NC0031879_Final Fact Sheet_20210330

Fact Sheet
NPDES Permit No. NCO031879
Permit Writer / Email Contact Diana Yitbarek / [e-mail]
Date: 3/30/2021
Division/Unit: NC DEQ Division of Water Resources / NPDES Municipal Permitting Unit
Fact Sheet Template: Version 1/9/2017
Permitting Action:
❑X 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, three effluent pollutant scans, four 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 N.A.
1. Basic Facility Information
Table 1. Facility Information
Facility Information
Applicant/Facility Name:
City of Marion/Corpening Creek Wastewater Treatment Plant (WWTP)
Applicant Address:
P.O. Box 700, Marion, NC 28752-0700
Facility Address:
3982 Highway 226 South, Marion, NC 28752
Permitted Discharge Flow:
2.5/3.0 million gallons per day (MGD)
Facility Type/Waste:
Major Municipal/ Domestic
Facility Class:
Class 111(2.5 MGD)/ Class IV (3.0 MGD) Biological - 15A NCAC 08G .0302
Treatment Units:
Influent pump station, bar screening and grit removal structures, two primary
clarifiers, two aeration basins, two secondary clarifiers, tertiary filters, chlorine
contact chamber, dechlorination/sulfar dioxide, gravity sludge thickeners, and
aerobic digester
Pretreatment Program (Y/N)
N — Industrial Waste Survey (IWS) requested by 7/l/2021
County:
McDowell
Region:
Asheville Regional Office (ARO)
Permitting Action: The City of Marion (City) applied for NPDES permit renewal for Corpening Creek WWTP
in August 2019. The WWTP has a design capacity of 3.0 MGD and is currently authorized to discharge 2.5
MGD (up to 3.0 MGD upon request) into Corpening Creek (also identified as Youngs Fork), a class C waters.
The class denotes use as a fishable/swimmable water. The Corpening Creek WWTP (Facility) serves about
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4,300 customers within the City and in areas outside the City. The pretreatment program is inactive since 2008.
An industrial waste survey (IWS) was requested by July 1, 2021.
August 5, 2020, City's cover letter for renewal application explains that their average flow has remained less
than 1.2 MGD and requests that the two tiers remain in effect (2.5 and 3.0 MGD), as with the last permit cycle.
Facility Background: In the past the facility has been dealing with inflow and infiltration (I/I) issues that
surged the treatment system and caused washouts. In 2011, the City completed Improvement Projects that
involved upgrades to the Facility to make it a true 3.0 MGD wastewater plant. Currently, the primary
clarifiers are being used as EQ basins to control the stormwater surges into the treatment system.
In 2015, the Division added an effluent limitation and monitoring page with a lower design flow tier of 2.5
MGD based on the City's request due to the sustained lower average flows. At the present time this fact sheet
assessment is based on a wastewater plant flow of 2.5 MGD.
2. Receiving Waterbody Information:
Table 2. Receiving Waterbodv Information
Outfalls/Receiving Stream(s):
Outfall 001 [35039105.311N 81057'28.2"W]/Corpening Creek (Youngs Fork)
Stream Segment/Assessment
Unit (AU):
11-32-1-4a
Stream Classification:
C
Drainage Area (mi2):
8.21
Summer 7Q10 (cfs)
2.3
Winter 7Q10 (cfs):
3.6
30Q2 (cfs):
6
Average Flow (cfs):
12
Instream Waste Concentration
(IWC) (% effluent):
63 % at 2.5 MGD (7Q10S)
67 % at 3.0 MGD (7Q10S)
303(d) listed/parameter:
Yes - For benthos and fish community
Subject to TMDL/parameter:
Yes- Mercury Statewide TMDL implemented in 2012
Basin/Sub-basin/ Hydrologic unit
code (HUC):
Catawba River Basin/03-08-30/03050101
USGS Topo Quad/State Grid:
Marion East/E11NW
Youngs Fork was listed in the NC 2014, 2018, and draft 2020 303(d) list for benthos and fish community and was
categorized as degraded aquatic life with an impaired condition, which means that the biological community
normally expected in a lake, stream or other waterway is unhealthy, much reduced, or absent, and the exact
pollutant cause is not known. Further information can be found at the 2010 Catawba River Basinwide Water
Quality Plan.
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3. Effluent Data Summary
Effluent data for Outfall 001 is summarized below from September 2016 through September 2020.
Table 3. Effluent Data Summary with permit limits Outfall 001. Parameters listed as in the last permit.
Parameter
Units
Average
Max.
Min.
Permit Limit
Flow
MGD
0.99
4.13
0.05
MA* 2.5 MGD
BODs
mg/1
4.4
212
2.0
MA 30.0 mg/I
WA* 45.0 mg/I
Total Suspended
n'gn
9.7
2140.0
2.2
MA 30.0 mg/I
Solids (TSS)
WA 45.0 mg/I
0.89
13.6
0.50
MA 1.5 mg/I
NH3N (Summer)
mg/1
WA 4.4 mg/I
NH3N (Winter)
mg/1
0.96
15.0
0.50
MA 3.3 mg/I
WA 9.8 mg/I
Dissolved Oxygen
mg/1
8.36
11.30
4.90
DA*>_ 5.0 mg/I
(DO)
Fecal Coliform
#/100 ml
3.7
2420.00
1.00
MA 200/100m1
(Geomean)
WA 400/100ml
pH
SU
6.4
7.1
5.7
6.0<pH<9.0
Total Residual
µg/1
20
45
20
DM* 27.00 Ng/I
Chlorine (TRC)
Temperature
°C
17.7
25
8
Total Nitrogen (TN)
mg/1
4.9
14.0
0.73
Total Phosphorus
m /1
g
1.72
5.20
0.12
(TP)
Total Cyanide
µg/l
5.39
9.00
5.0
MA 8.0 Ng/I
DM 33.0 pg/I
Total Copper
µg/l
3.72
16.00
1.0
Total Zinc
µg/1
46.9
94.00
17.0
*MA -Monthly Average, WA -Weekly Average, DM -Daily Maximum, DA=Daily Average.
Table 4. Effluent Data Summary from expanded effluent pollutant scan Outfall 001
Parameter
Units
Average
Max.
Mercury*
ng/l
1.34
3.03
Chloroform
µg/l
17.5
24
*See section 6.6 Mercury Statewide Total Maximum Daily Load (TMDL) Evaluation
Sample results for the sampled metals not included above, such as antimony, arsenic, beryllium, cadmium, chromium,
lead, nickel, selenium', silver, and thallium, were less than the method detection limit.
Chloroform has a water quality standard value for water supply of 60 µg/l. The maximum concentration detected is
currently within the accepted water quality standards.
1 See page 7 for discussion about practical quantification limits for selenium and silver
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4. Instream Data Summary
Instream monitoring may be required in certain situations, for example, 1) to verify model predictions when
model results for instream D.O. are within 1 mg/1 of instream standard at full permitted flow; 2) to verify
model predictions for outfall diffuser; 3) to provide data for future total maximum daily load (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).
Instream data summary and instream monitoring proposed for this permit action:
The current permit requires instream [upstream (U) and downstream (D)] monitoring for dissolved oxygen
and temperature. The U and D locations are about 100 feet and 200 feet from the outfall, respectively. The
figure below summarizes instream and effluent (Eff) data from the analyzed period, September 2016 -
September 2020.
Figure 1. Average, maximum, and minimum instream and effluent data summary
Temperature, C DO, mg/1
30.0 20.0
15.0
20.0
10.0
10.0 _ , � 5.0 , 1
0.0 0.0
Upstream Effluent Downstream Upstream Effluent Downstream
■ Average of Value ■ Max of Value Min of Value ■ Average of Value ■ Max of Value ■ Min of Value
T-tests were run to analyze relationships between instream sample results. A statistically significant
difference is determined when the t-test p-value result is < 0.05.
Temperature: The maximum downstream temperature was 24 degrees Celsius, and the maximum
temperature differential between the upstream and downstream samples was one degree Celsius. It was
concluded that there is statistically significant difference between the upstream and downstream temperatures.
DO: The minimum downstream DO detected was 4.6 mg/1 on 9/4/2018, and the maximum DO differential
between the upstream and downstream samples was 3.0 mg/l. It was concluded that there is not a statistically
significant difference between upstream and downstream DO.
Conductivity: Effluent conductivity and instream conductivity sampling have been added to the permit. An
industrial waste survey (IWS) was requested by July 1, 2021. If the IWS confirms industrial sources, instream
monitoring for conductivity will need to commence.
Hardness: Effluent hardness and instream hardness sampling, upstream of the discharge, have been added to
the permit at a monitoring frequency of quarterly. The NC 2007-2014 Water Quality Standard (WQS)
Triennial Review was approved by the NC Environmental Management Committee (EMC) on November 13,
2014. The US EPA subsequently approved the WQS revisions on April 6, 2016 with some exceptions. The
NC Division of Water Resources NPDES Permitting Unit is required to implement the new dissolved metal
standards in all permits public noticed after April 6, 2016. The new standards for most metals include acute
standards. Further, the freshwater standards for several metals are expressed as the dissolved form of the
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metals, and seven metals have hardness -dependent equations. As a result, the NPDES Permitting Unit will
need site -specific effluent hardness data and instream hardness data, upstream of the discharge, for each
facility monitoring these metals in order to calculate permit limitations.
Is this facility a member of a Monitoring Coalition with waived instream monitoring (YIN): NO
Name of Monitoring Coalition: NA
5. Compliance Summary
From November 2015 to November 2020 the Facility received a total of 20 notices of violation (NOVs) for
exceeding monthly average (MA) limits for ammonia and TSS, and weekly average (WA) limits for BOD5,
ammonia, and TSS; not reaching daily minimum (Dmin) for DO and pH, and for failing to comply with
sampling frequencies. The Facility also received 12 Enforcement Cases for exceeding MA and WA limits for
TSS and total ammonia. The ARO representative, Lauren Armeni, is working with the Facility to monitor the
Facility's compliance performance. The report on limit violations that proceeded to NOV or Enforcement
Case were as follows:
• Ammonia - 4 MA limit exceedances and 6 WA limit exceedances. The maximum MA limit
exceedance was 6.2 µg/1 in 2016 and the maximum WA limit exceedance was 13.67 µg/l in 2018.
• BOD5 - 1 WA limit exceedance in 2020 at 83.15 mg/1.
• TSS - 3 MA limit exceedances and 6 WA limit exceedances. The maximum MA limit exceedance
was 183.84 mg/l and the maximum WA limit exceedance was 726.47 mg/l.
• pH - 2 Daily Minimum not reached in 2020.
• DO - 1 Daily Minimum not reached in 2020.
Summary of the compliance record with aquatic toxicity test limits and any second species test results (past 5
years):
The Facility passed eighteen of eighteen quarterly chronic toxicity tests from February 2016 to May 2020 and
complied with all four 2nd species WET tests.
Summary of the results from the most recent compliance inspection:
The last facility inspection conducted in February 2021 reported that the facility has not had limit violations
since May 2020 and is in non-compliance with requirements outlined in Permit Conditions Part II Section C
(2) Proper Operation and Maintenance. Both primary clarifiers are being used as equalization basins; one of
the secondary clarifiers needs repair due to a broken arm. A new RAS pump is needed, and there is currently
no backup RAS pump.
The facility staff is aware that some system components are degrading and have plans to improve the system.
They plan to buy a new RAS pump in FY 22, and also plan to rehabilitate the offline aeration basin and
eventually the tertiary filters. They have also ordered parts to replace the sweep arm and drive unit in one of
the secondary clarifiers.
6. Water Quality -Based Effluent Limitations (WQBELs)
6.1 Dilution and Mixin Zones
ones
In accordance with 15A NCAC 2B.0206, the following stream flows are used for dilution considerations for
development of WQBELs: 1 Q 10 streamflow (acute Aquatic Life); 7Q 10 streamflow (chronic Aquatic Life;
non -carcinogen H.H.); 30Q2 streamflow (aesthetics); annual average flow (carcinogen, H.H.).
If applicable, describe any other dilution factors considered (e.g., based on CORMIX model results): NA
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If applicable, describe any mixing zones established in accordance with 15A NCAC 2B.0204(b): NA
Stream flow values were extracted from the previous fact sheet from 2015.
6.2 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 (D.O.) water quality standard. Secondary TBEL limits (e.g.,
BOD= 30 mg/l for Municipals) may be appropriate if deemed more stringent based on dilution and model
results.
If permit limits are more stringent than TBELs, describe how limits were developed:
The current permit limits for BOD are secondary TBELs and are based on 40 CFR 133.102. No changes are
proposed for this permit cycle.
6.3 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/l (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 N.C. water quality standard for protection of
aquatic life (17 ug/1) and capped at 28 ug/l (acute impacts). Due to analytical issues, all TRC values reported
below 50 ug/l are considered compliant with their permit limit.
Describe any proposed changes to ammonia and/or TRC limits for this permit renewal: There are no
proposed changes for ammonia. The current permit sets summer and winter MA and WA limits for ammonia
for both flow tiers. The limits are needed to protect aquatic life. The MA was exceeded twice in summer, to a
maximum of 4.82 mg/1(MA limit: 1.5 mg/1) and the WA was exceeded fourteen times in summer and four
times in winter (WA limit: 4.4 mg/1); however, none of the ammonia results from the evaluated period
exceeded 35 mg/l. The maximum value of ammonia reported for summer was 13.6 mg/1 and for winter 15
mg/l; The ammonia limits will be the same as the previous permit cycle.
With this permit renewal, the City requested ammonia limits to be established at a level that is compatible to
the surrounding WWTP facilities in the area (The permits for the surrounding facilities reflect a WA of 11 to
35 mg/l and a MA of 4 to 16mg/1). As mentioned above, the ammonia limits will be the same as the previous
permit cycle. The WQBELs for ammonia for each WWTP are based on WLA calculations for the facility's
specific flow tiers.
The facility uses chlorination as its primary disinfection. The current permit limits TRC at 27 and 25 ug/L as a
daily maximum for 2.5 and 3.0 MGD, respectively. Though several reported TRC values exceeded the 27
ug/L daily maximum limit, the facility is considered compliant with its permit since all reported values were
less than 50 ug/L. The maximum TRC value reported was 45 ug/L. The TRC limit has been reviewed in the
attached WLA and has been found to be protective. No changes are proposed for TRC.
6.4 Reasonable Potential Analysis (RPA) for Toxicants
The need for toxicant limits is based upon a demonstration of reasonable potential to exceed water quality
standards, a statistical evaluation that is conducted during every permit renewal utilizing the most recent
effluent data for each outfall. The RPA is conducted in accordance with 40 CFR 122.44 (d) (i). The NC RPA
procedure utilizes the following: 1) 95% Confidence Level/95% Probability; 2) assumption of zero
background; 3) use of detection limit for "less than" values; and 4) stream flows used for dilution
consideration based on 15A NCAC 2B.0206. Effective April 6, 2016, N.C. began implementation of
Page 6 of 14

dissolved metals criteria in the RPA process in accordance with guidance titled NPDES Implementation of
Instream Dissolved Metals Standards, dated June 10, 2016.
The RPAs were conducted for permitted flows of 2.5 MGD and 3.0 MGD with a 7Q 10 (Summer) of 2.3 cubic
feet per second (cfs) and default hardness values.
The City of Marion reported total selenium and total silver at less than detection, with detection levels <
10.0 µg/L, and < 5.0 µg/L respectively, in the Effluent Pollutant Scans. Based on the Reasonable
Potential Analysis (RPA), the City's allowable discharge concentrations are 8.00 µg/L and 0.096 µg/L for
total selenium and total silver, respectively. DWR's laboratory identifies the target Practical
Quantification Limits (PQLs) for total selenium and total silver as 1.0 µg/L. 15A NCAC 2B .0505 (e) (4)
requires that all test procedures must produce detection and reporting levels that are below the permit
discharge requirements and all data generated must be reported to the approved detection level or lower
reporting level of the procedure. If no approved methods are capable of achieving a detection level below
the permit discharge requirement (or allowable discharge concentration) the method with the lowest
detection level must be used. The City should use sufficiently sensitive test methods for all pollutants,
including when performing Effluent Pollutant Scans.
The results of the RPA showed that the facility does not require any additional toxicant limitations. The
answers below are based on the RPA.
RPAs were conducted on effluent toxicant data collected in the Permittee's 2016 to 2018 effluent pollutant
scans and DMRs. Pollutants of concern included toxicants with positive detections and associated water
quality standards/criteria. The data set was limited for arsenic, beryllium, cadmium, total phenolic
compounds, chromium, lead, nickel, selenium, and silver. 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: Cyanide (this is carried over from the previous permit)
Monitoring. Only. nly. 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: Copper (this is carried
over from the previous permit)
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: Antimony, arsenic,
beryllium, cadmium, chromium, cobalt, lead, molybdenum, nickel, selenium, silver, tin, titanium,
vanadium, zinc, total phenolic compounds, and chloroform.
These compounds will be monitored in the pretreatment program during this permit cycle: None.
Pretreatment program is currently inactive.
POTW Effluent Pollutant Scan Review: Three effluent pollutant scans were evaluated for additional
pollutants of concern.
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: NA
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: NA
RPA results as well as a copy of the Dissolved Metals Implementation Fact Sheet for freshwater are included
as attachments of this Fact Sheet.
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6.5 Toxicity Testing Limitations
Permit limits and monitoring requirements for Whole Effluent Toxicity (WET) have been established in
accordance with Division guidance (per WET Memo, 8/2/1999). Per WET guidance, all NPDES permits
issued to Major facilities or any facility discharging "complex" wastewater (contains anything other than
domestic waste) will contain appropriate WET limits and monitoring requirements, with several exceptions.
The State has received prior EPA approval to use an Alternative WET Test Procedure in NPDES permits,
using single concentration screening tests, with multiple dilution follow-up upon a test failure.
Describe proposed toxicity test requirement: This is a Major Publicly Owned Treatment Work (POTW), and
a chronic WET limit will continue on a quarterly frequency at Outfall 001 at 63% at 2.5 MGD using
Ceriodaphnia dubia. For the 3.0 MGD flow tier, a quarterly chronic WET limit would apply at 67% effluent
concentration, using Ceriodaphnia dubia, as well.
6.6 Mercury Statewide Total Maximum Daily Load (TMDL) Evaluation
There is a statewide TMDL for mercury approved by EPA in 2012. The TMDL target was to comply with
EPA's mercury fish tissue criteria (0.3 mg/kg) for human health protection. The TMDL established a
wasteload allocation for point sources of 37 kg/year (81 lb/year) and is applicable to municipals and industrial
facilities with known mercury discharges. Given the small contribution of mercury from point sources (-2%
of total load), the TMDL emphasizes mercury minimization plans (MMPs) for point source control.
Municipal facilities > 2 MGD and discharging multiple quantifiable levels of mercury (>1 ng/1) received 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
A mercury evaluation was conducted in accordance with the Permitting Guidance developed for the
implementation of the statewide Mercury TMDL to determine the need for a limit. The facility started
collecting data in 2012.
Table 5. Mercury Evaluation
2012
2013
2014
2015
2016
2017
2018
# of Samples
4
4
4
3
Mercury Annual Average (ng/1)
5.2
5.0
2.3
4.1
0.5
0.5
3.03
Mercury Annual Max (ng/1)
9.2
7.6
3.4
5.6
0.5
0.5
3.03
Below find summaries of compliance mercury data from 2016 to 2018. Based on the dataset, the water quality
based effluent limitation (WQBEL) for mercury is 19.1 and 17.9 ng/1 for 2.5 and 3.0 MGD. The technology
based effluent limit (TBEL) is 47 ng/1.
Table 6. Mercury Effluent Data Summary - 2.5 MGD
2C'=6
2C"7
2018
#ofSam ples
_
_
1
Annual Average, ng/L
U 5
U 5
K0
Maximum Value, ng/L
U 51,
0.50
3.03
TBEL, ng/L
47
WQBEL, ng/L
19.1
Page 8 of 14

