NC0081621_Fact Sheet_20240513

Fact Sheet
NPDES Permit No. NCOO81621
Permit Writer/Email Contact: Saad Masood, [e-mail]
Date: September 12,2023
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: Water& Sewer Authority of Cabanus County(WSACC)/Muddy Creek
Wastewater Treatment Plant(WWTP)
Applicant Address: 6400 Breezy Lane, Concord,NC 28025
Facility Address: 14655 Hopewell Church Road,Midland,NC 28107
Permitted Flow: 0.3 MGD with expansion tier at 1.0 MGD
Facility Type/Waste: MINOR Municipal; 97.7%domestic and 2.3%industrial
Facility Class: 0.3 MGD Flow Tier: Grade II Biological Water Pollution Control System
1.0 MGD Flow Tier: Grade III Biological Water Pollution Control System
Treatment Units: Pump station,Mechanical bar screen and backup manual bar screen,
Equalization basin, Two treatment trains containing: Influent splitter box
and two aeration basins, Two clarifiers; Tertiary filters,Ultra-violet
disinfection, Cascade aeration,Aerated sludge holding tanks, Stand—by
power
Pretreatment Program(Y/N) Y; LTMP
County: Cabarrus
Region Mooresville
*Based on permitted flows.
Briefly describe the proposed permitting action and facility background: WSACC applied for an NPDES
permit renewal for the 0.3 MGD Muddy Creek WWTP and maintenance of the expanded flow tier of 1.0
MGD on April 26, 2023. This facility serves a population of approximately 2,200 residents as well as 1
significant categorical industrial user(CIU)via an approved pretreatment program. Treated domestic and
industrial wastewater is discharged into the Rocky River, a class C waterbody in the Yadkin-Pee Dee
River Basin. Outfall 001 is approximately 41 miles upstream of the waters designated as WS-V;B.
Page 1 of 14

Expansion History An Authorization to Construct(A to C No. 081621A02)was issued to the Permittee
in December 2016 for expansion from 0.15 MGD to 0.3 MGD. The Division received the Engineer's
Certification for such construction on March 15,2019. Currently the facility is operating at a permitted
flow of 0.3 MGD.
The permit was modified in 2021 to include expansion that will take place by building a new facility with
a permitted flow of 1.0 MGD adjacent to the existing one. Once the new facility is constructed and
receives an authorization to operate,the existing facility will be taken offline. The new facility will have a
new outfall(Outfall 002)which will discharge into the same receiving stream,Rocky River, as the
existing outfall 001. The general location of the new outfall will be in the area near 35' 12' 26.38" N and
800 29' 32.70" W. , approximately 200 m downstream Outfall 001.
Sludge disposal: The Muddy Creek Wastewater Treatment Plant sludge management plan consists of
truck loading excess biosolids, from Muddy Creek WWTP to Rocky River Regional Wastewater
Treatment Plant(NPDES Number NC0036269)for final disposal. RRRWWTP is owned and operated by
the Water and Sewer Authority of Cabarrus County.
Inflow and Infiltration(I/I-' In their application,the Permittee noted that negligible 1/1 flow is experienced
at the Muddy Creek WWTP. All WSACC collection systems at Muddy Creek were smoke tested on
March 2, 2022. In addition to that,the City of Concord lines that connect to the WSACC system at
Muddy Creek was also smoke tested. 157 clean-out caps were o replaced and 4 manhole rings and covers
were repaired, after finding defects.
2. Receiving Waterbody Information:
Receiving Waterbody Information
Outfalls/Receiving Stream(s): Outfalls 001 & 002 (expansion)-Rocky River
Stream Segment: 13-170
Stream Classification: C
Drainage Area(mi2): 5531
Summer 7Q10(cfs) 38.71
Winter 7Q10(cfs): 831
30Q2 (cfs): 941
Average Flow(cfs): 5251
IWC (%effluent): 1.2 at 0.3 MGD and 3.9 at 1.0 MGD
2022 303(d)listed/parameter: Yes-impaired for turbidity, dissolved copper and dissolved zinc
Subject to TMDL/parameter: Yes- Statewide Mercury TMDL implementation.
Basin/HUC: Yadkin-Pee Dee River/03040105
USGS Topo Quad: G17NW
'Based on information provided by USGS in 2015
'2022 Integrated Report indicated the receiving stream is data inconclusive for fecal coliform.
3. Effluent Data Summary
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Effluent data for Outfall 001 is summarized below for the period of March 2019 through July 2023.
Table 1. Effluent Data Summary Outfall 001
Parameter Units Average Max Min Permit Limit
Flow MGD 0.7202 0.0723 MA 0.3
BOD summer mg/1 22 <2 WA 15.0
MA 10.0
BOD winter mg/1 19 <2 WA 30.0
MA 20.0
NH3N summer mg/1 0.2 4.7 <0.1 WA 12.0
MA 4.0
NH3N winter mg/l 0.2 10.4 <0.1 WA 24.0
MA 8.0
TSS mg/1 5.1 73.5 2.5 WA 45.0
MA 30.0
pH SU 6.8 8.4 6 6.0>pH<9.0
eomean
(geometric)
Fecal coliform #/100 ml g 1.4
) >2420 < 1 WA 400
MA 200
DO mg/1 9.0 12.8 6.5 DA>5.0
Temperature ° C 20.5 31 7 Monitor&
Report
Total Residual Chlorine* µg/l NA NA NA DM 28
Conductivity µmhos/cm 615 1328 285 Monitor&
Report
Total Hardness mg/1 66 105.3 39 Monitor&
Report
MA-Monthly Average,WA-Weekly Average,DM-Daily Maximum,DA=Daily Average
* Effluent total residual chlorine(TRC)monitoring and limitation only apply if
chlorine or a chlorine derivative is added to the waste stream during treatment.As no
chlorination was implemented at the facility during the period reviewed,no TRC data
were reported.
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/l 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): Yes
Name of Monitoring Coalition: Yadin-Pee Dee River Basin Association(YPDRBA)
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 200 feet above the outfall and downstream at NCSR 1140(Renee Ford Road),
located approximately 4.8 miles downstream of the outfall.As the permittee is a member of the
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YPDRBA, instream monitoring requirements are provisionally waived. The instream locations
correspond to YPDRBA stations Q8355000(Upstream) and Q8385000(Downstream). Instream data
have been summarized below in Table 2.
Table 2. Downstream Monitoring Data Summary
Parameter Units Q8355000 (Upstream) Q8385000 (Downstream)
Average Max Min Average Max Min
Temperature ° C 19.6 29.3 6.4 20.2 31.2 6.5
DO mg/1 8.2 12.7 5.9 9.0 17.4 6
Conductivity µmhos/cm 236 458 91 230 507 84
pH S.U. 7.2 8.3 5.6 7.6 9 6.3
Ammonia mg/1 0.12 0.87 0.02 0.12 0.66 0.02
TKN mg/1 1.1 2.82 0.52 1.1 2.69 0.46
NO2+NO3 mg/1 4.5 13.08 0.7 4.0 13.2 0.67
TP mg/1 0.6 1.46 0.17 0.5 1.5 0.13
Turbidity NTUs 58.5 240 3.6 55.5 250 2.1
Fecal #/100mL 7300 23(geomean) (geomean) 6900 8
Coliform 374 336
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.
Ambient temperature was not greater than 32 degrees Celsius [per 15A NCAC 02B .0211 (18)] at either
station during the period reviewed. Downstream temperature was greater than upstream temperature by
more than 2.8 degrees Celsius on one occasion during the period reviewed. Effluent temperature
monitoring was not conducted concurrent with the observed exceedance and thus a comparison could not
be made for that date. However,it was concluded that no statistically significant difference exists between
upstream and downstream temperature, implying that an effluent impact is not likely observed.
Monitoring has been maintained.
Average 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,with downstream DO being observed at levels generally higher.Monitoring has
been maintained.
It was concluded that no statistically significant difference exists between upstream and downstream
conductivity. As the facility treats industrial waste,monitoring has been maintained.
In addition to the parameters required in the permit,the YPDRBA monitored pH,turbidity, ammonia,
TKN,NO2+NO3, TP, and fecal coliform.
It was concluded that no statistically significant difference exists between upstream and downstream
ammonia, TKN,NO2+NO3, or TP. As such,no monitoring has been proposed. While instream ammonia,
TKN,NO2+NO3, and TP requirements are not proposed,YPDRBA is encouraged to continue conducting
ambient ammonia, TKN,NO2+NO3, and TP monitoring.
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,with downstream pH being observed generally
more basic than upstream.Review of effluent pH indicated an effluent that was generally more acidic
Page 4 of 14

than ambient pH.As such, it is not expected that the facility effluent is influencing the receiving stream.
While instream pH requirements are not proposed,YPDRBA is encouraged to continue conducting
ambient pH monitoring.
It was concluded that no statistically significant difference exists between upstream and downstream fecal
coliform. The 2022 Integrated Report identified the receiving stream as data inconclusive for fecal
coliform. Elevated levels of fecal coliform were observed both upstream and downstream during the
period reviewed. Review of concurrent precipitation data demonstrated a correlation between rain events
and elevated fecal coliform concentrations instream. As such, it is likely that ambient fecal coliform
levels are influenced by non-point sources during rain events. Instream fecal coliform monitoring has not
been added at this time.
The receiving stream is listed as impaired for turbidity in the 2022 303(d)list.Average turbidity was
observed at levels greater than the 50 NTUs standards [per 15A NCAC 02B .0211(21)] at both instream
locations during the period reviewed. However, it was concluded that no statistically significant
difference exists between upstream and downstream turbidity, implying that the effluent is not a primary
influence on turbidity levels in the receiving stream. As such,no monitoring has been proposed.While
instream turbidity requirements are not proposed,YPDRBA is encouraged to continue conducting
ambient turbidity monitoring.
5. Compliance Summary
Summarize the compliance record with permit effluent limits(past 5 years): In 2018,the facility reported
2 flow limit violations resulting in enforcement. The facility has expanded and has had no flow limit
violations since 2019.
Summarize the compliance record with aquatic toxicity test limits and any second species test results
(past 5 years): The facility passed 19 of 19 quarterly chronic toxicity tests, as well as all 4 second species
chronic toxicity tests from January 2019 to July 2023.
Summarize the results from the most recent compliance inspection: The last facility inspection conducted
in August 2021 reported that the facility was compliant.
6. Water Quality-Based Effluent Limitations (WQBELs)
Dilution and MixingZones
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.
Ifpermit limits are more stringent than TBELs, describe how limits were developed: For the flow 0.3
MGD,Limitations for BOD and ammonia are based on 1993 QUAL2E model for instream DO
protection.No changes were made from the current permit limits.
Page 5 of 14

BOD and ammonia limitations for 1.0 MGD flow tier are based on 2007 Speculative limits(based on
QUAL2E model)which was confirmed by an updated 2019 QUAL2K model that exists for the Rocky
River.
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/l(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/1(acute impacts). Due to analytical issues,all TRC values
reported below 50 ug/l 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, applicable only if chlorine or a chlorine derivative is
added to the waste stream during treatment. The TRC limits have been reviewed in the attached WLA for
toxicity and have been found to be protective.No changes were made.
See Oxygen-Consuming Waste Limitations for more information regarding ammonia limits. The ammonia
limits have been reviewed in the attached WLA for toxicity and have been found to be protective at both
flow tiers.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 March 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: None
• 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: None,
however due to listed impairment dissolved Zinc and Copper, Total Zinc and Total Copper
monitoring has been added.
• 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 Arsenic, Total Beryllium,Total Cadmium, Total Chromium,Total Lead,
Total Nickel, Total Selenium, Total Silver.
• 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
Phenolic Compounds, Total Cyanide
As more stringent allowable discharge concentrations are yielded at the higher flow tier and RPA
indicated no parameters assessed require limits or monitoring, only the 1.0 MGD flow tier was evaluated.
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.
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 Minor POTW at 0.3 MGD and Major POTW upon
expansion at 1.0 MGD, and a chronic WET limit will continue on a quarterly frequency at an effluent
concentration of 1.2%at 0.3 MGD and 3.9%at 1.0 MGD.
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 . 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
2021 2022 2023
#of Samples 1 2 3
Annual Average Conc. ng/L <0.5 <0.5 <0.5
Maximum Conc.,n /L <0.5 <0.5 <0.5
TBEL,n /L 47
WQBEL,ng/L 1010.7 @ 0.3 MGD and 311.6 @ 1.0
MGD
Page 7 of 14

