NC0043532_Fact Sheet_20231016

Fact Sheet
NPDES Permit No. NCOO43532
Permit Writer/Email Contact: Nick Coco, [e-mail]
Date: 10/6/2023
Division/Branch: NC Division of Water Resources/NPDES Municipal Permitting
Fact Sheet Template: Version 09Jan2017
Permitting Action:
❑ Renewal
© Renewal with Expansion
❑ New Discharge
❑ Modification (Fact Sheet should be tailored to mod request)
Note: A complete application should include the following:
• For New Dischargers, EPA Form 2A or 2D requirements, Engineering Alternatives Analysis, Fee
• For Existing Dischargers (POTW), EPA Form 2A, 3 effluent pollutant scans, 4 2nd species WET
tests.
• For Existing Dischargers (Non-POTW), EPA Form 2C with correct analytical requirements based
on industry category.
Complete applicable sections below. If not applicable, enter NA.
1. Basic Facility Information
Facility Information
Applicant/Facility Name:
Stanly County Utilities/West Stanly Wastewater Treatment Plant (WWTP)
Applicant Address:
1000 N. lst Street, Suite 12, Albemarle, NC 28001
Facility Address:
24939-B Barbees Grove Road (NCSR 1953), Oakboro, NC 28129
Permitted Flow:
1.2 MGD with proposed expansion to 2.5 MGD
Facility Type/Waste:
MAJOR Municipal; 89.2% domestic, 10.8% industrial*
Facility Class:
Grade III Biological Water Pollution Control System at both flow tiers
Treatment Units:
Influent pump station with bar screen, grit removal, flow measurement,
Influent flow splitter box, Influent composite sampler, Two aeration basins
with mechanical aerators, Clarifier splitter box, Two secondary clarifiers,
RAS/WAS pump station, Chlorine contact basin with dechlorination unit,
Effluent composite sampler, Effluent pump station, aerobic digester
Pretreatment Program (Y/N)
Y
County:
Stanly
Region
Mooresville
*Based on permitted flows.
Briefly describe the proposed permitting action and facility background: Stanly County Utilities applied
on July 7, 2023 for an NPDES permit renewal at 1.2 MGD for the West Stanly WWTP, with a request for
a proposed expansion tier at 2.5 MGD. The newly proposed 2.5 MGD expansion project is receiving
funding via US Department of Agriculture Rural Development (USDA-RD) and the American Rescue
Plan Act (ARPA). An Engineering Alternatives Analysis was submitted with the application. Flow
projections and engineering alternatives are discussed in detail below in Antidegradation Review.
This facility serves a population of approximately 6,100 residents across the towns of Locust, Oakboro,
Red Cross and Stanfield, as well as 1 categorical significant industrial user (CIU), Charlotte Pipe and
Foundry Company — 40 CFR 464.36 (Ferrous Casting) and 433.17 (Metal Finishing), via an approved
Page 1 of 17

pretreatment program. Charlotte Pipe and Foundry has not yet commenced discharge to the West Stanly
WWTP. Treated domestic and industrial wastewater is discharged via Outfall 002 into the Rocky River, a
Class C waterbody in the Yadkin -Pee Dee River Basin. Outfall 002 is located approximately 1.8 miles
away from the West Stanly WWTP. However, due to use of chlorination for disinfection, bacterial
regrowth along the long outfall line is not considered an issue. Outfall 002 is located approximately 20
miles upstream of the waters designated as WS-V, B.
Special Order By Consent (SOC) History: Stanly County Utilities was issued Environment Management
Commission (EMC) SOC WQ 519-003 on March 6, 2020 to set required steps toward compliance with
Total Suspended Solids (TSS) and fecal coliform permit requirements. Under the SOC, interim limits for
TSS of 45.0 mg/L (monthly average) and 70.0 mg/L (weekly average) and for fecal coliform of
400/100mL (monthly geomean) and 600/100mL (weekly geomean) were set at both Outfall 001 and 002.
On 12/22/2021, the SOC was amended to extend the construction timeline from 365 days to 525 days
following the beginning of construction. The SOC expired on January 31, 2023.
Expansion History: The Final Engineer's certification for completion of expansion of the West Stanly
WWTP from 0.9 MGD to 1.2 MGD was received by the Division on March 31, 2022. Expansion of the
facility results in the removal of the 0.9 MGD flow tier effluent limitation page as well as the removal of
emergency Outfall 001, which was an emergency gravity overflow outfall from the effluent pump station
to Long Creek. Outfall 001 is no longer considered as an active discharge location with the expansion of
the West Stanly WWTP to 1.2 MGD.
Inflow and Infiltration (I/I): In their application, Stanly County Utilities indicated an approximate average
daily volume of I/I experienced at the treatment works of 297,000 gallons per day (gpd). Stanly County
Utilities also noted that the City of Locust and the Town of Stanfield are billed at 100% of flow including
1/I, which financially leverages them to reduce their 1/1. Stanly County owns and maintains the Red Cross
sewer system and thus is responsible for reducing their 1/1. Frequent manhole inspections are made during
rain events; cleaning, televising, and smoke testing of sewer system are also performed. Repairs are
performed as I/1 is found. As part of the 2.5-MGD expansion, high flows will be equalized with an
equalization (EQ) tank.
Sludge disposal: Currently sludge is removed from the treatment process hauled off -site by a licensed
contractor, SynaGro, for land application.
2. Receiving Waterbody Information:
Receiving Waterbody Information
Outfalls/Receiving Stream(s):
Outfall 002 — Rocky River
Stream Segment:
13-17
Stream Classification:
C
Drainage Area (mi2):
965
Summer 7Q 10 (cfs)
29
Winter 7Q 10 (cfs):
51
30Q2 (cfs):
-
Average Flow (cfs):
920
IWC (% effluent):
6.0% at 1.2 MGD; 11.8% at proposed 2.5 MGD
2022 303(d) listed/parameter:
Yes; Listed as impaired for turbidity, copper and zinc and
data inconclusive for fecal coliform
Subject to TMDL/parameter:
Yes- State wide Mercury TMDL implementation
Basin/HUC:
Yadkin -Pee Dee River/03040105
USGS Topo Quad:
G17NE
Page 2 of 17

