NC0044440_Fact Sheet_20210528

Fact Sheet
NPDES Permit No. NCOO4444O
Permit Writer/Email Contact Nick Coco, [e-mail]:
Date: March 2, 2021
Division/Branch: NC Division of Water Resources/NPDES Municipal Permitting
Fact Sheet Template: Version 09Jan2017
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, 3 effluent pollutant scans, 4 2"d species WET
tests.
• For Existing Dischargers (Non-POTW), EPA Form 2C with correct analytical requirements based
on industry category.
Complete applicable sections below. If not applicable, enter NA.
1. Basic Facility Information
Facility Information
Applicant/Facility Name:
City of Cherryville/ Cherryville Wastewater Treatment Plant (WWTP)
Applicant Address:
116 S. Mountain Street, Cherryville, NC 28021
Facility Address:
736 Tot Dellinger Road, Cherryville, NC 28021
Permitted Flow:
2.0 MGD
Facility Type/Waste:
MAJOR Municipal; 100% domestic
Facility Class:
Grade III Biological Water Pollution Control System
Treatment Units:
Bar Screen, Grit Removal, Dual Oxidation Ditches, Dual Secondary
Clarifiers, Chlorination/Dechlorination System, Flow Measurement,
Cascade Aeration, Aerated Sludge Holding Tank, Sludge Storage
Lagoon
Pretreatment Program (Y/N)
N
County:
Gaston
Region
Mooresville
Briefly describe the proposed permitting action and facility background: The City of Cherryville has
applied for an NPDES permit renewal at 2.0 MGD for the Cherryville WWTP. This facility serves a
population of approximately 6,030 residents. Treated domestic wastewater is discharged into Indian
Creek, a class C water in the Catawba River Basin. The facility has a primary Outfall 001.
Page 1 of 9

2. Receiving Waterbodv Information:
Receiving Waterbody Information
Outfalls/Receiving Stream(s):
Outfall 001 - Indian Creek
Stream Index:
11-129-8-(5)
Stream Classification:
C
Drainage Area (mi2):
46.4
Summer 7Q10 (cfs)
6.1
Winter 7Q10 (cfs):
16
30Q2 (cfs):
-
Average Flow (cfs):
58
IWC (% effluent):
34
303(d) listed/parameter:
No
Subject to TMDL/parameter:
Yes- State wide Mercury TMDL implementation.
Subbasin/HUC:
03-08-35/03050102
USGS Topo Quad:
F13NW Lincolnton W, NC
3. Effluent Data Summary
Effluent data for Outfall 001 is summarized below for the period of January 2017 through December
2020.
Table 1. Effluent Data Summary Outfall 001
Parameter
Units
Average
Max
Min
Permit
Limit
Flow
MGD
0.6
1.916
0.155
MA 2.0
BOD
mg/1
6.7
54.4
1.5
WA 45
MA 30
TSS
mg/1
7.1
90
0.9
WA 45.0
MA 30.0
NH3N summer'
mg/1
0.4
6.4
0.1
WA 7.5
MA 2.5
NH3N winter'
mg/1
0.7
12
0.1
WA 30
MA 10
DO
mg/1
8.9
12.9
7
DA > 6.0
Fecal coliform
#/100 ml
3.1
730
< 1
(geometric)
WA 400
MA 200
Temperature
° C
18.3
29.7
5.4
pH
SU
6.8
7.7
5.5
6 0 < PH <
9.0
Total Residual Chlorine
µg/1
20.8
32
< 1
DM 28
Total Copper
µg/1
8.5
16
3
Monitor
Total Hardness
mg/1
36
44
32
Monitor
TN
mg/1
7.9
25
2.57
Monitor
TP
mg/1
2.0
4.8
0.232
Monitor
MA -Monthly Average, WA -Weekly Average, DM -Daily Maximum, DA-Daily Average, QA-Quarterly
Average
'The current ammonia limits became effective on May 1, 2020. Prior to that date, ammonia was limited
in the summer at a weekly average of 35.0 mg/L and a monthly average of 17.0 mg/L.
Page 2 of 9

4. Instream Data Summary
Instream monitoring may be required in certain situations, for example: 1) to verify model predictions
when model results for instream DO are within 1 mg/1 of instream standard at full permitted flow; 2) to
verify model predictions for outfall diffuser; 3) to provide data for future TMDL; 4) based on other
instream concerns. Instream monitoring may be conducted by the Permittee, and there are also
Monitoring Coalitions established in several basins that conduct instream sampling for the Permittee (in
which case instream monitoring is waived in the permit as long as coalition membership is maintained).
If applicable, summarize any instream data and what instream monitoring will be proposed for this
permit action: The current permit requires instream monitoring for dissolved oxygen and temperature
upstream of the outfall at least 100 feet and downstream of the outfall at NCSR 1002. The facility is also
required to sample for total hardness upstream. Instream DMR Data from January 2017 to December
2020 has been summarized in Table 2 below.
Table 2. Instream Data Summary
Parameter
Units
Upstream
Downstream
Average
Max
Min
Average
Max
Min
Dissolved
Oxygen
mg/1
8.7
12.7
6.4
8.8
13.8
5.9
Temperature
degC
18.0
25.9
1.9
18.4
26.2
1.4
Total Hardness
mg/1
40.1
162
11
-
-
-
Students t-tests were run at a 95% confidence interval to analyze relationships between instream
samples. A statistically significant difference is determined when the t-test p-value result is < 0.05.
The downstream temperature did not exceed 29 degrees Celsius [per 15A NCAC 02B .0211 (18)]. The
temperature differential was greater than 2.8 degrees Celsius on no occasion during the period reviewed.
It was concluded with 95% confidence that no statistically significant difference between upstream and
downstream temperature exists.
Downstream DO did not drop below 5 mg/L [per 15A NCAC 02B .0211 (6)] during the period reviewed.
It was concluded with 95% confidence that no statistically significant difference between upstream and
downstream DO exists.
The draft permit maintains the same instream monitoring requirements as the current permit.
Is this facility a member of a Monitoring Coalition with waived instream monitoring (Y/N): N
Name of Monitoring Coalition: NA
5. Compliance Summary
Summarize the compliance record with permit effluent limits (past 5 years): The facility reported one TSS
limit violation in 2018 and one pH limit violation in 2020.
Summarize the compliance record with aquatic toxicity test limits and any second species test results
(past 5 years): The facility passed 16 of 16 quarterly chronic toxicity tests from January 2017 to
December 2020, as well as 4 of 4 second species toxicity tests conducted in December 2017, December
2019,and March and May 2020.
Summarize the results from the most recent compliance inspection: The last facility inspection conducted
in July 2020 reported that the facility was in compliance with NPDES permit NC0044440.
Page 3 of 9

6. Water Quality -Based Effluent Limitations (WQBELs)
Dilution and Mixing Zones
In accordance with 15A NCAC 2B.0206, the following streamflows are used for dilution considerations
for development of WQBELs: 1Q10 streamflow (acute Aquatic Life); 7Q10 streamflow (chronic Aquatic
Life; non -carcinogen HH); 30Q2 streamflow (aesthetics); annual average flow (carcinogen, HH).
If applicable, describe any other dilution factors considered (e.g., based on CORMIX model results): NA
If applicable, describe any mixing zones established in accordance with 15A NCAC 2B. 0204(b): NA
Oxygen -Consuming Waste Limitations
Limitations for oxygen -consuming waste (e.g., BOD) are generally based on water quality modeling to
ensure protection of the instream dissolved oxygen (DO) water quality standard. Secondary TBEL limits
(e.g., BOD= 30 mg/1 for Municipals) may be appropriate if deemed more stringent based on dilution and
model results.
If permit limits are more stringent than TBELs, describe how limits were developed: Limitations for
BOD5 are secondary TBEL limits consistent in the permit since 1989 when a Level B model was
conducted. No changes are proposed.
Ammonia and Total Residual Chlorine Limitations
Limitations for ammonia are based on protection of aquatic life utilizing an ammonia chronic criterion of
1.0 mg/1 (summer) and 1.8 mg/1 (winter). Acute ammonia limits are derived from chronic criteria,
utilizing a multiplication factor of 3 for Municipals and a multiplication factor of 5 for Non -Municipals.
Limitations for Total Residual Chlorine (TRC) are based on the NC water quality standard for protection
of aquatic life (17 ug/1) and capped at 28 ug/1(acute impacts). Due to analytical issues, all TRC values
reported below 50 ug/1 are considered compliant with their permit limit.
Describe any proposed changes to ammonia and/or TRC limits for this permit renewal: The facility uses
gas chlorination for disinfection. The current permit limits TRC at a daily maximum of 28 ug/L. The
limits have been reviewed in the attached WLA spreadsheet and have been found to be protective. There
are no proposed changes for TRC.
The current ammonia limits took effect on May 1, 2020, per the 2.5-year compliance schedule for
ammonia included in the 2017 NPDES permit renewal. The limits are based on the results of instream
waste concentration -based calculations. The limits have been reviewed in the attached WLA spreadsheet
and have been found to be protective. There are no proposed changes for ammonia limits.
Reasonable Potential Analysis (RPA) for Toxicants
If applicable, conduct RPA analysis and complete information below.
The need for toxicant limits is based upon a demonstration of reasonable potential to exceed water quality
standards, a statistical evaluation that is conducted during every permit renewal utilizing the most recent
effluent data for each outfall. The RPA is conducted in accordance with 40 CFR 122.44 (d) (i). The NC
RPA procedure utilizes the following: 1) 95% Confidence Level/95% Probability; 2) assumption of zero
Page 4 of 9