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. Since the facility is<2 MGD, a mercury minimization plan(MMP)is
not required.
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. WSACC provided the chemical
addendum on October 23, 2023 and informed the Division that no additional sampling has been
conducted and thus no additional parameters have been identified.
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 BODS/TSS 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): NO
If YES, confirm that antibacksliding provisions are not violated: N/A
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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 213.0500; 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.
For instream monitoring,refer to Section 4.
The current permit requires effluent temperature monitoring be conducted 3/week at both flow tiers. Per
15A NCAC 02B .0508, a Grade II and Grade III facility discharging to water quality limited waters shall
conduct temperature monitoring daily.As such,the permit has been revised to reflect the requirements in
15A NCAC 02B .0508.
In addition,the current permit requires effluent monitoring for DO, TRC,pH, and conductivity be
conducted at the 0.3 MGD flow tier more frequently than required under 15A NCAC 02B .0508 for a
Grade 11 facility discharging to water quality limited waters. The permit has been revised to reflect the
requirements in 15A NCAC 02B .0508, except for effluent conductivity which has been maintained to
track industrial contributions.
The current permit does not currently require monitoring for TN at the 0.3 MGD flow tier. Per 15A
NCAC 02B .0508, a facility discharging 50,000 gpd<Q< 1 MGD into the Yadkin-Pee Dee River Basin
shall conduct effluent TN monitoring quarterly.As such,the permit has been revised to reflect the
requirements in 15A NCAC 02B .0508. In addition, as TN=TKN+NO2+NO3, effluent monitoring for
TKN and NO2+NO3 has been added to the permit.
WSACC has requested continuation of 2/week monitoring for BOD,ammonia,TSS and fecal coliform
based on the 2012 DWR Guidance Regarding the Reduction of Monitoring Frequencies in NPDES
Permits for Exceptionally Performing Facilities. The last three years of the facility's data for these
parameters have been reviewed in accordance with the criteria outlined in the guidance. Based on this
review,the Muddy Creek WWTP has demonstrated compliance with criteria outlined in the guidance.
However,per 15A NCAC 02B .0508,for Grade II facilities(0.3 MGD flow tier)discharging to water
quality limited streams, effluent BOD, ammonia, TSS and fecal coliform monitoring is required to be
conducted weekly,which is less frequent than the 2/week reduction.As such,the monitoring
requirements have been revised to reflect the rule. WSACC is encouraged but not required to continue
more frequent effluent monitoring.
In regards to the 1.0 MGD flow tier, as the expansion is the result of completion of construction of a
brand new facility, sampling will be conducted in accordance with the 15A NCAC 2B .0508 until the
Permittee requests to modify the monitoring frequency and sufficient data is collected to demonstrate
consistent, long-term treatment performance under new conditions. Three years of data will be needed to
demonstrate consistent, long term treatment performance under the new conditions to qualify for a
reduction in sampling.
As the expansion to 1.0 MGD is the result of completion of construction of a brand new facility and
requires the existing treatment works be closed out, Special Condition A.(5.)Facility Closure
Requirements has been maintained.
Page 9 of 14

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 Outfalls 001 and 002
Parameter Current Permit Proposed Change Basis for Condition/Change
Flow MA 0.3 MGD with No change 15A NCAC 2B .0505
expansion to 1.0 MGD
BOD5 @ 0.3 MGD flow: No change to limits at WQBEL. 1993 WLA; Effluent
Summer: either flow tier or Monitoring- 15A NCAC 02B
MA 10.0 mg/1 monitoring at 1.0 .0508 Water Quality Limited;
WA 15.0 mg/l MGD flow tier; Grade II facility. 2012 DWR
Winter: Guidance Regarding the
MA 20.0 mg/l Monitor and Report Reduction of Monitoring
WA 30.0 mg/l Weekly @ 0.3 MGD Frequencies in NPDES Permits
Monitor and report 2/week
flow tier for Exceptionally Performing
@ 1.0 MGD flow: Facilities- 3-year verification
Summer: required for 1.0 MGD.
MA 5.0 mg/l
WA 7.5 mg/l
Winter:
MA 10.0 mg/1
WA 15.0 mg/l
Monitor and report 3/week
NH3-N @ 0.3 MGD flow: No change to limits at WQBEL. 1993 WLA;verified
Summer: either flow tier or with 2023 WLA; Effluent
MA 4.0 mg/l monitoring at 1.0 Monitoring- 15A NCAC 02B
WA 12.0 mg/l MGD flow tier; .0508 Water Quality Limited;
Winter: Grade II facility. 2012 DWR
MA 8.0 mg/l Monitor and Report Guidance Regarding the
WA 24.0 mg/l Weekly @ 0.3 MGD Reduction of Monitoring
Monitor and report 2/week
flow tier Frequencies in NPDES Permits
@ 1.0 MGD flow: for Exceptionally Performing
Summer: Facilities- 3-year verification
MA 1.0 mg/1 required for 1.0 MGD.
WA 3.0 mg/l
Winter:
MA 2.0 mg/l
WA 6.0 mg/l
Monitor and report 3/week
TSS Both flow tiers: No change to limits at TBEL. Secondary treatment
MA 30 mg/l either flow tier or standards/40 CFR 133 / 15A
WA 45 mg/l NCAC 2B .0406; Effluent
Page 10 of 14

Monitor and report 2/week monitoring at 1.0 Monitoring— 15A NCAC 02B
@ 0.3 MGD and 3/week MGD flow tier; .0508 Water Quality Limited;
@ 1.0 MGD Grade II facility. 2012 DWR
Monitor and Report Guidance Regarding the
Weekly @ 0.3 MGD Reduction of Monitoring
flow tier Frequencies in NPDES Permits
for Exceptionally Performing
Facilities- 3-year verification
required for 1.0 MGD.
Fecal coliform Both flow tiers: No change to limits at WQBEL. State WQ standard,
MA 200/100ml either flow tier or 15A NCAC 2B .0200; Effluent
WA 400/100ml monitoring at 1.0 Monitoring— 15A NCAC 02B
Monitor and report 2/week MGD flow tier; .0508 Water Quality Limited;
@ 0.3 MGD and 3/week Grade II facility. 2012 DWR
@ 1.0 MGD Monitor and Report Guidance Regarding the
Weekly @ 0.3 MGD Reduction of Monitoring
flow tier Frequencies in NPDES Permits
for Exceptionally Performing
Facilities- 3-year verification
required for 1.0 MGD.
Temperature Both flow tiers: Both flow tiers: Surface Water Monitoring, 15A
Monitor and Report Monitor and Report NCAC 2B. 0508—Grade II and
3/week Daily III Water Quality Limited
DO Both flow tiers: No change to limits at WQBEL. State WQ standard,
>5 mg/1 either flow tier or 15A NCAC 2B .0200; Effluent
Monitor and Report monitoring at 1.0 Monitoring— 15A NCAC 02B
3/week MGD flow tier; .0508 Water Quality Limited;
Grade II facility
Monitor and Report
Weekly @ 0.3 MGD
flow tier
pH Both flow tiers: No change to limits at WQBEL. State WQ standard,
6—9 SU either flow tier or 15A NCAC 2B .0200; Effluent
Monitor and Report monitoring at 1.0 Monitoring— 15A NCAC 02B
3/week MGD flow tier; .0508 Water Quality Limited;
Grade II facility
Monitor and Report
Weekly @ 0.3 MGD
flow tier
Total Residual Both flow tiers: No change to limits at WQBEL. 2023 WLA. Effluent
Chlorine DM 28 ug/L either flow tier or Monitoring— 15A NCAC 02B
Monitor and Report monitoring at 1.0 .0508 Water Quality Limited;
3/week MGD flow tier; Grade II facility—active if
chlorination is used
Monitor and Report
2/Week @ 0.3 MGD
flow tier
Page 11 of 14

Conductivity Both flow tiers: No change at either Effluent Monitoring—tracking
Monitor and Report flow tier industrial conductivity
3/week
TKN No requirement Monitor and Report For calculation of TN
Quarterly @ 0.3 MGD
flow tier
Monitor and Report
Monthly @ 1.0 MGD
flow tier
NO2+NO3 No requirement Monitor and Report For calculation of TN
Quarterly @ 0.3 MGD
flow tier
Monitor and Report
Monthly @ 1.0 MGD
flow tier
Total Nitrogen @ 0.3 MGD flow tier:No No change to Effluent Monitoring— 15A
requirement monitoring at 1.0 NCAC 02B .0508 Water Quality
@ 1.0 MGD flow tier: MGD flow tier; Limited
Monitor and Report
Monthly Monitor and Report
Quarterly @ 0.3 MGD
flow tier
Total Phosphorus @ 0.3 MGD flow tier:No No change to Effluent Monitoring— 15A
requirement monitoring at 1.0 NCAC 02B .0508 Water Quality
@ 1.0 MGD flow tier: MGD flow tier; Limited
Monitor and Report
Monthly Monitor and Report
Quarterly @ 0.3 MGD
flow tier
Total Copper No requirement Both flow tiers: Verification that discharge
Add quarterly doesn't further impairment
monitoring
Total Zinc No requirement Both flow tiers: Verification that discharge
Add quarterly doesn't further impairment
monitoring
Total Hardness Both flow tiers: No changes Hardness-dependent dissolved
Quarterly monitoring metals water quality standards
Upstream and in Effluent approved in 2016
Both flow tiers: Evaluation of PFAS contribution:
Add quarterly discharging above WS waters;
PFAS No requirement monitoring with Implementation delayed until
delayed after EPA certified method
implementation becomes available.
Toxicity Test Quarterly Chronic limit, No change WQBEL. No toxics in toxic
1.2%effluent @ 0.3 MGD amounts. 15A NCAC 213.0200
and 3.9%effluent @ 1.0 and 15A NCAC 213.0500
MGD
Page 12 of 14

Effluent Three times per permit No change; conducted 40 CFR 122—pretreatment
Pollutant Scan cycle in 2026,2027,2028 facility
Instream Monitor and Report for No change Surface Water Monitoring, 15A
Monitoring temperature,dissolved NCAC 2B. 0508
oxygen, and conductivity
3/week during June
through September and
1/week during remainder
of the year;YPDRBA
waiver
Facility Closure Special Condition A.(4.) No change;renumber G.S. 143-215.1(b)—notification
Requirements to A.(5.) of closure and Division approval
upon completion of construction
of new facility
Electronic Electronic Reporting No change In accordance with EPA
Reporting I Special Condition Electronic 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: 03/10/2024
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 Saad Masood at(919) 707-9064 or via email at saad.masoodkdeq.nc.gov.
15. Fact Sheet Addendum (if applicable):
The draft was submitted to WSACC,EPA Region IV,and the Division's Mooresville Regional Office,
Aquatic Toxicology Branch and Operator Certification Program for review. Comments were received
from the WSACC on April 8,2024. The comments and Division responses are provided in the attached
addendum to the fact sheet.No comments were received from any other party.
Were there any changes made since the Draft Permit was public noticed(Yes/No): YES
If Yes, list changes and their basis below:
• The permit expiration date has been revised to reflect a 5-year permit cycle, changing the
expiration date from October 31,2028 to June 30,2029.
• The facility components list has been updated.
• Based on the expiration date change,the three expanded effluent dates have been adjusted to
2026,2027, and 2028.
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
Page 13 of 14

• Monitoring Frequency Reduction Evaluation
• Additional information Requested
• WET Testing and Self-Monitoring Summary
• POC Review Form
• Fact Sheet Addendum
Page 14 of 14

®Independent Tri1=e
See Proof on Next Page
AFFIDAVIT OF PUBLICATION
Concord Independent Tribune
PO Box 968
[phone]
State of Pennsylvania, County of Lancaster, ss:
Before the undersigned, a Notary Public duly commissioned,
qualified, and authorized by law to administer oaths, personally
appeared the Publisher's Representative, Yuade Moore,who by
being duly sworn deposes and says:,that he/she is authorized to
make this affidavit and sworn statement;that the notice or other
legal advertisement, a copy of which is attached hereto,was
published in the Concord Independent Tribune and that the said
newspaper in which such notice, paper document, or legal
advertisement was published,was at the time of each and every
such publication, a newspaper meeting all the requirements and
qualifications of Section 1-597 of the General Statutes of North
Carolina.
PUBLICATION DATES:
Mar. 10, 2024
NOTICE ID: mKr6P8UDAVjx5GuH17v4
PUBLISHER ID: COL-NC-400134
NOTICE NAME:Wastewater Permit NCO081621 Muddy Creek
WTP
Publication Fee: $134.83
(Signed)L'�3"AL`
Commonwealth of Pennsylvania-Notary Seal
VERIFICATION Nicole Burkholder,Notary Public
Lancaster County
My commission expires March 30,2027
State of Pennsylvania Commission Number 1342120
County of Lancaster
Subscribed in my presence and sworn to before me on this: 03/11/202
/yam W 5
Notary Public
Notarized remotely online using communication technology via Proof.
Wastewater Permit NCO081621 Muddy Creek WTP - Page 1 of 2