3. Effluent Data Summary
Effluent data for Outfall 002 is summarized below for the period of January 2019 through June 2023.
Table 1. Effluent Data Summary Outfall 002
Parameter
Units
Average
Max
Min
Permit Limit
Flow
MGD
0.61
2.871
0.01
MA 1.2
WA 15.0
BOD
mg/1
9.6
221
1.2
MA 10.0
WA 12.0
NH3N
mg/1
4.5
41
0.1
MA 4.0
WA 45.0
TSS*
mg/1
10.5
380
0.2
MA 30.0
6.0>pH<9.0
pH
SU
6.8
8.6
6
(geometric)
Fecal coliform*
#/100 ml
(geomean)
> 6000
< 1
WA 400
18.9
MA 200
DO
mg/1
8.5
12.78
5.25
DA > 6.0
Monitor &Report
Temperature
° C
18.1
27.4
7.6
TRC
ug/1
24.3
50
1
DM 28
Monitor &
TN
mg/1
10.3
41
0.92
Report
Monitor &
TP
mg/1
2.0
6.1
0.14
Report
Monitor &
Total Copper
ug/1
6.4
17
< 5
Report
Monitor &
Total Zinc
ug/1
39.8
82
14
Report
Monitor &
Total Hardness
mg/1
63
76
49.4
Report
MA -Monthly Average, WA -Weekly Average, DM -Daily Maximum, DA=Daily Average
*Interim SOC limits for TSS of 45.0 mg/L (monthly average) and 70.0 mg/L (weekly average) and for
fecal coliform of 400/100mL (monthly geomean) and 600/100mL (weekly geomean) were active until
1 /31 /2023.
The average annual flows experienced at the West Stanly WWTP are summarized in Table 2, shown
below.
Table 2. Average Effluent Flows
Year
Average Annual Flow
[MGD
Percent of Capacity [%]
2019
0.59
49
2020
0.67
56
2021
0.61
51
2022
0.55
46
2023
0.67 (year to date)
56
Page 3 of 17

4. Instream Data Summary
Instream monitoring may be required in certain situations, for example: 1) to verify model predictions
when model results for instream DO are within 1 mg/1 of instream standard at full permitted flow; 2) to
verify model predictions for outfall diffuser; 3) to provide data for future TMDL; 4) based on other
instream concerns. Instream monitoring may be conducted by the Permittee, and there are also
Monitoring Coalitions established in several basins that conduct instream sampling for the Permittee (in
which case instream monitoring is waived in the permit as long as coalition membership is maintained).
Is this facility a member of a Monitoring Coalition with waived instream monitoring (YIN): YES
Name of Monitoring Coalition: Yadkin -Pee Dee River Basin Association
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, temperature and
fecal coliform upstream at least 100 feet above the discharge point and downstream 1.7 miles below the
discharge point near the end of NCSR 1659 (Cornett Road). As the permittee is a member of the Yadkin -
Pee Dee River Basin Association (YPDRBA) instream monitoring requirements are provisionally waived.
The nearest upstream YPDRBA monitoring station is Q8480000, located approximately 7.4 mile
upstream of the outfall. No nearby YPDRBA monitoring station exists downstream of the discharge. The
Division's Ambient Monitoring System (AMS) has an active monitoring station Q9120000, located
approximately 10 miles downstream of the outfall. Due to the distance from outfall for each monitoring
station and the existence of numerous confluences between the outfall and instream stations, a statistical
analysis was not conducted. Instead, each station's data were used to assess compliance with stream
standards. Instream data have been summarized below in Table 3. ,
Table 3. Instream Monitoring Data Summary
Parameter
Units
Q8480000
(1/2018-12/2022)
Q9120000
(1/2018 - 3/2020)
Average
Max
Min
Average
Max
Min
Temperature
° C
20.4
32
4.3
18.7
31.9
5.7
DO
mg/1
8.7
14.2
5.9
9.95
15.6
6.8
Fecal Coliform
#/100mL
(geomean)
351
8200
38
(geomean)
244
3200
28
Turbidity
NTU
63
450
3.1
37
200
3.4
TKN
mg/1
1.1
3.49
0.41
0.8
1.6
0.51
NO2+NO3
mg/1
3.7
12.42
0.66
3.1
8.4
1.1
TP
mg/1
0.5
1.29
0.14
0.4
0.98
0.14
pH
s.u.
7.7
9
6.2
7.8
8.7
1 7.3
Conductivity
umhos/cm
224
487
83
208
423
80
TSS
mg/1
-
-
-
73.1
213
6.8
Upstream and downstream temperatures were not observed at levels greater than 32 degrees Celsius [per
15A NCAC 02B .0211 (18)] during the period reviewed.
Upstream and downstream DO did not drop below 5 mg/L [per 15A NCAC 02B .0211 (6)] during the
period reviewed.
Of the 58 samples collected from January 2018 through December 2022 at upstream station Q8480000,
fecal coliform was detected at levels greater than 200/100mL on 32 occasions and greater than
400/100mL on 25 occasions. Of the 26 samples collected from January 2018 through March 2020 at
Page 4 of 17