background; 3) use of detection limit for "less than" values; and 4) streamflows used for dilution
consideration based on 15A NCAC 2B.0206. Effective April 6, 2016, NC began implementation of
dissolved metals criteria in the RPA process in accordance with guidance titled NPDES Implementation of
Instream Dissolved Metals Standards, dated June 10, 2016.
A reasonable potential analysis was conducted on effluent toxicant data collected between April 2017
through January 2021. Pollutants of concern included toxicants with positive detections and associated
water quality standards/criteria. Based on this analysis, the following permitting actions are proposed for
this permit:
• Effluent Limit with Monitoring. The following parameters will receive a water quality -based
effluent limit (WQBEL) since they demonstrated a reasonable potential to exceed applicable
water quality standards/criteria: N/A
• Monitoring Only. The following parameters will receive a monitor -only requirement since they
did not demonstrate reasonable potential to exceed applicable water quality standards/criteria,
but the maximum predicted concentration was >50% of the allowable concentration: Total
Copper
• 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: NA
• POTW Effluent Pollutant Scan Review: Three effluent pollutant scans were evaluated for
additional pollutants of concern. (Scans from 2018, 2019, 2020 and some DMR data)
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: N/A
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: Total
Cyanide: RP was shown for limited data set due to a single detection that did not exceed
the allowable discharge concentration — apply Quarterly Monitoring; Total Zinc: No RP ,
Predicted Max > 50% of Allowable Cw - apply Quarterly Monitoring
o The following parameters will not receive a limit or monitoring, since they did not
demonstrate reasonable potential to exceed applicable water quality standards/criteria and
the maximum predicted concentration was <50% of the allowable concentration: Total
Arsenic, Total Beryllium, Total Cadmium, Total Phenolic Compounds, Total Chromium,
Total Lead, Total Nickel, Total Selenium, Total Silver
Note: The current permit required effluent pollutant scans in 2017, 2018 and 2019. The Permittee
submitted effluent pollutant scans for 2018, 2019 and 2020.
If applicable, attach a spreadsheet of the RPA results as well as a copy of the Dissolved Metals
Implementation Fact Sheet for freshwater/saltwater to this Fact Sheet. Include a printout of the RPA
Dissolved to Total Metal Calculator sheet if this is a Municipality with a Pretreatment Program.
Toxicity Testing Limitations
Permit limits and monitoring requirements for Whole Effluent Toxicity (WET) have been established in
accordance with Division guidance (per WET Memo, 8/2/1999). Per WET guidance, all NPDES permits
issued to Major facilities or any facility discharging "complex" wastewater (contains anything other than
domestic waste) will contain appropriate WET limits and monitoring requirements, with several
exceptions. The State has received prior EPA approval to use an Alternative WET Test Procedure in
NPDES permits, using single concentration screening tests, with multiple dilution follow-up upon a test
failure.
Page 5 of 9

Describe proposed toxicity test requirement: The permit requires quarterly chronic toxicity testing at
34% effluent concentration. No changes are proposed.
Mercury Statewide TMDL Evaluation
There is a statewide TMDL for mercury approved by EPA in 2012. The TMDL target was to comply
with EPA's mercury fish tissue criteria (0.3 mg/kg) for human health protection. The TMDL established a
wasteload allocation for point sources of 37 kg/year (81 lb/year), and is applicable to municipals and
industrial facilities with known mercury discharges. Given the small contribution of mercury from point
sources (-2% of total load), the TMDL emphasizes mercury minimization plans (MMPs) for point source
control. Municipal facilities > 2 MGD and discharging quantifiable levels of mercury (>1 ng/1) will
receive an MMP requirement. Industrials are evaluated on a case -by -case basis, depending if mercury is a
pollutant of concern. Effluent limits may also be added if annual average effluent concentrations exceed
the WQBEL value (based on the NC WQS of 12 ng/1) and/or if any individual value exceeds a TBEL
value of 47 ng/1.
Table 3. Mercury Effluent Data Summary (2.0 MGD)
2018
2019
2020
# of Samples
1
1
Annual Average Conc. ng/L
2.27
5.57
1.79
Maximum Conc., ng/L
2.27
5.57
1.79
TBEL, ng/L
47
WQBEL, ng/L
35.6
Describe proposed permit actions based on mercury evaluation: Since no annual average mercury
concentration exceeded the WQBEL, and no individual mercury sample exceeded the TBEL, no mercury
limit is required. Since the facility is not > 2.0 MGD, a mercury minimization plan (MMP) is not
required.
Other TMDL/Nutrient Management Strategy Considerations
If applicable, describe any other TMDLs/Nutrient Management Strategies and their implementation
within this permit: NA
Other WQBEL Considerations
If applicable, describe any other parameters of concern evaluated for WQBELs: NA
If applicable, describe any special actions (HQW or ORW) this receiving stream and classification shall
comply with in order to protect the designated waterbody: NA
If applicable, describe any compliance schedules proposed for this permit renewal in accordance with
15A NCAC 2H.0107(c)(2)(B), 40CFR 122.47, and EPA May 2007 Memo: NA
If applicable, describe any water quality standards variances proposed in accordance with NCGS 143-
215.3(e) and 15A NCAC 2B. 0226 for this permit renewal: NA
Page 6 of 9

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
BOD5/TSS for Monthly Average, and 45 mg/l for BOD5/TSS for Weekly Average). YES
If NO, provide a justification for alternative limitations (e.g., waste stabilization pond). NA
Are 85% removal requirements for BOD5/TSS included in the permit? YES
If NO, provide a justification (e.g., waste stabilization pond). NA
8. Antidegradation Review (New/Expanding Discharge):
The objective of an antidegradation review is to ensure that a new or increased pollutant loading will not
degrade water quality. Permitting actions for new or expanding discharges require an antidegradation
review in accordance with 15A NCAC 2B.0201. Each applicant for a new/expanding NPDES permit
must document an effort to consider non -discharge alternatives per 15A NCAC 2H.0105( c)(2). In all
cases, existing instream water uses and the level of water quality necessary to protect the existing use is
maintained and protected.
If applicable, describe the results of the antidegradation review, including the Engineering Alternatives
Analysis (EAA) and any water quality modeling results: NA
9. Antibacksliding Review:
Sections 402(o)(2) and 303(d)(4) of the CWA and federal regulations at 40 CFR 122.44(1) prohibit
backsliding of effluent limitations in NPDES permits. These provisions require effluent limitations in a
reissued permit to be as stringent as those in the previous permit, with some exceptions where limitations
may be relaxed (e.g., based on new information, increases in production may warrant less stringent TBEL
limits, or WQBELs may be less stringent based on updated RPA or dilution).
Are any effluent limitations less stringent than previous permit (YES/NO): NO
If YES, confirm that antibacksliding provisions are not violated: NA
10. Monitoring Requirements
Monitoring frequencies for NPDES permitting are established in accordance with the following
regulations and guidance: 1) State Regulation for Surface Water Monitoring, 15A NCAC 2B.0500; 2)
NPDES Guidance, Monitoring Frequency for Toxic Substances (7/15/2010 Memo); 3) NPDES Guidance,
Reduced Monitoring Frequencies for Facilities with Superior Compliance (10/22/2012 Memo); 4) Best
Professional Judgement (BPJ). Per US EPA (Interim Guidance, 1996), monitoring requirements are not
considered effluent limitations under Section 402(o) of the Clean Water Act, and therefore anti -
backsliding prohibitions would not be triggered by reductions in monitoring frequencies.
For instream monitoring, refer to Section 4.
The current permit requires effluent ammonia monitoring at a weekly frequency. Per 15A NCAC 02B
.0508, water quality limited Grade III facilities should be monitoring for effluent ammonia at a 3/week
frequency. As such, the monitoring frequency for effluent ammonia has been increased to 3/week.
Page 7 of 9