Table 7. Mercury Effluent Data Summary — 3.0 MGD
2016
2017
2019
# of Sam pl es
1
1
1
Annual Average,ng/L
0.5
0.5
3.0
Maximum Value, ng/L
0.50
0.W
3D3
TBEL, ng/L
47
WCLBEL, ng/L
17.9
Describe proposed permit actions based on mercury evaluation: Mercury evaluation results used 1631E. No
annual average mercury concentration exceeded the WQBEL, and no individual mercury sample exceeded the
TBEL. The maximum value reported in this period was 3.03 ng/l. No mercury limit is required and the
mercury minimization plan (MMP) will be removed in this permit cycle.
6.7 Other TMDL/Nutrient Management Strategy Considerations
If applicable, describe any other TMDLs/Nutrient Management Strategies and their implementation within
this permit:
During the 2010 permit renewal, effluent and instream monitoring for total nitrogen (TN) and total
phosphorous (TP) were included in the permit due to the impairment of Lake Rhodhiss (2010 NC 303(d)
List). Corpening Creek is within the Lake Rhodhiss' drainage basin. In 2015, the instream monitoring for TN
and TP was eliminated due to the Lake Rhodhiss being taken off the 303(d) list.
In 2014, the Division decided to change nutrient monitoring frequencies from weekly to monthly and
eliminate instream monitoring requirements for four facilities (Marion, Morganton, Lenoir, and Valdese)
discharging to Lake Rhodhiss. The permit reflects the monthly nutrient (T.P. and T.N.; TKN + NO3-N +
NO2-N) monitoring for 2.5 MGD and 3.0 MGD flows.
Annual nutrient T.N. and T.P. loads: The maximum T.N. and T.P. annual loads during the evaluated period
were 18,344 lb/yr (2019) and 5,246 lb/yr (2019). The Facility is currently operating at a flow limit of 2.5
MGD and there is no proposal to increase to 3.0 MGD. There are not annual load T.N. and T.P. limits for the
3.0 MGD flow tier. Annual loads for TN and TP will be revisited when a final nutrient TMDL for the
Catawba River Basin is concluded.
Table 8. Nutrients Effluent Data Summary
Parameter
2017
2018
2019
Annual TN load, Ib/yr
12,118
14,675
18,344
Annual TP load, Ib/yr
4,751
4,722
5,246
6.8 Other WQBEL Considerations
If applicable, describe any other parameters of concern evaluated for WQBELs: N.A.
If applicable, describe any special actions (HQW or ORW) this receiving stream and classification shall
comply with in order to protect the designated waterbody: N.A.
If applicable, describe any compliance schedules proposed for this permit renewal in accordance with 1 SA
NCAC 2H 0107(c)(2) (B), 40CFR 122.47, and EPA May 2007 Memo: N.A.
If applicable, describe any water quality standards variances proposed in accordance with NCGS 143-
215.3(e) and 1 SA NCAC 2B.0226 for this permit renewal: NA
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7. Technology -Based Effluent Limitations (TBELs)
Municipals (if not applicable, delete and skip to Industrials)
Are concentration limits in the permit at least as stringent as secondary treatment requirements (30 mg/l
BODS/TSS for Monthly Average, and 45 mg/l for BODS/TSS for Weekly Average). YES
If NO, provide a justification for alternative limitations (e.g., waste stabilization pond). NA
Are 85% removal requirements for BOD51TSS included in the permit? YES
If NO, provide a justification (e.g., waste stabilization pond). NA
8. Antidegradation Review (New/Expanding Discharge)
The objective of an antidegradation review is to ensure that a new or increased pollutant loading will not
degrade water quality. Permitting actions for new or expanding discharges require an antidegradation review
in accordance with 15A NCAC 213.0201. Each applicant for a new/expanding NPDES permit must document
an effort to consider non -discharge alternatives per 15A NCAC 2H.0105( c)(2). In all cases, existing instream
water uses and the level of water quality necessary to protect the existing use is maintained and protected.
If applicable, describe the results of the antidegradation review, including the Engineering Alternatives
Analysis (EAA) and any water quality modeling results: NA
9. Antibacksliding Review
Sections 402(o)(2) and 303(d)(4) of the CWA and federal regulations at 40 CFR 122.44(1) prohibit
backsliding of effluent limitations in NPDES permits. These provisions require effluent limitations in a
reissued permit to be as stringent as those in the previous permit, with some exceptions where limitations may
be relaxed (e.g., based on new information, increases in production may warrant less stringent TBEL limits,
or WQBELs may be less stringent based on updated RPA or dilution).
Are any effluent limitations less stringent than previous permit (YES/NO): YES. Monitoring and reporting for
Zinc was removed. Mercury Minimization Plan requirement was removed.
If YES, confirm that antibacksliding provisions are not violated: Confirmed. Zinc was removed based on
updated RPA and the MMP removal is consistent with EPA approved 2012 Statewide Mercury TMDL
Implementation.
10. Monitoring Frequency Requirements
Monitoring frequencies for NPDES permitting are established in accordance with the following regulations
and guidance: 1) State Regulation for Surface Water Monitoring, 15A NCAC 2B.0500; 2) NPDES Guidance,
Monitoring Frequency for Toxic Substances (7/15/2010 Memo); 3) NPDES Guidance, Reduced Monitoring
Frequencies for Facilities with Superior Compliance (10/22/2012 Memo); 4) Best Professional Judgement
(BPJ). Per US EPA (Interim Guidance, 1996), monitoring requirements are not considered effluent
limitations under Section 402(o) of the Clean Water Act, and therefore anti -backsliding prohibitions would
not be triggered by reductions in monitoring frequencies.
For instream monitoring, refer to Section 4.
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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 is proposing to extend this deadline from December
21, 2020, to December 21, 2025. This permit contains the requirements for electronic reporting, consistent
with Federal requirements.
12.Summary of Proposed Permitting Actions
Table 9. Current Permit Conditions and Proposed Changes for 2.5 MGD and 3.0 MGD
Parameter
Current Permit Limits and
Proposed Change
Basis for Condition/Change
Monitoring Frequency
Flow
MA 2.5 MGD
No changes
15A NCAC 2B .0505
and 3.0 MGD
The average flow for the past five years
is less than 1.15 MGD
Continuous
BODS
For 2.5 MGD and 3.0 MGD
No changes
TBEL. Secondary treatment
MA 30.0 mg/I
standards/40 CFR 133 / 15A NCAC 213
WA 45.0 mg/I
.0406.
3/week for 2.5 MGD
Daily for 3.0 MGD
TSS
For 2.5 MGD and 3.0 MGD
No changes
TBEL. Secondary treatment
MA 30 mg/I
standards/40 CFR 133 / 15A NCAC 213
WA 45 mg/I
.0406.
3/week for 2.5 MGD
Daily for 3.0 MGD
NH3-N (Summer)
For 2.5 MGD
No changes
WQBEL based on WLA calculations for
MA 1.5 mg/I
2.5 and 3.0 MGD using 1990 DWR
WA 4.4 mg/I
ammonia toxicity policy
For 3.0 MGD
MA 1.4 mg/I
WA 4.2 mg/I
3/week for 2.5 MGD
Daily for 3.0 MGD
NH3-N (Winter)
For 2.5 MGD
No changes
WQBEL based on WLA calculations for
MA 3.3 mg/I
2.5 and 3.0 MGD using 1990 DWR
WA 9.8 mg/I
ammonia toxicity policy
For 3.0 MGD
MA 3.0 mg/I
WA 9.0 mg/I
3/week for 2.5 MGD
Daily for 3.0 MGD
Page 11 of 14

Conductivity
None
If needed, effluent
The facility has potential industrial
conductivity
dischargers 15A NCAC 2B.0500
monitoring
Monitoring and reporting for
for 2.5 and 3.0 MGD
conductivity will begin only if the 2021
industrial waste survey (IWS) confirms
3/week for 2.5 MGD
industrial sources discharging
Daily for 3.0 MGD
pretreated wastewater into the Facility.
If needed, instream
conductivity
monitoring
for 2.5 and 3.0 MGD
Monitor and report
instream at a
variable" frequency
DO
Not less than 5 mg/I.
No changes
WQBEL. State WQ standard, 15A NCAC
2B .0200, 15A NCAC 2B.0500
Monitor and report
instream at a variable"
frequency
Monitor and report
effluent
3/week for 2.5 MGD
Daily for 3.0 MGD
Fecal coliform
MA 200 /100ml
No changes
WQBEL. State W.Q. standard, 15A
(Geometric Mean)
WA 400 /100ml
NCAC 26 .0200.
for 2.5 MGD and 3.0 MGD
3/week for 2.5 MGD
Daily for 3.0 MGD
pH
6-9 S.U.
No changes
WQBEL. State W.Q. standard, 15A
for 2.5 and 3.0 MGD
NCAC 26 .0200
3/week for 2.5 MGD
Daily for 3.0 MGD
TRC
DM 27.0 µg/I
No changes
WQBEL. State W.Q. standard, 15A
for 2.5 MGD and 25 µg/I
NCAC 2B .0200. The Division considers
for 3.0 MGD
all effluent TRC values reported below
50 ug/I to be in compliance with the
3/week for 2.5 MGD
permit.
Daily for 3.0 MGD
Temperature
Monitor and report
No changes
15A NCAC 26.0200 and 15A NCAC
effluent 3/week for
213.0500
for 2.5 MGD
Daily for 3.0 MGD
Monitor and report
instream at a variable"
frequency
Page 12 of 14

Total Hardness
None
Added quarterly
Hardness -dependent dissolved metals
monitoring upstream
water quality standards approved in
and in effluent
2016.
for 2.5 MGD and 3.0
MGD
Total Nitrogen (TN)
Monitor and report
No changes
15A NCAC 2B .0500 - Surface Water
monthly
Monitoring and Reporting.
for 2.5 MGD and 3.0 MGD
Total Phosphorus (TP)
Monitor and report
No changes
15A NCAC 2B .0500 - Surface Water
monthly
Monitoring and Reporting.
for 2.5 MGD and 3.0 MGD
Total Cyanide
For 2.5 MGD
No changes
RP, State WQ standards, 15A 2B .0200
MA 8.0 µg/I
WA 33.0 µg/I
For 3.0 MGD
MA 7.5 µg/I
WA 31.1 µg/I
Monitor and report
monthly for 2.5 MGD and
3.0 MGD
Total Copper
Quarterly monitoring for
No changes
Predicted Max >_ 50% of Allowable Cw -
2.5 MGD and 3.0 MGD
Continue Quarterly Monitoring
Total Zinc
Quarterly monitoring for
Removed
No RP. Predicted Max < 50% of
2.5 MGD and 3.0 MGD
Allowable Cw. No Monitoring required
Toxicity Test
Chronic limit, 63% at 2.5
No changes
WQBEL. No toxics in toxic amounts.
MGD or 67% at 3.0 MGD
15A NCAC 26.0200 and 15A NCAC
213.0500
Effluent Pollutant
Three times per permit
Next scans must be
40 CFR parts 423 and 122
Scan
cycle for 2.5 MGD and 3.0
performed in each of
MGD
the following years:
2023, 2024, and 2025.
Mercury Minimization
MMP
Removed
Consistent with EPA approved 2012
Plan (MMP)
for 2.5 MGD and 3.0 MGD
Statewide Mercury TMDL
Implementation.
Electronic Reporting
Electronic reporting
Added language for
In accordance with EPA Electronic
special condition
new electronic
Reporting Rule 2015 and Rule -Phase 2
for 2.5 MGD and 3.0 MGD
reporting deadline
Extension
December 21, 2025
* M.A. - Monthly Average, WA - Weekly Average, D.M. - Daily Max.
** Variable monitoring frequency is defined as follows: samples collected three times per week during June 1
through September 30 and once per week October 1 through May 31.
13. Public Notice Schedule
Permit to Public Notice: February 23, 2021
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
Page 13 of 14

within the 30 days comment period indicating the interest of the party filing such request and the reasons why
a hearing is warranted.
14. Fact Sheet Addendum (if applicable)
Were there any changes made since the Draft Permit was public noticed (Yes/No): Yes
If Yes, list changes and their basis below:
The Special Condition A. (5.) Electronic Reporting of Discharge Monitoring Reports was corrected to clarify
that duplicate signed copies shall be submitted only if a permittee is unable to use the eDMR system due to a
demonstrated hardship. Monitoring results obtained during the previous month(s) shall be summarized for
each month and submitted electronically using eDMR.
15. Fact Sheet Attachments (upon request):
1. RPA Sheets Summary for 2.5 and 3.0 MGD. Each sheet contains: input information tab, data
analyzed tab, results summary tab, and dissolve to total metals calculation tab.
2. BOD and TSS Removal Rate calculations
3. NH3/TRC/Fecal Waste Load Allocation (WLA) Spreadsheet for 2.5 and 3.0 MGD
4. Mercury TMDL Calculations for 2.5 and 3.0 MGD
5. Toxicity Summary/WET testing
6. Instream data summary and ttest
7. Pretreatment Summary
8. Limit violations summary, MA and WA limit exceedances, and compliance facility report from ECHO
9. Renewal Application Addendums
o Signed Effluent Pollutant Scans
o Addendum Form 2A
10. NPDES Implementation of Instream Dissolved Metals Standards Freshwater Standards
11. 2018 NC 303(d) List (one page)
12. 2021 Inspection Report
13. Affidavit
14. Questions and Responses from the Public Notice Period
Page 14 of 14

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
REQUIRED DATA ENTRY CHECK WQS
Table 1. Project Information
Facility Name
WWTP/WTP Class
NPDES Permit
Outfall
Flow, Ow (MGD)
Receiving Stream
HUC Number
Stream Class
❑ Apply WS Hardness WQC
7Q10s (cfs)
7Q10w (cfs)
30Q2 (cfs)
QA (cfs)
1 Q10S (cfs)
Effluent Hardness
--------------
Upstream Hardness
Combined Hardness Chronic
--------------
Combined Hardness Acute
Data Source(s)
❑ CHECK TO APPLY MODEL
❑ CHECK IF HQW OR DPW WQS
Corpening Creek
III
NCO031879
001
2.500
Corpening Creek (Youngs Fork)
03050101
C
2.300
3.60
6.00
12.00
1.93
49.33 mg/L (Avg)
25 mg/L (Avg)
----------------------
40.27 mg/L
----------------------
41.24 mg/L
- - - - - - - - - - - - - - - - - - - - - -
Note: 7Q10S, 7Q10W, 30Q2, and QA values were
taken from previous fact sheet. Limited dataset for
arsenic, beryllium, cadmium, total phenolic
compounds, chromium, lead, nickel, selenium, and
silver.
Par01
Par02
Par03
Par04
Par05
Par06E
Par07
Par08
Par09
Par10
Par91
Par12
Par13
Par14
Parts
Par16
Par17
Par18
Par19
Par20
Par21
Par22
Par23
Par24
Table 2. Parameters of Concern
Name WQS Type Chronic Modifier Acute PQL Units
Arsenic
Aquactic Life
C
150
FW
340
ug/L
Arsenic
Human Health
Water Supply
C
10
HH/WS
N/A
ug/L
Beryllium
Aquatic Life
NC
6.5
FW
65
ug/L
Cadmium
Aquatic Life
NC
0.8459
FW
5.0150
ug/L
Chlorides
Aquatic Life
NC
230
FW
mg/L
Chlorinated Phenolic Compounds
Water Supply
NC
1
A
ug/L
Total Phenolic Compounds
Aquatic Life
NC
300
A
ug/L
Chromium III
Aquatic Life
NC
173.9654
FW
1363.7927
1 ug/L
Chromium VI
Aquatic Life
NC
11
FW
16
pg/L
Chromium, Total
Aquatic Life
NC
N/A
FW
N/A
pg/L
Copper
Aquatic Life
NC
11.8434
FW
16.7832
ug/L
Cyanide
Aquatic Life
NC
5
FW
22
10
ug/L
Fluoride
Aquatic Life
NC
1,800
FW
ug/L
Lead
Aquatic Life
NC
5.0194
FW
132.2827
ug/L
Mercury
Aquatic Life
NC
12
FW
0.5
ng/L
Molybdenum
Human Health
NC
2000
HH
ug/L
Nickel
Aquatic Life
NC
55.7269
FW
511.9717
pg/L
Nickel
Water Supply
NC
25.0000
WS
N/A
pg/L
Selenium
Aquatic Life
NC
5
FW
56
ug/L
Silver
Aquatic Life
NC
0.06
FW
0.7012
ug/L
Zinc
Aquatic Life
NC
189.8090
FW
192.1174
ug/L
Chloroform
Water Supply
C
60
WS
pg/L
31879 RPA 2.5.xlsm, input
3/30/2021

Corpening Creek
NCO031879 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Qw (MGD) =
2.5000
WWTP/WTP Class: III
1Q10S(cfs)=
1.93
IWC% @ 1Q10S =
66.75279931
7Q10S (cfs) =
2.30
IWC% @ 7Q10S =
62.75303644
7Q10W (cfs) =
3.60
IWC% @ 7Q10W =
51.83946488
30Q2 (cfs) =
6.00
IWC% @ 30Q2 =
39.24050633
Avg. Stream Flow, QA (cfs) =
12.00
TW%C @ QA =
24.40944882
Receiving Stream: Corpening Creek (Youngs Fork) HUC 03050101
Stream Class: C
Outfall 001
Qw = 2.5 MGD
COMBINED HARDNESS (mg/L)
Acute = 41.24 mg/L
Chronic = 40.27 mg/L
YOU HAVE DESIGNATED THIS RECEIVING
STREAM AS WATER SUPPLY
Effluent Hard: 0 value > 100 mg/L
Effluent Hard Avg = 49.33 mg/L
PARAMETER
NC STANDARDS OR EPA CRITERIA
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
TYPE
�
CY
oApplied
�
Chronic Acute
n # Det. Max Pred Cw Allowable Cw
Standard
Acute (FW): 509.3
Arsenic
C
150 FW(7010s) 340
u;,,/L
_ _ _ ____
________ ______
3 0
15.0
_____
Chronic (FW) 239.0
C.V. (default)
M_ax_MD_L= 10
Arsenic
C
10 HH/WS(Qavg)
ug/L
Note: n 5 9
NO DETECTS
Chronic (HH) 41.0
Limited dataset. No RP, Predicted Max < 50% of
Allowable Cw - No Monitoring required, other than
Limited data set
Max MDL = 10
pollutant scan (PS)
Acute: 97.37
Beryllium
NC
6.5 FW(7Q10s) 65
ug/L
3 0
1.50__
Note: n 5 9
C.V. (default)
Chronic: 10.36
All values in limited dataset reported non -detect < 1
Limited data set
NO DETECTS
Max MDL = 1
ug/L - No Monitoring required, other than PS.
Acute: 7.513
Cadmium
NC
0.8459 FW(7Q10s) 5.0150
ug/L
3 0
1.500
Note: n < 9
C.V. (default)
------------------------------------------------
Chronic: 1.348
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
NO DETECTS
Max MDL = 1
Monitoring required, other than PS.
Acute: NO WQS
Total Phenolic Compounds
NC
300 A(30Q2)
ug/L
1 1
15.5
Note: n < 9
C.V. (default)
Chronic: 764.5
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
No value > Allowable Cw
Monitoring required, other than PS.
Acute: 2,043.0
Chromium III
NC
173.9654 FW(7Q10s) 1363.7927
µg/L
0 0
N/A
-_ _ _ _
----------
-Chronic:
--------------------------
277.2
See Chromium, Total
Acute: 24.0
Chromium VI
NC
11 FW(7Q10s) 16
µg/L
0 0
N/A
_ _ _ _
-- ----- - --
---------------
Chronic:
>_ 5 but < Cr VI Allowable
See Chromium, Total
Tot Cr value(s)
Cw
Chromium, Total
NC
µg/L
3 0
7.5
Max reported value = 2.5
a: No monitoring required if all Total Chromium
samples are < 5 pg/L or Pred. max for Total Cr is <
Note: n < 9
C.V. (default)
default
allowable Cw for Cr VI.
Limited data set
NO DETECTS
Max MDL = 5
Acute: 25.14
Copper
NC
11.8434 FW(7Q10s) 16.7832
ug/L
22 19
23.52
_ _ _ _ _ __ _
_ _ _ _ _ _ _ _ _ _ _
Chronic: 18.87
_
No RP , Predicted Max z 50%f Allowable Cw
No value > Allowable Cw
Continue Quarterly Monitoring
Acute: 33.0
Cyanide
NC
5 FW(7Q10s) 22
10
ug/L
51 14
5.0
___ ______
_____________
Chronic: 8.0
Predicted Max z 50% of Allowable Cw - Maintain
31879 RPA 2.5.xlsm, rpa
Page 1 of 2 3/30/2021