downstream station Q9120000, fecal coliform was detected at levels greater than 200/100mL on 14
occasions and greater than 400/100mL on 6 occasions.
Turbidity was observed at levels greater than 50 NTUs [15A NCAC 02B .0211 (21)] at both monitoring
stations during the period reviewed. Downstream turbidity was generally observed at levels less than
upstream turbidity.
pH was observed at levels within the range of 6.0 to 9.0 significant units [ 15A NCAC 02B .0211 (14)] at
both monitoring stations during the period reviewed.
As the receiving stream is listed as impaired for turbidity, dissolved copper and dissolved zinc and
inconclusive for fecal coliform in the 2022 303d list, instream monitoring for turbidity, fecal coliform,
dissolved copper and dissolved zinc has been added.
Based on discussions with the Division's Basin Planning Branch, instream monitoring for TP, TKN,
NO2+NO3, ammonia and pH have been added to the permit at a monthly frequency.
Due to the distance from Outfall 002 for both the YPDRBA station Q8480000 and AMS station
Q9120000 and the confluences with multiple interconnected streams in between, determination of
influence from the West Stanly WWTP outfall is difficult. The instream sampling locations may not be
representative of the discharge impact. As such, it is recommended that YPDRBA relocated their
monitoring station to the location of the inactive AMS station Q8510000, which exists approximately 2.2
miles above the outfall, and add a downstream monitoring station at the location of the inactive AMS
station Q8740000, which exists approximately 3 miles downstream of the outfall and is above the
confluence with Richardson Creek. The relocation and addition of the aforementioned YPDRBA stations
will provide more representative data to determine whether the West Stanly WWTP is influencing the
receiving stream. The recommended monitoring locations have been identified below in Figure 1.
ti / s
��/ 01-5-11-e� Stanly Se.hns:. .��,
Oakboif, West Stanly Outfall 002
WWTP
138
i
Inactive AMS
49R
fl Q8510000
Inactive AMS
08740000
YPDRBA
Q8480000
AMS Q9120000
Figure 1. Monitoring Station and Effluent Locations
Page 5 of 17

As the facility is pursuing expansion that would over double its capacity, tracking downstream impact is
critical. As such, the provisional waiver for instream monitoring has been revised and is only applicable if
the YPDRBA relocates station Q8480000 to a location closer to the West Stanly WWTP discharge and
activates a representative downstream station for sample collection. Instream sampling is to be conducted
by Stanly County in the event that YPDRBA does not accomplish the revisions for conducting sampling
that is representative of this facility's discharge.
5. Compliance Summary
Summarize the compliance record with permit effluent limits (past 5 years): The facility reported 6 fecal
coliform limit exceedances and 2 flow limit exceedances resulting in enforcement in 2018. In 2019, the
facility reported 7 TSS limit exceedances, 7 fecal coliform limit exceedances and 10 BOD limit
exceedances resulting in enforcement. The facility reported 2 TSS limit exceedances, 3 fecal coliform
limit exceedances, 15 ammonia limit exceedances, 2 flow limit exceedances and 5 BOD limit
exceedances resulting in enforcement in 2020. In 2021, the facility reported 1 TSS limit exceedance, 21
ammonia limit exceedances, 2 flow limit exceedances and 9 BOD limit exceedances resulting in
enforcement. The facility reported 2 BOD limit exceedances resulting in enforcement in 2022. In 2023,
the facility reported 3 ammonia limit exceedances and 3 BOD limit exceedances resulting in enforcement.
Summarize the compliance record with aquatic toxicity test limits and any second species test results
(past S years): The facility passed 18 of 18 quarterly chronic toxicity tests, as well as all 4 second species
chronic toxicity tests conducted from January 2019 to April 2023.
Summarize the results from the most recent compliance inspection: The last facility inspection conducted
in August 2022 reported that the facility was compliant. During the inspection, the Mooresville Regional
Office did note a buildup of solids on the influent bar screen and instructed the operator to check the wash
cycle of the influent screen to ensure proper cleaning.
6. Water Quality -Based Effluent Limitations (WQBELs)
The Division provided speculative limits for the 2.5 MGD expanded flow tier on January 27, 2020. These
limits, shown below, are proposed to be implemented in the permit.
Table 4. Speculative Limits for 2.5 MGD Expansion Tier
Effluent Chavaoteristic
Effluent Limitations
WFIthly
Average
weeklv
Average
Daily
Maximum
2.5 MGD
BOD{
5.0 Tn T L
7.5 mgfL
NH3 a 1
9.8rnT
5.4m
Nssolvod Oxygen
5,0 in L Daily Minimum Average
TSS
30.0 rr g/L
45.0 m L
28 ; V1
_ _
Ti3C
_
Fecal coliformn (gonrn trio 200/100 MI
m carp)
40(110fl nil
Chronic Toxicity, PassJFail
(Quarterly test
4.6°/Q
1. Subject to change. Updated flows will be determined upon receipt of application for expansion.
Page 6 of 17