Public Notice
North Carolina Environmental Management Camrnission/NPDES Unit
1617 Mail Service Center
Raleigh,NC 27699-1617
Notice of Intent to Issue a NPDES Wastewater Permit NCDDB1621 Mud-
dy Creek WTP
The North Carolina Environmental Managemern Commission proposes
to issue a NPDES wastewater discharge permit to the person(s)listed
below. Written comments regarding the proposed permit will be accept-
ed until 30 days after the publish date of this notice.The Director of the
NC Division of Water Resources(DWR)may hold a public hearing should
there be a significard degree of public interest.Please mail comments
and/or information requests to DWR at the above address. Interested
persons may visit the DWR at 512 N.Salisbury Street,Raleigh,NC 27604
to review the information on file. Additional information on NPDES per-
mits and this notice may be found on our website:https://deq.nc.gov/
public-notices-hearings,or by calling [phone]. The Town of
Bryson City LPO Box 1065,Dunn,NC 233351 has requested renewal and
expansion of NPDES permit NCO081621 for its Muddy Creek Wastewa-
ter Treatment Plante located in Cabarrus County.This permitted facility
discharges treated municipal wastewater to the Rocky River,a class C
water in the Yadkin-Pee Dee River Basin.Currently turbidity,dissolved
copper,and dissolved zinc are water quality limited.This discharge may
affect future allocations in this segment of the Rocky River.
Publication Dates:March 10,2024.COL-NC-4OD134
Wastewater Permit NC0081621 Muddy Creek WTP - Page 2 of 2

WATER&SEWER AUTHORITY
OF CABARRUS COUNTY
WSACC Administrative Offices
232 Davidson Hwy,Concord, NC
28027
704.786.1783 ♦ 704.795.1564 Fax
Rocky River Regional WWTP
6400 Breezy Lane,Concord, NC
ISO 14001:2015♦ NC Star Public Sector♦ OHSAS 18001 OV 28025
704.788.4164 ♦ 704.786.1967 Fax
RECEIVED
April 4, 2024
APR 0 8 2024
CERTIFIED MAIL
RETURN RECEIPT REQUESTED NCDEQ/DWR/NPDES
Mr. Saad Masood
NPDES Municipal Permitting Unit
NCDEQ/Division of Water Resources/Water Quality Permitting
1617 Mail Services Center
Raleigh,NC 27699-1617
SUBJECT: DRAFT—NPDES PERMIT NCO081621
MUDDY CREEK WASTEWATER TREATMENT PLANT
Dear Mr. Masood:
This letter is to provide comments of the Water and Sewer Authority of Cabarrus County
(WSACC) on the draft NPDES draft permit for the Muddy Creek Wastewater Treatment Plant
(MCWWTP).
Draft Permit Pagel "
• We request extension of the expiration date to five years from the issuance date.
Draft Permit page 2
• We request that the facility components be updated to the following:
➢ Pump Station
➢ Mechanical bar screen and backup manual bar screen
➢ Equalization Basin
➢ Two treatment trains, each containing:
o Influent splitter box
o Two aeration basins
➢ Two clarifiers
➢ Tertiary filters
➢ Ultra-violet disinfection

➢ Cascade aeration
➢ Aerated sludge holding tanks
➢ Stand-by power
Draft Permit page 3
• We request that daily effluent temperature monitoring be reduced(for 0.3 MGD and 1.0
MGD). The fact sheet states "However, it was concluded that no statistically significant
difference exists between upstream and downstream temperature, implying that an
effluent impact is not likely observed."
• We request a reduction in the effluent monitoring frequency for conductivity at 0.3
MGD. 15A NCAC 02B .0508 requires weekly monitoring for a Grade II facility
discharging to water quality limited waters.
Draft Permit page a e 10
• Under"FACILITY CLOSURE REQUIREMENTS"at this time do not know that Outfall
001 will no longer be in use once Outfall 002 is constructed. We request that the
language be changed to recognize that Outfall 001 may remain active after Outfall 002 is
constructed.
Fact Sheet page 1
• Treatment Units need to be updated to reflect the components list on page 2 of the draft
p p pg
permit.
Fact Sheet page 2
• We do not have a sufficient level of detail about future expansions to definitively say that
the next expansion will abandon the existing equipment/tanks and outfall entirely. The
next expansion may use much of the existing equipment/tankage. We request changes
here to consider the potential range of possibilities for the expansion design/construction.
NH3/TRC WLA Calculations sheet
• With the updated instream data for Rocky River we request that the NH3 limits be
reconsidered for both the 0.3 MGD and the 1.0 MGD page.
Monitoring Report Violations page
retracted b Core Basinger in a
The NOV for flow exceedance issued 1/31/2019 wasy y g
letter received by WSACC dated 4/18/2019. We request that the page be updated
accordingly.
Water Compliance Inspection Report page
0 The name of the Responsible Official needs to be updated to Harry M. Wilson.

Thank you for your consideration of this matter. If you should have any questions or need
additional information,please contact Matthew Isenhour, Operator in Responsible Charge (ORC)
at(704) 888-4888 or [e-mail], or myself at(704) 788-4164 xl 11 or
[e-mail]_g.
Sincerely,
C`ik
Mark Fowler
Facilities Director
ecc: Matthew Isenhour
James Sims
Cayce Atkinson
Thomas Hahn
Michael Wilson
File

Muddy Creek WWTP Fact Sheet Addendum NC0081621
Comments to the draft permit NC0081621, which was public noticed for 30-day comment period on
3/10/2024,were provided by WSACC with several requests. No comments were received from any other
party. Individual comments by the Permittee and Division responses are provided below.
1. Permit Expiration Date
a. We request extension of the expiration date to 5 years from the issuance date.
Response: The permit expiration date has been revised to reflect a 5-year permit cycle,
changing the expiration date from October 31, 2028 to June 30, 2029.
2. Facility Components List
a. We request the facility components be updated to the following(see comment set for list
of components).
Response:The facility components list has been updated.
3. Effluent Monitoring
a. We request that daily effluent temperature monitoring be reduced (for 0.3 MGD and 1.0
MGD). The fact sheet states "However, it was concluded that no statistically significant
difference exists between upstream and downstream temperature, implying that an
effluent impact is not likely observed."
Response: The frequency of effluent temperature monitoring is indicated in 15A NCAC
02B .0508.As such, no change has been made.
b. We request a reduction in the effluent monitoring frequency for conductivity at 0.3 MGD.
15A NCAC 02B .0508 requires weekly monitoring for a Grade II facility discharging to
water quality limited waters.
Response: The frequency of effluent conductivity monitoring was maintained at 3/week
to track industrial contributions based off submitted effluent data. As such, no change
has been made.
4. Outfall 001 Closure
a. Under" FACILITY CLOSURE REQUIREMENTS" at this time do not know that Outfall 001 will
no longer be in use once Outfall 002 is constructed. We request that the language be
changed to recognize that Outfall 001 may remain active after Outfall 002 is constructed.
Response: The expansion to 1.0 MGD in the permit specifies a discharge to Outfall 002.
The initial plan associated with expansion of the facility and activation of the new
discharge included closure of the existing Outfall 001. If the permittee wants to maintain
both outfalls,they would need to submit major modifications to the permit to reflect this
change. No changes were made.
5. Fact Sheet Comments
a. Treatment Units need to be updated to reflect the components list on page 2 of the draft
permit.
Response:The treatment units list has been updated.
b. We do not have a sufficient level of detail about future expansions to definitively say that
the next expansion will abandon the existing equipment/tanks and outfall entirely. The
next expansion may use much of the existing equipment/tankage. We request changes
here to consider the potential range of possibilities for the expansion design/
construction.

Muddy Creek WWTP Fact Sheet Addendum NC0081621
Response: The expansion to 1.0 MGD in the permit specifies a discharge to Outfall 002.
The initial plan associated with expansion of the facility and activation of the new
discharge included closure of the existing Outfall 001. No changes are proposed.
C. The NOV for flow exceedance issued 1/31/2019 was retracted by Corey Basinger in a
letter received by WSACC dated 4/18/2019. We request that the page be updated
accordingly.
Response:The violations summary has been updated.
6. Ammonia Requirements
a. With the updated instream data for Rocky River we request that the NH3 limits be
reconsidered for both the 0.3 MGD and the 1.0 MGD page.
Response: The updated instream data were used for reevaluation of ammonia toxicity.
However, the results of this reevaluation were less protective than the water quality
based effluent limits derived from the 2019 QUAL2K model developed forthe Rocky River.
As such, no changes are proposed for ammonia limits.

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 Muddy Creek WWTP Par01 Arsenic Aquactic Life C 150 FW 340 ug/L
WWTP/WTP Class II Par02 Arsenic Human Health C 10 HH/WS N/A ug/L
Water Supply
NPDES Permit NCO081621 Par03 Beryllium Aquatic Life NC 6.5 FW 65 ug/L
Outfall 001 Par04 Cadmium Aquatic Life NC 2.6065 FW 9.7214 ug/L
Flow, Qw (MGD) 0.300 Par05 Chlorides Aquatic Life NC 230 FW mg/L
Receiving Stream Rocky River Par06 Chlorinated Phenolic Compounds Water Supply NC 1 A ug/L
HUC Number 03040105 Par07 Total Phenolic Compounds Aquatic Life NC 300 A ug/L
Stream Class C Par08 Chromium III Aquatic Life NC 333.1081 FW 2559.4137 ug/L
❑ Apply WS Hardness WQC Par09 Chromium VI Aquatic Life NC 11 FW 16 dig/L
Lentic or Lotic Lotic Par10 Chromium, Total Aquatic Life NC N/A FW N/A pg/L
7Q10s (cfs) 38.70 Par11 Copper Aquatic Life NC 23.3254 FW 34.6252 ug/L
7Q10w (cfs) 83.00 Par12 Cyanide Aquatic Life NC 5 FW 22 10 ug/L
30Q2 (cfs) 94.00 Par13 Fluoride Aquatic Life NC 1,800 FW ug/L
QA(cfs) 525.00 Par14 Lead Aquatic Life NC 12.0532 FW 309.0820 ug/L
1Q10s (Cfs) 31.80 Par15 Mercury Aquatic Life NC 12 FW 0.5 ng/L
Effluent Hardness 66.03 mg/L (Avg) Par16 Molybdenum Human Health NC 2000 HH ug/L
------------- ----------------------
Upstream Hardness 89.29 mg/L (Avg) I Par17 Nickel Aquatic Life NC 109.0155 FW 980.9593 dig/L
Combined Hardness Chronic ——————— 89.01 mg/L ————— I Par18 Nickel Water Supply NC 25.0000 W S N/A pg/L
Combined Hardness Acute 88.95 mg/L I Par19 Selenium Aquatic Life NC 3.1 FW 56 ug/L
----------------------
Data Source(s) Par20 Silver Aquatic Life NC 0.06 FW 2.6302 ug/L
❑ CHECK TO APPLY MODEL Par21 Zinc Aquatic Life NC 371.6959 FW 368.4729 ug/L
Par22
Par23
Par24
Par25
Muddy Creek WWTP RPA updated, input
1/12/2024

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 Muddy Creek WWTP Par01 Arsenic Aquactic Life C 150 FW 340 ug/L
WWTP/WTP Class II Par02 Arsenic Human Health C 10 HH/WS N/A ug/L
Water Supply
NPDES Permit NCO081621 Par03 Beryllium Aquatic Life NC 6.5 FW 65 ug/L
Outfall 001 Par04 Cadmium Aquatic Life NC 2.5928 FW 9.6452 ug/L
Flow, Qw (MGD) 1.000 Par05 Chlorides Aquatic Life NC 230 FW mg/L
Receiving Stream Rocky River Par06 Chlorinated Phenolic Compounds Water Supply NC 1 A ug/L
HUC Number 03040105 Par07 Total Phenolic Compounds Aquatic Life NC 300 A ug/L
Stream Class C Par08 Chromium III Aquatic Life NC 331.2085 FW 2541.8295 ug/L
❑ Apply WS Hardness WQC Par09 Chromium VI Aquatic Life NC 11 FW 16 dig/L
Lentic or Lotic Lotic Par10 Chromium, Total Aquatic Life NC N/A FW N/A pg/L
7Q10s (cfs) 38.70 Par11 Copper Aquatic Life NC 23.1866 FW 34.3517 ug/L
7Q10w (cfs) 83.00 Par12 Cyanide Aquatic Life NC 5 FW 22 10 ug/L
30Q2 (cfs) 94.00 Par13 Fluoride Aquatic Life NC 1,800 FW ug/L
QA(cfs) 525.00 Par14 Lead Aquatic Life NC 11.9616 FW 306.2518 ug/L
1Q10s (Cfs) 31.80 Par15 Mercury Aquatic Life NC 12 FW 0.5 ng/L
Effluent Hardness 66.03 mg/L (Avg) Par16 Molybdenum Human Health NC 2000 HH ug/L
------------- ----------------------
Upstream Hardness 89.29 mg/L (Avg) I Par17 Nickel Aquatic Life NC 108.3734 FW 973.9983 dig/L
Combined Hardness Chronic ——————— 88.39 mg/L ————— I Par18 Nickel Water Supply NC 25.0000 W S N/A pg/L
Combined Hardness Acute 88.21 mg/L I Par19 Selenium Aquatic Life NC 3.1 FW 56 ug/L
----------------------
Data Source(s) Par20 Silver Aquatic Life NC 0.06 FW 2.5923 ug/L
❑ CHECK TO APPLY MODEL Par21 Zinc Aquatic Life NC 369.5032 FW 365.8542 ug/L
Par22
Par23
Par24
Par25
Muddy Creek WWTP RPA updated, input
1/12/2024