Corpening Creek Outfall 001
NCO031879 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 2.5 MGD
No value > Allowable Cw
limits and monitoring
Acute: 198.168
Lead
NC
5.0194 FW(7Q10s) 132.2827
ug/L
3 0
7.500
Note: n < 9
C.V. (default)
------------------------------------------------
Chronic: 7.999
No RP. All values reported non -detect < 5 ug/L - No
Limited data set
NO DETECTS
Max MDL = 5
monitoring required.
Acute (FW): 767.0
Nickel
NC
55.7269 FW(7Q10s) 511.9717
µg/L
3 0
15.0
_ _ _ _ _
---- --
Chronic (FW) 88.8
--------------------------
Note: n 5 9
C.V. (default)
M—ax_MD_L = 10 _ _ _ _
----------------------------
Nickel
NC
25.0000 WS(7Q10s)
µg/L
Limited data set
NO DETECTS
Chronic (WS) 39.8
No RP. All values reported non -detect < 10 ug/L
Predicted Max < 50% of Allowable Cw - No
Max MDL = 10
Monitoring required
Acute: 83.9
Selenium
NC
5 FW(7Q10s) 56
ug/L
3 0
15.0
Note: n 5 9
C.V. (default)
Chronic: 8.0
No RP. All values reported non -detect < 10 ug/L
Predicted Max < 50% of Allowable Cw - No
Limited data set
NO DETECTS
Max MDL = 10
Monitoring required
Acute: 1.050
Silver
NC
0.06 FW(7Q10s) 0.7012
ug/L
3 0
7.500
------------------------------------------------
Note: n < 9
C.V. (default)
Chronic: 0.096
All values reported non -detect < 5 ug/L - No
monitoring required.
Limited data set
NO DETECTS
Max MDL = 5
Acute: 287.8
No RP, Predicted Max < 50% of Allowable Cw - No
Zinc
NC
189.8090 FW(7Q10s) 192.1174
ug/L
22 22
114.7
Monitoring required
-- ----------
Chronic: 302.5
--------------------------
No value > Allowable Cw
Acute: NO WQS
Chloroform
C
60 WS(Qavg)
µg/L
3 3
72.00000
Note: n < 9
C.V. (default)
................. _
Chronic: 245.806
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
No value > Allowable Cw
Monitoring required
31879 RPA 2.5.xlsm, rpa
Page 2 of 2 3/30/2021

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
REQUIRED DATA ENTRY CHECK WQS
Table 1. Project Information
Facility Name
WWTP/WTP Class
NPDES Permit
Outfall
Flow, Ow (MGD)
Receiving Stream
HUC Number
Stream Class
❑ Apply WS Hardness WQC
7Q10s (cfs)
7Q10w (cfs)
30Q2 (cfs)
QA (cfs)
1 Q10S (cfs)
Effluent Hardness
--------------
Upstream Hardness
Combined Hardness Chronic
--------------
Combined Hardness Acute
Data Source(s)
❑ CHECK TO APPLY MODEL
❑ CHECK IF HQW OR DPW WQS
Corpening Creek
IV
NCO031879
001
3.000
Corpening Creek (Youngs Fork)
03050101
C
2.300
3.60
6.00
12.00
1.93
49.33 mg/L (Avg)
25 mg/L (Avg)
----------------------
41.28 mg/L
----------------------
42.2 mg/L
- - - - - - - - - - - - - - - - - - - - - -
Note: 7Q10S, 7Q10W, 30Q2, and QA values were
taken from previous fact sheet. Limited dataset for
arsenic, beryllium, cadmium, total phenolic
compounds, chromium, lead, nickel, selenium, and
silver.
Par01
Par02
Par03
Par04
Par05
Par06E
Par07
Par08
Par09
Par10
Par91
Par12
Par13
Par14
Parts
Par16
Par17
Par18
Par19
Par20
Par21
Par22
Par23
Par24
Table 2. Parameters of Concern
Name WQS Type Chronic Modifier Acute PQL Units
Arsenic
Aquactic Life
C
150
FW
340
ug/L
Arsenic
Human Health
Water Supply
C
10
HH/WS
N/A
ug/L
Beryllium
Aquatic Life
NC
6.5
FW
65
ug/L
Cadmium
Aquatic Life
NC
0.8619
FW
5.1160
ug/L
Chlorides
Aquatic Life
NC
230
FW
mg/L
Chlorinated Phenolic Compounds
Water Supply
NC
1
A
ug/L
Total Phenolic Compounds
Aquatic Life
NC
300
A
ug/L
Chromium III
Aquatic Life
NC
177.5331
FW
1389.5448
1 ug/L
Chromium VI
Aquatic Life
NC
11
FW
16
pg/L
Chromium, Total
Aquatic Life
NC
N/A
FW
N/A
pg/L
Copper
Aquatic Life
NC
12.0970
FW
17.1483
ug/L
Cyanide
Aquatic Life
NC
5
FW
22
10
ug/L
Fluoride
Aquatic Life
NC
1,800
FW
ug/L
Lead
Aquatic Life
NC
5.1601
FW
135.6928
ug/L
Mercury
Aquatic Life
NC
12
FW
0.5
ng/L
Molybdenum
Human Health
NC
2000
HH
ug/L
Nickel
Aquatic Life
NC
56.9079
FW
521.9609
pg/L
Nickel
Water Supply
NC
25.0000
WS
N/A
pg/L
Selenium
Aquatic Life
NC
5
FW
56
ug/L
Silver
Aquatic Life
NC
0.06
FW
0.7293
ug/L
Zinc
Aquatic Life
NC
193.8377
FW
195.8716
ug/L
Chloroform
Water Supply
C
60
WS
ug/L
31879 RPA 3.0.xlsm, input
3/30/2021

Corpening Creek Outfall 001
NCO031879 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 3 MGD
MAXIMUM DATA POINTS = 58
Qw (MGD) =
3.0000
WWTP/WTP Class: IV
1Q10S(cfs)=
1.93
IWC% @ 1Q10S =
70.66869301
7Q10S (cfs) =
2.30
IWC% @ 7Q10S =
66.90647482
7Q10W (cfs) =
3.60
IWC% @ 7Q10W =
56.36363636
30Q2 (cfs) =
6.00
IWC% @ 30Q2 =
43.66197183
Avg. Stream Flow, QA (cfs) =
12.00
TW%C @ QA =
27.92792793
Receiving Stream: Corpening Creek
(Youngs Fork) HUC 03050101 Stream Class: C
COMBINED HARDNESS (mg/L)
Acute = 42.2 mg/L
Chronic = 41.28 mg/L
YOU HAVE DESIGNATED THIS RECEIVING
STREAM AS WATER SUPPLY
Effluent Hard: 0 value > 100 mg/L
Effluent Hard Avg = 49.33 mg/L
PARAMETER
NC STANDARDS OR EPA CRITERIA
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
TYPE
o
Applied
Chronic Acute
n # Det. Max Pred Cw Allowable Cw
Standard
Acute (FW): 481.1
Arsenic
C
150 FW(7010s) 340
uWL
_ _ _ ---_ -_ --
--------------------------
3 0
15.0
Chronic (FW)-
C.V. (default)
M_ax_MD_L= 10
Arsenic
C
10 HH/WS(Qavg)
ug/L
Note: n 5 9
NO DETECTS
Chronic (HH) 35.8
Limited dataset. No RP, Predicted Max < 50% of
Allowable Cw - No Monitoring required, other than
Limited data set
Max MDL = 10
pollutant scan (PS)
Acute: 91.98
Beryllium
NC
6.5 FW(7Q10s) 65
ug/L
3 0
1.50
Note: n 5 9
C.V. (default)
Chronic: 9.72
All values in limited dataset reported non -detect < 1
Limited data set
NO DETECTS
Max MDL = 1
ug/L - No Monitoring required, other than PS.
Acute: 7.239
Cadmium
NC
0.8619 FW(7Q10s) 5.1160
ug/L
3 0
1.500
Note: n 5 9
C.V. (default)
------------------------------------------------
Chronic: 1.288
No detects
Limited data set
NO DETECTS
Max MDL = 1
Acute: NO WQS
Total Phenolic Compounds
NC
300 A(30Q2)
ug/L
1 1
15.5
Note: n 5 9
C.V. (default)
Chronic: 687.1
No RP, Predicted Max < 50 % of Allowable Cw - No
Limited data set
No value > Allowable Cw
Monitoring required, other than PS.
Acute: 1,966.3
Chromium III
NC
177.5331 FW(7Q10s) 1389.5448
µg/L
0 0
N/A
-_ _ _ _
----------
-Chronic:265.3
---------------
See Chromium, Total
Acute: 22.6
Chromium VI
NC
11 FW(7Q10s) 16
µg/L
0 0
N/A
-_ _ _ _
----- - --
-Chronic:
--------------------------
>_ 5 but < Cr VI Allowable
See Chromium, Total
Tot Cr value(s)
Cw
Chromium, Total
NC
µg/L
3 0
7.5
Max reported value = 2.5
a: No monitoring required if all Total Chromium
samples are < 5 pg/L or Pred. max for Total Cr is <
Note: n 5 9
C.V. (default)
allowable Cw for Cr VI.
Limited data set
NO DETECTS
Max MDL = 5
Acute: 24.27
Copper
NC
12.0970 FW(7Q10s) 17.1483
ug/L
22 19
23.52
_ _ _ _ _ __ _
Chronic: 18.08
_ _ _ _ _ _ _ _ _ _ _ _
No RP , Predicted Max z 50%f Allowable Cw
No value > Allowable Cw
Continue Quarterly Monitoring
Acute: 31.1
Cyanide
NC
5 FW(7Q10s) 22
10
ug/L
51 14
5.0
___ _____
Chronic: 7.5
___ _________
Predicted Max >_ 50% of Allowable Cw - Maintain
31879 RPA 3.0.xlsm, rpa
Page 1 of 2 3/30/2021

Corpening Creek Outfall 001
NCO031879 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 3 MGD
No value > Allowable Cw
limits and monitoring
Acute: 192.013
Lead
NC
5.1601 FW(7Q10s) 135.6928
ug/L
3 0
7.500
Note: n < 9
C.V. (default)
------------------------------------------------
Chronic: 7.712
No RP. All values reported non -detect < 5 ug/L - No
Limited data set
NO DETECTS
Max MDL = 5
monitoring required.
Acute (FW): 738.6
Nickel
NC
56.9079 FW(7Q10s) 521.9609
µg/L
3 0
15.0
_ _ _ _ _
---- - --
Chronic (FW)Note:
--------------------------
n 5 9
C.V. (default)
M—ax_MD_L = 10 _ _ _ _
----------------------------
Nickel
NC
25.0000 WS(7Q10s)
µg/L
Limited data set
NO DETECTS
Chronic (WS) 37.4
No RP. All values reported non -detect < 10 ug/L
Max MDL = 10
Predicted Max < 50% of Allowable Cw - No
Monitoring required
Acute: 79.2
Selenium
NC
5 FW(7Q10s) 56
ug/L
3 0
15.0__
Note: n 5 9
C.V. (default)
Chronic: 7.5
No RP. All values reported non -detect < 10 ug/L - No
Limited data set
NO DETECTS
Max MDL = 10
Monitoring required
Acute: 1.032
Silver
NC
0.06 FW(7Q10s) 0.7293
ug/L
3 0
7.500
------------------------------------------------
Note: n < 9
C.V. (default)
Chronic: 0.090
All values reported non -detect < 5 ug/L - No
monitoring required.
Limited data set
NO DETECTS
Max MDL = 5
Acute: 277.2
No RP, Predicted Max < 50% of Allowable Cw - No
Zinc
NC
193.8377 FW(7Q10s) 195.8716
ug/L
22 22
114.7
Monitoring required
-- ----------
Chronic: 289.7
--------------------------
No value > Allowable Cw
Acute: NO WQS
Chloroform
C
60 WS(Qavg)
ug/L
3 3
72.00000
Note: n < 9
C.V. (default)
................. _
Chronic: 214.839
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
No value > Allowable Cw
Monitoring required
--------------------------
Acute:
0 0
N/A
_ _ _ -----------------------------------------
Chronic:
No RP, Predicted Max < 50% of Allowable Cw -
Monitoring to continue as total nitrogen
31879 RPA 3.0.xlsm, rpa
Page 2 of 2 3/30/2021

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
6/4/2016
54.00 54
Std Dev.
5.0332
1
9/30/2020 25.00 25 Std Dev.
N/A
2
8/12/2017
50.00 50
Mean
49.3333
2
Mean
25.0000
3
11/10/2018
44.00 44
C.V. (default)
0.6000
3
C.V.
0.0000
4
n
3
4
n
1
5
10th Per value
45.20 mg/L
5
10th Per value
25.00 mg/L
6
Average Value
49.33 mg/L
6
Average Value
25.00 mg/L
7
Max. Value
54.00 mg/L
7
Max. Value
25.00 mg/L
8
8
9
9
10
10
11
11
12
12
13
13
14
14
15
15
16
16
17
17
18
18
19
19
20
20
21
21
22
22
23
23
24
24
25
25
26
26
27
27
28
28
29
29
30
30
31
31
32
32
33
33
34
34
35
35
36
36
37
37
38
38
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
51
52
52
53
53
54
54
55
55
56
56
57
57
58
58
31879 RPA 2.5.xlsm, data
1 - 3/30/2021

REASONABLE POTENTIAL ANALYSIS
Par01 & Par02
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Arsenic
Date Data BDL=1/2DL
5/26/2016 < 10 5
8/8/2017 < 10 5
11/27/2018 < 10 5
Use"PASTE SPECIAL
Values" then "COPY"
. Maximum data
points = 58
Results
Std Dev.
0.0000
Mean
5.0000
C.V. (default)
0.6000
n
3
Mult Factor = 3.00
Max. Value 5.0 ug/L
Max. Pred Cw 15.0 ug/L
-2-
31879 RPA 2.5.xlsm, data
3/30/2021

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
5/26/2016 < 1
0.5
Std Dev.
0.0000
1 5/26/2016 < 1
0.5
Std Dev.
0.0000
2
8/17/2017 < 1
0.5
Mean
0.5000
2 8/8/2017 < 1
0.5
Mean
0.5000
3
12/4/2018 < 1
0.5
C.V. (default)
0.6000
3 11/27/2018 < 1
0.5
C.V. (default)
0.6000
4
n
3
4
n
3
5
5
6
Mult Factor =
3.00
6
Mult Factor =
3.00
7
Max. Value
0.50 ug/L
7
Max. Value
0.500 ug/L
8
Max. Pred Cw
1.50 ug/L
8
Max. Pred Cw
1.500 ug/L
9
9
10
10
11
11
12
12
13
13
14
14
15
15
16
16
17
17
18
18
19
19
20
20
21
21
22
22
23
23
24
24
25
25
26
26
27
27
28
28
29
29
30
30
31
31
32
32
33
33
34
34
35
35
36
36
37
37
38
38
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
51
52
52
53
53
54
54
55
55
56
56
57
57
58
58
31879 RPA 2.5.xlsm, data
-3- 3/30/2021

REASONABLE POTENTIAL ANALYSIS
Par05
Chlorides
Use "PASTE SPECIAL-
Values" then "COPY".
Par06
Use "PASTE SF
Chlorinated Phenolic Compounds
Values" then "I
. Maximum c
Maximum data points =
points = 5
58
Date Data
BDL=1/2DL
Results
Date Data BDL=1/2DL Results
1
5/15/2016
220
220
Std Dev.
78.9892
1
Std Dev.
NO DATA
2
8/4/2016
262
262
Mean
253.6
2
Mean
NO DATA
3
11/14/2016
378
378
C.V. (default)
0.6000
3
C.V.
NO DATA
4
2/14/2017
163
163
n
5
4
n
0
5
5/5/2017
245
245
5
601
Mult Factor =
2.3
6
Mu It Factor =
N/A
7
Max. Value
378.0 mg/L
7
Max. Value
N/A
8
Max. Pred Cvv
877.0 mg/L
8
Max. Pred Cvv
N/A
9
9
10
10
11
11
12
12
13
13
14
14
15
15
16
16
17
17
18
18
19
19
20
20
21
21
22
22
23
23
24
24
25
25
26
26
27
27
28
28
29
29
30
30
31
31
32
32
33
33
34
34
35
35
36
36
37
37
38
38
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
51
52
52
53
53
54
54
55
55
56
56
57
57
58
58
31879 RPA 2.5.xlsm, data
-4- 3/30/2021

REASONABLE POTENTIAL ANALYSIS
COPY"
Total Phenolic Compounds
late
;8
Date Data
BDL=1/2DL
Results
1
5/26/2016 <
5 2.5
Std Dev.
2
8/17/2017 <
5 2.5
Mean
3
11/27/2018 <
5 2.5
C.V. (default)
4
n
5
6
Mult Factor =
ug/L
7
Max. Value
ug/L
8
Max. Fred Cw
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Par08
Use "PASTE SPECIAL
Values" then "COPY"
Chromium III
. Maximum data
points = 58
Date
Data BDL=1/2DL Results
0.0000
1
Std Dev.
2.5000
2
Mean
0.6000
3
C.V.
3
4
n
5
6.20
6
Mult Factor =
2.5 ug/L
7
Max. Value
15.5 ug/L
8
Max. Fred Cw
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Use "PASTE SF
Values" then
Maximum c
points = 5
NO DATA
NO DATA
NO DATA
0
N/A
N/A
N/A
31879 RPA 2.5.xlsm, data
-5- 3/30/2021

REASONABLE POTENTIAL ANALYSIS
COPY"
Chromium VI
late
;8
Date Data BDL=1/2DL Results
1
Std Dev.
2
Mean
3
C.V.
4
n
5
6
Mult Factor =
Ng/L
7
Max. Value
pg/L
8
Max. Fred Cw
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Par10
Use "PASTE SPECIAL
Values" then "COPY"
Total
. Maximum dChromium,ChrO1Um,
points = 58
Date Data
BDL=1/2DL
Results
NO DATA
1
5/26/2016 <
5.00 2.5
Std Dev.
NO DATA
2
8/17/2017 <
5.00 2.5
Mean
NO DATA
3
11/27/2018 <
5.00 2.5
C.V. (default)
0
4
n
5
N/A
6
Mult Factor =
N/A Ng/L
7
Max. Value
N/A pg/L
8
Max. Fred Cw
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Use "PASTE SF
Values" then
Maximum c
points = 5
0.0000
2.5000
0.6000
3
3.00
2.5
7.5
31879 RPA 2.5.xlsm, data
-6- 3/30/2021