11. Electronic Reporting Requirements
The US EPA NPDES Electronic Reporting Rule was finalized on December 21, 2015. Effective
December 21, 2016, NPDES regulated facilities are required to submit Discharge Monitoring Reports
(DMRs) electronically. While NPDES regulated facilities would initially be required to submit additional
NPDES reports electronically effective December 21, 2020, EPA extended this deadline from December
21, 2020, to December 21, 2025. The current compliance date, effective January 4, 2021, was extended as
a final regulation change published in the November 2, 2020 Federal Register. This permit contains the
requirements for electronic reporting, consistent with Federal requirements.
12.Summary of Proposed Permitting Actions:
Table 4. Current Permit Conditions and Proposed Changes 2.0 MGD
Parameter
Current Permit
Proposed Change
Basis for Condition/Change
Flow
MA 2.0 MGD
No change
15A NCAC 2B .0505
BOD5
MA 30 mg/1
WA 45 mg/1
No change
TBEL. Secondary treatment
standards/40 CFR 133 / 15A
NCAC 2B .0406; 1989 Level B
Model.
NH3-N
Summer:
MA 2.5 mg/1
WA 7.5 mg/1
Winter:
MA 10.0 mg/1
WA 30.0 mg/1
Monitor and Report
Weekly
No change to limits.
Increase monitor and report to
3/Week
WQBEL. 2021 WLA review. 15A
NCAC 2B.
Surface Water Monitoring, 15A
NCAC 2B .0508
TSS
MA 30 mg/1
WA 45 mg/1
No change
TBEL. Secondary treatment
standards/40 CFR 133 / 15A
NCAC 2B .0406;
Fecal coliform
MA 200 /100m1
WA 400 /100m1
No change
WQBEL. State WQ standard, 15A
NCAC 2B
Dissolved
Oxygen
DA > 6.0 mg/L
No change
WQBEL. State WQ standard, 15A
NCAC 2B
Temperature
Monitor and Report
3/Week
No change
Surface Water Monitoring, 15A
NCAC 2B .0508
pH
6 — 9 SU
Monitor and Report
3/Week
No change
WQBEL. State WQ standard, 15A
NCAC 2B
Total Residual
Chlorine
DM 28 ug/L
No change
WQBEL. State WQ standard, 15A
NCAC 2B; 2021 WLA review
Total Nitrogen
Monitor and Report
Monthly
No change
Surface Water Monitoring, 15A
NCAC 2B .0508
Total
Phosphorous
Monitor and Report
Monthly
No change
Surface Water Monitoring, 15A
NCAC 2B .0508
Total Cyanide
No requirement
Monitor and Report Quarterly
Based on RPA; RP for Limited
Dataset (n<8 samples) - apply
Quarterly Monitoring
Page 8 of 9

Total Copper
Monitor and Report
Quarterly
No change
Based on RPA; No RP , Predicted
Max > 50% of Allowable Cw -
apply Quarterly Monitoring
Total Zinc
No requirement
Monitor and Report Quarterly
Based on RPA; No RP , Predicted
Max > 50% of Allowable Cw -
apply Quarterly Monitoring
Total Hardness
Quarterly
monitoring
Upstream and in
Effluent
No change
Hardness -dependent dissolved
metals water quality standards
approved in 2016
Chronic Toxicity
Chronic limit, 34%
effluent
No change
WQBEL. No toxics in toxic
amounts. 15A NCAC 2B
Effluent
Pollutant Scan
Three times per
permit cycle
No change; conducted in 2023,
2024, 2025
40 CFR 122
Electronic
Reporting
Electronic
Reporting Special
Condition
No change
In accordance with EPA Electronic
Reporting Rule 2015.
MGD — Million gallons per day, MA - Monthly Average, WA — Weekly Average, DM — Daily Max, QA
— Quarterly Average, DA — Daily Average
13. Public Notice Schedule:
Permit to Public Notice: March 12, 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 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):
The draft was submitted to the Town of Cherryville, EPA Region IV, and the Division's Mooresville
Regional Office, Aquatic Toxicology Branch and Operator Certification Program for review. No
comments were received from any party.
Were there any changes made since the Draft Permit was public noticed (Yes/No): YES
If Yes, list changes and their basis below:
• As the Permittee is not a member of a Monitoring Coalition, the footnote language in Section
A.(1.) referencing monitoring coalition sampling of upstream hardness has been removed.
• The expiration date for the permit was modified to more closely fit a 5-year permit cycle.
Accordingly, the specified years for the Effluent Pollutant Scans have been modified (2023, 2024,
2025). See Special Condition A. (3.).
15. Fact Sheet Attachments (if applicable):
• RPA Spreadsheet Summary
• BOD and TSS Removal
• Waste Load Allocation Spreadsheet
• Mercury TMDL Spreadsheet
• Toxicity Summary
• Pretreatment Summary
Page 9 of 9

AFFIDAVIT OF INSERTION OF ADVERTISEMENT
The Gaston Gazette
Gastonia, N.C.
Gaston County
The Gaston Gazette does certify that the advertisement for:
PUBLIC NOTICE North Carolina Environmental Management CommissionlNPDES Unit
1617 Mail Service
Measuring 9.94 inches appeared in The Gaston Gazette, a newspaper published in
Gaston County, Gastonia, N.C., in issue(s):
03/12/2021
Name of Account: NCDENR—Division of Water Resources — Gazette
Order Number: 54608087
Ad Number: 54750127
Sworn to, and subscribed before me this 12 th day of March, 2021.
Print Name (Classified Representative) Signature (Classified Representat
6f ino
``+��e�0$1 Slff���� Stephanie B. Sisk, Notary Public
►�E ;Sk ��i• i My Commission Expires March 23, 2025
v
s 1 y
'e'*/, AND ,oN

PUBLIC NOTICE
North Carolina Environmental
Management
Commission/NPDES Unit
1617 Mall Service Center
Raleigh, NC 27699-1617
Notice of Intent to Issue a NPDES
Wastewater Permit NC004444D
Cher yvllle WWTP
The North Carolina Environmental Management
Cornmission proposes to Issue a NPDES wastewater
discharge permit to the person(s) fisted below. Writ-
ten comments regarding the proposed permit wilt be
accepted until 30 days after the publish date of this
notice. The Dinx,Eur of the NC Division of Water Re-
sources (DWR) may hokt a public hearing should
there bea significant degree of public interest.
Please _DWR at moments an Vor information requests
he above address. Interested persons
may visit the DWR at 512 N. Salisbury Street, Ra-
leigh, NC 27604 to review information on file. Addi-
tionalinformation on NPDES permits and this notice
may be found on our website:
•
AA
iNkkzesgim The City of ,or by calling [phone].
Cherryville, NC � Tot Dellinger Roadfor mmewal ,
NPDES wC 28021)�44h40 foapplr
permit
its Chenyvile
WWTP, located in Gaston County. This permitted fa-
dIn-
dian Creek,class C waterthe wastewater River
Basin. Currently ammonia nitrogen, fecal conform,
pH and total residual chlorine are water quality im-
ited. This discharge may affect future allocations in
this portion of Indian Creek.
3H12, 2021
54608087

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
REQUIRED DATA ENTRY
Table 1. Project Information
❑ CHECK IF HQW OR ORW WQS
Facility Name
WWTP/WTP Class
NPDES Permit
Outfall
Flow, Qw (MGD)
Receiving Stream
HUC Number
Stream Class
Cherryville WWTP
q
Grade III
NC0044440
001
2.000
Indian Creek
03050102
C
❑ Apply WS Hardness WQC
7Q10s (cfs)
7Q10w (cfs)
30Q2 (cfs)
QA (cfs)
1 Q10s (cfs)
6.10
16.00
6.10
58.00
5.08
Effluent Hardness
Upstream Hardness
Combined Hardness Chronic
Combined Hardness Acute
36.22 mg/L (Avg)
40.08 mg/L (Avg)
38.78 mg/L
38.62 mg/L
Data Source(s)
7Q10s used for 30Q2 calculations.
❑ CHECK TO APPLY MODEL
Table 2. Parameters of Concern
Par01
Par02
Par03
Par04
Par05
Par06
Par07
Par08
Par09
Par10
Par11
Par12
Par13
Par14
Par15
Par16
Par17
Par18
Par19
Par20
Par21
Par22
Par23
Par24
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
0.8221
FW
4.7356
ug/L
Chlorides
Aquatic Life
NC
230
FW
Chlorinated Phenolic Compounds
Water Supply
NC
1
A
ug/L
yTotal Phenolic Compounds
Aquatic Life
NC
300
A
ug/L
Chromium III
Aquatic Life
NC
168.6843
FW
1292.3344
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
11.4686
FW
15.7756
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
4.8130
FW
122.9332
ug/L
Mercury
Aquatic Life
NC
12
FW
0.5
ng/L
Molybdenum
Human Health
NC
2000
HH
ug/L
Nickel
Aquatic Life
NC
53.9803
FW
484.2860
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
0.6262
ug/L
Zinc
Aquatic Life
NC
183.8510
FW
181.7128
ug/L
FW RPA, input
3/3/2021