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 3/7/2019 53.8 53.8 Std Dev. 9.3115 1 3/7/2019 55 55 Std Dev. 21.3202
2 4/23/2019 67.5 67.5 Mean 66.0346 2 5/30/2019 100 100 Mean 89.2889
3 5/8/2019 58.7 58.7 C.V. 0.1410 3 9/25/2019 115 115 C.V. 0.2388
4 6/4/2019 61 61 n 52 4 10/8/2019 112 112 n 18
5 7/9/2019 69.2 69.2 10th Per value 57.89 mg/L 5 3/12/2020 68.7 68.7 10th Per value 61.57 mg/L
6 8/1/2019 56.8 56.8 Average Value 66.03 mg/L 6 6/25/2020 63.7 63.7 Average Value 89.29 mg/L
7 9/3/2019 71.1 71.1 Max.Value 105.30 mg/L 7 7/14/2020 90.3 90.3 Max.Value 120.00 mg/L
8 10/8/2019 54.8 54.8 8 10/7/2020 89.1 89.1
9 11/7/2019 50.8 50.8 9 1/11/2021 56.6 56.6
10 12/3/2019 59.3 59.3 10 4/21/2021 80.8 80.8
11 1/7/2020 64.2 64.2 11 8/30/2021 102 102
12 2/6/2020 57.8 57.8 12 10/14/2021 106 106
13 3/17/2020 65.1 65.1 13 2/1/2022 101 101
14 4/14/2020 67.4 67.4 14 4/5/2022 75 75
15 5/19/2020 64.2 64.2 15 7/5/2022 73 73
16 6/9/2020 68.4 68.4 16 10/26/2022 120 120
17 7/23/2020 72 72 17 11/1/2022 120 120
18 9/3/2020 65 65 18 2/22/2023 79 79
19 10/6/2020 71.9 71.9 19
20 11/3/2020 105.3 105.3 20
21 12/1/2020 65.1 65.1 21
22 1/5/2021 61 61 22
23 2/2/2021 60.8 60.8 23
24 3/2/2021 62.2 62.2 24
25 4/6/2021 79.6 79.6 25
26 5/11/2021 66.4 66.4 26
27 6/1/2021 78.7 78.7 27
28 7/13/2021 69 69 28
29 8/3/2021 65.7 65.7 29
30 9/7/2021 67 67 30
31 10/5/2021 63 63 31
32 11/2/2021 67 67 32
33 12/28/2021 67 67 33
34 1/5/2022 70 70 34
35 2/1/2022 76 76 35
36 3/29/2022 69 69 36
37 4/5/2022 67 67 37
38 5/3/2022 64 64 38
39 6/28/2022 65 65 39
40 7/12/2022 68 68 40
41 8/2/2022 64 64 41
42 9/27/2022 60 60 42
43 10/4/2022 59 59 43
44 11/1/2022 60 60 44
45 12/28/2022 74 74 45
46 1/10/2023 68 68 46
47 2/7/2023 62 62 47
48 3/2/2023 74 74 48
49 4/4/2023 66 66 49
50 5/9/2023 66 66 50
51 6/27/2023 39 39 51
52 7/18/2023 86 86 52
53 53
54 54
55 55
56 56
57 57
58 58
Muddy Creek W WTP RPA updated,data
1 3/11/2024

REASONABLE POTENTIAL ANALYSIS
Par01&Par02
Use'PASTE SPECIAL
Arsenic Values"then"COPY"
.Maximum data
points=58
Date Data BDL=1/2DL Results
1 10/8/2020 < 2.5 1.25 Std Dev. 0.1472
2 10/13/2020 < 2.5 1.25 Mean 1.2086
3 10/20/2020 < 2.5 1.25 C.V. 0.1218
4 11/3/2020 < 2.5 1.25 n 58
5 11/5/2020 < 2.5 1.25
6 11/10/2020 < 2.5 1.25 Mult Factor= 1.00
7 11/12/2020 < 2.5 1.25 Max.Value 1.3 ug/L
8 12/1/2020 < 2.5 1.25 Max.Fred Cw 1.3 ug/L
9 12/3/2020 < 2.5 1.25
10 12/8/2020 < 2.5 1.25
11 12/10/2020 < 2.5 1.25
12 1/5/2021 < 2.5 1.25
13 1/7/2021 < 2.5 1.25
14 1/14/2021 < 2.5 1.25
15 1/19/2021 < 2.5 1.25
16 2/2/2021 < 2.5 1.25
17 2/4/2021 < 2.5 1.25
18 2/9/2021 < 2.5 1.25
19 2/11/2021 < 2.5 1.25
20 3/2/2021 < 2.5 1.25
21 3/4/2021 < 2.5 1.25
22 3/9/2021 < 2.5 1.25
23 3/11/2021 < 2.5 1.25
24 4/1/2021 < 2.5 1.25
25 4/6/2021 < 2.5 1.25
26 4/8/2021 < 2.5 1.25
27 4/13/2021 < 2.5 1.25
28 5/4/2021 < 2.5 1.25
29 5/6/2021 < 2.5 1.25
30 5/11/2021 < 2.5 1.25
31 5/13/2021 < 2.5 1.25
32 6/1/2021 < 2.5 1.25
33 6/3/2021 < 2.5 1.25
34 6/8/2021 < 2.5 1.25
35 6/10/2021 < 2.5 1.25
36 7/1/2021 < 2.5 1.25
37 7/6/2021 < 2.5 1.25
38 7/8/2021 < 2.5 1.25
39 7/13/2021 < 2.5 1.25
40 8/3/2021 < 2.5 1.25
41 8/5/2021 < 2.5 1.25
42 8/12/2021 < 2.5 1.25
43 8/17/2021 < 2.5 1.25
44 9/7/2021 < 2.5 1.25
45 9/9/2021 < 2.5 1.25
46 9/14/2021 < 2.5 1.25
47 9/16/2021 < 2.5 1.25
48 10/5/2021 < 2.5 1.25
49 10/7/2021 < 2.5 1.25
50 10/12/2021 < 2.5 1.25
51 10/14/2021 < 2.5 1.25
52 1/5/2022 < 2.5 1.25
53 4/5/2022 < 2 1
54 7/12/2022 < 2 1
55 10/4/2022 < 2 1
56 1/10/2023 < 1 0.5
57 4/4/2023 < 1 0.5
58 7/18/2023 1.1 1.1
Muddy Creek W WTP RPA updated,data
-2- 3/11/2024

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 10/8/2020 < 2.5 1.25 Std Dev. 0.2304 1 10/8/2020 < 2.5 1.25 Std Dev. 0.3072
2 10/13/2020 < 2.5 1.25 Mean 1.1724 2 10/13/2020 < 2.5 1.25 Mean 1.1466
3 10/20/2020 < 2.5 1.25 C.V. 0.1965 3 10/20/2020 < 2.5 1.25 C.V. 0.2679
4 11/3/2020 < 2.5 1.25 n 58 4 11/3/2020 < 2.5 1.25 n 58
5 11/5/2020 < 2.5 1.25 5 11/5/2020 < 2.5 1.25
6 11/10/2020 < 2.5 1.25 Mult Factor= 1.00 6 11/10/2020 < 2.5 1.25 Mult Factor= 1.00
7 11/12/2020 < 2.5 1.25 Max.Value 1.25 ug/L 7 11/12/2020 < 2.5 1.25 Max.Value 1.250 ug/L
8 12/1/2020 < 2.5 1.25 Max.Pred Cw 1.25 ug/L 8 12/1/2020 < 2.5 1.25 Max.Pred Cw 1.250 ug/L
9 12/3/2020 < 2.5 1.25 9 12/3/2020 < 2.5 1.25
10 12/8/2020 < 2.5 1.25 10 12/8/2020 < 2.5 1.25
11 12/10/2020 < 2.5 1.25 11 12/10/2020 < 2.5 1.25
12 1/5/2021 < 2.5 1.25 12 1/5/2021 < 2.5 1.25
13 1/7/2021 < 2.5 1.25 13 1/7/2021 < 2.5 1.25
14 1/14/2021 < 2.5 1.25 14 1/14/2021 < 2.5 1.25
15 1/19/2021 < 2.5 1.25 15 1/19/2021 < 2.5 1.25
16 2/2/2021 < 2.5 1.25 16 2/2/2021 < 2.5 1.25
17 2/4/2021 < 2.5 1.25 17 2/4/2021 < 2.5 1.25
18 2/9/2021 < 2.5 1.25 18 2/9/2021 < 2.5 1.25
19 2/11/2021 < 2.5 1.25 19 2/11/2021 < 2.5 1.25
20 3/2/2021 < 2.5 1.25 20 3/2/2021 < 2.5 1.25
21 3/4/2021 < 2.5 1.25 21 3/4/2021 < 2.5 1.25
22 3/9/2021 < 2.5 1.25 22 3/9/2021 < 2.5 1.25
23 3/11/2021 < 2.5 1.25 23 3/11/2021 < 2.5 1.25
24 4/1/2021 < 2.5 1.25 24 4/1/2021 < 2.5 1.25
25 4/6/2021 < 2.5 1.25 25 4/6/2021 < 2.5 1.25
26 4/8/2021 < 2.5 1.25 26 4/8/2021 < 2.5 1.25
27 4/13/2021 < 2.5 1.25 27 4/13/2021 < 2.5 1.25
28 5/4/2021 < 2.5 1.25 28 5/4/2021 < 2.5 1.25
29 5/6/2021 < 2.5 1.25 29 5/6/2021 < 2.5 1.25
30 5/11/2021 < 2.5 1.25 30 5/11/2021 < 2.5 1.25
31 5/13/2021 < 2.5 1.25 31 5/13/2021 < 2.5 1.25
32 6/1/2021 < 2.5 1.25 32 6/1/2021 < 2.5 1.25
33 6/3/2021 < 2.5 1.25 33 6/3/2021 < 2.5 1.25
34 6/8/2021 < 2.5 1.25 34 6/8/2021 < 2.5 1.25
35 6/10/2021 < 2.5 1.25 35 6/10/2021 < 2.5 1.25
36 7/1/2021 < 2.5 1.25 36 7/1/2021 < 2.5 1.25
37 7/6/2021 < 2.5 1.25 37 7/6/2021 < 2.5 1.25
38 7/8/2021 < 2.5 1.25 38 7/8/2021 < 2.5 1.25
39 7/13/2021 < 2.5 1.25 39 7/13/2021 < 2.5 1.25
40 8/3/2021 < 2.5 1.25 40 8/3/2021 < 2.5 1.25
41 8/5/2021 < 2.5 1.25 41 8/5/2021 < 2.5 1.25
42 8/12/2021 < 2.5 1.25 42 8/12/2021 < 2.5 1.25
43 8/17/2021 < 2.5 1.25 43 8/17/2021 < 2.5 1.25
44 9/7/2021 < 2.5 1.25 44 9/7/2021 < 2.5 1.25
45 9/9/2021 < 2.5 1.25 45 9/9/2021 < 2.5 1.25
46 9/14/2021 < 2.5 1.25 46 9/14/2021 < 2.5 1.25
47 9/16/2021 < 2.5 1.25 47 9/16/2021 < 2.5 1.25
48 10/5/2021 < 2.5 1.25 48 10/5/2021 < 2.5 1.25
49 10/7/2021 < 2.5 1.25 49 10/7/2021 < 2.5 1.25
50 10/12/2021 < 2.5 1.25 50 10/12/2021 < 2.5 1.25
51 10/14/2021 < 2.5 1.25 51 10/14/2021 < 2.5 1.25
52 1/5/2022 < 2.5 1.25 52 1/5/2022 < 2.5 1.25
53 4/5/2022 < 1 0.5 53 4/5/2022 < 0.5 0.25
54 7/12/2022 < 1 0.5 54 7/12/2022 < 0.5 0.25
55 10/4/2022 < 1 0.5 55 10/4/2022 < 0.5 0.25
56 1/10/2023 < 1 0.5 56 1/10/2023 < 0.5 0.25
57 4/4/2023 < 1 0.5 57 4/4/2023 < 0.5 0.25
58 7/18/2023 < 1 0.5 58 7/18/2023 < 0.5 0.25
Muddy Creek WWTP RPA updated,data
-3- 3/11/2024