REASONABLE POTENTIAL ANALYSIS
COPY"
late
;8
Ng/L
pg/L
1
Copper
Date Data
BDL=1/2DL
Results
1
9/19/2016
6
6
Std Dev.
2
11/1/2016
2
2
Mean
3
1/6/2017
3
3
C.V.
4
2/7/2017
4
4
n
5
5/9/2017
2
2
6
8/1/2017
5
5
Mult Factor =
7
11/7/2017
4
4
Max. Value
8
1/8/2018
2
2
Max. Fred Cw
9
2/6/2018
1
1
10
5/8/2018
2
2
11
8/7/2018
2
2
12
11 /6/2018
3
3
13
2/5/2019
5
5
14
5/7/2019
2
2
15
8/6/2019 <
5
2.5
16
9/9/2019
3
3
17
10/7/2019
5
5
18
11 /5/2019
3
3
19
1 /7/2020 <
2
1
20
2/4/2020 <
2
1
21
5/5/2020
3
3
22
8/4/2020
16
16
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Use"PASTE SPECIAL
Values" then "COPY"
. Maximum data
points = 58
3.5227
0.8853
22
1.47
16.00 ug/L
23.52 ug/L
2
Cyanide
Date Data
BDL=1/2DL
Results
1
9/12/2016 <
5
5
Std Dev.
2
9/16/2016
6
5
Mean
3
10/3/2016 <
5
5
C.V.
4
11/1/2016
8
5
n
5
12/6/2016 <
5
5
6
1/6/2017
9
5
Mult Factor =
7
1/30/2017
6
5
Max. Value
8
2/6/2017 <
5
5
Max. Fred Cw
9
3/6/2017
6
5
10
4/10/2017
7
5
11
5/9/2017 <
5
5
12
6/5/2017
7
5
13
7/10/2017
6
5
14
8/1/2017 <
5
5
15
9/5/2017 <
5
5
16
10/6/2017 <
5
5
17
11 /7/2017 <
5
5
18
12/4/2017
6
5
19
1 /8/2018 <
5
5
20
2/5/2018 <
5
5
21
3/6/2018 <
5
5
22
4/2/2018 <
5
5
23
5/7/2018 <
5
5
24
6/5/2018 <
5
5
25
7/9/2018 <
5
5
26
8/7/2018 <
5
5
27
9/10/2018 <
5
5
28
10/2/2018 <
5
5
29
11 /6/2018 <
5
5
30
12/4/2018 <
5
5
31
1/8/2019 <
5
5
32
2/5/2019 <
5
5
33
3/5/2019 <
5
5
34
4/2/2019 <
5
5
35
5/7/2019
5
5
36
6/4/2019
7
5
37
7/9/2019 <
5
5
38
8/6/2019 <
5
5
39
9/9/2019 <
5
5
40
10/7/2019 <
5
5
41
11 /5/2019
5
5
42
12/10/2019 <
5
5
43
1 /7/2020 <
5
5
44
2/4/2020 <
5
5
45
3/3/2020 <
5
5
46
4/7/2020 <
5
5
47
5/5/2020 <
5
5
48
6/2/2020
6
5
49
7/7/2020 <
5
5
50
8/4/2020
6
5
51
9/1/2020 <
5
5
52
53
54
55
56
57
58
Use "PASTE SF
Values" then
Maximum c
points = 5
5.00
0.0000
51
1.00
5.0
5.0
Mr!
31879 RPA 2.5.xlsm, data
3/30/2021

REASONABLE POTENTIAL ANALYSIS
PaF'14
PaF'15
�ECIAL
Use "PASTE SPECIAL
Mercury
COPY"
Lead
Values" then "COPY"
. Maximum data
;8
points = 58
1
Date
5/26/2016 <
BDL=1/2DL
5.00 2.5
Results
Std Dev.
0.0000
1
Date Data
5/26/2016 <
BDL=1/2DL
0.50 0.25
Results
Std Dev.
2
8/8/2017 <
5.00 2.5
Mean
2.5000
2
8/4/2017 <
0.50 0.25
Mean
3
11/27/2018 <
5.00 2.5
C.V. (default)
0.6000
3
11/15/2018
3.03 3.03
C.V. (default)
4
n
3
4
n
5
5
6
Mult Factor =
3.00
6
Mult Factor =
ug/L
7
Max. Value
2.500 ug/L
7
Max. Value
ug/L
8
Max. Fred Cw
7.500 ug/L
8
Max. Fred Cw
9
9
10
10
11
11
12
12
13
13
14
14
15
15
16
16
17
17
18
18
19
19
20
20
21
21
22
22
23
23
24
24
25
25
26
26
27
27
28
28
29
29
30
30
31
31
32
32
33
33
34
34
35
35
36
36
37
37
38
38
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
51
52
52
53
53
54
54
55
55
56
56
57
57
58
58
Use "PASTE SF
Values" then
Maximum c
points = 5
1.1767
0.6000
3
3.00
3.0
9.1
31879 RPA 2.5.xlsm, data
-8- 3/30/2021

REASONABLE POTENTIAL ANALYSIS
Par16
Par17 8� Par18
>ECIAL
Use "PASTE SPECIAL
Nickel
COPY"
late
Molybdenum
Values" then "COPY"
. Maximum data
;8
points = 58
Date
1
Data BDL=1/2DL Results
Std Dev.
NO DATA
1
Date Data
5/26/2016 < 10.00
BDL=1/2DL
5
Results
Std Dev.
2
Mean
NO DATA
2
8/8/2017 < 10.00
5
Mean
3
C.V.
NO DATA
3
11/29/2018 < 10.00
5
C.V. (default)
4
n
0
4
n
5
5
6
Mult Factor =
N/A
6
Mult Factor =
ng/L
7
Max. Value
N/A ug/L
7
Max. Value
ng/L
8
Max. Fred Cw
N/A ug/L
8
Max. Fred Cw
9
9
10
10
11
11
12
12
13
13
14
14
15
15
16
16
17
17
18
18
19
19
20
20
21
21
22
22
23
23
24
24
25
25
26
26
27
27
28
28
29
29
30
30
31
31
32
32
33
33
34
34
35
35
36
36
37
37
38
38
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
51
52
52
53
53
54
54
55
55
56
56
57
57
58
58
Use "PAS
SPECIAL-Vz
then "COP
Maximum
points =
0.0000
5.0000
0.6000
3
3.00
5.0
15.0
31879 RPA 2.5.xlsm, data
-9- 3/30/2021

REASONABLE POTENTIAL ANALYSIS
;TE Par19
dues"
,Y•
data
58
Selenium
Date Data
BDL=1/2DL
Results
1
5/26/2016 < 10.00
5
Std Dev.
2
8/8/2017 < 10.00
5
Mean
3
11/27/2018 < 10.00
5
C.V. (default)
4
n
5
6
Mult Factor =
Ng/L
7
Max. Value
pg/L
8
Max. Pred Cw
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Use"PASTE 7
SPECIAL -Values"
then "COPY".
Maximum data
points = 58
5.0000
0.6000
3
3.00
5.0 ug/L
15.0 ug/L
Use"PASTE:
Silver V alues" then
Maximum data
58
Date Data
BDL=1/2DL
Results
1 5/26/2016 <
5.00 2.5
Std Dev.
2 8/11/2017 <
5.00 2.5
Mean
3 11/21/2018 <
5.00 2.5
C.V. (default)
4
n
5
6
Mult Factor =
7
Max. Value
8
Max. Pred Cw
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
2.5000
0.6000
3
3.00
2.500
7.500
31879 RPA 2.5.xlsm, data
_10- 3/30/2021

REASONABLE POTENTIAL ANALYSIS
3PECIAL-
..COPY".
a points = Par21
ug/L
ug/L
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
Zinc
Date Data
BDL=1/2DL
Results
9/19/2016
69
69
Std Dev.
11/1/2016
67
67
Mean
1/6/2017
49
49
C.V.
2/7/2017
58
58
n
5/9/2017
30
30
8/1/2017
38
38
Mult Factor =
11/7/2017
17
17
Max. Value
1/8/2018
36
36
Max. Pred Cw
2/6/2018
27
27
5/8/2018
46
46
8/7/2018
35
35
11 /6/2018
37
37
2/5/2019
35
35
5/7/2019
19
19
8/6/2019
65
65
9/9/2019
76
76
10/7/2019
66
66
11 /5/2019
47
47
1 /7/2020
35
35
2/4/2020
45
45
5/5/2020
41
41
8/4/2020
94
94
Par22
Use "PASTE SPECIAL
Values" then "COPY"
. Maximum data
points = 58
46.9091
0.4133
22
1.22
94.0 ug/L
114.7 ug/L
Chloroform
Date Data
BDL=1/2DL
Results
1
6/3/2016
13.8 13.8
Std Dev.
2
8/31/2017
14.7 14.7
Mean
3
12/6/2018
24 24
C.V.(default)
4
n
5
6
Mult Factor =
7
Max. Value
8
Max. Pred Cw
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
l�fii !
31879 RPA 2.5.xlsm, data
3/30/2021

REASONABLE POTENTIAL ANALYSIS
Use "PASTE SPECIAL -
Values" then "COPY".
Maximum data points = 58
17.5000
0.6000
3.00
24.000000 Ng/L
72.000000 Ng/L
-12-
31879 RPA 2.5.xlsm, data
3/30/2021

NCO031879 Corpening Creek WWTP
CBOD monthly removal rate
Month
September-16
October-16
November-16
December-16
January-17
February-17
March-17
April-17
May-17
June-17
July-17
August-17
September-17
October-17
November-17
December-17
January-18
February-18
March-18
April-18
May-18
June-18
July-18
August-18
September-18
October-18
November-18
December-18
January-19
February-19
RR (%)
98.60
99.16
98.74
99.18
97.82
98.30
98.59
98.90
96.72
98.75
98.08
97.56
96.04
97.86
99.06
98.52
98.90
98.43
97.71
97.88
98.89
98.10
99.15
98.29
99.32
97.76
99.32
99.29
98.76
97.56
Month
March-19
April-19
May-19
June-19
July-19
August-19
September-19
October-19
November-19
December-19
January-20
February-20
March-20
April-20
May-20
June-20
July-20
August-20
September-20
October-20
November-20
December-20
January-21
February-21
March-21
April-21
May-21
June-21
July-21
August-21
Overall CBOD removal rate
RR (%)
99.77
98.53
97.85
97.98
98.69
98.95
98.67
98.43
99.31
99.08
99.39
93.88
98.62
99.37
91.07
98.99
98.82
97.93
98.96
98.28
Month
September-16
October-16
November-16
December-16
January-17
February-17
March-17
April-17
May-17
June-17
July-17
August-17
September-17
October-17
November-17
December-17
January-18
February-18
March-18
April-18
May-18
June-18
July-18
August-18
September-18
October-18
November-18
December-18
January-19
February-19
11/30/2020
TSS monthly removal rate
RR (%)
97.83
99.38
98.94
99.38
97.67
96.76
97.98
98.98
97.62
99.59
99.28
98.34
97.46
97.98
98.64
99.19
99.29
98.95
98.37
98.53
99.30
99.22
99.53
92.88
99.38
94.82
98.92
98.84
96.82
97.82
Month
March-19
April-19
May-19
June-19
July-19
August-19
September-19
October-19
November-19
December-19
January-20
February-20
March-20
April-20
May-20
June-20
July-20
August-20
September-20
October-20
November-20
December-20
January-21
February-21
March-21
April-21
May-21
June-21
July-21
August-21
Overall TSS removal rate
RR (%)
99.82
98.79
98.30
98.56
98.70
98.99
98.64
97.57
99.14
98.19
98.86
84.50
98.25
99.45
29.32
99.29
98.79
97.77
98.77
96.72

NH3/TRC WLA Calculations
Facility: City of Marion/Corpening Creek Wastewater Treatment Plant (WWTP)
PermitNo. NCO031879
Prepared By: Diana Yitbarek
Enter Design Flow (MGD): 2.5
Enter s7Q10 (cfs): 2.3
Enter w7Q10 (cfs): 3.6
Total Residual Chlorine (TRC)
Ammonia (Summer)
Daily Maximum Limit (ug/1)
Monthly Average Limit (mg NH3-N/1)
s7Q10 (CFS)
2.3
s7Q10 (CFS)
2.3
DESIGN FLOW (MGD)
2.5
DESIGN FLOW (MGD)
2.5
DESIGN FLOW (CFS)
3.875
DESIGN FLOW (CFS)
3.875
STREAM STD (UG/L)
17.0
STREAM STD (MG/L)
1.0
Upstream Bkgd (ug/1)
0
Upstream Bkgd (mg/1)
0.22
IWC (%)
62.75
IWC (%)
62.75
Allowable Conc. (ug/1)
27
Allowable Conc. (mg/1)
1.5
Maintain limit at 27 ug/I
Maximum MA ammonia (summer): 3.65 mg/I.
Daily Max 13.6 mg/I
Current MA limit: 1.5 mg/I
Maintain limit
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/1)
Fecal Coliform
w7Q10 (CFS)
3.6
Monthly Average Limit:
200/100ml DESIGN FLOW (MGD)
2.5
(If DF >331; Monitor)
DESIGN FLOW (CFS)
3.875
(If DF<331; Limit)
STREAM STD (MG/L)
1.8
Dilution Factor (DF)
1.59 Upstream Bkgd (mg/1)
0.22
IWC (%)
51.84
Allowable Conc. (mg/1)
3.3
Maintain 200/100 ml MA limit
Maximum MA ammonia (summer): 4.82 mg/1.
Daily Max 15 mg/I
Current MA limit: 3.3 mg/I
Maintain limit
Total Residual Chlorine
1. Cap Daily Max limit at 28 ug/I to protect for acute toxicity
Ammonia (as NH3-N
1. If Allowable Conc > 35 mg/I, Monitor Only Summer Winter
2. Monthly Avg limit x 3 = Weekly Avg limit (Municil WA ammonia, mg/1 4.39 9.80
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: City of Marion/Corpening Creek Wastewater Treatment Plant (WWTP)
PermitNo. NCO031879
Prepared By: Diana Yitbarek
Enter Design Flow (MGD): 3
Enter s7Q10 (cfs): 2.3
Enter w7Q10 (cfs): 3.6
Total Residual Chlorine (TRC)
Ammonia (Summer)
Daily Maximum Limit (ug/1)
Monthly Average Limit (mg NH3-N/1)
s7Q10 (CFS)
2.3
s7Q10 (CFS)
2.3
DESIGN FLOW (MGD)
3
DESIGN FLOW (MGD)
3
DESIGN FLOW (CFS)
4.65
DESIGN FLOW (CFS)
4.65
STREAM STD (UG/L)
17.0
STREAM STD (MG/L)
1.0
Upstream Bkgd (ug/1)
0
Upstream Bkgd (mg/1)
0.22
IWC (%)
66.91
IWC (%)
66.91
Allowable Conc. (ug/1)
25
Allowable Conc. (mg/1)
1.4
Maintain limit at 27 ug/I
Maximum MA ammonia (summer): 3.65 mg/I
Daily Max 13.6 mg/I
Current MA limit: 1.4 mg/I
Maintain limit
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/1)
Fecal Coliform
w7Q10 (CFS)
3.6
Monthly Average Limit:
200/100ml DESIGN FLOW (MGD)
3
(If DF >331; Monitor)
DESIGN FLOW (CFS)
4.65
(If DF<331; Limit)
STREAM STD (MG/L)
1.8
Dilution Factor (DF)
1.49 Upstream Bkgd (mg/1)
0.22
IWC (%)
56.36
Allowable Conc. (mg/1)
3.0
Maintain 200/100 ml MA limit
Maximum MA ammonia (summer): 4.82 mg/I
Daily Max 15 mg/I
Current MA limit: 3.0 mg/I
Maintain limit
Total Residual Chlorine
1. Cap Daily Max limit at 28 ug/I to protect for acute toxicity
Ammonia (as NH3-N)
1. If Allowable Conc > 35 mg/I, 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)

Corpening Creek WWTP/NC0031879
Mercury Data Statistics (Method 1631E)
2016
2017
2018
# of Samples
1
1
1
Annual Average, ng/L
0.5
0.5
3.0
Maximum Value, ng/L
0.50
0.50
3.03
TBEL, ng/L
47
WQBEL, ng/L
19.1

Corpening Creek WWTP/NC0031879
Mercury Data Statistics (Method 1631E)
2016
2017
2018
# of Samples
1
1
1
Annual Average, ng/L
0.5
0.5
3.0
Maximum Value, ng/L
0.50
0.50
3.03
TBEL, ng/L
47
WQBEL, ng/L
17.9

PART E. TOXICITY TESTING DATA, EPA FORM 35-10-2A
CORPENING CREEK WWTP, NC0031879
SUBMITTED: 7/29/2019
RECEIVED BY WATER QUALITY PERMITTING SECTION: 8/5/2019
In accordance with EPA-35-10-2A Part EA, if applicant previously submitted biomonitoring test
data, dates and summary of the results was to be added to the application. To the best of my
knowledge, that information was inadvertently omitted. Below is the required information.
Ceriodaphnia, tested Feb, May, Aug, and Nov
Dates entered Aquatic Toxicology Branch System: 25 Feb 19
30 May 19
21 Aug 19
26 Nov 19
Flathead Minnow, tested Aug, Sep, Oct, and Nov
Submittal Dates: 8/4/19
10/6/19
11/3/19
*Sep data submitted 1/12/2021
*Data may have been previously submitted, but was not in the Chronic Toxicity database
Summary:
All testing events passed without any issues noted.

Whole Effluent Toxicity Testing and Self Monitoring Summary
Marion-Corpening Cr. WWTP
NCO031879/001 County:
McDowell
Ceri7dPF
Begin:
5/1/2016 chr lim: 63% @ 2.5M
NonComp:
Single
J
F M
A
M
2016
-
Pass -
-
Pass
2017
-
Pass -
-
Pass
2018
-
Pass -
-
Pass
2019
-
Pass -
-
Pass
2020
-
Pass -
-
Pass
Mars Hill WTP
NCO083712/001 County:
Madison
Ceri7dPF
Begin:
7/1/2011 Chr Monit: 5.78%
NonComp:
J
F M
A
M
2016
Pass
- -
Pass
-
2017
Pass
- -
Pass
-
2018
Pass
- -
Pass
-
2019
Pass
- -
Pass
-
2020
Pass
- -
Pass
-
Region: ARO
Basin: CTB30
Feb May Aug Nov
7Q10: 2.3
PF: 3.0 IWC: 67
Freq: Q
J
J
A
S
O
Pass
Pass
Pass
-
-
>100(P)Pass
-
>100(
Region: ARO
Basin: FRB04
Jan Apr Jul Oct
7Q10:
PF: IWC:
Freq: Q
J
J
A
S
O
-
Pass
-
-
Pass
-
Pass
-
-
Pass
-
Pass
-
-
Pass
-
Pass
-
-
Pass
Marshall WWTP
NCO021733/001
County: Madison Region: ARO
Basin: FRB04 Feb May Aug Nov
Fthd24PF
Begin: 4/1/2012 24hr p/f ac lim: 90%
+ NonComp: Single 7Q10: 535
PF: 0.40 IWC: 0.12 Freq: Q
J F M
A M J J
A S O
2016
- Pass -
- Pass - -
Pass - -
2017
- Pass -
- Pass - -
Pass - -
2018
- Pass -
- Pass - -
Pass - -
2019
- Pass -
- Pass - -
Pass - -
2020
- Pass -
- Pass - -
- - -
Martin County WTP NCO089435/001 County: Martin Region: WARO
Ceri7dPF Begin: 4/1/2014 Chr Monit: 90% NonComp: 7Q10:
J F M A M J
2016 - - Pass - - H
2017 - - Pass - - Pass
2018 - - Pass - - Pass
2019 - - Pass - - Pass
2020 - - Pass - - Pass
Maxton WTP NCO048577/001 County: Robeson
Ceri7dPF Begin: 9/1/2014 Chr Monit: 90% NonComp:
J F M A M
2016 Fail - - Pass -
2017 Fail - - Pass -
2018 Pass - - Fail -
2019 Fail - - Fail -
2020 Fail - - Pass -
SOC JOC:
N
Pass
Pass
Pass
>100 Pass
SOC JOC:
N
SOC JOC:
N
Pass
Pass
Pass
Pass
Basin: ROA09 Mar Jun Sep Dec SOC JOC:
PF: IWC: Freq: Q
J A S O N
Pass -
Pass
Pass
Pass
Region: FRO Basin: LUM51 Jan Apr Jul Oct SOC JOC:
7Q10: PF: IWC: Freq: Q
J J A S O N
- Fail - - Pass -
- Fail - - Fail -
Fail - - Fail -
NR Pass
D
D
D
D
Pass
Pass
Pass
Pass
D
Legend: P= Fathead minnow (Pimphales promelas), H=No Flow (facilitv is active), s = Split test between Certified Labs Page 73 of 122