REASONABLE POTENTIAL ANALYSIS
H1
Effluent Hardness
Date Data BDL=1/2DL
40
38
38
44
40
36
32
40
32
36
32
32
32
36
32
40
36
36
12/11/2017
12/13/2017
12/14/2017
3/13/2018
6/13/2018
9/12/2018
12/12/2018
3/13/2019
6/19/2019
9/11/2019
12/11/2019
3/18/2020
6/10/2020
9/9/2020
12/9/2020
2/13/2018
3/5/2019
2/25/2020
40
38
38
44
40
36
32
40
32
36
32
32
32
36
32
40
36
36
Results
Std Dev.
Mean
C.V.
n
10th Per value
Average Value
Max. Value
Use "PASTE SPECIAL.
Values" then "COPY"
. Maximum data
points = 58
H2
Upstream Hardness
3.6871
36.2222
0.1018
18
32.00 mg/L
36.22 mg/L
44.00 mg/L
-1-
Date Data
3/13/2018
6/13/2018
9/12/2018
12/12/2018
3/13/2019
6/19/2019
9/11/2019
12/11/2019
3/18/2020
6/10/2020
9/9/2020
12/9/2020
11
87
41
56
162
16
20
16
16
16
24
16
BDL=1/2DL
11
87
41
56
162
16
20
16
16
16
24
16
Results
Std Dev.
Mean
C.V.
n
10th Per value
Average Value
Max. Value
Use "PASTE SPECIAL.
Values" then "COPY"
. Maximum data
points = 58
44.4429
40.0833
1.1088
12
16.00 mg/L
40.08 mg/L
162.00 mg/L
FW RPA, data
3/3/2021

REASONABLE POTENTIAL ANALYSIS
Par01 & Par02
Arsenic
Date Data BDL=1/2DL Results
1 2/13/2018 < 2 1 Std Dev.
2 3/5/2019 < 10 5 Mean
3 2/25/2020 < 10 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
Use "PASTE SPECIAL.
Values" then "COPY"
. Maximum data
points = 58
2.3094
3.6667
0.6000
3
3.00
5.0 ug/L
15.0 ug/L
-2-
FW RPA, data
3/3/2021

REASONABLE POTENTIAL ANALYSIS
Par03
Beryllium
Date Data BDL=1/2DL Results
1 2/13/2018 < 5 2.5 Std Dev.
2 3/5/2019 < 5 2.5 Mean
3 2/25/2020 < 5 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
Use "PASTE SPECIAL.
Values" then "COPY"
. Maximum data
points = 58
Par04
Cadmium
0.0000
2.5000
0.6000
3
3.00
2.50 ug/L
7.50 ug/L
-3-
Date Data BDL=1/2DL Results
1 2/13/2018 < 2 1 Std Dev.
2 3/5/2019 < 2 1 Mean
3 2/25/2020 < 2 1 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
Use "PASTE SPECIAL.
Values" then "COPY"
. Maximum data
points = 58
0.0000
1.0000
0.6000
3
3.00
1.000 ug/L
3.000 ug/L
FW RPA, data
3/3/2021

REASONABLE POTENTIAL ANALYSIS
Par07
Total Phenolic Compounds
Date Data BDL=1/2DL Results
1 2/13/2018 19 19 Std Dev.
2 3/5/2019 < 10 5 Mean
3 2/25/2020 14 14 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
Use "PASTE SPECIAL.
Values" then "COPY"
. Maximum data
points = 58
Par10
Chromium, Total
7.0946
12.6667
0.6000
3
3.00
19.0 ug/L
57.0 ug/L
-4-
Date Data BDL=1/2DL Results
1 2/13/2018 < 5 2.5 Std Dev.
2 3/5/2019 < 5 2.5 Mean
3 2/25/2020 < 5 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
Use "PASTE SPECIAL.
Values" then "COPY"
. Maximum data
points = 58
0.0000
2.5000
0.6000
3
3.00
2.5 pg/L
7.5 pg/L
FW RPA, data
3/3/2021

REASONABLE POTENTIAL ANALYSIS
Pall
Copper
Date Data BDL=1/2DL
12
7
12
9
9
3
6
5
6
6
8
8
5
13
16
11
7
5
8
3/8/2017
6/7/2017
9/13/2017
12/13/2017
3/13/2018
6/13/2018
9/12/2018
12/12/2018
3/13/2019
6/19/2019
9/11/2019
12/11/2019
3/18/2020
6/10/2020
9/9/2020
12/9/2020
2/13/2018
3/5/2019
2/25/2020
12
7
12
9
9
3
6
5
6
6
8
8
5
13
16
11
7
5
8
Results
Std Dev.
Mean
C.V.
n
Mult
Max.
Max.
Factor =
Value
Pred Cw
Use "PASTE SPECIAL.
Values" then "COPY"
. Maximum data
points = 58
Par12
Cyanide
3.3096
8.2105
0.4031
19
1.26
16.00 ug/L
20.16 ug/L
-5-
Date Data BDL=1/2DL
5
5
11
5
5
5
5
3/8/2017 < 5
6/14/2017 < 5
9/13/2017 11
12/20/2017 < 5
2/13/2018 < 5.0
3/5/2019 < 5
2/25/2020 < 5
Results
Std Dev.
Mean
C.V. (default)
n
Mult Factor =
Max. Value
Max. Pred Cw
Use "PASTE SPECIAL.
Values" then "COPY"
. Maximum data
points = 58
2.2678
5.86
0.6000
7
2.01
11.0 ug/L
22.1 ug/L
FW RPA, data
3/3/2021

REASONABLE POTENTIAL ANALYSIS
Par14
Lead
Date
2/13/2018 < 5
3/5/2019 < 10
2/25/2020 < 10
BDL=1/2DL Results
2.5 Std Dev.
5 Mean
5 C.V. (default)
n
Mult Factor =
Max. Value
Max. Pred Cw
Use "PASTE SPECIAL.
Values" then "COPY"
. Maximum data
points = 58
Par17 & Par18
Nickel
1.4434
4.1667
0.6000
3
3.00
5.000 ug/L
15.000 ug/L
-6-
Date Data BDL=1/2DL Results
1 2/13/2018 < 10 5 Std Dev.
2 3/5/2019 < 10 5 Mean
3 2/25/2020 < 10 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
Use "PASTE
SPECIAL -
Values" then
"COPY" .
Maximum data
points = 58
0.0000
5.0000
0.6000
3
3.00
5.0 pg/L
15.0 pg/L
FW RPA, data
3/3/2021

REASONABLE POTENTIAL ANALYSIS
Par19
Selenium
Date Data BDL=1/2DL
5
5
5
2/13/2018 <
3/5/2019 <
2/25/2020 <
10
10
10
Results
Std Dev.
Mean
C.V. (default)
n
Mult Factor =
Max. Value
Max. Pred Cw
Use "PASTE
SPECIAL -Values
then "COPY" .
Maximum data
points = 58
Par20
Silver
0.0000
5.0000
0.6000
3
3.00
5.0 ug/L
15.0 ug/L
-7-
Date Data BDL=1/2DL
2.5
2.5
2.5
2/13/2018 <
3/5/2019 <
2/25/2020 <
5
5
5
Results
Std Dev.
Mean
C.V. (default)
n
Mult Factor =
Max. Value
Max. Pred Cw
Use "PASTE SPECIAL -
Values" then "COPY" .
Maximum data points =
58
0.0000
2.5000
0.6000
3
3.00
2.500 ug/L
7.500 ug/L
FW RPA, data
3/3/2021

REASONABLE POTENTIAL ANALYSIS
Par21
Zinc
Date Data BDL=1/2DL Results
1 3/8/2017 87 87 Std Dev.
2 6/7/2017 41 41 Mean
3 9/13/2017 56 56 C.V. (default)
4 12/13/2017 162 162 n
5 2/13/2018 46 46
6 3/5/2019 20 20 Mult Factor =
7 2/25/2020 27 27 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
Use "PASTE SPECIAL.
Values" then "COPY"
. Maximum data
points = 58
48.8935
62.7143
0.6000
7
2.01
162.0 ug/L
325.6 ug/L
-8-
FW RPA, data
3/3/2021