The percent effluent at which chronic toxicity testing shall be conducted as identified in the January 27,
2020 letter has not been adopted. More information regarding the 2.5 MGD expanded flow tier chronic
toxicity testing requirement may be found below in Toxicity Testing Requirements.
The current permit sets a dissolved oxygen (DO) requirement of a daily average greater than or equal to
6.0 mg/L at the 1.2 MGD flow tier. The speculative DO limit identified in the January 27, 2020 letter
indicates a daily average greater than or equal to 5.0 mg/L. As the requirement is less restrictive at a
higher flow, the DO limit identified in the January 27, 2020 letter has not been adopted and the DO
requirements set for the 1.2 MGD flow tier have been applied to the expansion 2.5 MGD flow tier. The
DO limit has been set as a daily average greater than or equal to 6.0 mg/L at the 2.5 MGD flow tier.
Dilution and Mixing Zones
In accordance with 15A NCAC 213.0206, the following streamflows are used for dilution considerations
for development of WQBELs: 1Q10 streamflow (acute Aquatic Life); 7Q10 streamflow (chronic Aquatic
Life; non -carcinogen HH); 30Q2 streamflow (aesthetics); annual average flow (carcinogen, HH).
If applicable, describe any other dilution factors considered (e.g., based on CORMIX model results): NA
If applicable, describe any mixing zones established in accordance with 15A NCAC 2B.0204(b): NA
Oxygen -Consuming Waste Limitations
Limitations for oxygen -consuming waste (e.g., BOD) are generally based on water quality modeling to
ensure protection of the instream dissolved oxygen (DO) water quality standard. Secondary TBEL limits
(e.g., BOD= 30 mg/1 for Municipals) may be appropriate if deemed more stringent based on dilution and
model results.
Ifpermit limits are more stringent than TBELs, describe how limits were developed: The current permit
limitations for BOD and ammonia at the 1.2 MGD flow tier are based on a 2005 QUAL2E model
prepared for Rocky River and Mallard Creek applying 1.2 MGD discharge from the West Stanly WWTP.
No changes are proposed for the 1.2 MGD flow tier BOD limits.
Proposed BOD and ammonia permit limitations for the 2.5 MGD flow tier are based on freezing current
permitted BOD ultimate loading (i.e., facility will not be allowed to discharge oxygen -consuming waste
above what is currently permitted). Requests for seasonal limits in accordance with 15A NCAC 02B
.0404 will need to be supported by a QUAL2K or equivalent water quality model. The resultant limits at
expanded flows are considered technologically -feasible.
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 NC water quality standard for protection
of aquatic life (17 ug/1) and capped at 28 ug/l (acute impacts). Due to analytical issues, all TRC values
reported below 50 ug/l are considered compliant with their permit limit.
Describe any proposed changes to ammonia and/or TRC limits for this permit renewal: The current TRC
limit was reviewed in the attached wasteload allocation. The limit of 28 µg/l is found to be protective, and
there are no proposed changes. TRC limits at 2.5 MGD have been assessed in the attached wasteload
allocation and the limit of 28 µg/1 has been added at 2.5 MGD.
Page 7 of 17

Please see Oxygen -Consuming Waste Limitations for information regarding ammonia limitations.
Ammonia limits have been reviewed in the attached WLA based on Instream Waste Concentration -based
calculations for ammonia toxicity and have been found to be protective.
Reasonable Potential AnalysisRPA) for Toxicants
If applicable, conduct RPA analysis and complete information below.
The need for toxicant limits is based upon a demonstration of reasonable potential to exceed water quality
standards, a statistical evaluation that is conducted during every permit renewal utilizing the most recent
effluent data for each outfall. The RPA is conducted in accordance with 40 CFR 122.44 (d) (i). The NC
RPA procedure utilizes the following: 1) 95% Confidence Level/95% Probability; 2) assumption of zero
background; 3) use of 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. Effluent and upstream hardness data provided
by the County from January 2019 to April 2023 were used in RPA calculations for hardness -dependent
metals.
A reasonable potential analysis was conducted on effluent toxicant data collected between June 2018 and
January 2023. Pollutants of concern included toxicants with positive detections and associated water
quality standards/criteria. Based on this analysis, the following permitting actions are proposed for this
permit:
• Effluent Limit with Monitoring. The following parameters will receive a water quality -based
effluent limit (WQBEL) since they demonstrated a reasonable potential to exceed applicable
water quality standards/criteria: None
• Monitoring Only. The following parameters will receive a monitor -only requirement since they
did not demonstrate reasonable potential to exceed applicable water quality standards/criteria,
but the maximum predicted concentration was >50% of the allowable concentration: None
• No Limit or Monitoring: The following parameters will not receive a limit or monitoring, since
they did not demonstrate reasonable potential to exceed applicable water quality
standards/criteria and the maximum predicted concentration was <50% of the allowable
concentration: Total Copper, Total Zinc (See note below)
• POTW Effluent Pollutant Scan Review: Three effluent pollutant scans (Three conducted in 2022
— after expansion to 1.2 MGD per permit requirement) 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: Total Cyanide (monitor and report at 1.2 MGD; limit and
monitoring for 2.5 MGD)
o The following parameter(s) will receive a monitor -only requirement, since as part of a
limited data set, one sample exceeded the allowable discharge concentration: None
o The following parameters will not receive a limit or monitoring, since they did not
demonstrate reasonable potential to exceed applicable water quality standards/criteria and
the maximum predicted concentration was <50% of the allowable concentration: Total
Arsenic, Total Beryllium, Total Cadmium, Total Phenolic Compounds, Total Chromium,
Total Lead, Total Nickel, Total Selenium, Total Silver
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.
Stanly County reported Total Cadmium 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. The County's allowable discharge
Page 8 of 17