Data
Parameter Location Average of Value Max of Value Min of Value
00010 - Temperature, Water Deg. Centigrade Downstream 16.9 24.0 2.0
Effluent 17.8 25.0 8.0
U stream 1 16.4 23.0 1.0
00010 - Temperature, Water Deg. Centigrade Total 17.2 25.0 1.0
00300 - Oxygen, Dissolved (DO) Downstream 9.0 14.2 4.6
Effluent 8.4 11.3 4.9
Upstream 9.2 15.3 4.6
00300 - Oxygen, Dissolved DO Total 8.8 15.3 4.6
Grand Total 13.0 25.0 1.0
Temperature, C
30.0
25.0
20.0
15.0
10.0
5.0
0.0
18.0
16.0
14.0
12.0
10.0
8.0
6.0
4.0
2.0
0.0
IN.
III
IN=
Upstream
Effluent
Downstream
00010 -
Temperature, Water Deg.
Centigrade
■ Average of Value ■ Max of Value ■ Min of Value
DO, mg/1
III III III
Upstream Effluent Downstream
00300 - Oxygen, Dissolved (DO)
■ Average of Value ■ Max of Value ■ Min of Value

Sum of Value Parameter Location
00300 -
Oxygen,
Dissolved
DO
Years
Date
Downstream Upstream
2016
Sep
101.9 105.1
Oct
45.3 44.4
Nov
42.7 39.8
Dec
42.7 41.8
2017
Jan
53.9 55.5
Feb
41.3 45.2
Mar
40.1 36.6
Apr
38.6 38.3
May
43.5 44.4
Jun
104.9 110
Jul
103.8 108.7
Aug
115.4 119.6
Sep
108.6 110.4
Oct
42 43.6
Nov
52.8 54.7
Dec
45.7 47.9
2018
Jan
63.9 68
Feb
43.8 44.2
Mar
46.7 48.2
Apr
51.5 52.8
May
36.92 37.52
Jun
104 107.8
Jul
116 117.8
Aug
105.2 106.8
Sep
95.1 97.3
Oct
42.3 45.7
Nov
40.6 41.4
Dec
52.1 52
45.3 44.8
2019
Jan
Feb
44.6 45.2
Mar
45.3 45.9
Apr
52.9 54
May
38.2 39.2
Jun
106.6 110.6
Jul
122.4 120.8
Aug
94 97.7
Sep
94.6 98.3
Oct
58.3 59.1
Nov
41.5 41.6
Dec
49.2 51.2
2020
Jan
43.5 44.2
Feb
41.6 44.4
Mar
51.7 53.5
Apr
39 39.3
May
36.6 36.8
Jun
119.3 120
F-Test Two -Sample for Variances
Variable 1 Variable 2
Mean 68.263673 66.8922449
Variance 989.33216 943.181197
Observations 49 49
df 48 48
F 1.0489312
P(F<=f) one -tail 0.4346221
F Critical one -tail 1.6153703
Comment: The variance of Variable 1 is higher than the va
We accept the null hypothesis. The variances of the two sE
t-Test: Two -Sample Assuming Equal Variances
Variable 1
Variable 2
Mean
68.263673
66.8922449
Variance
989.33216
943.181197
Observations
49
49
Pooled Variance
966.25668
Hypothesized Mean Differenc(
0
df
96
t Stat
0.2183786
P(T<=t) one -tail
0.4137989
t Critical one -tail
1.6608814
P(T<=t) two -tail
0.8275977
t Critical two -tail
1.9849843
We look at the p-value, two tail. Since we set alpha value <

2020
Jul
105.3
104.3
Aug
98.6
99.3
Sep
127.9
129.2
Grand Total
3277.72
3344.92

1 /24/2021
Mail - Yitbarek, Diana - Outlook
Re: [External] Request - NC0031879, Corpening Creek WWTP, City of Marion, McDowell
County, ARC)
Yitbarek, Diana <[e-mail]>
Thu 1/7/2021 14:40
To: Tim Horton <[e-mail]>
Cc: Montebello, Michael J <[e-mail]>
Dear Tim Horton - I checked with the pretreatment staff. We will need the City to perform an
industrial waste survey (IWS) to ensure that the POTW's list of Industrial Users (IUs) and the
pollutants in their waste streams are current. The IWS will help determine if any of the IUs should
become Significant Industrial Users (SIU) or if the IU might need regulation as a non-SIU (NSCIU).
The SIU criteria are found in 15A NCAC 02H .0903(b)(30).
Guidance on how to conduct an IWS can be found here and you can find further information about
IWS on our website.
If you can complete the IWS within 180 days, that would be appreciated.
Please let me know if you have any questions.
-Diana
Diana Yitbarek
Engineer
T: [phone]
[e-mail]
NPDES Municipal Permitting Unit
NC Department of Environmental Quality Division of Water Resources
Mailing: 1617 Mail Service Center, Raleigh, NC 27699-1617
Physical: 512 N. Salisbury Street,_Ern. 925T, Raleigh, NC 27604-1170
w t
EkQa
GgwiwrOILniaixaw�isi p,iavty
*Please check with the appropriate staff before visiting our offices, as we may be able to handle your requests by phone or email. We can
also be available via Microsoft Teams if requested. Thanks for your patience and stay safe.
Email correspondence to and from this address is subject to the North Carolina Public Records Law and may be disclosed to third parties.
From: Yitbarek, Diana <[e-mail]>
Sent: Thursday, January 7, 2021 12:00
To: Tim Horton <[e-mail]>
Subject: Re: [External] Request - NC0031879, Corpening Creek WWTP, City of Marion, McDowell County, ARO
Good morning, Dear Tim Horton
Thanks for your message and congratulations on your new position as WWTP Superintendent.
Addressing your questions:
Item#1 - According to our records, the City of Marion's pretreatment (PT) program is on the
inactive list since 2008. I will check in with the PT staff to get more information about this and get
back to you.
https://outlook.office365.com/mail/search/id/AAQkADNmOTIxZjdhLTEyMWYtNDEzMS1 iOGNiLTkxNmZhYWJmZThIMAAQAPL9AOBgXltliG6Kn1osTH... 1/3

1/24/2021
Mail - Yitbarek, Diana - Outlook
Item#3 - The City submitted the permit application (attached to this email) on August 5, 2019. I
only have that scanned version. Hopefully, you find the editable version in your files. If not, let me
know, and I can point you to the updated fillable 2A form for permit applications.
Item#5 - The mercury minimization plan (MMP) was one of the special conditions included in the
permit. I will attach the permit here. See section A. (6), page 10/11, and please let me know if you
have any questions.
Best,
-Diana
Diana Yitbarek
Engineer
T: [phone]
[e-mail]
NPDES Municipal Permitting Unit
NC Department of Environmental Quality Division of Water Resources
Mailing: 1617 Mail Service Center, Raleigh, NC 27699-1617
Physical: 512 N. Salisbury Street, Rm. 925T, Raleigh, NC 27604-1170
xt �
ovPM PIFn++�rn�i+l gq�llMy
*Please check with the appropriate staff before visiting our offices, as we may be able to handle your requests by phone or email. We can
also be available via Microsoft Teams if requested. Thanks for your patience and stay safe.
Email correspondence to and from this address is subject to the North Carolina Public Records Law and may be disclosed to third parties.
From: Tim Horton <[e-mail]>
Sent: Thursday, January 7, 2021 07:27
To: Yitbarek, Diana <[e-mail]>
Subject: [External] Request - NC0031879, Corpening Creek WWTP, City of Marion, McDowell County, ARO
CAUTION: External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment
to Report Spam.
Good Morning,
Larry Carver retired 28 Feb 20. 1 am the new WWTP Superintendent. I have questions regarding
Items #1, #3, and #5.
Item#1
Item 1.7of Table 2 "Indicate the number of SIUs and NSCIUs that discharge to the POTW".
I'm researching pretreatment status
Item#3
I can't open the file to complete the required section.
Item#5
I'm unfamiliar with the Mercury Minimization Plan. I'll research it.
https://outlook.office365.com/mail/search/id/AAQkADNmOTIxZjdhLTEyMWYtNDEzMS1 iOGNiLTkxNmZhYWJmZThIMAAQAPL9AOBgXltliG6Kn1osTH... 2/3

1 /24/2021
Thanks,
Mail - Yitbarek, Diana - Outlook
Tim Horton
Wastewater Superintendent
City of Marion
[phone] (office)
[phone] (mobile)
[e-mail]
On Tue, Jan 5, 2021 at 1:52 PM Yitbarek, Diana <[e-mail]> wrote:
Dear Larry Carver,
I hope this message finds you well. I am the assigned permit writer for the subject WWTP. I recently started
reviewing the NPDES permit application for renewal submitted by the City on August 5, 2019, and have a
couple of requests:
1. Since the EPA form 2A has been updated, I will need you to complete this form. Please send it to me, and
I'll attach it as an addendum to your application.
2. Please submit the signed Annual Monitoring and Pollutant Scan for 2016, 2017, and 2018. Scanned
copies with your signature would suffice.
3. Please fill out Part E. Toxicity Testing Data of the permit application, attach testing results, and resubmit.
4. Please provide coordinates for upstream and downstream location points.
5. Please submit the WWTP's mercury minimization plan and summarized results since the last permit
renewal.
If you provide this information within the next three weeks, that would be appreciated. Thanks for your
continued cooperation with the NPDES program and your work protecting public health and the environment.
Please confirm the reception of this email and let me know if you have any questions.
-Diana
Diana Yitbarek
Engineer
T: [phone]
[e-mail]
NPDES Municipal Permitting Unit
NC Department of Environmental Quality Division of Water Resources
Mailing: 1617 Mail Service Center, Raleigh, NC 27699-1617
Physical: 512 N. Salisbury Street, Rm. 925T, Raleigh, NC 27604-1170
�� ID�_EA.
Dgp+�jn�r��i of Fny�ronniraiial {k,sliYy
*Please check with the appropriate staff before visiting our offices, as we may be able to handle your requests by phone or email. We
can also be available via Microsoft Teams if requested. Thanks for your patience and stay safe.
Email correspondence to and from this address is subject to the North Carolina Public Records Law and may be disclosed to third parties.
https://outlook.office365.com/mail/search/id/AAQkADNmOTIxZjdhLTEyMWYtNDEzMS1 iOGNiLTkxNmZhYWJmZThIMAAQAPL9AOBgXltliG6Kn1osTH... 3/3

ECH(s
Enforcement and
Compliance History Online
Detailed Facility Report
Facility Summary_
CORPENING CREEK WWTP
3982 NC HWY 226 S, MARION, NC 28752
FRS (Facility Registry Service) ID: 110028271313
EPA Region: 04
Latitude: 35.652445
Longitude:-81.95739
Locational Data Source: FRS
Industry: Sewerage Systems
Indian Country: N
Enforcement and Compliance Summary
statute
CwA
Insp (5 Years)
3
Date of Last Inspection
03/21/2019
Current Compliance Status
Violation Identified
Qtra with NC (of 12)
12
Qtrs with Significant Violation
I
Informal Enforcement Actions (5 years)
10
Formal Enforcement Actions (5 years)
6
Penalties from Formal Enforcement Actions (5 years)
$8,193
EPA Cases (5 years)
--
Penalties from EPA Cases (5 years)
—
Regulatory Information
Clean Air Act (CAA): No Information
Clean Water Act (CWA): Minor, Permit Admin Continued (NCL031879), Major, Permit Expired (NC0031879), Minor,
Permit Effective (NCG110102)
Resource Conservation and Recovery Act (RCRA): No Information
Safe Drinking Water Act (SDWA): No Information
Other Regulatory Reports

Air Emissions Inventory (EIS): No Information
Greenhouse Gas Emissions (eGGRT): No Information
Toxic Releases (TRI): No Information
Compliance and Emissions Data Reporting Interface (CEDRI): No Information
Known Data Problems
Facility/System Characteristics
Facility/System Characteristics
S stem
FRS
Statute
Identifier
Universe
Status
Areas
Permit Expiration Date
Indian Court,
N
Latitude
35.652445
Longitude
.81.95739
110028271313
ICIS-NPDES
CWA
NCL031879
Minor: Associated Permit Record
Admin Continued
Biosolids
12/31/2020
N
35.652445
-81.95739
ICIS-NPDES
CWA
NC0031879
Major: NPDES Individual Permit
Expired
Biosolids, POTW
O1/31/2020
N
35.652298
-81.956771
ICIS-NPDES
I CWA
I NCGlIO102
I Minor: General Permit Covered Facility
Effective
05/31/2023
N
35.652298
-81.956771
Facility Address
System
Statute
Identifier
110028271313
Facility Name
Facility Address
3982 NC HWY 226 S, MARION, NC 28752
FRS
CORPENING CREEK WWI?
ICIS-NPDES
CWA
NCL031879
CITY OF MARION
PO DRAWER 700, MARION, NC 28752
ICIS-NPDES
CWA
NC0031879
CORPENING CREEK W WTP
3982 NC HWY 226 S, MARION, NC 28752
ICIS-NPDES
CWA
NCGI10102
CORPENING CREEK W WTP
3982 NC HWY 226 S, MARION, NC 28752
Facility SIC (Standard Industrial Classification) Codes Facility NAICS (North American Industry
System I Identifier — SIC Code SIC Description Classification System) Codes
ICIS-NPDES
NC0031879
4952
Sewerage Systems
NPDES
NC0031879
4952
Sewerage Systems
ICIS-NPDES
NCGI10102
4952
Sewerage Systems
NPDES
NCGI10102
4952
Sewerage Systems
Facility Industrial Effluent Guidelines
IdentifierI Effluent Guideline 40 CFR PartEffluent Guideline Descri lion
NCGI10102 401 General provisions
Enforcement and Compliance
Compliance Monitoring History (5 years)
Sy>icm Identifier NAICS Code NAICS Description
No data records returned
Facility Tribe Information
ff!5L'
ervation Name Tribe Name EPA Tribal ID Distance to Tribe miles
No data records returned
Statute
Source ID
System
Activity Type
Com liance Monitoring Type
Lead Agency
State
Date
03/21/2019
Finding if aERlicable)
CWA
NC0031879
ICIS-NPDES
Inspection/Evaluation
Base Program - Evaluation
CWA
NCGI10102
ICIS-NPDES
Inspcction/Evalua0on
Base Program - Evaluation
State
O1/16/2019
CWA
NCGI10102
ICIS-NPDES
Inspection/Evaluation
Base Program - Evaluation
State
11/15/2018
Entries in italics are not counted in EPA compliance monitoring strategies or annual results.

Compliance Summary Data
Statute
CWA
I Source ID
I CL03 Vl
Current SNC (Significant Noncom liance /HPV (Hieh Prioritv Violation
Current As Of
Qtra with NC (Noncompliance) of 12
Data Last Refreshed
01/15/2021
No
09/30/2020
0
CWA
NC0031879
No
09/30/2020
12
01/15/2021
CWA
NCGI10102
No
09/30/2020
0
01/15/2021
Three -Year Compliance History by Quarter
CWA (Source Ill: NCL031879)
10/01-12/31/17 01/01-03/31/18 04/O1-06/30/18 07/01-09/30/18 10/O1-12/31/18 01/01-03/31/19 04/O1-06/30/19 07/01-09/30/19 10/01-12/31/19 01/01-03/3 U20
04/O1-06/30/20 07/01-09/30/20 10/01-01/15/21
Facility -Level Status
o Violation No Violation No Viola on No Mo a on No Violation No Violation o o a on o Molation No Molation No o a on
Ne o a on No Violation Undetermined
Identified Identified Identified Identified Identified Identified Identified Identified Identified Identified
Identified Identified
Quarterly Noncompliance Report
History
Violation
Violation
Violation
Violation
Violation
Violation
Violation
Violation
Violation
Volation
' rg°r re
Violation
Vol-ted
Facility -Level Statue
Identified
Identified
Identified
Identified
Identified
Identified
Identified
Identified
Identified
Identified
Catego
Undetermined
Noncomplian
Quarterly Noncompliance Report
Reportable
Reportable
Reportable
Reportable
Reportable
Reportable
Reportable
Reportable
Reportable
Reportable
Ettlucnt - Non-
Reportable
History
Noncompliance
Noncompliance
Noncompliance
Noncompliance
Noncompliance
Noncompliance
Noncompliance
Noncompliance
Noncompliance
Noncompliance
monthly Average
Noncompliance
Limit
Pollutant
Disch
Mon
Freq
Point
Loc
ROD, 5-day,
CWA
20 deg. C
©
001 -
M
Eftuent�
Goss
89
CWA I total [as N)© 1001 M - I Effluent
I Mthly I I 43%
M Goss
CWA I total [as Nj 1001 - Effluent I Nf I I 39
© M Gros
CWA [Dp) © 0`1 - I!ftluent Neither
M Gross
Solids, total
CWA suspendedff3l 0W - Effluent Mthly
M Goss
141%
108% [ [ 1 1 19%
2%
35% 1 508%
Solids, total
CWA suspended MGros
0- Eftluent �_d
53% Ih% 34% 151% 1514%
M
CWA pit Efluent Neither LIMIT LIMIT
M Gross VIOLATION VIOLATION
Late or Missing Discharge Monitoring
Report (DMR) Measurements
Counts of Missing DMR Measurements I9
1-1 lCn .T•N!`rll nl ail I 9.1I I,I III 'a/111 n6 1I nl 0111 1 K 10.n 1..1 it n n1 1 10 fis Ill n6.L n Jill.1n 10 11.n 111 Ln I n.. ndin 1n.9( ne.1n, INnI-n1/1 [/01
Facility -Level Status
Violation
No Violation
No Violation
No Violation
No Violation
No Violation
No Molation
No Molation
No Molation
No Molation
No Molation
No Violation
U°determined
tified
Identified
Identified
Identified
Identified
Identified
Identified
Identified
Identified
Identified
Identified
Identified
Quarterly Noncompliance Report
History
Informal Enforcement Actions (5 Years)
Statute
S stem
Source ID
T e of Action
Lead Agency
State
Date
CWA
ICIS-NPDES
NC0031879
Base Program- Notice of Violation
06/09/2020
CWA
ICIS-NPDES
NC0031879
Base Program- Notice of Violation
State
04/22/2020
CWA
ICIS-NPDES
NC0031879
Base Program- Notice of Violation
State
03/29/2019
CWA
ICIS-NPDES
NC0031979
Base Program- Notice of Violation
State
02/07/2019
CWA
ICIS-NPDES
NC0031879
Base Program- Notice of Violation
State
10/03/2018
CWA
ICIS-NPDES
NC0031879
Base Program- Notice of Violation
State
06Y07/2018
CWA
ICIS-NPDES
NC0031879
Base Program- Notice of Violation
State
06/02/2017
CWA
]CIS-NPDES
NC0031879
Base Program- Notice of Violation
State
09/08/2016