REASONABLE POTENTIAL ANALYSIS
Par07 Par10
Use"PASTE SPECIAL Use"PASTE SPECIAL
Total Phenolic Compounds Values"then"COPY• Chromium,Total Values"then"COPY"
.Maximum data .Maximum data
points=58 points=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 7/23/2020 < 10 5 Std Dev. 8.1854 1 10/8/2020 < 2.5 1.25 Std Dev. 0.3652
2 10/5/2021 < 20 10 Mean 12.0000 2 10/13/2020 < 2.5 1.25 Mean 1.2888
3 4/5/2022 21 21 C.V.(default) 0.6000 3 10/20/2020 < 2.5 1.25 C.V. 0.2833
4 n 3 4 11/3/2020 < 2.5 1.25 n 58
5 5 11/5/2020 < 2.5 1.25
6 Mult Factor= 3.00 6 11/10/2020 < 2.5 1.25 Mult Factor= 1.00
7 Max.Value 21.0 ug/L 7 11/12/2020 < 2.5 1.25 Max.Value 4.0 pg/L
8 Max.Fred Cw 63.0 ug/L 8 12/1/2020 < 2.5 1.25 Max.Fred Cw 4.0 pg/L
9 9 12/3/2020 < 2.5 1.25
10 10 12/8/2020 < 2.5 1.25
11 11 12/10/2020 < 2.5 1.25
12 12 1/5/2021 < 2.5 1.25
13 13 1/7/2021 < 2.5 1.25
14 14 1/14/2021 < 2.5 1.25
15 15 1/19/2021 < 2.5 1.25
16 16 2/2/2021 < 2.5 1.25
17 17 2/4/2021 < 2.5 1.25
18 18 2/9/2021 < 2.5 1.25
19 19 2/11/2021 < 2.5 1.25
20 20 3/2/2021 < 2.5 1.25
21 21 3/4/2021 < 2.5 1.25
22 22 3/9/2021 < 2.5 1.25
23 23 3/11/2021 < 2.5 1.25
24 24 4/1/2021 < 2.5 1.25
25 25 4/6/2021 < 2.5 1.25
26 26 4/8/2021 < 2.5 1.25
27 27 4/13/2021 < 2.5 1.25
28 28 5/4/2021 < 2.5 1.25
29 29 5/6/2021 < 2.5 1.25
30 30 5/11/2021 < 2.5 1.25
31 31 5/13/2021 < 2.5 1.25
32 32 6/1/2021 < 2.5 1.25
33 33 6/3/2021 < 2.5 1.25
34 34 6/8/2021 < 2.5 1.25
35 35 6/10/2021 < 2.5 1.25
36 36 7/1/2021 < 2.5 1.25
37 37 7/6/2021 < 2.5 1.25
38 38 7/8/2021 < 2.5 1.25
39 39 7/13/2021 < 2.5 1.25
40 40 8/3/2021 < 2.5 1.25
41 41 8/5/2021 < 2.5 1.25
42 42 8/12/2021 < 2.5 1.25
43 43 8/17/2021 < 2.5 1.25
44 44 9/7/2021 < 2.5 1.25
45 45 9/9/2021 < 2.5 1.25
46 46 9/14/2021 < 2.5 1.25
47 47 9/16/2021 < 2.5 1.25
48 48 10/5/2021 < 2.5 1.25
49 49 10/7/2021 < 2.5 1.25
50 50 10/12/2021 < 2.5 1.25
51 51 10/14/2021 < 2.5 1.25
52 52 1/5/2022 < 2.5 1.25
53 53 4/5/2022 < 2 1
54 54 7/12/2022 4 4
55 55 10/4/2022 < 2 1
56 56 1/10/2023 < 2.5 1.25
57 57 4/4/2023 < 2.5 1.25
58 58 7/18/2023 < 2.5 1.25
Muddy Creek W WTP RPA updated,data
-4- 3/11/2024

REASONABLE POTENTIAL ANALYSIS
Pal Par12
Use"PASTE SPECIAL Use"PASTE SPECIAL
Copper Values"then"COPY" Cyanide Values"then"COPY"
pp .Maximum data y .Maximum data
points=58 points=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 10/8/2020 5.6 5.6 Std Dev. 4.1446 1 7/23/2020 < 5 5 Std Dev. 0.0000
2 10/13/2020 < 5 2.5 Mean 7.2086 2 10/5/2021 < 5 5 Mean 5.00
3 10/20/2020 < 5 2.5 C.V. 0.5749 3 4/5/2022 < 5 5 C.V.(default) 0.6000
4 11/3/2020 5.8 5.8 n 58 4 n 3
5 11/5/2020 5.2 5.2 5
6 11/10/2020 7.4 7.4 Mult Factor= 1.00 6 Mult Factor= 3.00
7 11/12/2020 7 7 Max.Value 17.20 ug/L 7 Max.Value 5.0 ug/L
8 12/1/2020 < 2.5 1.25 Max.Fred Cw 17.20 ug/L 8 Max.Fred Cw 15.0 ug/L
9 12/3/2020 < 2.5 1.25 9
10 12/8/2020 < 2.5 1.25 10
11 12/10/2020 < 2.5 1.25 11
12 1/5/2021 < 5 2.5 12
13 1/7/2021 < 5 2.5 13
14 1/14/2021 < 5 2.5 14
15 1/19/2021 5.7 5.7 15
16 2/2/2021 5.3 5.3 16
17 2/4/2021 5.8 5.8 17
18 2/9/2021 < 5 2.5 18
19 2/11/2021 5.2 5.2 19
20 3/2/2021 < 5 2.5 20
21 3/4/2021 < 5 2.5 21
22 3/9/2021 5.1 5.1 22
23 3/11/2021 5.8 5.8 23
24 4/1/2021 10.3 10.3 24
25 4/6/2021 5.5 5.5 25
26 4/8/2021 5.4 5.4 26
27 4/13/2021 6.2 6.2 27
28 5/4/2021 8.1 8.1 28
29 5/6/2021 7.2 7.2 29
30 5/11/2021 6.8 6.8 30
31 5/13/2021 5.2 5.2 31
32 6/1/2021 8.7 8.7 32
33 6/3/2021 9.8 9.8 33
34 6/8/2021 10.4 10.4 34
35 6/10/2021 7.2 7.2 35
36 7/1/2021 13.2 13.2 36
37 7/6/2021 9.7 9.7 37
38 7/8/2021 11.4 11.4 38
39 7/13/2021 11.3 11.3 39
40 8/3/2021 13.8 13.8 40
41 8/5/2021 12.8 12.8 41
42 8/12/2021 9.7 9.7 42
43 8/17/2021 7.3 7.3 43
44 9/7/2021 17.2 17.2 44
45 9/9/2021 15.4 15.4 45
46 9/14/2021 15.2 15.2 46
47 9/16/2021 12.4 12.4 47
48 10/5/2021 12.1 12.1 48
49 10/7/2021 11.6 11.6 49
50 10/12/2021 11 11 50
51 10/14/2021 10.4 10.4 51
52 1/5/2022 < 5 2.5 52
53 4/5/2022 4 4 53
54 7/12/2022 6 6 54
55 10/4/2022 8 8 55
56 1/10/2023 6.5 6.5 56
57 4/4/2023 < 5 2.5 57
58 7/18/2023 14.4 14.4 58
Muddy Creek W WTP RPA updated,data
-5- 3/11/2024

REASONABLE POTENTIAL ANALYSIS
Par14 Use"PASTE SPECIAL Par17&Par18 Use"PASTE
Values"then"COPY" SPECIAL-Values'
Lead .Maximum data Nickel then"COPY".
points=58 Maximum data
Date BDL=II2DL Results Date Data BDL=II2DL Results points=58
1 10/8/2020 < 2.5 1.25 Std Dev. 0.1737 1 10/8/2020 2.6 2.6 Std Dev. 1.7745
2 10/13/2020 < 2.5 1.25 Mean 1.1983 2 10/13/2020 < 2.5 1.25 Mean 2.7957
3 10/20/2020 < 2.5 1.25 C.V. 0.1450 3 10/20/2020 < 2.5 1.25 C.V. 0.6347
4 11/3/2020 < 2.5 1.25 n 58 4 11/3/2020 5.1 5.1 n 58
5 11/5/2020 < 2.5 1.25 5 11/5/2020 2.8 2.8
6 11/10/2020 < 2.5 1.25 Mult Factor= 1.00 6 11/10/2020 3.8 3.8 Mult Factor= 1.00
7 11/12/2020 < 2.5 1.25 Max.Value 1.250 ug/L 7 11/12/2020 2.9 2.9 Max.Value 6.3 pg/L
8 12/1/2020 < 2.5 1.25 Max.Fred Cw 1.250 ug/L 8 12/1/2020 < 2.5 1.25 Max.Fred Cw 6.3 pg/L
9 12/3/2020 < 2.5 1.25 9 12/3/2020 < 2.5 1.25
10 12/8/2020 < 2.5 1.25 10 12/8/2020 < 2.5 1.25
11 12/10/2020 < 2.5 1.25 11 12/10/2020 < 2.5 1.25
12 1/5/2021 < 2.5 1.25 12 1/5/2021 < 2.5 1.25
13 1/7/2021 < 2.5 1.25 13 1/7/2021 < 2.5 1.25
14 1/14/2021 < 2.5 1.25 14 1/14/2021 < 2.5 1.25
15 1/19/2021 < 2.5 1.25 15 1/19/2021 < 2.5 1.25
16 2/2/2021 < 2.5 1.25 16 2/2/2021 < 2.5 1.25
17 2/4/2021 < 2.5 1.25 17 2/4/2021 < 2.5 1.25
18 2/9/2021 < 2.5 1.25 18 2/9/2021 < 2.5 1.25
19 2/11/2021 < 2.5 1.25 19 2/11/2021 < 2.5 1.25
20 3/2/2021 < 2.5 1.25 20 3/2/2021 < 2.5 1.25
21 3/4/2021 < 2.5 1.25 21 3/4/2021 < 2.5 1.25
22 3/9/2021 < 2.5 1.25 22 3/9/2021 < 2.5 1.25
23 3/11/2021 < 2.5 1.25 23 3/11/2021 < 2.5 1.25
24 4/1/2021 < 2.5 1.25 24 4/1/2021 < 2.5 1.25
25 4/6/2021 < 2.5 1.25 25 4/6/2021 < 2.5 1.25
26 4/8/2021 < 2.5 1.25 26 4/8/2021 < 2.5 1.25
27 4/13/2021 < 2.5 1.25 27 4/13/2021 < 2.5 1.25
28 5/4/2021 < 2.5 1.25 28 5/4/2021 < 2.5 1.25
29 5/6/2021 < 2.5 1.25 29 5/6/2021 < 2.5 1.25
30 5/11/2021 < 2.5 1.25 30 5/11/2021 < 2.5 1.25
31 5/13/2021 < 2.5 1.25 31 5/13/2021 < 2.5 1.25
32 6/1/2021 < 2.5 1.25 32 6/1/2021 5.2 5.2
33 6/3/2021 < 2.5 1.25 33 6/3/2021 5 5
34 6/8/2021 < 2.5 1.25 34 6/8/2021 4.4 4.4
35 6/10/2021 < 2.5 1.25 35 6/10/2021 2.6 2.6
36 7/1/2021 < 2.5 1.25 36 7/1/2021 3.4 3.4
37 7/6/2021 < 2.5 1.25 37 7/6/2021 4.4 4.4
38 7/8/2021 < 2.5 1.25 38 7/8/2021 4 4
39 7/13/2021 < 2.5 1.25 39 7/13/2021 3.3 3.3
40 8/3/2021 < 2.5 1.25 40 8/3/2021 5 5
41 8/5/2021 < 2.5 1.25 41 8/5/2021 5.1 5.1
42 8/12/2021 < 2.5 1.25 42 8/12/2021 5.4 5.4
43 8/17/2021 < 2.5 1.25 43 8/17/2021 5.4 5.4
44 9/7/2021 < 2.5 1.25 44 9/7/2021 6.3 6.3
45 9/9/2021 < 2.5 1.25 45 9/9/2021 6.1 6.1
46 9/14/2021 < 2.5 1.25 46 9/14/2021 5.7 5.7
47 9/16/2021 < 2.5 1.25 47 9/16/2021 5.2 5.2
48 10/5/2021 < 2.5 1.25 48 10/5/2021 4.6 4.6
49 10/7/2021 < 2.5 1.25 49 10/7/2021 4.6 4.6
50 10/12/2021 < 2.5 1.25 50 10/12/2021 3.5 3.5
51 10/14/2021 < 2.5 1.25 51 10/14/2021 3.8 3.8
52 1/5/2022 < 2.5 1.25 52 1/5/2022 < 2.5 1.25
53 4/5/2022 < 2 1 53 4/5/2022 2 2
54 7/12/2022 < 2 1 54 7/12/2022 6 6
55 10/4/2022 < 2 1 55 10/4/2022 < 5 2.5
56 1/10/2023 < 1 0.5 56 1/10/2023 < 2.5 1.25
57 4/4/2023 < 1 0.5 57 4/4/2023 < 2.5 1.25
58 7/18/2023 < 1 0.5 58 7/18/2023 5.2 5.2
Muddy Creek W WTP RPA updated,data
-6- 3/11/2024