concentration for Total Silver at 1.2 MGD is 1.0 µg/L. The County's allowable discharge concentrations
at 2.5 MGD are 8.7 µg/L and 0.5 µg/L for Total Cadmium and Total Silver, respectively. DWR's
laboratory identifies the target Practical Quantification Limits (PQLs) for Total Cadmium and Total
Silver as 0.5 µg/L, and 1.0 µg/L, respectively. 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 County should use sufficiently sensitive test methods for all pollutants, including when
performing Effluent Pollutant Scans.
Note on total copper and total zinc: While no reasonable potential for excursions above their respective
surface water quality standards was observed, quarterly monitoring for total copper and total zinc has
been maintained in the permit due to the receiving stream's impairment for both parameters. Additionally,
copper and zinc are parameters associated with Charlotte Pipe and Foundry Company, which will be
sending its wastewater to the West Stanly WWTP in the future.
Toxicity Testing Limitations
Permit limits and monitoring requirements for Whole Effluent Toxicity (WET) have been established in
accordance with Division guidance (per WET Memo, 8/2/1999). Per WET guidance, all NPDES permits
issued to Major facilities or any facility discharging "complex" wastewater (contains anything other than
domestic waste) will contain appropriate WET limits and monitoring requirements, with several
exceptions. The State has received prior EPA approval to use an Alternative WET Test Procedure in
NPDES permits, using single concentration screening tests, with multiple dilution follow-up upon a test
failure.
Describe proposed toxicity test requirement: This is a Major POTW, chronic WET testing will continue
on a quarterly frequency. At the existing 1.2 MGD flow tier, chronic WET testing is conducted at 6.0%.
No changes are proposed to the WET testing requirements at the 1.2 MGD flow tier.
The 2020 speculative limits provided for the proposed expansion to 2.5 MGD noted chronic WET testing
should be conducted quarterly at 4.6%. However, based on the summer 7Q10 of 29 cubic feet per second
and the proposed 2.5 MGD discharge, the percent effluent appropriate for the expanded 2.5 MGD flow in
the receiving stream is 11.8% effluent. As such, quarterly chronic WET testing shall be conducted at
11.8% effluent upon expansion to the 2.5 MGD flow tier. Chronic toxicity testing shall be conducted
during the months of January, April, July and October for both flow tiers.
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
Page 9 of 17

Table 5. Mercury Effluent Data Summary
2022
# of Samples
3
Annual Average Conc. n /L
1.1
Maximum Conc., n /L
2.27
TBEL, n /L
47
WQBEL, n
199.1 1.2 MGD & 101.81 g 2.5 MGD
Describe proposed permit actions based on mercury evaluation: Since no annual average mercury
concentration exceeded the WQBEL, and no individual mercury sample exceeded the TBEL, no mercury
limit is required. Since the facility is < 2.0 MGD, no mercury minimization plan (MMP) condition is
required. While the expanded flow tier is above 2.0 MGD, the facility reported only one detection with
quantifiable levels of mercury (> 1 ng/1). As such, no MMP condition has been added to the expanded
flow tier.
As Stanly County conducted sampling and submitted effluent low level mercury data from their effluent
pollutant scans, the requirements of Special Condition A.(6.) Effluent Mercury Analysis have been
satisfied and the condition has been removed from the permit.
Other TMDL/Nutrient Management Strategy Considerations
If applicable, describe any other TMDLs/Nutrient Management Strategies and their implementation
within this permit: N/A; This segment of the Yadkin -Pee Dee River that receives the discharge from
Outfall 002 is downstream from High Rock Lake, which is currently undergoing criteria development for
chlorophyll -a. While no nutrient modeling is in development currently, consideration of nutrient loading
may occur in future permit cycles.
Other WQBEL Considerations
If applicable, describe any other parameters of concern evaluated for WQBELs: As required by Session
Law 2018-5, Senate Bill 99, Section 13.1(r), every applicant shall submit documentation of any additional
pollutants for which there are certified methods with the permit application if their discharge is
anticipated via a Chemical Addendum to NPDES Application table. As an attachment to the permit
application, the County informed the Division that no monitoring for additional pollutants has been
conducted (see renewal application) and therefore no additional pollutants of concern have been
identified.
As the West Stanly WWTP discharges approximately 20 miles upstream of WS waters, monitoring of
HAS chemicals will be added to the permit at a frequency of quarterly. Since an EPA method for
sampling and analyzing PFAS in wastewater is not currently available, the PFAS sampling requirement in
the Permit includes a compliance schedule which delays the effective date of this requirement until the
first full calendar quarter beginning 6 months after EPA has a final wastewater method in 40 CFR 136
published in the Federal Register. This date may be extended upon request and if there are no NC -
certified labs.
As the West Stanly WWTP is set to receive industrial flow from a metal finisher, Charlotte Pipe, 1,4-
dioxane is a parameter of consideration. To further understand any contribution of 1,4-dioxane from this
facility, quarterly effluent monitoring has been added, to be effective upon commencement of discharge
from Charlotte Pipe to the West Stanly WWTP. After a 24-month sampling period, the Permittee may
request the Division conduct a review of submitted data for assessment and approval of a 1,4-dioxane
monitoring frequency reduction from quarterly to annually.
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
Page 10 of 17

If applicable, describe any compliance schedules proposed for this permit renewal in accordance with
15A NCAC 2K 0107(c)(2)(B), 40CFR 122.47, and EPA May 2007 Memo: NA
If applicable, describe any water quality standards variances proposed in accordance with NCGS 143-
215.3(e) and 15A NCAC 2B.0226 for this permit renewal: NA
7. Technology -Based Effluent Limitations (TBELs)
Municipals (if not applicable, delete and skip to Industrials)
Are concentration limits in thepermit at least as stringent as secondary treatment requirements (30 mg/l
BODS/TSSfor Monthly Average, and 45 mg/l for BODS/TSSfor 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; On occasion, it 85%
removal of BOD and TSS were not achieved during the period reviewed. However, overall BOD and TSS
removal rates were > 85%. The West Stanly WWTP was under SOC for TSS until January 31, 2023.
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: The proposed expansion is receiving funding via
US Department of Agriculture Rural Development (USDA-RD) and is subject to the National
Environmental Policy Act (NEPA). USDA Rural Utility Services completed an environmental assessment
and provided a Finding of No Significant Impact (FONSI) on December 9, 2022. A notice of the FONSI
was published in The Stanly News and Press on December 9, 2022, satisfying NEPA requirements. While
the proposed expansion is also receiving additional funding via the American Rescue Plan Act (ARPA),
the ARPA funding is not subject to review under the State Environmental Policy Act (SEPA).
An Engineer's Alternatives Analysis (EAA) was submitted by The Wooten Company (Wooten), the
consulting firm hired by Stanly County, on July 7, 2023. In their EAA, Wooten noted that Stanly County
has contractual agreements with four municipal systems for treatment of wastewater at the West Stanly
WWTP including Red Cross, Oakboro, Stanfield and Locust. While the West Stanly WWTP service area
includes these municipalities, the facility does not handle the entirety of the wastewater flow from the
towns. To estimate the population attributable to the West Stanly WWTP service area from each town,
Wooten provided a breakdown of the metered connections from the respective towns and incorporated the
US Census information from 2018 to identify the average number of persons per residence to calculate
population. Based on this assumption, Wooten estimated approximately 6,125 residents in the West
Stanly WWTP service area, which closely resembles the estimated population indicated in the renewal
application. Wooten then used US Census data to determine individual growth rates for Red Cross
(0.58%), Oakboro (1.30%), Stanfield (1.12%) and Locust (5.00%) from 2010 to 2020. Division staff used
NC Office of State Budget and Management (OSBM) to determine growth rates for the individual town
and used the resultant growth rates as a means of checking the population projections provided by
Wooten. The OSBM noted individual growth rates for Red Cross (0.33%), Oakboro (1.44%), Stanfield
(0.66%) and Locust (4.74%) from 2010 to 2020. Wooten also provided a letter from Charlotte Pipe, the
Page 11 of 17