State
06/28/2016
State
06/28/2016
tools.
State/Local Penalty
Assessed
$1,122
SEP Cost Comp Action Cost
$0 $0
$614
$0
$0
$1,364
So
$0
$1,617
So
$0
$1,363
Sa
S0
$2,113
ao
So
Environmental Conditions
Watershed(s)
12-Digit WBD (Watershed Boundary Dataset) HUC WBD (Watershed Boundary Dataset) Subwatershed State Water Body Name (ICI (Integrated Beach Closures Beach Closures Within Pollutants Potentially Watershed with ESA (Endangered Species
(RAD (Reach Address Database)) Name RAD Reach Address Database Compliance Information System)) Within Last Yeaz Last iwo Years Related to Ira a rment Act -listed Aquatic Species?
030501010601 No. Muddy Creek YOUNGS FORK (COPERNING CREED No No Y
Assessed Waters From Latest State Submission (ATTAINS)
State Report Cycle Assessment Unit ID Assessment Unit Name Water Condition Cause Groups Impaired Drinkin Water Use A uatic Life Fish Consum lion Use Recreation Use Other Use
NCI 2016 I NCIl-32-1-46 Youngs Fork(Copeming Creek) Impaired-303(d)Listed -With Restoration Plan CAUSE UNKNOWN -IMPAIRED BIOTA Not Supporting
Air Quality Nonattainment Areas
Pollutant i Within Nonattainment Status Area? Nonattainment Status Applicable Standard(s) Within Maintenance Status Area? Maintenance Status Applicable Standards)
No data records returned
Pollutants
Toxics Release Inventory History of Reported Chemicals Released in Pounds per Year at Site
TRI Facili IDlYcarl Total Air Emissions I Surface Water Discharges Off -Site Transf to POTWa(Publicly Owned Treatment Works Underground Iniections I Releases to Land Total On -site Relesaea Total Off -site Transfers
No data records returned
Toxics Release Inventory Total Releases and Transfers in Pounds by Chemical and Year
Chemical Name
No data records returned
Demographic Profile

EJSCREEN EJ Indexes
Eleven primary environmental justice (EJ) indexes of EJSCREEN, EPA's screening tool for EJ concerns. EPA uses these
indexes to identify geographic areas that may warrant further consideration or analysis for potential EJ concerns. The
index values below are for the Census block group in which the facility is located. Note that use of these indexes does not
designate an area as an "EJ community" or "EJ facility." EJSCREEN provides screening level indicators, not a
determination of the existence or absence of EJ concerns. For more information, see the EJSCREEN home page.
Census Block Group EJ Indexes (percentile)
Particulate Matter (PM 2.5)
52.9
Ozone NATA Diesel PM
53.3
�ATA Air -xi- Cancer Risk
53
ATA Respiratory Hazard Index (HI)
52.9
Traffic Proximity
47.4
Lead Paint Indicator
45.3
Superfund Proximity
54.4
Risk Management Plan (RMP) Proximity
54.7
Hazardous Waste Proximity
54.6
Wastewater Discharge Proximity
18.4
Demographic Profile of Surrounding Area (3 Miles)
Number of EJ Indexes Above 80th Percentile
View EJSCREEN Report
This section provides demographic information regarding the community surrounding the facility. ECHO compliance data
alone are not sufficient to determine whether violations at a particular facility had negative impacts on public health or the
environment. Statistics are based upon the 2010 U.S. Census and 2006-2010 American Community Survey 5-Year
Summary and are accurate to the extent that the facility latitude and longitude listed below are correct. EPXs spatial
processing methodology considers the overlap between the selected radii and the census blocks (for U.S. Census
demographics) and census block groups (for ACS demographics) in determining the demographics surrounding the
facility. For more detail about this methodology, see the DFR Data Dictionary.
General Statistics
otal Persons
5,706
opnlatuat Density
203/sq.mi.
rcent Minority
16%
Households in Area
1,945
Housing Units in Area
2,254
Households on Public Assistance
36
rsons Below Poverty Level
1,832
Geography
Radius of Selected Area
Center Latitude
LCenter Longitude
�µ�.and Area
(Water Area
Age Breakdown - Persons (%)
Children 5 years and younger 298 (5%)
Minors 17 years and younger 1, 126 (20%)
Adults 18 years and older 4,580 (80%)
Seniors 65 years and older 803 (14%)
Race Breakdown - Persons (%)
White 4,873 (85%)
African -American 415 (7°/a)
Hispanic -Origin 382 (7%)
Asion/Pacific Islander 36 (1%)
American Indian 28 (0%)
10ther/Multimcial 355 (61/4)
Education Level (Persons 25 & older -Persons
,Less than 9th Grade 303 (8.72%)
Breakdown -Households (% )
9th through 12th Grade 617 (17.75%)
LLIncome
µ,ess than $15,000 416 (23.94%)
High School Diploma 1,288 (37.05%)
$15,000 - $25,000 357 (20.54%)
Some College/2-year 929 (26.73%)
$25,000 - $50,000 423 (24.34%)
B.S./B.A. (Bachelor of Science/Bachelor of Arts) or More 339 (9.75%)
$50,000 - $75,000 311 (17.89%)
1
1
Greater than $75,000 231 (13.29%)

MONITORING REPORT(MR) VIOLATIONS for:
Report Date:
02/04/21 Page
1 of 5
Permit:
NCO031879
MRS Betweei 11 - 2015 and11 - 2020
Region:
%
Violation Category:%
Program Category:
Facility Name: %
Param Nam(%
County:
%
Subbasin: %
Violation Action: %
Major Minor:
%
PERMIT: NCO031879
FACILITY: City of Marion - Corpening Creek WWTP
COUNTY: McDowell
REGION: Asheville
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
05 - 2020
001
Effluent
BOD, 5-Day (20 Deg. C) -
05/23/20
3 X week
mg/I
45
85.13
89.2
Weekly Average
Proceed to NOV
Concentration
Exceeded
12-2015
001
Effluent
Chlorine, Total Residual
12/31/15
5 X week
ug/I
25
27
8
Daily Maximum
No Action, BPJ
Exceeded
01 -2016
001
Effluent
Chlorine, Total Residual
01/07/16
5 X week
ug/I
25
31
24
Daily Maximum
No Action, BPJ
Exceeded
02 - 2016
001
Effluent
Chlorine, Total Residual
02/03/16
5 X week
ug/I
25
47
88
Daily Maximum
No Action, BPJ
Exceeded
02 - 2016
001
Effluent
Chlorine, Total Residual
02/17/16
5 X week
ug/I
25
40
60
Daily Maximum
No Action, BPJ
Exceeded
02 - 2016
001
Effluent
Chlorine, Total Residual
02/26/16
5 X week
ug/I
25
35
40
Daily Maximum
No Action, BPJ
Exceeded
03 - 2016
001
Effluent
Chlorine, Total Residual
03/03/16
5 X week
ug/I
25
27
8
Daily Maximum
No Action, BPJ
Exceeded
03 - 2016
001
Effluent
Chlorine, Total Residual
03/16/16
5 X week
ug/I
25
26
4
Daily Maximum
No Action, BPJ
Exceeded
03 - 2016
001
Effluent
Chlorine, Total Residual
03/24/16
5 X week
ug/I
25
27
8
Daily Maximum
No Action, BPJ
Exceeded
04 - 2016
001
Effluent
Chlorine, Total Residual
04/08/16
5 X week
ug/I
25
48
92
Daily Maximum
No Action, BPJ
Exceeded
05-2016
001
Effluent
Chlorine, Total Residual
05/12/16
3 X week
ug/I
27
48
77.8
Daily Maximum
No Action, BPJ
Exceeded
12-2016
001
Effluent
Chlorine, Total Residual
12/06/16
3 X week
ug/I
27
32
18.5
Daily Maximum
No Action, BPJ
Exceeded
12-2016
001
Effluent
Chlorine, Total Residual
12/07/16
3 X week
ug/I
27
35
29.6
Daily Maximum
No Action, BPJ
Exceeded
12-2016
001
Effluent
Chlorine, Total Residual
12/13/16
3 X week
ug/I
27
29
7.4
Daily Maximum
No Action, BPJ
Exceeded
12-2016
001
Effluent
Chlorine, Total Residual
12/14/16
3 X week
ug/I
27
45
66.7
Daily Maximum
No Action, BPJ
Exceeded
12-2016
001
Effluent
Chlorine, Total Residual
12/20/16
3 X week
ug/I
27
34
25.9
Daily Maximum
No Action, BPJ
Exceeded

MONITORING REPORT(MR) VIOLATIONS for:
Report Date:
02/04/21 Page
2 of 5
Permit:
NCO031879
MRS Betweei 11 - 2015 and11 - 2020
Region:
%
Violation Category:%
Program Category: %
Facility Name: %
Param Nam(%
County:
%
Subbasin: %
Violation Action: %
Major Minor:
%
PERMIT: NCO031879
FACILITY: City of Marion - Corpening Creek WWTP
COUNTY: McDowell
REGION: Asheville
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
01 -2017
001
Effluent
Chlorine, Total Residual
01/03/17
3 X week
ug/I
27
34
25.9
Daily Maximum
No Action, BPJ
Exceeded
01 -2017
001
Effluent
Chlorine, Total Residual
01/05/17
3 X week
ug/I
27
40
48.1
Daily Maximum
No Action, BPJ
Exceeded
01 -2017
001
Effluent
Chlorine, Total Residual
01/11/17
3 X week
ug/I
27
40
48.1
Daily Maximum
No Action, BPJ
Exceeded
01 -2017
001
Effluent
Chlorine, Total Residual
01/18/17
3 X week
ug/I
27
41
51.9
Daily Maximum
No Action, BPJ
Exceeded
03-2017
001
Effluent
Chlorine, Total Residual
03/13/17
3 X week
ug/I
27
31
14.8
Daily Maximum
No Action, BPJ
Exceeded
08-2017
001
Effluent
Chlorine, Total Residual
08/14/17
3 X week
ug/I
27
44
63.0
Daily Maximum
No Action, BPJ
Exceeded
01 -2018
001
Effluent
Chlorine, Total Residual
01/04/18
3 X week
ug/I
27
43
59.3
Daily Maximum
No Action, BPJ
Exceeded
02-2018
001
Effluent
Chlorine, Total Residual
02/07/18
3 X week
ug/I
27
29
7.4
Daily Maximum
No Action, BPJ
Exceeded
04-2018
001
Effluent
Chlorine, Total Residual
04/04/18
3 X week
ug/I
27
37
37.0
Daily Maximum
No Action, BPJ
Exceeded
12-2018
001
Effluent
Chlorine, Total Residual
12/28/18
3 X week
ug/I
27
29
7.4
Daily Maximum
No Action, BPJ
Exceeded
06-2020
001
Effluent
Chlorine, Total Residual
06/09/20
3 X week
ug/I
27
29
7.4
Daily Maximum
No Action, BPJ
Exceeded
08-2020
001
Effluent
Chlorine, Total Residual
08/25/20
3 X week
ug/I
27
28
3.7
Daily Maximum
No Action, BPJ
Exceeded
04-2016
001
Effluent
Cyanide, Total (as Cn)
04/09/16
Monthly
ug/I
7.5
9
20
Weekly Average
No Action, BPJ
Exceeded
03 - 2016
001
Effluent
Nitrogen, Ammonia Total (as
03/26/16
5 X week
mg/I
9
11.08
23.1
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
03 - 2016
001
Effluent
Nitrogen, Ammonia Total (as
03/31 /16
5 X week
mg/I
3
6.2
106.8
Monthly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
04 - 2016
001
Effluent
Nitrogen, Ammonia Total (as
04/02/16
5 X week
mg/I
4.2
14.6
247.6
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case

MONITORING REPORT(MR) VIOLATIONS for:
Report Date:
02/04/21 Page
3 of 5
Permit:
NCO031879
MRS Betweei 11 - 2015 and11 - 2020
Region:
%
Violation Category:%
Program Category: %
Facility Name: %
Param Nam(%
County:
%
Subbasin: %
Violation Action: %
Major Minor:
%
PERMIT: NCO031879
FACILITY: City of Marion - Corpening Creek WWTP
COUNTY: McDowell
REGION: Asheville
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
04 - 2016
001
Effluent
Nitrogen, Ammonia Total (as
04/09/16
5 X week
mg/I
4.2
12.54
198.6
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
04 - 2016
001
Effluent
Nitrogen, Ammonia Total (as
04/30/16
5 X week
mg/I
1.4
3.93
180.6
Monthly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
03 - 2018
001
Effluent
Nitrogen, Ammonia Total (as
03/24/18
3 X week
mg/I
9.8
13.67
39.5
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
03 -2018
001
Effluent
Nitrogen, Ammonia Total (as
03/31/18
3 X week
mg/I
3.3
4.71
42.7
Monthly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
05 - 2019
001
Effluent
Nitrogen, Ammonia Total (as
05/25/19
3 X week
mg/I
4.4
9.17
108.3
Weekly Average
Proceed to NOV
N) - Concentration
Exceeded
05 -2019
001
Effluent
Nitrogen, Ammonia Total (as
05/31/19
3 X week
mg/I
1.5
3.62
141.0
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
05 - 2020
001
Effluent
Nitrogen, Ammonia Total (as
05/23/20
3 X week
mg/I
4.4
5.23
18.9
Weekly Average
Proceed to NOV
N) - Concentration
Exceeded
12-2015
001
Effluent
Oxygen, Dissolved (DO)
12/07/15
5 X week
mg/I
5
4.3
14
Daily Minimum Not
No Action, BPJ
Reached
05-2020
001
Effluent
Oxygen, Dissolved (DO)
05/26/20
3 X week
mg/I
5
4.9
2.0
Daily Minimum Not
Proceed to NOV
Reached
01 -2016
001
Effluent
pH
01/05/16
5 X week
su
6
5.8
3.3
Daily Minimum Not
No Action, BPJ
Reached
01 -2016
001
Effluent
pH
01/06/16
5 X week
su
6
5.9
1.7
Daily Minimum Not
No Action, BPJ
Reached
01 -2016
001
Effluent
pH
01/07/16
5 X week
su
6
5.8
3.3
Daily Minimum Not
No Action, BPJ
Reached
01 -2016
001
Effluent
pH
01/08/16
5 X week
su
6
5.9
1.7
Daily Minimum Not
No Action, BPJ
Reached
01 -2016
001
Effluent
pH
01/14/16
5 X week
su
6
5.8
3.3
Daily Minimum Not
No Action, BPJ
Reached
01 -2016
001
Effluent
pH
01/15/16
5 X week
su
6
5.8
3.3
Daily Minimum Not
No Action, BPJ
Reached
01 -2016
001
Effluent
pH
01/25/16
5 X week
su
6
5.9
1.7
Daily Minimum Not
No Action, BPJ
Reached

MONITORING REPORT(MR) VIOLATIONS for:
Report Date:
02/04/21 Page
4 of 5
Permit:
NCO031879
MRS Betweei 11 - 2015 and11 - 2020
Region:
%
Violation Category:%
Program Category: %
Facility Name: %
Param Nam(%
County:
%
Subbasin: %
Violation Action: %
Major Minor:
%
PERMIT: NCO031879
FACILITY: City of Marion - Corpening Creek WWTP
COUNTY: McDowell
REGION: Asheville
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
01 -2016
001
Effluent
pH
01/26/16
5 X week
su
6
5.7
5
Daily Minimum Not
No Action, BPJ
Reached
12-2017
001
Effluent
pH
12/27/17
3 X week
su
6
5.7
5
Daily Minimum Not
Proceed to NOD
Reached
05-2020
001
Effluent
pH
05/21/20
3 X week
su
6
5.8
3.3
Daily Minimum Not
Proceed to NOV
Reached
05-2020
001
Effluent
pH
05/26/20
3 X week
su
6
5.8
3.3
Daily Minimum Not
Proceed to NOV
Reached
02 - 2016
001
Effluent
Solids, Total Suspended -
02/27/16
5 X week
mg/I
45
393.12
773.6
Weekly Average
Proceed to
Concentration
Exceeded
Enforcement Case
02 - 2016
001
Effluent
Solids, Total Suspended -
02/29/16
5 X week
mg/I
30
96.83
222.8
Monthly Average
Proceed to
Concentration
Exceeded
Enforcement Case
08 - 2018
001
Effluent
Solids, Total Suspended -
08/25/18
3 X week
mg/I
45
68.67
52.6
Weekly Average
Proceed to
Concentration
Exceeded
Enforcement Case
10 - 2018
001
Effluent
Solids, Total Suspended -
10/13/18
3 X week
mg/I
45
49.5
10
Weekly Average
Proceed to NOV
Concentration
Exceeded
01 -2019
001
Effluent
Solids, Total Suspended -
01/26/19
3 X week
mg/I
45
60.13
33.6
Weekly Average
Proceed to NOV
Concentration
Exceeded
02 - 2020
001
Effluent
Solids, Total Suspended -
02/15/20
3 X week
mg/I
45
112.82
150.7
Weekly Average
Proceed to
Concentration
Exceeded
Enforcement Case
02 - 2020
001
Effluent
Solids, Total Suspended -
02/29/20
3 X week
mg/I
30
40.48
34.9
Monthly Average
Proceed to
Concentration
Exceeded
Enforcement Case
05 -2020
001
Effluent
Solids, Total Suspended -
05/23/20
3 X week
mg/I
45
726.47
1,514.4
Weekly Average
Proceed to NOV
Concentration
Exceeded
05 -2020
001
Effluent
Solids, Total Suspended -
05/31/20
3 X week
mg/I
30
182.38
507.9
Monthly Average
Proceed to NOV
Concentration
Exceeded
Monitoring Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
12 - 2018
001
Effluent
BOD, 5-Day (20 Deg. C) -
12/29/18
3 X week
mg/I
Frequency Violation
Proceed to NOV
Concentration
12-2018
001
Effluent
Chlorine, Total Residual
12/29/18
3 X week
ug/I
Frequency Violation
Proceed to NOV

MONITORING REPORT(MR) VIOLATIONS for:
Permit: NCO031879 MRS Betweei 11 - 2015 and11 - 2020 Region: %
Facility Name: % Param Nam(% County: %
Major Minor: %
Report Date: 02/04/21 Page 5 of 5
Violation Category:% Program Category: %
Subbasin: % Violation Action: %
PERMIT: NCO031879 FACILITY: City of Marion - Corpening Creek WWTP COUNTY: McDowell REGION: Asheville
Monitoring Violation
MONITORING VIOLATION UNIT OF CALCULATED %
REPORT OUTFALL LOCATION PARAMETER DATE FREQUENCY MEASURE LIMIT VALUE Over VIOLATION TYPE VIOLATION ACTION
12-2018
001
Effluent
Coliform, Fecal MF, MFC
12/29/18
3 Xweek
#/100ml
Broth, 44.5 C
03-2017
001
Effluent
Nitrogen, Ammonia Total (as
03/04/17
3 X week
mg/I
N) - Concentration
12-2018
001
Effluent
Nitrogen, Ammonia Total (as
12/29/18
3 X week
mg/I
N) - Concentration
12 - 2018
001
Effluent
Oxygen, Dissolved (DO)
12/29/18
3 X week
mg/I
12 - 2018
001
Effluent
pH
12/29/18
3 X week
su
12-2018
001
Effluent
Solids, Total Suspended -
12/29/18
3 X week
mg/I
Concentration
12-2018
001
Effluent
Temperature, Water Deg.
12/29/18
3 X week
deg c
Centigrade
Frequency Violation
Proceed to NOV
Frequency Violation
Proceed to NOV
Frequency Violation
Proceed to NOV
Frequency Violation
Proceed to NOV
Frequency Violation
Proceed to NOV
Frequency Violation
Proceed to NOV
Frequency Violation
Proceed to NOV