Cherryville WWTP
N C0044440
Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Qw (MGD) = 2.0000
1Q10S (cfs) = 5.08
7Q1OS (cfs) = 6.10
7Q1OW (cfs) = 16.00
30Q2 (cfs) = 6.10
Avg. Stream Flow, QA (cfs) = 58.00
Receiving Stream: Indian Creek HUC 03050102
WWTP/WTP Class: Grade III
IWC% @ 1Q10S = 37.89731051
IWC% @ 7Q1OS = 33.69565217
IWC% @ 7Q1OW = 16.23036649
IWC% @ 30Q2 = 33.69565217
IW%C @ QA = 5.073649755
Stream Class: C
Outfall 001
Qw = 2 MGD
COMBINED HARDNESS (mg/L)
Acute = 38.62 mg/L
Chronic = 38.78 mg/L
PARAMETER
TYPE
NC STANDARDS OR EPA CRITERIA
_1
n
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
Chronic Stapda d AcuteoCi
n # Det. Max Pred Cw Allowable Cw
Arsenic
Arsenic
C
C
150 FW(7Q10s) 340
10 HH/WS(Qavg)
ug/L
ug/L
3 0
Note: n < 9
Limited data set
15.0
C.V. (default)
NO DETECTS
Acute (FW): 897.2
_ _ _ _ _ _ _ _ _ _ _ _ _
Chronic (FW): 445.2
Max MDL = 10
Chronic (HH): 197.1
Max MDL = 10
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required
Beryllium
NC
6.5 FW(7Q10s) 65
ug/L
3 0
Note: n < 9
Limited data set
7.50
C.V. (default)
NO DETECTS
Acute: 171.52
____ _ ______ _____
Chronic: 19.29
Max MDL = 5
_ _ _ _ _ _ _ _ _ _ _ _ _ _
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required
Cadmium
NC
0.8221 FW(7Q10s) 4.7356
ug/L
3 0
Note: n < 9
Limited data set
3.000
C.V. (default)
NO DETECTS
Acute: 12.496
____ _ ______ _____
Chronic: 2.440
Max MDL = 2
_ _ _ _ _ _ _ _ _ _ _______
All values reported non -detect < 2 ug/L. No
monitoring required.
Total Phenolic Compounds
NC
300 A(30Q2)
ug/L
3 2
Note: n < 9
Limited data set
57.0
C.V. (default)
Acute: NO WQS
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Chronic: 890.3
No value > Allowable Cw
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required
Chromium III
NC
168.6843 FW(7Q10s) 1292.3344
µg/L
0 0
N/A
Acute: 3,410.1
--_ _ ----_ _
--500.6--------------------------------
Chronic:
Chromium VI
NC
11 FW(7Q10s) 16
µg/L
0 0
N/A
Acute: 42.2
--_ _ ----- _ _
---------------------------------
Chronic: 32.6
Chromium, Total
NC
µg/L
3 0
Note: n < 9
Limited data set
7.5
C.V. (default)
NO DETECTS
Max reported value = 2.5
Max MDL = 5
a: No monitoring required if all Total Chromium
samples are < 5 pg/L or Pred. max for Total Cr is <
allowable Cw for Cr VI.
Copper
NC
11.4686 FW(7Q10s) 15.7756
ug/L
19 19
20.16
Acute: 41.63
____ _ ____________
Chronic: 34.04
No value > Allowable Cw
_ _ _ _ _ _ _ _ _ _ _ _ ___
No RP , Predicted Max >_ 50% of Allowable Cw
apply Quarterly Monitoring
Cyanide
NC
5 FW(7Q10s) 22
10
ug/L
7 1
Note: n < 9
Limited data set
22.1
C.V. (default)
Acute: 58.1
____ _ ______ _____
Chronic: 14.8
No value > Allowable Cw
_ _ _ _ _ _ _ _ _ _ _ _____
RP for Limited Dataset (n<8 samples) - apply
Quarterly Monitoring
Page 1 of 2
FW RPA, rpa
3/3/2021

Cherryville WWTP
N C0044440
Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
Outfall 001
Qw = 2 MGD
Lead
NC
4.8130 FW(7Q10s) 122.9332
ug/L
3 0
Note: n < 9
Limited data set
15.000
C.V. (default)
NO DETECTS
Acute: 324.385
_ _ _ _ _ _ _ _ _ _ _ _ _
Chronic: 14.284
Max MDL = 10
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
All values reported non -detect < 5 ug/L and < 10 ug/L.
No monitoring required.
Acute (FW): 1,277.9
Nickel
NC
53.9803 FW(7Q10s) 484.2860
µg/L
_ _ _ _ _ _ _ _ _ _ _ _ _
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _
3 0
15.0
Chronic (FW): 160.2
No RP, Predicted Max < 50% of Allowable Cw - No
Note: n < 9
C.V. (default)
Max MDL = 10
Monitoring required
Nickel
NC
25.0000 WS(7Q10s)
µg/L
Limited data set
NO DETECTS
Chronic (WS): 74.2
Max MDL = 10
Acute: 147.8
Selenium
NC
5 FW(7Q10s) 56
ug/L
3 0
15.0
____ _ ______ _____
_ _ _ _ _ _ _ _ _ _ _______
Note: n < 9
Limited data set
C.V. (default)
NO DETECTS
Chronic: 14.8
Max MDL = 10
All values reported non -detect < 5 ug/L. No
monitoring required.
Acute: 1.652
Silver
NC
0.06 FW(7Q10s) 0.6262
ug/L
3 0
7.500
____ _ ______ _____
_ _ _ _ _ _ _ _ _ _ _______
Note: n < 9
C.V. (default)
Chronic: 0.178
All values reported non -detect < 5 ug/L. No
monitoring required. Permittee shall report to PQL of
Limited data set
NO DETECTS
Max MDL = 5
1 ug/L
Acute: 479.5
Zinc
NC
183.8510 FW(7Q10s) 181.7128
ug/L
7 7
325.6
____ _ _______________________________________
Note: n < 9
Limited data set
C.V. (default)
Chronic: 545.6
No value > Allowable Cw
No RP , Predicted Max >_ 50% of Allowable Cw -
apply Quarterly Monitoring
Page 2 of 2
FW RPA, rpa
3/3/2021

Permit No. NC0044440
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 April6, 2016, with some exceptions. Therefore, metal limits in draft
permits out to public notice after April6, 2016 must be calculated to protect the new standards - as
approved.
Table 1. NC Dissolved Metals Water Quality Standards/Aquatic Life Protection
Parameter
Acute FW, µg/1
(Dissolved)
Chronic FW, 14/1
(Dissolved)
Acute SW, 14/1
(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*{1.1366724ln hardness](0.041838)} • e^{0.9151 [ln 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]-4.4451 }
Chromium III, Acute
WER*0.316 • e^{0.8190[ln hardness]+3.7256}
Chromium III, Chronic
WER*0.860 • e^{0.8190[ln hardness]+0.6848}
Copper, Acute
WER*0.960 • e^{0.9422[ln hardness]-1.700}
Copper, Chronic
WER*0.960 • e^{0.8545[ln hardness]-1.702}
Lead, Acute
WER*{1.462034ln hardness](0.145712)} • e^{1.273[In hardness]-1.460}
Lead, Chronic
WER*{1.46203-[ln hardness](0.145712)} • e^{1.273[In hardness]-4.705}
Nickel, Acute
WER*0.998 • e^{0.8460[ln hardness]+2.255}
Nickel, Chronic
WER*0.997 • e^{0.8460[ln hardness]+0.0584}
Page 1 of 4

Permit No. NC0044440
Silver, Acute
WER*0.85 • e^{1.72[ln hardness]-6.59}
Silver, Chronic
Not applicable
Zinc, Acute
WER*0.978 • e^{0.8473[ln hardness]+0.884}
Zinc, Chronic
WER*0.986 • e^{0.8473[ln hardness]+0.884}
General Information on the Reasonable Potential Analysis (RPA)
The RPA process itself did not change as the result of the new metals standards. However, application of
the dissolved and hardness -dependent standards requires additional consideration in order to establish the
numeric standard for each metal of concern of each individual discharge.
The hardness -based standards require some knowledge of the effluent and instream (upstream) hardness
and so must be calculated case -by -case for each discharge.
Metals limits must be expressed as `total recoverable' metals in accordance with 40 CFR 122.45(c). The
discharge -specific standards must be converted to the equivalent total values for use in the RPA
calculations. We will generally rely on default translator values developed for each metal (more on that
below), but it is also possible to consider case -specific translators developed in accordance with
established methodology.
RPA Permitting Guidance/WQBELs for Hardness -Dependent Metals - Freshwater
The RPA is designed to predict the maximum likely effluent concentrations for each metal of concern,
based on recent effluent data, and calculate the allowable effluent concentrations, based on applicable
standards and the critical low -flow values for the receiving stream.
If the maximum predicted value is greater than the maximum allowed value (chronic or acute), the
discharge has reasonable potential to exceed the standard, which warrants a permit limit in most cases. If
monitoring for a particular pollutant indicates that the pollutant is not present (i.e. consistently below
detection level), then the Division may remove the monitoring requirement in the reissued permit.
1. To perform a RPA on the Freshwater hardness -dependent metals the Permit Writer compiles the
following information:
• Critical low flow of the receiving stream, 7Q10 (the spreadsheet automatically calculates
the 1Q10 using the formula 1Q10 = 0.843 (s7Q10, 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. NC0044440
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 1Q10 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(1
+1 [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 = (s7Q10 + Qw) (Cwqs) — (s7Q10) (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 s7Q10)
s7Q10 = 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 s7Q10 may be incorporated as applicable:
1Q10 = used in the equation to protect aquatic life from acute toxicity
Page 3 of 4