CIU sending flow to the West Stanly WWTP, which requested an additional 0.5 MGD of flow due to
process expansion plans.
In addition to the growth rates identified for each municipality via the US Census data, Wooten
considered known, planned developments for the towns, and provided letters from developers expressing
their intent to build in the area. This incorporation of development mostly affected the population
projections for Oakboro and Locust. While Division staff believe that this skews the population high and
is not entirely representative, the overall flow projection calculation was similar average daily flow
projections (-2 MGD) at 2040. Division staff calculated the flow projection based on the existing 1.2
MGD flow tier, and the projected growth of service population, a flow rate of 70 gallons per person per
day, and a 15% reserve flow for potential industrial and commercial users. The Division concurs with the
proposal of a facility upgrade to 2.5 MGD.
The following alternatives were evaluated for the proposed discharee:
Alternative Description
20-year Net Present Worth (NPW)
Connection to an Existing WWTP
$142,130,000
Land Application
$138,700,000
Wastewater Reuse
Deemed infeasible
Surface Discharge NPDES
$65,300,000
Combination of Alternatives
$98,270,000
Connection to an Existing WWTP: The decommissioning of the West Stanly WWTP and pumping of
wastewater to the Long Creek WWTP was considered. This alternative would require a wastewater
service agreement between Stanly County and the City of Albemarle, the upgrade of the existing McCoy
Pump Station, the construction of approximately 9 miles of 24-inch sewer force main, and the
construction of an intermediate pump station. The total construction cost of connecting to the Long Creek
WWTP was estimated to be approximately $33.4 million. For estimating the annual operation and
maintenance cost for this alternative, Wooten assumed a cost of $5.34/1,000 gallons of wastewater as a
Sewer Treatment Charge by City of Albemarle. Based on this assumption, the annual operation and
maintenance cost for this alternative was reported as $6.65 million. The 20-year Net Present Worth
(NPW) was estimated as $142 million.
Land Application: The disposal of the entire 2.5 MGD of treated wastewater via land application was
considered. Near the WWTP site, approximately 200 acres of both cleared and forested land with suitable
soils is available for disposal of treated wastewater by land application using a spray irrigation system.
The estimated required land, based on an annual hydraulic loading rate of 19.41 ft/year, a capacity of 2.5
MGD and a 1.33 factor of safety for setbacks and access roads, was calculated to be 192 acres. The
required storage volume was calculated to be 75 million gallons, based on 30-days of storage at 2.5 MGD.
The total construction cost of upgrading the West Stanly WWTP to 2.5 MGD and constructing a spray
irrigation system was estimated to be approximately $93.4 million. The estimated annual operation and
maintenance cost for the expansion was estimated to be $2.8 million. The 20-year NPW for this
alternative was estimated to be $138.7 million.
Wastewater Reuse: Wastewater reuse was considered. The only reuse option available for the treated
effluent from the West Stanly WWTP is Charlotte Pipe and they currently use only 130,000 gallons per
day of reuse water. As no other customers are available, the option has been deemed infeasible.
Direct Discharge to Surface Waters: The total construction cost to expand the West Stanly WWTP to
2.5 MGD is $32.6 million. The estimated annual operation and maintenance cost for the expansion was
estimated to be $2 million. The 20-year NPW for this alternative was estimated to be $65.3 million.
Page 12 of 17

Combination of Direct Discharge to Surface Waters and Land Application: The disposal of just the
expanded 1.3 MGD flow of treated wastewater via land application was considered. The estimated
required land was calculated to be 99.8 acres. The required storage volume was calculated to be 39
million gallons, based on 30-days of storage at 1.3 MGD. The total construction cost of upgrading the
West Stanly WWTP to 2.5 MGD and constructing a spray irrigation system was estimated to be
approximately $54.4 million. The estimated annual operation and maintenance cost for the expansion was
estimated to be $2.7 million. The 20-year NPW for this alternative was estimated to be $98.3 million.
The most economically feasible and chosen option was the expansion of the West Stanly WWTP. The
Division has reviewed the alternatives and concurs with this decision.
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.
As the West Stanly WWTP is set to receive industrial flow, 3/week effluent conductivity monitoring has
been added to the permit, to be effective upon commencement of discharge from Charlotte Pipe to the
West Stanly WWTP.
For calculation of total nitrogen, monitoring and reporting of TKN and NO2+NO3 has been added to the
permit at a quarterly frequency to match the total nitrogen monitoring requirement.
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.
Page 13 of 17