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 10/8/2020 < 5 2.5 Std Dev. 0.6144 1 3/5/2019 < 2.5 1.25 Std Dev. 0.2902
2 10/13/2020 < 5 2.5 Mean 2.2931 2 3/6/2019 < 2.5 1.25 Mean 1.1176
3 10/20/2020 < 5 2.5 C.V. 0.2679 3 3/7/2019 < 2.5 1.25 C.V. 0.2597
4 11/3/2020 < 5 2.5 n 58 4 5/7/2019 < 2.5 1.25 n 34
5 11/5/2020 < 5 2.5 5 5/8/2019 < 2.5 1.25
6 11/10/2020 < 5 2.5 Mult Factor= 1.00 6 6/4/2019 < 2.5 1.25 Mult Factor= 1.07
7 11/12/2020 < 5 2.5 Max.Value 2.5 ug/L 7 6/5/2019 < 2.5 1.25 Max.Value 1.250 ug/L
8 12/1/2020 < 5 2.5 Max.Fred Cw 2.5 ug/L 8 6/6/2019 < 2.5 1.25 Max.Fred Cw 1.338 ug/L
9 12/3/2020 < 5 2.5 9 6/11/2019 < 2.5 1.25
10 12/8/2020 < 5 2.5 10 7/1/2019 < 2.5 1.25
11 12/10/2020 < 5 2.5 11 7/2/2019 < 2.5 1.25
12 1/5/2021 < 5 2.5 12 7/3/2019 < 2.5 1.25
13 1/7/2021 < 5 2.5 13 7/9/2019 < 2.5 1.25
14 1/14/2021 < 5 2.5 14 8/6/2019 < 2.5 1.25
15 1/19/2021 < 5 2.5 15 8/7/2019 < 2.5 1.25
16 2/2/2021 < 5 2.5 16 8/8/2019 < 2.5 1.25
17 2/4/2021 < 5 2.5 17 9/3/2019 < 2.5 1.25
18 2/9/2021 < 5 2.5 18 9/5/2019 < 2.5 1.25
19 2/11/2021 < 5 2.5 19 9/6/2019 < 2.5 1.25
20 3/2/2021 < 5 2.5 20 10/2/2019 < 2.5 1.25
21 3/4/2021 < 5 2.5 21 10/3/2019 < 2.5 1.25
22 3/9/2021 < 5 2.5 22 11/5/2019 < 2.5 1.25
23 3/11/2021 < 5 2.5 23 11/7/2019 < 2.5 1.25
24 4/1/2021 < 5 2.5 24 11/12/2019 < 2.5 1.25
25 4/6/2021 < 5 2.5 25 11/14/2019 < 2.5 1.25
26 4/8/2021 < 5 2.5 26 1/2/2020 < 2.5 1.25
27 4/13/2021 < 5 2.5 27 2/4/2020 < 2.5 1.25
28 5/4/2021 < 5 2.5 28 2/6/2020 < 2.5 1.25
29 5/6/2021 < 5 2.5 29 4/5/2022 < 1 0.5
30 5/11/2021 < 5 2.5 30 7/12/2022 < 1 0.5
31 5/13/2021 < 5 2.5 31 10/4/2022 < 1 0.5
32 6/1/2021 < 5 2.5 32 1/10/2023 < 1 0.5
33 6/3/2021 < 5 2.5 33 4/4/2023 < 1 0.5
34 6/8/2021 < 5 2.5 34 7/18/2023 < 1 0.5
35 6/10/2021 < 5 2.5 35
36 7/1/2021 < 5 2.5 36
37 7/6/2021 < 5 2.5 37
38 7/8/2021 < 5 2.5 38
39 7/13/2021 < 5 2.5 39
40 8/3/2021 < 5 2.5 40
41 8/5/2021 < 5 2.5 41
42 8/12/2021 < 5 2.5 42
43 8/17/2021 < 5 2.5 43
44 9/7/2021 < 5 2.5 44
45 9/9/2021 < 5 2.5 45
46 9/14/2021 < 5 2.5 46
47 9/16/2021 < 5 2.5 47
48 10/5/2021 < 5 2.5 48
49 10/7/2021 < 5 2.5 49
50 10/12/2021 < 5 2.5 50
51 10/14/2021 < 5 2.5 51
52 1/5/2022 < 5 2.5 52
53 4/5/2022 < 1 0.5 53
54 7/12/2022 < 1 0.5 54
55 10/4/2022 < 1 0.5 55
56 1/10/2023 < 1 0.5 56
57 4/4/2023 < 1 0.5 57
58 7/18/2023 < 1 0.5 58
Muddy Creek W WTP RPA updated,data
-7- 3/11/2024

REASONABLE POTENTIAL ANALYSIS
Par21
Use"PASTE SPECIAL
ZincValues"then"COPY"
.Maximum data
points=58
Date Data BDL=1/2DL Results
1 10/8/2020 43.4 43.4 Std Dev. 36.6726
2 10/13/2020 < 25 12.5 Mean 59.7069
3 10/20/2020 38.6 38.6 C.V. 0.6142
4 11/3/2020 46.6 46.6 n 58
5 11/5/2020 47 47
6 11/10/2020 63 63 Mult Factor= 1.00
7 11/12/2020 65 65 Max.Value 258.0 ug/L
8 12/1/2020 40.3 40.3 Max.Pred Cw 258.0 ug/L
9 12/3/2020 24.7 24.7
10 12/8/2020 22.3 22.3
11 12/10/2020 23.1 23.1
12 1/5/2021 33 33
13 1/7/2021 34.3 34.3
14 1/14/2021 37.3 37.3
15 1/19/2021 51 51
16 2/2/2021 43.4 43.4
17 2/4/2021 47.8 47.8
18 2/9/2021 56 56
19 2/11/2021 46.7 46.7
20 3/2/2021 49.4 49.4
21 3/4/2021 41.6 41.6
22 3/9/2021 65.6 65.6
23 3/11/2021 60.8 60.8
24 4/1/2021 51 51
25 4/6/2021 51.2 51.2
26 4/8/2021 50.6 50.6
27 4/13/2021 59.5 59.5
28 5/4/2021 59.3 59.3
29 5/6/2021 58.9 58.9
30 5/11/2021 57 57
31 5/13/2021 48.9 48.9
32 6/1/2021 90.3 90.3
33 6/3/2021 106 106
34 6/8/2021 114 114
35 6/10/2021 54 54
36 7/1/2021 58.4 58.4
37 7/6/2021 103 103
38 7/8/2021 133 133
39 7/13/2021 112 112
40 8/3/2021 64.8 64.8
41 8/5/2021 55.9 55.9
42 8/12/2021 43.2 43.2
43 8/17/2021 41.7 41.7
44 9/7/2021 95.6 95.6
45 9/9/2021 88.3 88.3
46 9/14/2021 97.8 97.8
47 9/16/2021 77 77
48 10/5/2021 70.7 70.7
49 10/7/2021 71.3 71.3
50 10/12/2021 53.5 53.5
51 10/14/2021 53.3 53.3
52 1/5/2022 < 25 12.5
53 4/5/2022 42 42
54 7/12/2022 21 21
55 10/4/2022 33 33
56 1/10/2023 46 46
57 4/4/2023 36.9 36.9
58 7/18/2023 258 258
Muddy Creek WWTP RPA updated,data
-8- 3/11/2024

Muddy Creek WWTP > Outfall 001
NCO081621 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 0.3 MGD
MAXIMUM DATA POINTS = 58
Qw (MGD) = 0.3000 WWTP/WTP Class: II COMBINED HARDNESS (mg/L)
1Q10S (cfs) = 31.80 IWC% @ 1Q10S = 1.441190144 Acute = 8 8.9 5 mg/L
7Q10S (cfs) = 38.70 IWC% @ 7Q10S = 1.187284565 Chronic= 89.01 mg/L
7Q10W (cfs) = 83.00 IWC% @ 7Q10W= 0.557119751
30Q2 (cfs) = 94.00 IWC% @ 30Q2 = 0.492245805
Avg. Stream Flow, QA(cfs) = 525.00 IW%C @ QA= 0.088493049
Receiving Stream: Rocky River HUC 03040105 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): 23,591.6
Arsenic C 150 FW(7Q10s) 340 ug/L ___
58 1 1.3 Chronic (FW) 12,633.9
No value >Allowable Cw
_ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _
Arsenic C 10 HH/WS(Qavg) ug/L Chronic (HH) 11,300.3 No RP, Predicted Max< 50% of Allowable Cw- No
No value >Allowable Cw Monitoring required
Acute: 4,510.16
Beryllium NC 6.5 FW(7Q10s) 65 ug/L 58 0 1.25
Chronic: 547.47 No RP, Predicted Max< 50% of Allowable Cw- No
NO DETECTS Max MDL= 2.5 Monitoring required
Acute: 674.537
Cadmium NC 2.6065 FW(7Q10s) 9.7214 ug/L 58 0 1.250
Chronic: 219.532 No RP, Predicted Max< 50% of Allowable Cw- No
NO DETECTS Max MDL 2.5 Monitoring required
Acute: NO WQS
Total Phenolic Compounds NC 300 A(30Q2) ug/L 3 1 63.0 _ ___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Note: n< 9 C.V. (default) Chr onic: 60,945.2 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: 177,590.3
Chromium III NC 333.1081 FW(7Q10s) 2559.4137 µg/L 0 0 N/A
--Chronic: --- 28,056.3-- ---------------------------
Acute: 1,110.2
Chromium VI NC 11 FW(7Q10s) 16 µg/L 0 0 N/A
--Chronic: -----926.5--- ---------------------------
Tot Cr value(s) < 5 and< Cr VI Allowable Cw
Chromium, Total NC µg/L 58 1 4.0 Max reported value - 4 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: 2,402.55
Copper NC 23.3254 FW(7Q10s) 34.6252 ug/L 58 44 17.20
Chronic: 1,964.60 No RP, Predicted Max< 50% of Allowable Cw- No
No value > Allowable Cw [No
onitoring required
Acute: 1,526.5
Cyanide NC 5 FW(7Q10s) 22 10 ug/L 3 0 15.0 ___ _ ______ ____
Note: n< 9 C.V. (default) Chronic: 421.1 RP, Predicted Max< 50% of Allowable Cw- No
Limited data set NO DETECTS Max MDL 10 Monitoring required
Muddy Creek WWTP RPA updated, rpa
Page 1 of 2 1/12/2024

Muddy Creek WWTP Outfall 001
NCO081621 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 0.3 MGD
Acute: 21,446.306
Lead NC 12.0532 FW(7Q10s) 309.0820 ug/L 58 0 1.250
Chronic: 1,015.192 No RP, Predicted Max< 50% of Allowable Cw- No
NO DETECTS Max MDL= 2.5 Monitoring required
Acute (FW): 68,065.9
Nickel NC 109.0155 FW(7Q10s) 980.9593 µg/L _
58 28 6.3 Chronic (FW) 9,181.9 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) 2,105.6
No value >Allowable Cw
Acute: 3,885.7
Selenium NC 3.1 FW(7Q10s) 56 ug/L 58 0 2.5
Chronic: 261.1 No RP, Predicted Max< 50% of Allowable Cw- No
NO DETECTS Max MDL 5 Monitoring required
Acute: 182.499
Silver NC 0.06 FW(7Q10s) 2.6302 ug/L 34 0 1.338
Chronic: 5.054 No RP, Predicted Max< 50% of Allowable Cw- No
NO DETECTS Max MDL= 2.5 Monitoring required
Acute: 25,567.3 No RP, Predicted Max< 50% of Allowable Cw- No
Zinc NC 371.6959 FW(7Q10s) 368.4729 ug/L 58 56 258.0 Monitoring required
------------------- -----------------------------
Chronic: 31,306.4
No value >Allowable Cw
Muddy Creek WWTP RPA updated, rpa
Page 2 of 2 1/12/2024