Permit No. NC0044440
QA = used in the equation to protect human health through the consumption of water,
fish, and shellfish from carcinogens
30Q2 = used in the equation to protect aesthetic quality
6. The permit writer enters the most recent 2-3 years of effluent data for each pollutant of concern.
Data entered must have been taken within four and one-half years prior to the date of the permit
application (40 CFR 122.21). The RPA spreadsheet estimates the 95th percentile upper
concentration of each pollutant. The Predicted Max concentrations are compared to the Total
allowable concentrations to determine if a permit limit is necessary. If the predicted max exceeds
the acute or chronic Total allowable concentrations, the discharge is considered to show
reasonable potential to violate the water quality standard, and a permit limit (Total allowable
concentration) is included in the permit in accordance with the U.S. EPA Technical Support
Document for Water Quality -Based Toxics Control published in 1991.
7. When appropriate, permit writers develop facility specific compliance schedules in accordance
with the EPA Headquarters Memo dated May 10, 2007 from James Hanlon to Alexis Strauss on
40 CFR 122.47 Compliance Schedule Requirements.
8. The Total Chromium NC WQS was removed and replaced with trivalent chromium and
hexavalent chromium Water Quality Standards. As a cost savings measure, total chromium data
results may be used as a conservative surrogate in cases where there are no analytical results
based on chromium III or VI. In these cases, the projected maximum concentration (95th %) for
total chromium will be compared against water quality standards for chromium III and
chromium VI.
9. Effluent hardness sampling and instream hardness sampling, upstream of the discharge, are
inserted into all permits with facilities monitoring for hardness -dependent metals to ensure the
accuracy of the permit limits and to build a more robust hardness dataset.
10. Hardness and flow values used in the Reasonable Potential Analysis for this permit included:
Parameter
Value
Comments (Data Source)
Average Effluent Hardness (mg/L)
[Total as, CaCO3 or (Ca+Mg)]
36.22
Average from DMRs and Effluent
Pollutant Scans
Average Upstream Hardness (mg/L)
[Total as, CaCO3 or (Ca+Mg)]
40.88
Average from DMRs
7Q10 summer (cfs)
6.1
NPDES Files
1Q10 (cfs)
5.08
Calculated in RPA
Permitted Flow (MGD)
2.0
NPDES Files
Date: 3/3/2021
Permit Writer: Nick Coco
Page 4 of 4

NC0044440 Cherryville WWTP 3/3/2021
BOD monthly removal rate
Month RR (%) Month RR (%)
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
March-19
April-19
May-19
June-19
July-19
99.20
97.61
94.72
95.96
95.85
92.28
94.94
96.56
97.99
97.35
97.79
97.67
96.02
94.47
88.26
96.77
98.19
98.86
96.62
98.00
97.05
91.58
93.15
95.51
96.19
98.65
98.16
96.67
96.23
98.78
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
September-21
October-21
November-21
December-21
January-22
Overall BOD removal rate
99.23
99.06
98.65
99.19
98.61
96.16
93.78
97.47
96.76
97.17
97.22
97.12
97.50
97.50
98.12
96.12
95.90
96.65
TSS monthly removal rate
Month RR (%) Month RR (%)
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
March-19
April-19
May-19
June-19
July-19
98.77
92.96
92.50
96.84
98.39
97.53
96.70
97.46
98.47
97.49
97.82
97.44
95.64
94.13
87.07
97.96
98.71
99.66
97.59
98.04
97.31
91.53
91.50
96.51
99.47
99.21
99.31
98.76
97.24
99.46
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
September-21
October-21
November-21
December-21
January-22
Overall TSSD removal rate
99.46
99.23
99.21
99.29
98.90
95.71
94.54
98.21
97.45
97.78
97.56
97.90
95.30
98.60
98.95
96.55
95.61
97.06

NH3/TRC WLA Calculations
Facility: Cherryville WWTP
PermitNo. NC0020761
Prepared By: Nick Coco
Enter Design Flow (MGD):
Enter s7Q10 (cfs):
Enter w7Q10 (cfs):
2
6.1
16
Total Residual Chlorine (TRC)
Daily Maximum Limit (ug/I)
s7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (UG/L)
Upstream Bkgd (ug/I)
IWC (%)
Allowable Conc. (ug/I)
Fecal Coliform
Monthly Average Limit:
(If DF >331; Monitor)
(If DF<331; Limit)
Dilution Factor (DF)
6.1
2
3.1
17.0
0
33.70
50
Capped at 28 ug/L. Limit used.
Ammonia (Summer)
Monthly Average Limit (mg NH3-N/I)
s7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
Upstream Bkgd (mg/I)
IWC (%)
Allowable Conc. (mg/I)
6.1
2
3.1
1.0
0.22
33.70
2.5
Consistent with existing limit. Maintain limit.
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/I)
w7Q10 (CFS)
200/100mI DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
2.97 Upstream Bkgd (mg/I)
IWC (%)
Allowable Conc. (mg/I)
Total Residual Chlorine
1. Cap Daily Max limit at 28 ug/I to protect for acute toxicity
16
2
3.1
1.8
0.22
16.23
10.0
Consistent with existing limit. Maintain limit.
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)

3/3/21 WQS = 12 ng/L
Facility Name
Cherryville WWTP/NC0044440
/Permit No. :
MERCURY WQBEL/TBEL EVALUATION V:2013-6
Total Mercury 1631E PQL = 0.5 ng/L 7Q10s =
Date Modifier Data Entry Value Permitted Flow =
2/13/18 2.27
3/5/19 5.57
2/25/20 1.79
No Limit Required
No MMP Required
2.27
5.57
1.79
6.100
2.000
cfs
WQBEL = 35.61 ng/L
47 ng/L
2.3
5.6
1.8
ng/L - Annual Average for 2018
ng/L - Annual Average for 2019
ng/L - Annual Average for 2020

Cherryville WWTP/NC0044440
Mercury Data Statistics (Method 1631E)
2018
2019
2020
# of Samples
1
1
1
Annual Average, ng/L
2.3
5.6
1.8
Maximum Value, ng/L
2.27
5.57
1.79
TBEL, ng/L
47
WQBEL, ng/L
35.6

MERITECH, INC.
ENVIRONMENTAL LABORATORIES
Laboratory Certification No. 165
Client: Town of Cherryville Date Sampled 02./13/18
Cherryville, NC Digested 02/14/18
Attention
NPDES #
Analysis 02/22/18
Analyst: CWL
EPA 1631 Low Level Mercury Analysis
Meriteclh ID 11 Sample ID Result Reporting Limit
MI3L K0117Y Method Blank < 0.5 ng/L 0.5 ng/L
M02141829 Field Blank < 1.0 ng/L 1.0 ng/L
M02141830 Tftluent 2.27 ng/L 1.0 ng/L
1 hereby certify that I have reviewed and approve these data.
Laboratory Representative
642 Tama) Rd - PO Box 27 - Reidsville, NC 27320
[phone] Ph - [phone] Fax
E-Mail: [e-mail]

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MERITECH, INC.
ENVIRONMENTAL LABORATORIES
Laboratory Certification No. 165
Clio►►t: Town of Cherryville WWTP Date Sampled 03/05/19
Cherryville, NC Digested 03/06/19
Attention
NPDES #
Analysis 03/27/19
Analyst: Stmunit
EPA 1.631. Low Level Mercury Analysis
Meritech ID ii Sample ID Result Reporting Limit
MBLK0327 Method Blank < 0.5 ng/L 0.5 ng/L
M03061905 Field Blank < 1.0 ng/L 1.0 ng/L
M03061906 Effluent 5.57 ng/L 1.0 ng/L
I hereby certify that I have reviewed and approve these data.
Laboratory Representative
642 Tamco Rd - PO Box 27 - Reidsville, NC 27320
[phone] Ph - [phone] Fax
E-Mail: [e-mail]

tNVIl3ONMGIJTALT!C5{tU LCIC;i[ s, U:C
Analyi;eal Labe. aiorles
Summit Envirotunanial 9ecln»ologies, Ltc.
3310 Win S1,
Cuyahoga Falls, Ohlo 44223
TEL: [phone] FAX: [phone]
Website: !It p,1/u'uriv settek cone
WO#:
Date Reported:
Company:
Address:
19031437
4/3/2019
Merited Environmental .Laboratories
642 Tatnco Rd.
Reidsville NC 27320
Received: 3/22/2019
Project/I:
Client 1D#
Lab ID# Collected Anaiyte Result Units
Matrix Method DE PQL Run Analyst
030605 C-FB
005 3/5/2019 Mercury 0.920 ng/L
Non- EPA 1631 1 0,500 3/27/2019 KMO
Potable E
Water
Client ID#
Lab ID# Collected Analyte Result Units
Matrix Method DE PQL Run Analyst
030606 C-EFF 006 3/5/2019 Mercury 5.57 ng/L
Non- EPA 1631 1 0.500 3/27/2019 KMO
Potable E
Water
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MONITORING REPORT(MR) VIOLATIONS for:
Report Date: 03/01/21 Page 1 of 1
Permit: NC0044440 MRs Betweel 2 - 2017 and 2 - 2021
Facility Name: % Param Name%
Major Minor: %
Region: % Violation Category:Limit Violation Program Category: %
County: % Subbasin:% Violation Action: %
PERMIT: NC0044440
FACILITY: City of Cherryville - Cherryville WWTP
COUNTY: Gaston REGION: Mooresville
Limit Violation
MONITORING UNIT OF
OUTFALL LOCATION PARAMETER VIOLATION FREQUENCY
REPORT DATE MEASURE
LIMIT
CALCULATED
VALUE
ok
Over
VIOLATION TYPE VIOLATION ACTION
07-2017 001 Effluent Chlorine, Total Residual 07/21/17 3 X week ug/I 28 32 14.3 Daily Maximum No Action, BPJ
Exceeded
08-2019 001 Effluent Chlorine, Total Residual 08/16/19 3 X week ug/I 28 29 3.6 Daily Maximum No Action, BPJ
Exceeded
04-2020 001 Effluent pH 04/23/20 3 X week su 6 5.5 8.3 Daily Minimum Not Proceed to NOD
Reached
04-2018 001 Effluent Solids, Total Suspended - 04/14/18 3 X week mg/I 45 48 6.7 Weekly Average Proceed to NOD
Concentration Exceeded