12.Summary of Proposed Permitting Actions:
Table 6. Current Permit Conditions and Proposed Changes 1.2 MGD flow tier
Parameter
Current Permit
Proposed Change
Basis for Condition/Change
Flow
MA 1.2 MGD
No change
15A NCAC 2B .0505
BOD5
MA 10.0 mg/l
No change
WQBEL. 2005 QUAL2E model,
WA 15.0 mg/1
Surface Water Monitoring, 15A NCAC
Monitor and report 3/week
2B. 0500
NH3-N
MA 4.0 mg/l
No change
WQBEL. 2005 QUAL2E model,
WA 12.0 mg/1
Surface Water Monitoring, 15A NCAC
Monitor and report 3/week
2B. 0500
TSS
MA 30.0 mg/l
No change
TBEL. Secondary treatment
WA 45.0 mg/1
standards/40 CFR 133 / 15A NCAC 2B
Monitor and report 3/week
.0406; Surface Water Monitoring, 15A
NCAC 2B. 0500
Fecal coliform
MA 200 /100m1
No change
WQBEL. State WQ standard, 15A
WA 400 /100ml
NCAC 2B .0200; Surface Water
Monitor and report 3/week
Monitoring, 15A NCAC 2B. 0500
DO
> 6.0 mg/l
No change
WQBEL. 2005 QUAL2E model;
Monitor and report 3/week
Surface Water Monitoring, 15A NCAC
2B. 0500
pH
6 — 9 SU
No change
WQBEL. State WQ standard, 15A
Monitor and report 3/week
NCAC 2B .0200; Surface Water
Monitoring, 15A NCAC 2B. 0500
Conductivity
No requirement
Monitor and report
Surface Water Monitoring, 15A NCAC
3/week; effective upon
2B. 0500
commencement of
discharge of CIU
Temperature
Monitor and report Daily
No change
Surface Water Monitoring, 15A NCAC
2B. 0500
Total Residual
DM 28 ug/L
No change
WQBEL. 2023 WLA review and
Chlorine
Monitor and report 3/week
Surface Water Monitoring, 15A NCAC
2B. 0500
Total
Monitor and report
No change
Surface Water Monitoring, 15A NCAC
Nitrogen
quarterly
2B. 0500
TKN
No requirement
Monitor and report
For calculation of Total Nitrogen
quarterly
NO3+NO2
No requirement
Monitor and report
For calculation of Total Nitrogen
quarterly
Total
Monitor and report
No change
Surface Water Monitoring, 15A NCAC
Phosphorous
quarterly
2B. 0500
Total
Quarterly monitoring
No change
Hardness -dependent dissolved metals
Hardness
Upstream and in Effluent
water quality standards approved in
2016
Total Cyanide
No requirement
Monitor and Report
Based on results of RPA; RP for
Quarterly
Limited Dataset (n<8 samples) with < 2
values > Allowable Cw - apply
Quarterly Monitoring
Page 14 of 17

Total Copper
Monitor and Report
No change
Receiving stream is impaired for total
Quarterly
copper; Total copper is associated with
CIU
Total Zinc
Monitor and Report
No change
Receiving stream is impaired for total
Quarterly
zinc; Total zinc is associated with CIU
Monitor and Report
quarterly with
potential to reduce to
Based on pretreatment program; to
1,4-dioxane
No requirement
annual —effective
receive industrial flow from metal
upon commencement
finisher
of discharge of CIU;
Add reopener
condition
Add Quarterly
Evaluation of PFAS contribution: major
PFAS
No requirement
monitoring with
discharger above WS-V waters;
delayed
Implementation delayed until after EPA
im lementation
certified method becomes available.
Add monthly
monitoring for fecal
coliform, turbidity,
Monitor DO, conductivity
TKN, NO2+NO3, TP,
and temperature 3/Week
ammonia and pH; Add
Surface Water Monitoring, 15A NCAC
during June, July, August
quarterly monitoring
2B. 0500; Based on discussion with
and September and
for dissolved copper
basin planning branch; instream data
Instream
ek the remainder of
and dissolved zinc;
necessary for tracking impact of
monitoring
h
the e year; Provisional
Provisional waiver for
expanding facility; instream monitoring
waiver i
instream monitoring
waiver maintained if YPDRBA
monitoring due
ue tto o
further conditioned
activates a downstream station and
membership in YPDRBA
upon activation of
relocates existing upstream station
downstream station
and relocation of
upstream station by
YPDRBA
Toxicity Test
Chronic limit, 6.0%
No change
WQBEL. No toxics in toxic amounts.
effluent
15A NCAC 2B.0200 and 15A NCAC
213.0500
Effluent
Three times per permit
No change; conducted
40 CFR 122
Pollutant Scan
cycle
in 2025, 2026, 2027
Effluent
Special Condition A.(6.)
Remove requirement
Condition has been satisfied and is no
Mercury
Effluent Mercury Analysis
longer applicable.
sampling
Electronic
Electronic Reporting
No change
In accordance with EPA Electronic
Reporting
Special Condition
Reporting Rule 2015.
MGD — Million gallons per day, MA - Monthly Average, WA — Weekly Average, DM — Daily Max
Page 15 of 17