Muddy Creek WWTP > Outfall 001
NCOO81621 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 1 MGD
MAXIMUM DATA POINTS = 58
Qw (MGD) = 1.0000 WWTP/WTP Class: II COMBINED HARDNESS (mg/L)
1Q10S (cfs) = 31.80 IWC% @ 1Q10S = 4.647676162 Acute = 88.21 mg/L
7Q10S (cfs) = 38.70 IWC% @ 7QIOS = 3.850931677 Chronic= 88.39 mg/L
7QIOW (cfs) = 83.00 IWC% @ 7Q10W= 1.833234772
30Q2 (cfs) = 94.00 IWC% @ 30Q2 = 1.622187336
Avg. Stream Flow, QA(cfs) = 525.00 IW%C @ QA= 0.294369006
Receiving Stream: Rocky River HUC 03040105 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): 7,315.5
Arsenic C 150 FW(7Q10s) 340 ug/L ___
58 1 1.3 Chronic (FW) 3,895.2
No value >Allowable Cw
_ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _
Arsenic C 10 HH/WS(Qavg) ug/L Chronic (HH) 3,397.1 No RP, Predicted Max< 50% of Allowable Cw- No
No value >Allowable Cw Monitoring required
Acute: 1,398.55
Beryllium NC 6.5 FW(7Q10s) 65 ug/L 58 0 1.25
Chronic: 168.79 No RP, Predicted Max< 50% of Allowable Cw- No
NO DETECTS Max MDL= 2.5 Monitoring required
Acute: 207.526
Cadmium NC 2.5928 FW(7Q10s) 9.6452 ug/L 58 0 1.250
Chronic: 67.330 No RP, Predicted Max< 50% of Allowable Cw- No
NO DETECTS Max MDL 2.5 Monitoring required
Acute: NO WQS
Total Phenolic Compounds NC 300 A(30Q2) ug/L 3 1 63.0 _ ____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Note: n<9 C.V. (default) Chr onic: 18,493.5 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: 54,690.3
Chromium III NC 331.2085 FW(7Q10s) 2541.8295 µg/L 0 0 N/A
--Chronic: ----8,600.7 -- ---------------------------
Acute: 344.3
Chromium VI NC I 1 FW(7Q10s) 16 µg/L 0 0 N/A
--Chronic: -----285.E--- ---------------------------
Tot Cr value(s) < 5 and< Cr VI Allowable Cw
Chromium, Total NC µg/L 58 1 4.0 Max reported value - 4 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: 739.12
Copper NC 23.1866 FW(7Q10s) 34.3517 ug/L 58 44 17.20
Chronic: 602.10 No RP, Predicted Max< 50% of Allowable Cw- No
No value > Allowable Cw [No
onitoring required
Acute: 473.4
Cyanide NC 5 FW(7QIOs) 22 10 ug/L 3 0 15.0 ___ _ ______ ____
Note: n< 9 C.V. (default) Chr onic: 129.8 RP, Predicted Max< 50% of Allowable Cw- No
Limited data set NO DETECTS Max MDL 10 Monitoring required
Muddy Creek WWTP RPA updated, rpa
Page 1 of 2 1/12/2024

Muddy Creek WWTP Outfall 001
NCO081621 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 1 MGD
Acute: 6,589.354
Lead NC 11.9616 FW(7Q10s) 306.2518 ug/L 58 0 1.250
Chronic: 310.616 No RP, Predicted Max< 50% of Allowable Cw- No
NO DETECTS Max MDL=2.5 Monitoring required
Acute (FW): 20,956.7
Nickel NC 108.3734 FW(7Q10s) 973.9983 µg/L _
58 28 6.3 Chronic (FW) 2,814.2 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) 649.2
No value >Allowable Cw
Acute: 1,204.9
Selenium NC 3.1 FW(7Q10s) 56 ug/L 58 0 2.5
Chronic: 80.5 No RP, Predicted Max< 50% of Allowable Cw- No
NO DETECTS Max MDL 5 Monitoring required
Acute: 55.777
Silver NC 0.06 FW(7Q10s) 2.5923 ug/L 34 0 1.338
Chronic: 1.558 No RP, All values non-detect< 2.5 ug/L or 1 ug/L-
no monitoring required. Permittee shall use PQL < 1
NO DETECTS Max MDL=2.5 ug/L
Acute: 7,871.8 No RP, Predicted Max< 50% of Allowable Cw- No
Zinc NC 369.5032 FW(7Q10s) 365.8542 ug/L 58 56 258.0 Monitoring required
-- ---- --- -- ---------------------------Chronic: 9
No value >Allowable Cw
Muddy Creek WWTP RPA updated, rpa
Page 2 of 2 1/12/2024

Permit No. NCO081621
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/1 Chronic FW, µg/1 Acute SW, µg/l 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
213.0200 (e.g., arsenic at 10 µg/1 for human health protection; cyanide at 5 µg/L and fluoride at
1.8 mg/L for aquatic life protection).
Table 2.Dissolved Freshwater Standards for Hardness-Dependent Metals
The Water Effects Ratio (WER)is equal to one unless determined otherwise under 15A
NCAC 02B .0211 Subparagraph(11)(d)
Metal NC Dissolved Standard, µg/I
Cadmium,Acute WER*{1.136672-[In hardness](0.04183 8)) •e^{0.9789 [ln hardness]-3.443}
Cadmium,Acute Trout waters WER*{1.136672-[In hardness](0.04183 8)) •e^{0.9789[ln hardness]-3.866}
Cadmium,Chronic WER*{1.101672-[ln hardness](0.04183 8)) •e^{0.7977[ln hardness]-3.9091
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]-1.7021
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. NCO081621
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. NCO081621
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+s7Q 10, cfs)
The Combined Hardness for acute is the same but the calculation uses the IQ 10 flow.
3. The permit writer converts the numeric standard for each metal of concern to a total recoverable
metal,using the EPA Default Partition Coefficients (DPCs) or site-specific translators, if any
have been developed using federally approved methodology.
EPA default partition coefficients or the"Fraction Dissolved"converts the value for
dissolved metal at laboratory conditions to total recoverable metal at in-stream
ambient conditions. This factor is calculated using the linear partition coefficients
found in The Metals Translator: Guidance for Calculating a Total Recoverable
Permit Limit from a Dissolved Criterion (EPA 823-B-96-007,June 1996) and the
equation:
Cdiss — 1
Ctotal 1 + { [KPO] [SS(l+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. NC0081621
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) 66.03 Average from 312019 to 712023
[Total as, CaCO3 or(Ca+Mg)]
Average Upstream Hardness(mg/L) 89.29 Average from 312019 to 212023
[Total as, CaCO3 or(Ca+Mg)]
7Q10 summer(cfs) 38.7 Historical;Previous Fact Sheet
1Q10(cfs) 31.80 Calculated in RPA
0.3 with
Permitted Flow(MGD) expansion to NPDES Files
1.0
Date: 03/11/2024
Permit Writer: Saad Masood
Page 4 of 4

3/11/24 WQS= 12 ng/L MERCURY WQBEL/TBEL EVALUATION V:2013-6
Facility Name
Muddy Creek WWTP/ NC0081621 No Limit Required
/Permit No.
No MMP Required
Total Mercury 1631E PQL= 0.5 ng/L 7Q10s = 38.700 cfs WQBEL= 311.61 ng/L
Date Modifier Data Entry Value Permitted Flow= 1.000 47 ng/L
10/5/21 < 1 0.5 0.5 ng/L-Annual Average for 2021
7/12/22 < 1 0.5
10/4/22 < 1 0.5 0.5 ng/L-Annual Average for 2022
1/10/23 < 1 0.5
4/4/23 < 1 0.5
7/18/23 < 1 0.5 0.5 ng/L-Annual Average for 2023

Muddy Creek WWTP/ NCO081621
Mercury Data Statistics (Method 1631E)
2021 2022 2023
#of Samples 1 2 3
Annual Average, ng/L 0.5 0.5 0.5
Maximum Value, ng/L 0.50 0.50 0.50
TBEL, ng/L 47
WQBEL, ng/L 311.6

NH3/TRC WLA Calculations
Facility: Muddy Creek WWTP
PermitNo. NC0081621
Prepared By: Saad Masood
Enter Design Flow (MGD): 0.3
Enter s7Q10 (cfs): 38.7
Enter w7Q10 (cfs): 83
Total Residual Chlorine (TRC) Ammonia (Summer)
Daily Maximum Limit (ug/1) Monthly Average Limit(mg NH3-N/1)
s7Q10 (CFS) 38.7 s7Q10 (CFS) 38.7
DESIGN FLOW (MGD) 0.3 DESIGN FLOW (MGD) 0.3
DESIGN FLOW (CFS) 0.465 DESIGN FLOW (CFS) 0.465
STREAM STD (UG/L) 17.0 STREAM STD (MG/L) 1.0
Upstream Bkgd (ug/1) 0 Upstream Bkgd (mg/1) 0.22
IWC (%) 1.19 IWC (%) 1.19
Allowable Conc. (ug/1) 1432 Allowable Conc. (mg/1) 65.9
Cap at 28 ug/L. Maintian Limit. Less stringent than current limits. Maintain limits.
Ammonia (Winter)
Monthly Average Limit(mg NH3-N/1)
Fecal Coliform w7Q10 (CFS) 83
Monthly Average Limit: 200/100m1 DESIGN FLOW (MGD) 0.3
(If DF >331; Monitor) DESIGN FLOW (CFS) 0.465
(If DF<331; Limit) STREAM STD (MG/L) 1.8
Dilution Factor(DF) 84.23 Upstream Bkgd (mg/1) 0.22
IWC (%) 0.56
Allowable Conc. (mg/1) 283.8
Less stringent than current limits. Maintain limits.
Total Residual Chlorine
1. Cap Daily Max limit at 28 ug/l 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)

NH3/TRC WLA Calculations
Facility: Muddy Creek WWTP
PermitNo. NC0081621
Prepared By: Saad Masood
Enter Design Flow (MGD): 1
Enter s7Q10 (cfs): 38.7
Enter w7Q10 (cfs): 83
Total Residual Chlorine (TRC) Ammonia (Summer)
Daily Maximum Limit (ug/1) Monthly Average Limit(mg NH3-N/1)
s7Q10 (CFS) 38.7 s7Q10 (CFS) 38.7
DESIGN FLOW (MGD) 1 DESIGN FLOW (MGD) 1
DESIGN FLOW (CFS) 1.55 DESIGN FLOW (CFS) 1.55
STREAM STD (UG/L) 17.0 STREAM STD (MG/L) 1.0
Upstream Bkgd (ug/1) 0 Upstream Bkgd (mg/1) 0.22
IWC (%) 3.85 IWC (%) 3.85
Allowable Conc. (ug/1) 441 Allowable Conc. (mg/1) 20.5
Cap at 28 ug/L. Maintian Limit. Less stringent than current limits. Maintain limits.
Ammonia (Winter)
Monthly Average Limit(mg NH3-N/1)
Fecal Coliform w7Q10 (CFS) 83
Monthly Average Limit: 200/100m1 DESIGN FLOW (MGD) 1
(If DF >331; Monitor) DESIGN FLOW (CFS) 1.55
(If DF<331; Limit) STREAM STD (MG/L) 1.8
Dilution Factor(DF) 25.97 Upstream Bkgd (mg/1) 0.22
IWC (%) 1.83
Allowable Conc. (mg/1) 86.4
Less stringent than current limits. Maintain limits.
Total Residual Chlorine
1. Cap Daily Max limit at 28 ug/l 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)

NCO081621 Muddy Creek WWTP 10/10/2023
BOD monthly removal rate TSS monthly removal rate
Month RR(%) Month RR(%) Month RR(%) Month RR(%)
March-19 98.52 September-21 99.04 March-19 97.92 September-21 98.77
April-19 98.82 October-21 99.04 April-19 97.77 October-21 99.18
May-19 98.71 November-21 99.10 May-19 98.03 November-21 98.97
June-19 98.10 December-21 99.36 June-19 97.50 December-21 99.29
July-19 97.69 January-22 99.17 July-19 97.74 January-22 98.92
August-19 97.46 February-22 99.34 August-19 97.97 February-22 99.17
September-19 96.85 March-22 98.95 September-19 96.52 March-22 98.51
October-19 97.74 April-22 98.48 October-19 97.31 April-22 97.87
November-19 98.24 May-22 99.04 November-19 97.82 May-22 99.16
December-19 98.54 June-22 98.61 December-19 97.82 June-22 98.94
January-20 98.84 July-22 98.34 January-20 98.40 July-22 98.22
February-20 98.08 August-22 99.04 February-20 95.95 August-22 98.32
March-20 97.63 September-22 98.91 March-20 96.91 September-22 99.19
April-20 98.49 October-22 99.25 April-20 97.54 October-22 99.16
May-20 97.42 November-22 99.21 May-20 95.49 November-22 99.17
June-20 97.92 December-22 98.98 June-20 97.04 December-22 98.95
July-20 98.97 January-23 98.85 July-20 98.89 January-23 98.18
August-20 99.05 February-23 98.81 August-20 98.06 February-23 98.87
September-20 98.10 March-23 99.07 September-20 97.32 March-23 98.64
October-20 98.71 April-23 99.02 October-20 98.50 April-23 98.55
November-20 98.86 May-23 99.21 November-20 98.40 May-23 99.17
December-20 98.83 June-23 98.68 December-20 99.03 June-23 98.86
January-21 98.44 July-23 99.25 January-21 97.13 July-23 98.94
February-21 98.22 August-23 February-21 97.69 August-23
March-21 98.88 September-23 March-21 98.79 September-23
April-21 98.81 October-23 April-21 98.98 October-23
May-21 98.99 November-23 May-21 99.17 November-23
June-21 98.50 December-23 June-21 98.34 December-23
July-21 98.82 January-24 July-21 98.04 January-24
August-21 98.31 February-24 August-21 97.05 February-24
Overall BOD removal rate 98.63 Overall TSSD removal rate 98.15