Permit No. NC0031879
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
(Dissolved)
Chronic FW, µg/l
(Dissolved)
Acute SW, µg/l
(Dissolved)
Chronic SW, µg/1
(Dissolved)
Arsenic
340
150
69
36
Beryllium
65
6.5
---
---
Cadmium
Calculation
Calculation
40
8.8
Chromium III
Calculation
Calculation
---
---
Chromium VI
16
11
1100
50
Copper
Calculation
Calculation
4.8
3.1
Lead
Calculation
Calculation
210
8.1
Nickel
Calculation
Calculation
74
8.2
Silver
Calculation
0.06
1.9
0.1
Zinc
Calculation
Calculation
90
81
Table 1 Notes:
1. FW= Freshwater, SW= Saltwater
2. Calculation = Hardness dependent standard
3. Only the aquatic life standards listed above are expressed in dissolved form. Aquatic life
standards for Mercury and selenium are still expressed as Total Recoverable Metals due to
bioaccumulative concerns (as are all human health standards for all metals). It is still necessary
to evaluate total recoverable aquatic life and human health standards listed in 15A NCAC
2B.0200 (e.g., arsenic at 10 µg/1 for human health protection; cyanide at 5 µg/L and fluoride at
1.8 mg/L for aquatic life protection).
Table 2. Dissolved Freshwater Standards for Hardness -Dependent Metals
The Water Effects Ratio (WER) is equal to one unless determined otherwise under 15A
NCAC 02B .0211 Subparagraph (11)(d)
Metal
NC Dissolved Standard, µg/I
Cadmium, Acute
WER* { 1. 136672-[ln hardness] (0.041838)} e^{0.9151 [In hardness]-3.1485}
Cadmium, Acute Trout waters
WER*{1.136672-[ln hardness] (0.041838)} e^{0.9151[ln hardness]-3.6236}
Cadmium, Chronic
WER*{1.101672-[ln hardness] (0.041838)} e^{0.7998[ln hardness]-4.44511
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]-1.7001
Copper, Chronic
WER*0.960 e^{0.8545[ln hardness]-1.702}
Lead, Acute
WER*{1.46203-[ln hardness](0.145712)} • e^{l.273[ln hardness]-1.460}
Lead, Chronic
WER*{1.46203-[ln hardness](0.145712)} • e^{l.273[ln hardness]-4.705}
Nickel, Acute
WER*0.998 eA10.8460[ln hardness]+2.255}
Nickel, Chronic
WER*0.997 eA10.8460[ln hardness]+0.0584}
Page 1 of 4

Permit No. NCO041696
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.
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. NCO041696
The overall hardness value used in the water quality calculations is calculated as follows:
Combined Hardness (chronic)
_ (Permitted Flow, cfs *Avg. Effluent Hardness, mg/L) + (s7Q10, cfs *Avg. Upstream Hardness, mg/L)
(Permitted Flow, cfs + s7Q10, cfs)
The Combined Hardness for acute is the same but the calculation uses the 1 Q 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('+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. NC0041696
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.
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)
[Total as, CaCO3 or (Ca+Mg)]
49.33
Data provided in DMRs
Average Upstream Hardness (mg/L)
[Total as, CaCO3 or (Ca+Mg)]
25
Default value used
7Q 10 summer (cfs)
2.3
NPDES Files
1Q10 (cfs)
1.93
Calculated in RPA
Permitted Flow (MGD)
2.5
NPDESpermit application
Date: 1/11/2021
Permit Writer: Diana Yitbarek
Page 4 of 4

2018 NC Category 5 Assessments "303(d) List" Final
11-38-34
11-32-1-4a
Catawba River Basin
Wilson Creek
From source to Johns River
Classification B;Tr,ORW Length or Area
kssessment Criteria Status Reason for Rating
Exceeding Criteria
Youngs Fork (Coperning Creek)
From source to Marion WWTP
Upper Catawba Subbasin 03050101
23 Units IFW Miles (Previous AU Number) L
Parameter of Interest Category
pH (6 su, AL, FW) 5
Classification �___ (Length or Area I I 4 (Units fW Miles --] (Previous AU Number)
\ssessment Crit R
Exceeding Criteria Poor
11-32-1-4b Youngs Fork (Coperning Creek)
From Marion WWTP to North Muddy Creek
Classification C (Length or Area
Benthos (Nar, AL, FW)
2 (Units FW Miles (Previous AU Number
kssessment Criteria Status Reason for Rating Parameter of Interest Category
Exceeding Criteria Fair iBenthos (Nar, AL, FW) 5
Exceeding Criteria Fair Fish Community (Nar, AL, FW) 0
11-39-1 Zacks Fork Creek
From source to Lower Creek
Classification C
Length or Area
kssessment Criteria Status Reason for Rating Is
Exceeding Criteria FCB 5in30 GM >200 or >20%
8 Units IFW Miles J Previous AU Number
Parameter of Interest Category j,
Fecal Coliform (GM 200/400, REC, FW)
South Fork Catawba Subbasin 03050102
6/3/2019 2018 NC Category 5 Assessments "303(d) List" Approved by EPA May 22,2019 Page 47 of 262

DocuSign Envelope ID: EFC010C6-F66F-4429-960B-126FC3D6F34D
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 NCO031879 I11 121 21/02/05 I17 18I � I 19 I s I 201 I
211IIIII 111111III II III III1 I I IIIII IIIIIIIII II r6
Inspection
Work Days Facility Self -Monitoring Evaluation Rating B1 QA ---------------------- Reserved -------------------
67
I 72 I n, I 71 I 74 79 I I I I I I I80
701 I 71 I LL -1 I I
LJ
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 Dermit Number)
11:00AM 21/02/05
16/05/01
Corpening Creek WWTP
3982 NC Hwy 226 S
Exit Time/Date
Permit Expiration Date
Marion NC 28752
12:30PM 21/02/05
20/01/31
Name(s) of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s)
Other Facility Data
Name, Address of Responsible Official/Title/Phone and Fax Number
Contacted
Larry Carver,PO Box 700 Marion NC 287520700//828-652-8843/8286591943
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
D—Signed by:
Lauren E Armeni �y�,�, Amu' DWR/ARO WQ/828-296-4500/ 2/18/2021
Mikal Willmer D13869d&fty: DWR/Division of Water Qua lity/828-296-4686/ 2/18/2021
Signature of Management Q A Reviewer Agency/Office/Phone and Fax Numbers Date
DocuSigned by: 2/18/2021
1&.
kEE rm ��4�3F
(Rev 9-94) Previous editions are obsolete.
Page#

DocuSign Envelope ID: EFC010C6-F66F-4429-960B-126FC3D6F34D
NPDES yr/mo/day Inspection Type (Cont.)
NCO031879 I11 12I 21/02/05 117 18 i c i
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
Lauren Armeni and Mikal Willmer, with the Asheville Regional Office, conducted a compliance
evaluation inspection of the Corpening Creek WWTP on February 5, 2021. This inspection was
conducted to determine whether the facility is being operated and maintained in compliance with
NPDES Permit No. NC0031879. Tim Horton (ORC), Jeff Sanders (Lead Operator), and Doug Mackey
(Interim Lead Operator) were present and assisted in the inspection.
Facility consists of a mechanical step bar screen backed up by a manual bar screen, grit chamber, two
circular primary clarifiers (both of these clarifiers are currently being used as EQ basins), two aeration
basins (one is operational), two circular secondary clarifiers, baffled chlorine contact chamber, gas
chlorination and sulfur dioxide dechlorination, step aeration, two gravity sludge thickeners, and one
aerobic digester.
The following items were noted during the inspection:
Primary Clarifiers: Both primary clarifiers are currently being used as EQ basins. Both sweep arms on
the clarifiers are broken and in need of repair. Additionally, the weirs still need to be leveled. The ORC
stated the plan is to level the weirs themselves this year. The first clarifier arm stopped working
around one year ago, and the second clarifier arm stopped working a couple months ago. The water
within the clarifiers was black with scum on the surface. The sludge blanket in both clarifiers is 9 feet
with a depth of 16 feet. Sludge was pumped out of one of the primary clarifiers around 10 years ago
using a vacuum truck. The pipes from the primary clarifiers to the thickeners have been clogged for
more than 10 years.
Aeration Basins: One of the two aeration basins is currently operational. The #1 aeration basin is
currently being used as a backup EQ basin as needed and some aerators need replaced. The ORC
stated they would like to get it cleaned out and back in operation since all the valves work and it would
add to their treatment capacity; however, rainfall has made this difficult. This facility utilizes brush
aerators. The ORC stated that the DO levels were maintained around 1 mg/L in the aeration basin
during operation. The measured DO on the day of inspection was around 3.0 mg/L. The MLSS is still
being maintained at 7,000 mg/L; however, the effluent numbers appear to be in compliance and are
meeting ammonia
limits.
Secondary Clarifiers: The weirs on primary clarifier #2 still needs to be leveled and is on the docket to
be leveled this year; however, this issue is not currently impacting treatment. The sludge blankets
have been significantly reduced due to better solids management within the plant (blankets were
previously run 8-9 feet). The sludge blanket in both clarifiers was around two feet and the depth of the
clarifiers is ten feet. The sweep arm on secondary clarifier #1 starts and stops, and it appears that the
suction arm is clogged and the drive unit is not operational. The staff plans on draining the clarifier
and they are having someone out to figure out the exact issue and make necessary repairs.
The plant currently has two RAS pumps. One is around 40 years old and the other is around 20 years
old. The older RAS pump is not being used, so currently there is no backup. In the new fiscal year
(FY22), the plant is planning on buying a new RAS pump and using the 20-year old pump as the
backup. Both WAS pumps are operational and in good condition.
Tertiary Filters: The tertiary filters are not in use at this time. The ORC indicated they would like to
have them operational at some point, but they will first need to be rehabilitated It is recommended that
the tertiary filters be added back to the permit since they are still a system component, just not
Page#

DocuSign Envelope ID: EFC010C6-F66F-4429-960B-126FC3D6F34D
Permit: NCO031879 Owner -Facility: Corpening Creek WWTP
Inspection Date: 02/05/2021 Inspection Type: Compliance Evaluation
currently in operation.
Overall, the facility is in non-compliance with the requirements outlined in the permit for the following
reasons:
1. Both primary clarifiers are being used as equalization basins. Both primary clarifiers need to be
repaired and utilized as they were intended to, otherwise an engineering analysis and permit
modification may need to be performed. The sludge blankets are 9 feet in both primary clarifiers, whicf
is a concern for high flows into the plant.
2. The #1 secondary clarifier is in need of repair due to a broken arm.
3. A new RAS pump is needed. There is currently not a backup RAS pump due to the age of the
previous backup RAS pump (-40 years old).
Page#

DocuSign Envelope ID: EFC010C6-F66F-4429-960B-126FC3D6F34D
Permit: NCO031879 Owner -Facility:
Inspection Date: 02/05/2021 Inspection Type:
Corpening Creek WWTP
Compliance Evaluation
Permit
Yes
No
NA
NE
(If the present permit expires in 6 months or less). Has the permittee submitted a new 0
❑
❑
❑
application?
Is the facility as described in the permit?
0
❑
❑
❑
# Are there any special conditions for the permit?
❑
❑
0
❑
Is access to the plant site restricted to the general public?
0
❑
❑
❑
Is the inspector granted access to all areas for inspection?
0
❑
❑
❑
Comment: The permittee has submitted a new application and the permit is currently in draft and under
review.
Record Keeping
Yes
No
NA
NE
Are records kept and maintained as required by the permit?
0
❑
❑
❑
Is all required information readily available, complete and current?
0
❑
❑
❑
Are all records maintained for 3 years (lab. reg. required 5 years)?
0
❑
❑
❑
Are analytical results consistent with data reported on DMRs?
0
❑
❑
❑
Is the chain -of -custody complete?
0
❑
❑
❑
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 operatc
❑
❑
❑
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?
0
❑
❑
❑
Facility has copy of previous year's Annual Report on file for review?
M
❑
❑
❑
MOT, 171,"M
Operations & Maintenance Yes No NA NE
Is the plant generally clean with acceptable housekeeping? 0 ❑ ❑ ❑
Page# 4

DocuSign Envelope ID: EFC010C6-F66F-4429-960B-126FC3D6F34D
Permit: NCO031879 Owner -Facility: Corpening Creek WWTP
Inspection Date: 02/05/2021 Inspection Type: Compliance Evaluation
Operations & Maintenance Yes No NA NE
Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable ❑ ❑ ❑
Solids, pH, DO, Sludge Judge, and other that are applicable?
Comment: The facility checks sludge depth daily using a sludge fudge. Dissolved oxygen and MLSS
are checked weekly.
Bar Screens
Type of bar screen
a.Manual
b.Mechanical
Are the bars adequately screening debris?
Is the screen free of excessive debris?
Is disposal of screening in compliance?
Is the unit in good condition?
Yes No NA NE
❑ ❑ ❑
■ ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
Comment: The mechanical bar screen was previously down for approximately 6 months to a year, but
is now repaired and fully operational.
Grit Removal Yes No NA NE
Type of grit removal
a.Manual ❑
b.Mechanical
Is the grit free of excessive organic matter? 0 ❑ ❑ ❑
Is the grit free of excessive odor? 0 ❑ ❑ ❑
# Is disposal of grit in compliance? 0 ❑ ❑ ❑
Comment: Grit removal was previously not working for approximately 6 months to a year, but is now
repaired and fully operational. Since the bar screen and grit removal were down for this
amount of time, solids management became an issue, but the ORC appears to have this
under control now.
Primary Clarifier
Is the clarifier free of black and odorous wastewater?
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?
Yes No NA NE
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■ ❑ ❑ ❑
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■ ❑ ❑ ❑
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■ ❑ ❑ ❑
Page# 5

DocuSign Envelope ID: EFC010C6-F66F-4429-960B-126FC3D6F34D
Permit: NCO031879 Owner -Facility: Corpening Creek WWTP
Inspection Date: 02/05/2021 Inspection Type: Compliance Evaluation
Primary Clarifier
Yes
No
NA
NE
Is the drive unit operational?
❑
0
❑
❑
Is the sludge blanket level acceptable?
❑
0
❑
❑
Is the sludge blanket level acceptable? (Approximately'/ of the sidewall depth)
❑
0
❑
❑
Comment: Both Drimary clarifiers are currently being used as EQ basins, and the weirs need leveled on
both. The wastewater within the primary clarifiers appeared black with scum on the surface.
The ORC stated the drive units malfunctioning may be the reason the sweep arms stopped
working. The sludge blanklet levels in both clarifiers are at 9 feet out of 16 feet.
See summary for further details.
Aeration Basins
Mode of operation
Type of aeration system
Is the basin free of dead spots?
Are surface aerators and mixers operational?
Are the diffusers operational?
Is the foam the proper color for the treatment process?
Does the foam cover less than 25% of the basin's surface?
Is the DO level acceptable?
Is the DO level acceptable?(1.0 to 3.0 mg/1)
Yes No NA NE
Ext. Air
Surface
■
❑
❑
❑
■
❑
❑
❑
❑
❑
■
❑
■
❑
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❑
■
❑
❑
❑
■
❑
❑
❑
■
❑
❑
❑
Comment: Aeration basin #2 is currently in operation and Aeration basin #1 currently needs to be
cleaned out in order to be put back online.
See summary for futher details.
Secondary Clarifier
Is the clarifier free of black and odorous wastewater?
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'/ of the sidewall depth)
Yes No NA NE
■ ❑ ❑ ❑
■ ❑ ❑ ❑
❑ ■ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
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❑ ■ ❑ ❑
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■ ❑ ❑ ❑
■ ❑ ❑ ❑
Page# 6

DocuSign Envelope ID: EFC010C6-F66F-4429-960B-126FC3D6F34D
Permit: NCO031879
Inspection Date: 02/05/2021
Secondary Clarifier
Owner -Facility: Corpening Creek WWTP
Inspection Type: Compliance Evaluation
Yes No NA NE
Comment: The weirs on secondary clarifier #2 need to be leveled. The drive unit and sweep arm are
not operational on secondary clarifier #1.
See summary for further details.
Pumps-RAS-WAS
Yes
No
NA
NE
Are pumps in place?
0
❑
❑
❑
Are pumps operational?
0
❑
❑
❑
Are there adequate spare parts and supplies on site?
❑
0
❑
❑
Comment: The current RAS pump is -20 years old and is operational, but no backup
RAS pump
is
available. The WAS pumps are working and in good condition.
Filtration (High Rate Tertiary)
Type of operation:
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: The tertiary filters are not in use at this time.
See summary for further details.
Disinfection -Gas
Are cylinders secured adequately?
Are cylinders protected from direct sunlight?
Is there adequate reserve supply of disinfectant?
Is the level of chlorine residual acceptable?
Is the contact chamber free of growth, or sludge buildup?
Is there chlorine residual prior to de -chlorination?
Does the Stationary Source have more than 2500 Ibs of Chlorine (CAS No. 7782-50-5)?
If yes, then is there a Risk Management Plan on site?
If yes, then what is the EPA twelve digit ID Number? (1000- - )
If yes, then when was the RMP last updated?
Comment: All cylinders are adequately secured and out of direct sunlight.
Yes No NA NE
❑ ❑ ■ ❑
❑ ❑ ■ ❑
❑ ❑ ■ ❑
❑ ❑ ■ ❑
❑ ❑ ■ ❑
❑ ❑ ■ ❑
Yes No NA NE
❑ ❑ ❑
❑ ❑ ❑
❑ ❑ ❑
❑ ❑ ❑ ■
■ ❑ ❑ ❑
❑ ❑ ❑ ■
❑ ■ ❑ ❑
❑ ❑ ■ ❑
Page# 7

DocuSign Envelope ID: EFC010C6-F66F-4429-960B-126FC3D6F34D
Permit: NCO031879 Owner -Facility:
Inspection Date: 02/05/2021 Inspection Type:
Corpening Creek WWTP
Compliance Evaluation
De -chlorination
Yes
No
NA
NE
Type of system ?
Gas
Is the feed ratio proportional to chlorine amount (1 to 1)?
0
❑
❑
❑
Is storage appropriate for cylinders?
0
❑
❑
❑
# Is de -chlorination substance stored away from chlorine containers?
0
❑
❑
❑
Comment:
Are the tablets the proper size and type? ❑ ❑ 0 ❑
Are tablet de -chlorinators operational? ❑ ❑ 0 ❑
Number of tubes in use?
Comment:
Flow Measurement - Effluent
Yes
No
NA NE
# Is flow meter used for reporting?
0
❑
❑
❑
Is flow meter calibrated annually?
0
❑
❑
❑
Is the flow meter operational?
M
❑
❑
❑
(If units are separated) Does the chart recorder match the flow meter?
0
❑
❑
❑
Comment:
Effluent Sampling
Yes
No
NA
NE
Is composite sampling flow proportional?
0
❑
❑
❑
Is sample collected below all treatment units?
0
❑
❑
❑
Is proper volume collected?
❑
❑
❑
Is the tubing clean?
0
❑
❑
❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees
0
❑
❑
❑
Celsius)?
Is the facility sampling performed as required by the permit (frequency, sampling type
0
❑
❑
❑
representative)?
Comment:
Laboratory
Yes
No
NA
NE
Are field parameters performed by certified personnel or laboratory?
0
❑
❑
❑
Are all other parameters(excluding field parameters) performed by a certified lab?
0
❑
❑
❑
# Is the facility using a contract lab?
0
❑
❑
❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees
❑
❑
❑
Celsius)?
Page# 8

DocuSign Envelope ID: EFC010C6-F66F-4429-960B-126FC3D6F34D
Permit: NCO031879 Owner -Facility:
Inspection Date: 02/05/2021 Inspection Type:
Corpening Creek WWTP
Compliance Evaluation
Laboratory
Yes
No
NA
NE
Incubator (Fecal Coliform) set to 44.5 degrees Celsius+/- 0.2 degrees?
❑
❑
❑
Incubator (BOD) set to 20.0 degrees Celsius +/- 1.0 degrees?
❑
❑
❑
Comment: Environmental Testing is used for toxicity, metals, total cyanide, total nitrogen, and total
phosphorus.
Standby Power
Is automatically activated standby power available?
Is the generator tested by interrupting primary power source?
Is the generator tested under load?
Was generator tested & operational during the inspection?
Do the generator(s) have adequate capacity to operate the entire wastewater site?
Is there an emergency agreement with a fuel vendor for extended run on back-up power?
Is the generator fuel level monitored?
Yes No NA NE
• ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
❑ ❑ ❑ ■
• ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
Comment: A new generator was installed in February 2020. The generator was assessed during the
inspection, and it was found that the digital fuel level was inaccurate (said zero gallons but
tank was full). It is recommended to repair this function so it is always known what the
precise fuel level is.
Aerobic Digester
Is the capacity adequate?
Is the mixing adequate?
Is the site free of excessive foaming in the tank?
# Is the odor acceptable?
# Is tankage available for properly waste sludge?
Comment: The ORC stated that some blowers were
that need repaired.
Yes No NA NE
■ ❑ ❑ ❑
❑ ❑ ❑
❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
aired in early 2020. but there are still blowers
Page# 9

