laboratory Instrument
Services, LLC. The ORC and staff must ensrue the contracted company that performs
the calibrations provides all calibration data including instantaneous confirmation
measurements.
De-chlorination Yes No NA NE
Type of system ? Gas
Is the feed ratio proportional to chlorine amount (1 to 1)? 0 ❑ ❑ ❑
Is storage appropriate for cylinders? ■ ❑ ❑ ❑
# Is de-chlorination substance stored away from chlorine containers? 0 ❑ ❑ ❑
Comment:
Are the tablets the proper size and type? ❑ ❑ 0 ❑
Are tablet de-chlorinators operational? ❑ ❑ ■ ❑
Number of tubes in use?
Comment:
Effluent Pipe Yes No NA NE
Is right of way to the outfall properly maintained? ❑ ❑ ❑
Are the receiving water free of foam other than trace amounts and other debris? ❑ ❑ ❑
If effluent (diffuser pipes are required) are they operating properly? ❑ ❑ 0 ❑
Page# 8

Permit: NC0020737 Owner-Facility: Pilot Creek WWTP
Inspection Date: 10/26/2023 Inspection Type: Compliance Evaluation
Effluent Pipe Yes No NA NE
Comment: The effluent appeared clear with no floatable solids or foam.
Aerobic Digester Yes No NA NE
Is the capacity adequate? 0 ❑ ❑ ❑
Is the mixing adequate? 0 ❑ ❑ ❑
Is the site free of excessive foaming in the tank? ■ ❑ ❑ ❑
# Is the odor acceptable? ■ ❑ ❑ ❑
# Is tankage available for properly waste sludge? ❑ ❑ ❑
Comment: Both aerobic digesters were operational and in service.
Solids Handling Equipment Yes No NA NE
Is the equipment operational? 0 ❑ ❑ ❑
Is the chemical feed equipment operational? 0 ❑ ❑ ❑
Is storage adequate? ■ ❑ ❑ ❑
Is the site free of high level of solids in filtrate from filter presses or vacuum filters? ❑ ❑ ❑
Is the site free of sludge buildup on belts and/or rollers of filter press? ❑ ❑ ❑
Is the site free of excessive moisture in belt filter press sludge cake? ❑ ❑ ❑
The facility has an approved sludge management plan? 0 ❑ ❑ ❑
Comment: The belt press was operation; however, the unit was not in service at the time of the
inspection. Dewatered bio-solids are transported and disposed at a permitted landfill
by City staff.
Standby Power Yes No NA NE
Is automatically activated standby power available? 0 ❑ ❑ ❑
Is the generator tested by interrupting primary power source? 0 ❑ ❑ ❑
Is the generator tested under load? 0 ❑ ❑ ❑
Was generator tested & operational during the inspection? 0 ❑ ❑ ❑
Do the generator(s) have adequate capacity to operate the entire wastewater site? ■ ❑ ❑ ❑
Is there an emergency agreement with a fuel vendor for extended run on back-up 0 ❑ ❑ ❑
power?
Is the generator fuel level monitored? ❑ ❑ ❑
Comment: The facility is equipped with two generators (1 —aeration basin #3 blowers and 1 — rest
of WWTP) that are serviced twice per year by Carolina Power Solutions.
Page# 9

mlvs
KINGS MOUNTAIN
NORTH CAROLINA
htt&zg.aevated.
Nick Coco, PE(he/him/his)
Engineer/I/
NPDES Municipal Permitting Unit
NC DEQ/Division of Water Resources/Water Quality Permitting
Nick,
Please see the following information regarding your request for:
Brief narrative of treatment process(attached)
Sludge Management Plan (attached)
Waiver for 24 hour staffing at Pilot Creek
Pilot Creek WWTP has implemented a comprehensive SCADA Monitoring System known as VSCADA.
Alarms generated are continuously routed to a stand-by phone and also to a supervisor phone.The alarms
generated include the following:
Power outage, diesel generator start, Inf.screw pump off, Blowers(2 per basin)off, Inf. PH low, Inf.flow low/high,
Eff. PH low,C12 and S02 bldg. detector alarms. Other SCADA readings on screen which can be accessed remotely
via cell phone include: Inf. Flow/PH, Eff. Flow/PH/DO, Inf. Flow/PH, Flow from each CL2 contact chamber and Cl2
PPD feed for each, Eff.S02 feed rate in PPD,Sludge digester#1 and#2 level in feet.Also,we can remotely monitor
4 main pump stations for PH (McGill, Hwy.74, Long Branch and Beason Creek).
Again all of these parameters can be accessed remotely via City cell phone.The Collections Dept. has this capability
for all 42 pump stations operated by the City and also has remote monitoring and alarms to a City Standby cell.
Visitation schedule is 365 days per year with the ORC and/or back-up ORC visiting the WWTP Mon.thru Fri. and a
certified operator is on-site for weekends and holidays. Rounds are completed 365 days per year and all operating
equipment is checked daily.Additional personnel are available for unforeseen/major issues that may arise.
Thanks for your kind consideration.
Sincerely,
Lee Bailey,COKM WWTP ORC Pilot Creek NCO020737
Kevin Hodges,COKM WWTP Back-up ORC Pilot Creek NCO020737
City of Kings Mountain I City Hall 1 101 W Gold St. Kings Mountain,NC 28086
Phone:[phone] [e-mail] www.cityofkm.com

TO
SLUDGE DISPOSAL MANAGEMENT PLAN
PILOT CREEK WASTEWATER TREATMENT FACILITY
Wastewater Treatment Facility
The Wastewater Treatment Facility (Picot Creek W W7P),
operated by the City of zings wMountain, is an extended
aeration activateds(udge facility. The treatment facility is
located at 200 Potts Creek Road, .zings .Mountain, NC and
services the city andsurroundng areas.
The waste activateds(udge is pumped from secondary
clarifiers to one of two aerobic holding tanks. The waste
concentration ranges from 2°o to 3°0 TotaCSuspendedSolids.
7'he sludge is then aerated andpH adjusted as needed: The
solids are pumped to a 2.2 meter BeCt Filter Press for further
dewatering to a cake of 15°o to 18% TotaCSolids. The facility
produces approximately Boo dry tons per year which is
transported to the Cleveland County landfi((for finaCdisposaC.
Disposal Facility Information
Cleve land County l andfi(( (Se(f.McNe illy l andfiCO
250 FieCdtng Road
Cherryvi((e, NC 28021
Contact Person: -Air. Sam -'Al. lockridge
Phone Number: 704-484-5100

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