Reduction in Frequency Evalaution
Facility: Muddy Creek WWTP
Permit No. NC0081621
Review period(use 3 7/2020-7/2023
yrs)
Approval Criteria: Y/N?
1. Not currently under SOC Y
2. Not on EPA Quarterly noncompliance report Y
3.Facility or employees convicted of CWA N
violations
#of non
Monthly Monthly 50% 3-yr mean #daily 200% #daily Reduce
200% monthly #civil penalty
Data Review Units average (geo mean <50%? samples <15? samples <20? >27 >17 Frequency?
average limit limit MA for FC) MA >200% WA >200% limit asessment (Yes/No)
violations
BOD(Weighted) mg/L 21.25 14.1667 7.1 2.5364486 Y 28.3 0 Y 0 N 0 N Y
TSS mg/L 45 30 15 1.4339028 Y 60 1 Y 0 N 0 N Y
Ammonia(weighted) mg/L 17 1 5.666671 2.8 1 0.1043803 1 Y 11.3 0 Y 0 N 0 N Y
Fecal Coliform #/100 400 1 200 1 1001 0.8265746 1 Y 800 1 8 1 Y 1 0 N 0 N Y

MONITORING REPORT(MR)VIOLATIONS for: Report Date: 09/11/23 Page 1 of 1
Permit: NC008162 MRs Betweel 9 - 2018 and 9 - 2023 Region: % Violation Category:Limit Violation Program Category:
Facility Name:% Param Nam(% County: % Subbasin:% Violation Action:%
Major Minor: %
PERMIT: NCO081621 FACILITY: Water and Sewer Authority of Cabarrus County- COUNTY: Cabarrus REGION: Mooresville
Muddy Creek WWTP
Limit Violation
MONITORING VIOLATION UNIT OF CALCULATED %
REPORT OUTFALL LOCATION PARAMETER DATE FREQUENCY MEASURE LIMIT VALUE Over VIOLATION TYPE VIOLATION ACTION
11-2018 001 Effluent Flow,in conduit or thru 11/30/18 Continuous mgd 0.15 0.211 40.6 Monthly Average Proceed to NOD
treatment plant Exceeded
12-2018 001 Effluent Flow,in conduit or thru 12/31/18 Continuous mgd 0.15 0.215 43.1 Monthly Average Proceed to NOD
treatment plant Exceeded
01-2019 001 Effluent Flow,in conduit or thru 01/31/19 Continuous mgd 0.15 0.187 24.7 Monthly Average Proceed to NOV
treatment plant Exceeded
02-2019 001 Effluent Flow,in conduit or thru 02/28/19 Continuous mgd 0.15 0.182 21.3 Monthly Average No Action, BPJ
treatment plant Exceeded
03-2019 001 Effluent Flow,in conduit or thru 03/31/19 Continuous mgd 0.15 0.153 1.9 Monthly Average No Action, BPJ
treatment plant Exceeded

Request for Reduction of Monitoring Frequencies
The facility's request to modify the monitoring frequency for BODS,TSS, NH3-N and Fecal Coliform was
approved in September 2014.The reduced monitoring frequency was evaluated during 2018 NPDES
permit renewal and such evaluation resulted in maintaining the reduced monitoring frequencies for
BODS,TSS, NH3-N and Fecal Coliform for the 0.3 MGD flow tier. However,the permit specifies that for
the first six months after expansion to 0.3 MGD, sampling will be 3/week. If no compliance problems
occur, sampling will revert to 2/week after the first six months.Since the facility expanded to 0.3 MGD in
April 2019, and no compliance problems has occurred since then, the Permittee can revert to 2/week
sampling starting in October 2019. The reduced monitoring frequency will be re-evaluated again during
the next permit cycle. In regards to 1.0 MGD facility, sampling will be conducted in accordance with the
15A NCAC 2B .0500 until the Permittee requests to modify the monitoring frequency and sufficient data
is collected to demonstrate consistent, long-term treatment performance under new conditions.Three
years of data will be needed to demonstrate consistent, long term treatment performance under the
new conditions to qualify for a reduction in sampling.
Since October of 2019, under the 0.3 MGD permit, there have been no violations of the NPDES permit.
WSACC requests to continue the 2/week monitoring for BODS, NH3-N and Fecal Coliform.
Thank you,
4W 0- _,,� L
Matthew Isenhour
Muddy Creek WWTP ORC

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 NCO081621 I11 121 21/08/26 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 131 QA ----------------------Reserved-------------------
67 70LJ 71Ity 72 L-J 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) 01:OOPM 21/08/26 21/06/01
Muddy Creek WWTP
14655 Hopewell Church Rd Exit Time/Date Permit Expiration Date
Midland NC 28107 03:04PM 21/08/26 23/10/31
Name(s)of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s) Other Facility Data
Matthew Dwayne Isenhour/ORC/704-788-4164/
Name,Address of Responsible Official/Title/Phone and Fax Number
Contacted
Coleman M Keeter,232 Davidson Hwy Concord NC 280270428/Executive
Director/704-786-1783/7047951564 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
Roberto Scheller DWR/MRO WQ/707-235-2204/
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 (Cont.) 1
31 NCO081621 I11 12I 21/08/26 117 18 i c i
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
Muddy Creek WWTP has expanded from a 0.15 MGD to 0.30 MGD. The curent permit was modified
and became effective June 1, 2021 and expires October 31, 2023. Treated effluent is discharged via
Outfall #001 to the Rocky River in subbasin 03-07-12 in the Yadkin-Pee Dee River Basin. It was
noted that the receiving stream is listed as impaired waters for Copper, Zinc, and Trubidity on the
North Carolina 2018 303(d) list of Imparied Waters.
At time of inspection the subject facility appeared to be well operated and maintained. Records
reviewed were readily available for inspection. Effluent was clear with no visible suspended solids.
Effluent sampler was recorded at 2 Degrees Celsius. Review of compliance history from August 2020
to July 2021 found no reported limit violations. Flow meter was last calibrated on July, 2021.
Bio-soilds are trucked to the Rocky River WWTP for disposal.
Page# 2

Permit: NCO081621 Owner-Facility: Muddy Creek WWTP
Inspection Date: 08/26/2021 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: Modified permit became effective June 1, 2021 and expires October 31, 2023.
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? ■ ❑ ❑ ❑
Comment:
Laboratory Yes No NA NE
Are field parameters performed by certified personnel or laboratory? ■ ❑ ❑ ❑
Page# 3

Permit: NCO081621 Owner-Facility: Muddy Creek WWTP
Inspection Date: 08/26/2021 Inspection Type: Compliance Evaluation
Laboratory Yes No NA NE
Are all other parameters(excluding field parameters) performed by a certified lab? 0 ❑ ❑ ❑
# Is the facility using a contract lab? ■ ❑ ❑ ❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 0 ❑ ❑ ❑
degrees Celsius)?
Incubator (Fecal Coliform) set to 44.5 degrees Celsius+/- 0.2 degrees? ❑ ❑ 0 ❑
Incubator (BOD) set to 20.0 degrees Celsius +/- 1.0 degrees? ❑ ❑ 0 ❑
Comment:
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? 0 ❑ ❑ ❑
Is disposal of screening in compliance? 0 ❑ ❑ ❑
Is the unit in good condition? ❑ ❑ ❑
Comment: Debris disposed of in landfill.
Influent Sampling Yes No NA NE
# Is composite sampling flow proportional? ❑ ❑ ❑ ❑
Is sample collected above side streams? ❑ ❑ ❑ ❑
Is proper volume collected? ❑ ❑ ❑ ❑
Is the tubing clean? ❑ ❑ ❑ ❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 ❑ ❑ ❑ ❑
degrees Celsius)?
Is sampling performed according to the permit? ❑ ❑ ❑ ❑
Comment:
Equalization Basins Yes No NA NE
Is the basin aerated? ❑ ❑ ❑ ❑
Is the basin free of bypass lines or structures to the natural environment? ❑ ❑ ❑ ❑
Is the basin free of excessive grease? ❑ ❑ ❑ ❑
Are all pumps present? ❑ ❑ ❑ ❑
Page# 4

Permit: NCO081621 Owner-Facility: Muddy Creek WWTP
Inspection Date: 08/26/2021 Inspection Type: Compliance Evaluation
Equalization Basins Yes No NA NE
Are all pumps operable? ❑ ❑ ❑ ❑
Are float controls operable? ❑ ❑ ❑ ❑
Are audible and visual alarms operable? ❑ ❑ ❑ ❑
# Is basin size/volume adequate? ❑ ❑ ❑ ❑
Comment:
Chemical Feed Yes No NA NE
Is containment adequate? 0 ❑ ❑ ❑
Is storage adequate? 0 ❑ ❑ ❑
Are backup pumps available? 0 ❑ ❑ ❑
Is the site free of excessive leaking? 0 ❑ ❑ ❑
Comment:
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? ❑ ❑ 0 ❑
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 ❑ ❑ ❑
Comment:
Pumps-RAS-WAS Yes No NA NE
Are pumps in place? 0 ❑ ❑ ❑
Are pumps operational? ■ ❑ ❑ ❑
Are there adequate spare parts and supplies on site? 0 ❑ ❑ ❑
Comment: New RAW/WAS pumps installed as part of plant upgrade.
Secondary Clarifier Yes No NA NE
Is the clarifier free of black and odorous wastewater? 0 ❑ ❑ ❑
Page# 5

Permit: NCO081621 Owner-Facility: Muddy Creek WWTP
Inspection Date: 08/26/2021 Inspection Type: Compliance Evaluation
Secondary Clarifier Yes No NA NE
Is the site free of excessive buildup of solids in center well of circular clarifier? ■ ❑ ❑ ❑
Are weirs level? ■ ❑ ❑ ❑
Is the site free of weir blockage? ■ ❑ ❑ ❑
Is the site free of evidence of short-circuiting? ■ ❑ ❑ ❑
Is scum removal adequate? ■ ❑ ❑ ❑
Is the site free of excessive floating sludge? ■ ❑ ❑ ❑
Is the drive unit operational? ■ ❑ ❑ ❑
Is the return rate acceptable (low turbulence)? ■ ❑ ❑ ❑
Is the overflow clear of excessive solids/pin floc? ■ ❑ ❑ ❑
Is the sludge blanket level acceptable? (Approximately '/4 of the sidewall depth) ■ ❑ ❑ ❑
Comment: Two new secondary clarifiers installed as part of plant upgrade.
Operations & Maintenance Yes No NA NE
Is the plant generally clean with acceptable housekeeping? ■ ❑ ❑ ❑
Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable ■ ❑ ❑ ❑
Solids, pH, DO, Sludge Judge, and other that are applicable?
Comment:
Filtration (High Rate Tertiary) Yes No NA NE
Type of operation: Cross flow
Is the filter media present? ■ ❑ ❑ ❑
Is the filter surface free of clogging? ■ ❑ ❑ ❑
Is the filter free of growth? ■ ❑ ❑ ❑
Is the air scour operational? ■ ❑ ❑ ❑
Is the scouring acceptable? ■ ❑ ❑ ❑
Is the clear well free of excessive solids and filter media? ■ ❑ ❑ ❑
Comment: Facility has fabric covered drum type filters.
Disinfection - UV Yes No NA NE
Are extra UV bulbs available on site? ❑ ❑ ■ ❑
Are UV bulbs clean? ■ ❑ ❑ ❑
Is UV intensity adequate? ■ ❑ ❑ ❑
Is transmittance at or above designed level? ■ ❑ ❑ ❑
Page# 6

Permit: NC0081621 Owner-Facility: Muddy Creek WWTP
Inspection Date: 08/26/2021 Inspection Type: Compliance Evaluation
Disinfection - UV Yes No NA NE
Is there a backup system on site? 0 ❑ ❑ ❑
Is effluent clear and free of solids? 0 ❑ ❑ ❑
Comment: Effluent passing through UV was clear with no visible suspended solids.
Standby Power Yes No NA NE
Is automatically activated standby power available? 0 ❑ ❑ ❑
Is the generator tested by interrupting primary power source? ❑ ❑ ❑
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 ■ ❑ ❑ ❑
power?
Is the generator fuel level monitored? ❑ ❑ ❑
Comment:
Page# 7