Whole Effluent Toxicity Testing and Self Monitoring Summary
Charlotte -Douglas Airport-003 NC0083887/003 County: Mecklenburg Region: MRO Basin: CTB34 SOC JOC:
Ceri24PF Begin: 8/1/2006 24hr LC50 ac monit e NonComp: 7010: NA PF: NA IWC: NA Freq: A
J
2017 Pass
2018 Pass
2019
2020
F
Pass
M A M J J A 5 0 N D
Pass - - - - - - - - Pass
- - - - - - - Pass
Pass
Chemical Specialties, Inc. (Venator) NC0006351/001 County: Cabarrus Region: MRO Basin: YAD11 Jan Apr Jul Oct
Ceri7dPF Begin: 5/1/2014 Perm chr lim: 0.96% NonComp: Single 7010: 4.0 PF: 0.025 IWC: 0.96 Freq: Q
SOC JOC:
J F M A M J J A 5 0 N D
2017 H H H H H H H - - H H
2018 H H H H H H H H H >0.96
2019 Invalid Invalid 2.72 2.72 - H - - H -
2020 Invalid >3.84 H - >3.84 >3.84 - - H -
H
Chemours - Fayetteville Works NC0003573/001 County: Bladen Region: FRO Basin: CPF16 Feb May Aug Nov
Ceri7dPF Begin: 3/1/2012 chr lim: 3.3% NonComp: Single 7Q10: 791.0 PF: 17 IWC: 3.3 Freq: Q
SOC JOC:
J F M A M J J A 5 0 N
2017 - Pass - - Pass - - Pass - - Pass
2018 - Pass - - Pass - - Pass - - Pass
2019 - Pass - - Pass - - Pass - - Pass
2020 - Pass - - Pass - - Pass - - Pass
Cherryville WWTP NC0044440/001 County: Gaston Region: MRO Basin: CTB35 Mar Jun Sep Dec
Ceri7dPF Begin: 8/1/2017 chr lim: 34% NonComp: Single 7010: 6.1 PF: 2.0 IWC: 34 Freq: Q
SOC JOC:
J F M A M J J A S 0 N D
2017 - - Pass - - Pass - - Pass - - Pass >100(P)
2018 - - Pass - - Pass - - Pass - - Pass
2019 - - Pass - Pass - - Pass - - Pass >100(P)
2020 - - Pass - >100(P) Pass - - Pass - - Pass
Chowan County Valhalla WTP NC0032719/001 County: Chowan Region: WARO Basin: CHO04 Feb May Aug Nov
Ceri7dPF Begin: 5/1/2014 Chr P/F Monit: 90% NonComp: 7010: 0 PF: 0.06 IWC: 100 Freq: Q
SOC JOC:
J
2017
2018
2019
2020
F M A
Pass -
Pass -
Pass -
Pass -
M J J A 5 0 N
Pass - - Pass - - Fail
Pass - - Pass - - Pass
Pass - - Fail - - Pass
Pass - - Pass - - Pass
Cirty of Burlington WTP NC0083828/001 County: Alamance Region: WSRO
Ceri7dPF Begin: 11/1/2016 Cerio7PF Monit @ 8 NonComp: 7010:
Basin: CPF03 SOC JOC:
PF:
IWC: Freq: A
J F
2018
2020
M A M
Pass
Pass
J
l A S 0 N D
Legend: P= Fathead minnow (Pimphales promelas), H=No Flow (facility is active), s = Split test between Certified Labs
Page 15 of 104

United States Environmental Protection Agency
E PA Washington, D.C. 20460
Water Compliance Inspection Report
Form Approved.
OMB No. 2040-0057
Approval expires 8-31-98
Section A: National Data System Coding (i.e., PCS)
Transaction Code NPDES yr/mo/day Inspection
1 IN 2 I5 �-I 3 I NC0044440 I11 12 I 20/07/15 117
Type
18 [=
Illiiiiiiii
73I I 174
L�
Inspector Fac Type
19 G I 201
21111111i illliliiiIIiiillliilIliii
Reserved
1 751
166
I I I 1180
11
Inspection Work Days Facility Self -Monitoring Evaluation Rating B1 QA
6711.0 I 7° I4 1 711N72 I N I
1
Section B: Facility Data
Name and Location of Facility Inspected (For Industrial Users discharging to POTW, also include
POTW name and NPDES permit Number)
Cherryville WWTP
736 Tot Dellinger Rd
Cherryville NC 28021
Entry Time/Date
11:OOAM 20/07/15
Permit Effective Date
17/08/01
Exit Time/Date
12:OOPM 20/07/15
Permit Expiration Date
20/07/31
Name(s) of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s)
///
Larry Gene Wright/ORC/704-435-1739/
Other Facility Data
Name, Address of Responsible Official/Title/Phone and Fax Number
Contacted
Larry Wright,116 S Mountain St Cherryville NC 280213421/Plant
Supervisor/ORC/704-435-1739/7044351713 No
Section C: Areas Evaluated During Inspection (Check only those areas evaluated)
Permit Flow Measurement Operations & Maintenar Records/Reports
Self -Monitoring Progran Sludge Handling Dispos 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
Ori A Tuvia DWR/MRO WQ/704-663-1699/
Signature of Management Q A Reviewer Agency/Office/Phone and Fax Numbers Date
EPA Form 3560-3 (Rev 9-94) Previous editions are obsolete.
Page# 1

NPDES yr/mo/day
31 NC0044440 111 121 20/07/15
117
Inspection Type
18 [j
1
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
Page# 2

Permit: NC0044440
Inspection Date: 07/15/2020
Owner - Facility: Cherryville VVVVTP
Inspection Type: Compliance Evaluation
Permit
(If the present permit expires in 6 months or less). Has the permittee submitted a new
application?
Is the facility as described in the permit?
# Are there any special conditions for the permit?
Is access to the plant site restricted to the general public?
Is the inspector granted access to all areas for inspection?
Yes No NA NE
• ❑ ❑ ❑
• ❑ ❑ ❑
❑ • ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
Comment: The subject permit expires on July 31, 2020. The facility has applied for permit renewal.
Record Keeping
Are records kept and maintained as required by the permit?
Is all required information readily available, complete and current?
Are all records maintained for 3 years (lab. reg. required 5 years)?
Are analytical results consistent with data reported on DMRs?
Is the chain -of -custody complete?
Dates, times and location of sampling
Name of individual performing the sampling
Results of analysis and calibration
Dates of analysis
Name of person performing analyses
Transported COCs
Are DMRs complete: do they include all permit parameters?
Has the facility submitted its annual compliance report to users and DWQ?
(If the facility is = or > 5 MGD permitted flow) Do they operate 24/7 with a certified 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?
Facility has copy of previous year's Annual Report on file for review?
Yes No NA NE
❑ ❑ ❑ •
• ❑ ❑ ❑
❑ ❑ ❑ •
• ❑ ❑ ❑
• ❑ ❑ ❑
•
•
•
•
•
•
• ❑ ❑ ❑
❑ ❑ ❑ •
❑ ❑ • ❑
• ❑ ❑ ❑
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Comment: Inspection conducted during Covid-19 restrictions. A full file review was not conducted.
Requested Lab results, Chain of Custody, ORC Log, and Field parameter results taken
including the calibration data, for the month of March 2020. These were sent via email in
timely manner and were complete.
Page# 3