DocuSign Envelope ID: 99D100F8-7020-490D-8F54-F06156F28DAB
State of North Carolina
®r- Division of Water Resources
Water Quality Regional Operations Section
Environmental Staff Report
Quality
To: ® NPDES Unit ❑ Non -Discharge Unit Application No.: NCO031879
Attn: Diana Yitbarek Facility name: Corpening Creek WWTP
From: Lauren Armeni
Asheville Regional Office
Note: This form has been adapted from the non -discharge fg acili , staff report to document the review of both non -
discharge and NPDES permit applications and/or renewals. Please complete all sections as they are applicable.
I. GENERAL AND SITE VISIT INFORMATION
1. Was a site visit conducted? ® Yes or ❑ No
a. Date of site visit: 02/05/2021
b. Site visit conducted by: Lauren Armeni & Mikal Willmer
c. Inspection report attached? ® Yes or ❑ No (See Laserfiche for Inspection)
d. Person contacted: Tim Horton and their contact information: (82�8 652-8843 ext.
e. Driving directions: Take exit 86 off of I-40 E for NC-226 S toward Marion/Shelby. Turn left onto NC-
226 S and the WWTP (3982 NC-226 S) is on the right approximately 0.5 miles down.
2. Discharge Point(s):
Latitude: 35.651658
Latitude:
Longitude:-81.957656
Longitude:
3. Receiving stream or affected surface waters: Youngs Fork (Corpening Creek)
Classification: C
River Basin and Subbasin No. CTB, 03050101
Describe receiving stream features and pertinent downstream uses: River is protected for class C uses.
11. PROPOSED FACILITIES: NEW APPLICATIONS
1. Facility Classification: (Please attach completed rating sheet to be attached to issued permit)
Proposed flow:
Current permitted flow:
2. Are the new treatment facilities adequate for the type of waste and disposal system? ❑ Yes or ❑ No
If no, explain:
3. Are site conditions (soils, depth to water table, etc) consistent with the submitted reports? ❑ Yes ❑ No ❑ N/A
If no, please explain:
4. Do the plans and site map represent the actual site (property lines, wells, etc.)? ❑ Yes ❑ No ❑ N/A
If no, please explain:
5. Is the proposed residuals management plan adequate? ❑ Yes ❑ No ❑ N/A
If no, please explain:
FORM: WQROSSR 04-14 Page 1 of 6

DocuSign Envelope ID: 99D100F8-7020-490D-8F54-F06156F28DAB
6. Are the proposed application rates (e.g., hydraulic, nutrient) acceptable`? ❑ Yes ❑ No ❑ N/A
If no, please explain:
7. Are there any setback conflicts for proposed treatment, storage and disposal sites? ❑ Yes or ❑ No
If yes, attach a map showing conflict areas.
8. Is the proposed or existing groundwater monitoring program adequate? ❑ Yes ❑ No ❑ N/A
If no, explain and recommend any changes to the groundwater monitoring program:
9. For residuals, will seasonal or other restrictions be required? ❑ Yes ❑ No ❑ N/A
If yes, attach list of sites with restrictions (Certification B)
Describe the residuals handling and utilization scheme:
10. Possible toxic impacts to surface waters:
11. Pretreatment Program (POTWs only):
III. EXISTING FACILITIES: MODIFICATION AND RENEWAL APPLICATIONS
1. Are there appropriately certified Operators in Charge (ORCs) for the facility? ® Yes ❑ No ❑ N/A
ORC: Tim Horton Certificate #:1008211 Backup ORC: Jeffery Sanders Certificate #:992546
2. Are the design, maintenance and operation of the treatment facilities adequate for the type of waste and disposal
system? ❑ Yes or ® No
If no, please explain: Both primary clarifiers are currently being used as EQ basins because the primary clarifier
sweep arms and drive units are not operational.
Description of existing facilities:
• Influent pump station,
• Mechanical step bar screen backed up by a manual bar screen,
• Grit chamber,
• Two circular primary clarifiers (both of these clarifiers are currently being used as EO basins),
• Two aeration basins (one is in operation),
• Two circular secondary clarifiers,
• Tertiary filters,
• Baffled chlorine contact chamber,
• Gas chlorination and sulfur dioxide dechlorination,
• Step aeration,
• Two gravity sludge thickeners,
• One aerobic digester
Proposed flow: No Change.
Current permitted flow: 3.0 MGD
Explain anything observed during the site visit that needs to be addressed by the permit, or that may be important
for the permit writer to know (i.e., equipment condition, function, maintenance, a change in facility ownership,
etc.) Facility equipment is aging, and some equipment needs to be brought off line in the future for repairs.
Both primary clarifiers are currently being used as EO basins. The sweep arms and drive units are broken
on both of the primary clarifiers and the middle wells are rusting out. Additionally, the pipes from the
primary clarifiers to the thickeners are clogged, so wasting cannot be done. One of the two aeration basins
FORM: WQROSSR 04-14 Page 2 of 6

DocuSign Envelope ID: 99D100F8-7020-490D-8F54-F06156F28DAB
is currently in operation, although the second aeration could be put back online if cleaned. The tertiary
filters are not in use at this time. The ORC indicated they would like to have them operational at some
point, but they will first need to be rehabilitated. It is recommended that the tertiary filters be added back
to the permit since they are still a system component, lust not currently in operation. See inspection report
for further details on system components.
3. Are the site conditions (e.g., soils, topography, depth to water table, etc) maintained appropriately and adequately
assimilating the waste? ❑ Yes or ❑ No ®N/A
If no, please explain:
4. Has the site changed in any way that may affect the permit (e.g., drainage added, new wells inside the compliance
boundary, new development, etc.)? ❑ Yes or ® No
If yes, please explain:
5. Is the residuals management plan adequate? ® Yes or ❑ No
If no, please explain:
6. Are the existing application rates (e.g., hydraulic, nutrient) still acceptable`? ❑ Yes or ❑ No ® N/A
If no, please explain:
7. Is the existing groundwater monitoring program adequate? ❑ Yes ❑ No ® N/A
If no, explain and recommend any changes to the groundwater monitoring program:
8. Are there any setback conflicts for existing treatment, storage and disposal sites? ❑ Yes or ® No
If yes, attach a map showing conflict areas.
9. Is the description of the facilities as written in the existing permit correct? ® Yes or ❑ No
If no, please explain: See inspection report for details of system components.
10. Were monitoring wells properly constructed and located? ❑ Yes ❑ No ® N/A
If no, please explain:
FORM: WQROSSR 04-14 Page 3 of 6

DocuSign Envelope ID: 99D100F8-7020-490D-8F54-F06156F28DAB
11. Are the monitoring well coordinates correct in BIMS? ❑ Yes ❑ No ❑ N/A
If no, please complete the following (expand table if necessary):
Monitoring Well
Latitude
Longitude
O l 11
O I //
O / //
O I II
O / //
O I it
12. Has a review of all self -monitoring data been conducted (e.g., DMR, NDMR, NDAR, GW)? ® Yes or ❑ No
Please summarize any findings resulting from this review: Ammonia limits were exceeded in March and April
2016, March 2018, May 2019, and May 2020; however ammonia has not been an issue in the past 6+
months. Additionally, TSS limits were exceeded in February 2016, August and October 2018, January
2019, and February and May 2020; however, TSS limits have not been an issue in the past 6+ months. No
violations have been issued to the facility since May 2020.
Provide input to help the permit writer evaluate any requests for reduced monitoring, if applicable.
13. Are there any permit changes needed in order to address ongoing BIMS violations? ❑ Yes or ® No
If yes, please explain:
14. Check all that apply:
❑ No compliance issues ❑ Current enforcement action(s) ❑ Currently under JOC
® Notice(s) of violation ❑ Currently under SOC ❑ Currently under moratorium
Please explain and attach any documents that may help clarify answer/comments (i.e., NOV, NOD, etc.)
If the facility has had compliance problems during the permit cycle, please explain the status. Has the RO been
working with the Permittee? Is a solution underway or in place? The facility has had compliance issues during
the hermit cvcle as noted above. but have not had a limit violation since Mav 2020. Both Drimary clarifiers
are being used as EO basins, and we believe this should be reevaluated by the facility. The facility staff are
aware that some system components are degrading and they are very interested in improving them. Their
plan is to buy a new RAS pump in FY 22, and they also hope to rehabilitate the offline aeration basin and
eventually tertiary filters. Solids management has greatly improved (sludge blankets are maintained at a
much lower level) and thev are still fine tuning it. Thev have also ordered Darts to replace the sweet arm
and drive unit in one of the secondary clarifiers.
Have all compliance dates/conditions in the existing permit been satisfied? ❑ Yes ❑ No ® N/A
If no, please explain:
15. Are there any issues related to compliance/enforcement that should be resolved before issuing this permit?
❑ Yes ®No❑N/A
If yes, please explain:
16. Possible toxic impacts to surface waters: Chlorine can impact surface waters if not properly removed. No
issues reported with the dechlorination feed at the facility and no permit issues related to chlorine
residual.
17. Pretreatment Program (POTWs only): N/A — IWS requested by 7/1/2021.
FORM: WQROSSR 04-14 Page 4 of 6

DocuSign Envelope ID: 99D100F8-7020-490D-8F54-F06156F28DAB
IV. REGIONAL OFFICE RECOMMENDATIONS
1. Do you foresee any problems with issuance/renewal of this permit? ❑ Yes or ® No
If yes, please explain:
2. List any items that you would like the NPDES Unit or Non -Discharge Unit Central Office to obtain through an
additional information request:
Item Reason
3. List specific permit conditions recommended to be removed from the permit when issued:
Condition Reason
4. List specific special conditions or compliance schedules recommended to be included in the permit when issued:
Condition Reason
5. Recommendation: ❑ Hold, pending receipt and review of additional information by regional office
® Hold, pending review of draft permit by regional office
❑ Issue upon receipt of needed additional information
❑ Issue
❑ Deny (Please state reasons: )
6. Signature of report preparer:
Docu Signed by:
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CB17648770724F6...
DocuSigned by:
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Signature of assistant regional supervisor: E397192DABFB4FF...
2/18/2021
Date:
FORM: WQROSSR 04-14 Page 5 of 6

DocuSign Envelope ID: 99D100F8-7020-490D-8F54-FO6156F28DAB
V. ADDITIONAL REGIONAL STAFF REVIEW ITEMS
See inspection report from February 2021 for facility recommendations.
FORM: WQROSSR 04-14 Page 6 of 6

DocuSign Envelope ID: A045B785-2D59-476B-9979-2F7BA0164F82
ROY COOPER
Governor
MICHAEL S. REGAN
5ecrutary
S. DANIEL SMITH
arecror
NORTH CAROLINA
Envifionmental Quality
SENT VIA ELECTRONIC MAIL ONLY. NO HARD COPY WILL BE MAILED
February 17, 2021
J. R. Boyette, City Manager
City of Marion
Email: [e-mail]
SUBJECT: NOTICE OF VIOLATION
Tracking Number: NOV-2021-PC-0144
Permit No. NCO031879
Corpening Creek WWTP
McDowell County
Dear Permittee:
The North Carolina Division of Water Resources conducted an inspection of the Corpening Creek WWTP on
February 5, 2021. This inspection was conducted to verify that the facility is operating in compliance with the
conditions and limitations specified in NPDES WW Permit No. NC0031879. A summary of the findings and
comments noted during the inspection are provided in the enclosed copy of the inspection report.
The Compliance Evaluation inspection was conducted by Division of Water Resources staff from the Asheville
Regional Office. The following violation(s) were noted during the inspection:
Inspection Area Description of Violation
Primary Clarifier Both primary clarifiers are being used as equalization basins, and both sweep arms are
not operational. Additionally, the sludge blankets are 9 feet out of 16 feet in both
primary clarifiers.
Permit Standard Conditions Section C. 2 requires the permittee to properly
operate and maintain all facilities and systems of treatment which are installed
to achieve compliance.
Secondary Clarifier The #1 secondary clarifier is currently out of operation because it is in need of repair due
to a broken drive unit and sweep arm.
Permit Standard Conditions Section C. 2 requires the permittee to properly
operate and maintain all facilities and systems of treatment which are installed
to achieve compliance.
North Carolina Department of Environrnenta; Q¢airty I Diusion of Water Resm r-�--s
Ashev,;e RegionalOff:ce I Z090 U.S. 7-DHghway I SwanRSROs, North Csro:irs 2S77S

DocuSign Envelope ID: A045B785-2D59-476B-9979-2F7BA0164F82
Pumps-RAS-WAS A new RAS pump is needed since there is currently no backup RAS pump.
Permit Standard Conditions Section C. 2 requires the permittee to properly
operate and maintain all facilities and systems of treatment which are installed
to achieve compliance.
In addition, the issue below must also be addressed:
*The tertiary filters are currently not listed in the permit, but should be added back to the permit
because they are existing structures at the WWTP.
Remedial actions should have already been taken to correct this problem and prevent further occurrences in the
future. The Division of Water Resources may pursue enforcement action for this and any additional violations of
State law.
To prevent further action, please respond in writing to this office within 30 days upon your receipt of this Notice
of Violation regarding your plans or measures to be taken to address the indicated violations and other identified
issues, if applicable.
If you should have any questions, please do not hesitate to contact Lauren Armeni with the Water Quality
Regional Operations Section in the Asheville Regional Office at 828-296-4500.
Sincerely,
ocuSigned bbJyy:
E�D
>(Jo?�1-397192DABFB4FF...
Daniel Boss, Assistant Regional Supervisor
Water Quality Regional Operations Section
Asheville Regional Office
Division of Water Resources, NCDEQ
ATTACHMENTS: Inspection Report
Ec: Brant Sikes, Public Works Director
Tim Horton, ORC
LF
NorthCaroiinaDepartnientofEnvironrnenta;Qua:rty I DiusionofWater Resources
Ashev.;e Regnnai4ffice 1 2090 U.S. 7-DHghw'ay I SwanRSROs, North Csro:ins 23773
`•• "'� 3237%-45D0

The McDowell News
Advertising Affidavit
PO Box 968
Hickory, NC 28603
NC DENR/DWQ
ATTN: WREN THEDFORD
1617 MAIL SERVICE CENTER
RALEIGH, NC 27699-1617
Account Number
3142720
Date
February 26, 2021
Date Category Description Ad Number Ad Size
02/26/2021 Legal Notices Public Notice North Carolina Environmental Management Coon 0000704704 2 x 29 L
Publisher of
The McDowell News
McDowell County
Before the undersigned, a Notary Public duly commissioned, qualified,
and authorized by law to administer oaths, personally appeared the
Publisher's Representative who by being duly swom 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 McDowell News on the following dates:
02/26/2021
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 ] •597 of the General Statutes of Nortiny/��. _
Billing Representative
Newspaper reference: 0000704704
Sworn to and subscribed before me, this 26th day of February, 2021.
Notary Public Sharon R Carsten
State of Virginia NOTARY PUBLIC
County of Hanover Commonwealth of Virginia
Notary Registration Number 329549
My commission expiresCemmisssinn r=rni.es ,July 31 2021
THIS IS NOT A BILL. PLEASE PAY FROM INVOICE. THANK YOU

North Carolina Environmental Management Commission/NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
Notice of Intent to Issue a NPDES wastewater Permit NCO031879
Corpening Creek W WTP The North Carolina Environmental Management
Commission proposes to issue a NPDES wastewater discharge permit to
the person(s) listed below. Written comments regarding the proposed
permit will be accepted until 30 days after the publish date of this notice.
The Director of the NC Division of Water Resources (DWR) may hold a pub-
lic hearing should there be a significant degree of public interest. Please
mail comments and/or information requests to DWR at the above ad-
dress. Interested persons may visit the DWR at 512 N. Salisbury Street, Ra-
leigh, NC 27604 to review information on file. Additional information on
NPDES permits and this notice may be found on our website: hhttp;//deq.n
ing [phone]. The City of Marion (3982 Hwy 226 South,
has requested renewal of permit NCO031879 for its Corp
wastewater treatment plant in McDowell County. This perm
discharges treated domestic wastewater to Youngs Fork
Creek) in the Catawba River Basin. Currently, flow, biochen
demand, dissolved oxygen, total suspended solids, fecal colifr
monia, total cyanide, and total residual chlorine are water qu
parameters in the permit. This discharge may affect future a
this segment of Youngs Fork (Corpening Creek).

The Division received comments/questions from the Corpening WWTP through the public
comment period, February 26, 2021— March 26, 2021, and provided the following responses:
1. Question: On page 7, the fourth paragraph uses terms "TGP3B" and "THP3B." What do those
mean?
Response: TGP313 and THP313 are whole effluent toxicity (WET) parameter codes for the pass/fail
chronic toxicity tests. Please find here the test description for each code.
"All toxicity testing results required as part of this permit condition will be entered electronically
using the Division's eDMR system for the months in which tests were performed, using the parameter
code TGP3B for the pass/fail results and THP313 for the Chronic Value." - Permit, page 7.
2. Question: On page two under changes second one from the bottom, the change discusses the
Electronic Reporting Rule. As I read the change and the Special Condition Section A (5), it looks
like I'm to submit an electronic DMR and a paper copy too. We received other guidance in Nov
2019.
Response: Duplicate signed copies shall be submitted only if a permittee is unable to use the eDMR
system due to a demonstrated hardship.
The section on the permit was recently updated. I will make sure to update it on the final permit as
follows:
"Monitoring results obtained during the previous month(s) shall be summarized for each month and
submitted electronically using eDMR. The eDMR system allows permitted facilities to enter
monitoring data and submit DMRs electronically using the internet. The eDMR system may be
accessed at: https://deq.nc.gov/about/divisions/water-resources/edmr
If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the facility
being physically located in an area where less than 10 percent of the households have broadband
access, then a temporary waiver from the NPDES electronic reporting requirements may be granted
and discharge monitoring data may be submitted on paper DMR forms (MR 1, 1. 1, 2, 3) or alternative
forms approved by the Director. Duplicate signed copies shall be submitted to the following mailing
address:"
Question: In your letter which accompanied our new proposed permit, page one, bullet point six,
Total Selenium and Silver limits are discussed. It is noted that the detection limits for both per
DWR's Lab is 1.0 ug/L. Can we get a copy of all of the Annual Pollutant Parameters we are required
to analyze? Also, the letter states, "Based on the RPA, the City's allowable discharge concentrations
are 8.00ug/L and 0.096ug/L for Total Selenium and Total Silver respectively. " As I understand the
discussion of RPA, Fact Sheet, pages 6-7, the City's values change from permit to permit based on the
documentation we provide. Is this correct? Is the discrepancy the detection limit used by our
contracted lab not at the appropriate level?
Response: The list of all the Pollutant Parameters the City is required to analyze once a year (in 2023,
2024, and 2025) is in the permit Section A. (4.) Effluent Pollutant Scan, page 8 of 12.
You are correct. The City's limit values change from permit to permit. The limits are calculated using
the recent discharge monitoring reports (eDMRs) and the effluent pollutant scans provided.
Correct. The current detection level used does not produce detection and reporting levels below the
City's allowable discharge concentrations of 8.00 µg/L and 0.096µg/L for Total Selenium and Total
Silver.

4. Question: On the effluent limits pages, Sections A. (1.) and A.(2.), hardness is discussed. In footnote
5, it states hardness should be performed in conjunction with hardness -dependent metals --cadmium,
copper, lead, nickel, silver, and zinc. The following question was recently raised: Is this stating we
are to analyze all of those metals? Since copper is the only metal listed on our permit, I was
understanding copper is the only one that applies to us. Am I correct?
Response: Copper is the only hardness dependent metal that Corpening Creek WWTP is required to
test in a quarterly basis. Effluent hardness sampling shall be performed in conjunction with testing for
copper and whenever you sample for the effluent pollutant scan.
Three effluent pollutant scans shall be sampled. The list of pollutants to sample include all the
hardness -dependent metals (cadmium, copper, lead, nickel, silver, and zinc).