Permit: NC0044440
Inspection Date: 07/15/2020
Owner - Facility: Cherryville wwTP
Inspection Type: Compliance Evaluation
Laboratory Yes No NA NE
Are field parameters performed by certified personnel or laboratory? ❑ ❑ ❑ •
Are all other parameters(excluding field parameters) performed by a certified lab? ❑ ❑ ❑ •
# Is the facility using a contract lab? ❑ ❑ ❑ •
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees ❑ ❑ ❑ •
Celsius)?
Incubator (Fecal Coliform) set to 44.5 degrees Celsius+/- 0.2 degrees? ❑ ❑ ❑ •
Incubator (BOD) set to 20.0 degrees Celsius +/- 1.0 degrees? ❑ ❑ ❑ •
Comment: Inspection conducted during Covid-19 restrictions. No lab review conducted.
Influent Sampling
# Is composite sampling flow proportional?
Is sample collected above side streams?
Is proper volume collected?
Is the tubing clean?
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees
Celsius)?
Is sampling performed according to the permit?
Comment: The subject permit requires influent composite BOD and TSS samples.
Effluent Sampling
Is composite sampling flow proportional?
Is sample collected below all treatment units?
Is proper volume collected?
Is the tubing clean?
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees
Celsius)?
Is the facility sampling performed as required by the permit (frequency, sampling type
representative)?
Yes No NA NE
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Yes No NA NE
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Comment: The subject permit requires effluent composite and grab samples. The ORC and staff
perform periodic aliquot verifications on the composite sampler (influent and effluent)
Upstream / Downstream Sampling
Is the facility sampling performed as required by the permit (frequency, sampling type, anc
sampling location)?
Comment:
Yes No NA NE
• ❑ ❑ ❑
Page# 4

Permit: NC0044440
Inspection Date: 07/15/2020
Owner - Facility: Cherryville VVVVTP
Inspection Type: Compliance Evaluation
Operations & Maintenance
Is the plant generally clean with acceptable housekeeping?
Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable
Solids, pH, DO, Sludge Judge, and other that are applicable?
Yes No NA NE
• ❑ ❑ ❑
• ❑ ❑ ❑
Comment: The facility appeared to be properly operated and well maintained. The ORC and staff
incorporate a comprehensive process control program with all measurements being
properly documented and maintained on -site. The facility is equipped with a computer
monitoring system to assist the wastewater staff in the operation/tracking of treatment
equipment/processes.
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
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•
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Comment: A new mechanical bar screen was installed since the past inspection. The new bar screen
has greatly reduced the debris observed in the downstream treatment units.
Grit Removal
Type of grit removal
a.Manual
b.Mechanical
Is the grit free of excessive organic matter?
Is the grit free of excessive odor?
# Is disposal of grit in compliance?
Comment: Screenings and grit are disposed at the County Landfill
Pump Station - Influent
Is the pump wet well free of bypass lines or structures?
Is the wet well free of excessive grease?
Are all pumps present?
Are all pumps operable?
Are float controls operable?
Is SCADAtelemetry available and operational?
Yes No NA NE
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Yes No NA NE
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Page# 5

Permit: NC0044440
Inspection Date: 07/15/2020
Owner - Facility: Cherryville VVVVTP
Inspection Type: Compliance Evaluation
Pump Station - Influent Yes No NA NE
Is audible and visual alarm available and operational?
❑ ❑ ❑ •
Comment: The influent pump station has the capability of diverting influent flows (via gravity line) to an
equalization basin (lagoon) during high flow events/emergency conditions.
Oxidation Ditches
Are the aerators operational?
Are the aerators free of excessive solids build up?
# 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?
Are settleometer results acceptable (> 30 minutes)?
Is the DO level acceptable?(1.0 to 3.0 mg/I)
Are settelometer results acceptable?(400 to 800 ml/I in 30 minutes)
Yes No NA NE
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• ❑ ❑ ❑
❑ ❑ ❑ •
❑ ❑ ❑ •
❑ ❑ ❑ •
❑ ❑ ❑ •
Comment: The facility is equipped with dual oxidation ditches; however, only one train was in service
due to low influent flows. Sodium hydroxide is added on an as -needed basis to maintain
appropriate alkalinity/pH levels. Excessive vegetation was observed at the middle of the
active oxidation ditch. Facility staff should preform cleanup of the vegetation.
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'/4 of the sidewall depth)
Yes No NA NE
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Comment: The facility is equipped with two secondary clarifiers; however, only one clarifier was in
service due to the low flow.
Pumps-RAS-WAS
Are pumps in place?
•
Yes No NA NE
❑ ❑ ❑
Page# 6

Permit: NC0044440
Inspection Date: 07/15/2020
Owner - Facility: Cherryville VVVVTP
Inspection Type: Compliance Evaluation
Pumps-RAS-WAS
Are pumps operational?
Are there adequate spare parts and supplies on site?
Comment:
Yes No NA NE
• ❑ ❑ ❑
• ❑ ❑ ❑
Disinfection -Gas Yes No NA NE
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: The chlorination/dechlorination systems are serviced annually by a contracted company .
De -chlorination
Type of system ?
Is the feed ratio proportional to chlorine amount (1 to 1)?
Is storage appropriate for cylinders?
# Is de -chlorination substance stored away from chlorine containers?
Comment:
Are the tablets the proper size and type?
Are tablet de -chlorinators operational?
Number of tubes in use?
Comment:
Flow Measurement - Effluent
# Is flow meter used for reporting?
Is flow meter calibrated annually?
Is the flow meter operational?
(If units are separated) Does the chart recorder match the flow meter?
Yes No NA NE
Gas
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❑ ❑ ■ ❑
• ❑ • ❑
Yes No NA NE
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❑ ❑ ❑ •
Page# 7

Permit: NC0044440
Inspection Date: 07/15/2020
Owner - Facility: Cherryville VVVVTP
Inspection Type: Compliance Evaluation
Flow Measurement - Effluent Yes No NA NE
Comment: The flow meter is calibrated annually.
Effluent Pipe
Is right of way to the outfall properly maintained?
Are the receiving water free of foam other than trace amounts and other debris?
If effluent (diffuser pipes are required) are they operating properly?
Comment:
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?
Yes No NA NE
❑ ❑ ❑ •
❑ ❑ ❑ •
❑ ❑ ❑ •
Yes No NA NE
• ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
Comment: Aerobically digested biosolids are land applied by a contracted company (Synacro) under
the authority of Permit No. WQ0000430.
Lagoons
Type of lagoons?
# Number of lagoons in operation at time of visit?
Are lagoons operated in?
# Is a re -circulation line present?
Is lagoon free of excessive floating materials?
# Are baffles between ponds or effluent baffles adjustable?
Are dike slopes clear of woody vegetation?
Are weeds controlled around the edge of the lagoon?
Are dikes free of seepage?
Are dikes free of erosion?
Are dikes free of burrowing animals?
# Has the sludge blanket in the lagoon (s) been measured periodically in multiple
locations?
# If excessive algae is present, has barley straw been used to help control the growth?
Is the lagoon surface free of weeds?
Is the lagoon free of short circuiting?
Yes No NA NE
❑ ❑ • ❑
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Page# 8

Permit: NC0044440
Inspection Date: 07/15/2020
Owner - Facility: Cherryville VVVVTP
Inspection Type: Compliance Evaluation
Lagoons Yes No NA NE
Comment:
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
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• ❑ ❑ •
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Comment: The standby qenerator is tested under load (quarterly basis) and periodically serviced by a
contracted company
Page# 9

City of Chenyville
WASTEWATER TREATMENT PLANT
116 South Mountain Street
Cherryville, North Carolina 26021
Phone: [phone]
www.cityofcherryville.com
The Cherryville Wastewater Treatment Plant was first opened in 1981.
It is designed to treat two million gallon a day plant or 2.0 MGD.
Since losing our industry back in June 2001, we are only running half the plant.
Our daily average flows are: Influent 0.981 MGD Effluent 0.572 MGD
Our Influent Flow comes into the Influent Bar Screen and Grit Removal then is pumped over to the
treatment plant. The flow comes into the Influent splitter box then into the oxidation ditch. From there
it goes into the secondary clarifiers. The sludge is then pumped through the RAS building. The clear
effluent is then treated with Chlorine Gas at the Chlorine contact chamber. Then Sulfur Dioxide gas is
used to remove the Chlorine. Then the effluent goes down the final process of Aeration steps before
leaving the plant. The influent Samples are taken at the Influent Pump Station. And the Effluent Samples
are taken at the bottom of the aeration steps at the Effluent before being discharged into Indian Creek.
Our upstream sample location is below the darn at the water plant. The downstream sample location is
located downstream at the Bridge on Bud Black Rd.
Our biosoilds are sent to the aeration sludge holding tank and then emptied into our sludge lagoon. We
contract with Synagro for our biosolid land application program. Our sludge is land applied to local
farmers one time per year.
The address of the Wastewater Plant is 736 Tot Dellinger Rd. Cherryville, NC 28021
Phone number 704-435-1739
Larry Wright
Plant Superintendent/ORC
[e-mail]
704-214-1162 — cell
704-308-3552 — office
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2019 2020
Influent Effluent ., Influent Effluent
January 32.37 27.43
February 32.65 26.66
March 22.97 28.1
April 29.35 23.05
May 26.77 18.38
June 26.97 16.79
July 24.24 13.79
August 23.23 12.65
September 25.1 11.84
October 26.06 13.97
November 26.62 15.53
December 33.81 20.51
34.45 14.73
35.63 14.04
25.78 16
31.52 19.31
27.73 19.19
22.62 15.67
26.58 14.05
28.92 16.5
28.46 16.89
31.66 19.88
30.25 21.13
34.32 21.24
Total 330.14 228.7 357. ,20088,E
Daily Average 0.904 0.627 '0.981 0.572