Table 7. Current Permit Conditions and Proposed Changes 2.5 MGD flow tier
Parameter
Proposed Change
Basis for Condition/Change
Flow
MA 2.5 MGD
15A NCAC 2B .0505
BOD5
MA 5.0 mg/1
WQBEL. 2005 QUAL2E model, Surface Water
WA 7.5 mg/1
Monitoring, 15A NCAC 2B. 0500
Monitor and report 3/week
NH3-N
MA 1.8 mg/1
WQBEL. 2005 QUAL2E model, Surface Water
WA 5.4 mg/1
Monitoring, 15A NCAC 2B. 0500
Monitor and report 3/week
TSS
MA 30.0 mg/1
TBEL. Secondary treatment standards/40 CFR 133 /
WA 45.0 mg/l
15A NCAC 2B .0406; Surface Water Monitoring, 15A
Monitor and report 3/week
NCAC 2B. 0500
Fecal coliform
MA 200 /100m1
WQBEL. State WQ standard, 15A NCAC 2B .0200;
WA 400 /100m1
Surface Water Monitoring, 15A NCAC 2B. 0500
Monitor and report 3/week
DO
> 6.0 mg/1
WQBEL. 2005 QUAL2E model; Surface Water
Monitor and report 3/week
Monitoring, 15A NCAC 2B. 0500
pH
6 — 9 SU
WQBEL. State WQ standard, 15A NCAC 2B .0200;
Monitor and report 3/week
Surface Water Monitoring, 15A NCAC 2B. 0500
Conductivity
Monitor and report 3/week;
Surface Water Monitoring, 15A NCAC 2B. 0500
effective upon commencement
of discharge of CIU
Temperature
Monitor and report Daily
Surface Water Monitoring, 15A NCAC 2B. 0500
Total Residual
DM 28 ug/L
WQBEL. 2023 WLA review and Surface Water
Chlorine
Monitor and report 3/week
Monitoring, 15A NCAC 2B. 0500
Total Nitrogen
Monitor and report quarterly No
Surface Water Monitoring, 15A NCAC 2B. 0500
change
TKN
Monitor and report quarterly
For calculation of Total Nitrogen
NO3+NO2
Monitor and report quarterly
For calculation of Total Nitrogen
Total Phosphorous
Monitor and report quarterly
Surface Water Monitoring, 15A NCAC 2B. 0500
Total Hardness
Quarterly monitoring Upstream
Hardness -dependent dissolved metals water quality
and in Effluent
standards approved in 2016
Total Cyanide
MA 42.4 µg/L
WQBEL. Based on results of RPA; RP for Limited
DM 157.6 µg/L
Dataset (n<8) but 2 values > Allowable Cw - apply
Monitor and Report Monthly
Monthly Monitoring with Limit
Total Copper
Monitor and Report Quarterly
Receiving stream is impaired for total copper; Total
copper is associated with CIU
Total Zinc
Monitor and Report Quarterly
Receiving stream is impaired for total zinc; Total zinc
is associated with CIU
1,4-dioxane
Monitor and Report quarterly
Based on pretreatment program; to receive industrial
with potential to reduce to
flow from metal finisher
annual — effective upon
commencement of discharge of
CIU; Add reopener condition
Add Quarterly monitoring with
Evaluation ofPFAS contribution: major discharger
PFAS
delayed implementation
above WS-V waters; Implementation delayed until
after EPA certified method becomes available.
Page 16 of 17

Monitor DO, conductivity and
temperature 3/Week during
June, July, August and
September and 1/Week the
remainder of the year; Monthly
monitoring for fecal coliform,
Surface Water Monitoring, 15A NCAC 2B. 0500;
turbidity, TKN, NO2+NO3, TP,
Based on discussion with basin planning branch;
Instream
ammonia and pH; Quarterly
instream data necessary for tracking impact of
monitoring
monitoring for dissolved copper
expanding facility; instream monitoring waiver
and dissolved zinc; Provisional
maintained if YPDRBA activates a downstream
waiver of instream monitoring
station and relocates existing upstream station
due to membership in YPDRBA
- waiver further conditioned
upon activation of downstream
station and relocation of
upstream station by YPDRBA
Toxicity Test
Chronic limit, 11.8% effluent
WQBEL. No toxics in toxic amounts. 15A NCAC 213
.0200 and 15A NCAC 2B .0500
Effluent Pollutant
Three times per permit cycle;
40 CFR 122
Scan
conducted in three following
years after expansion occurs
Electronic
Electronic Reporting Special
In accordance with EPA Electronic Reporting Rule
Reporting
Condition J
2015.
MGD — Million gallons per day, MA - Monthly Average, WA — Weekly Average, DM — Daily Max
13. Public Notice Schedule:
Permit to Public Notice: xx/xx/xxxx
Per 15A NCAC 2H .0109 & .0111, The Division will receive comments for a period of 30 days following
the publication date of the public notice. Any request for a public hearing shall be submitted to the
Director within the 30 days comment period indicating the interest of the party filing such request and the
reasons why a hearing is warranted.
14. NPDES Division Contact
If you have any questions regarding any of the above information or on the attached permit, please
contact Nick Coco at [phone] or via email at [e-mail].
15. Fact Sheet Addendum (if applicable):
Were there any changes made since the Draft Permit was public noticed (Yes/No): NO
If Yes, list changes and their basis below: NA
16. Fact Sheet Attachments (if applicable):
• RPA Spreadsheet Summary
• NPDES Implementation of Instream Dissolved Metals Standards — Freshwater Standards
• NH3/TRC WLA Calculations
• BOD & TSS Removal Rate Calculations
• Mercury TMDL Calculations
• WET Testing and Self -Monitoring Summary
• MFR spreadsheet
• Compliance Inspection Report
• Chemical Addendum
Page 17 of 17

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Table 1. Project Information
❑ CHECK IF HQW OR ORW WQS
Facility Name
West Stanly WWTP
WWTP/WTP Class
III
NPDES Permit
NCO043532
Outfall
002
Flow, Qw (MGD)
1.200
Receiving Stream
Rocky River
HUC Number
03040105
Stream Class
❑ Apply WS Hardness WQC
C
7Q10s (cfs)
29.000
7Q10w (cfs)
51.00
30Q2 (cfs)
29.00
920.00
QA (cfs)
1 Q10s (cfs)
23.88
Effluent Hardness
62.14 mg/L (Avg)
Upstream Hardness
51.28 mg/L (Avg)
Combined Hardness Chronic
51.93 mg/L
Combined Hardness Acute
52.06 mg/L
Data Source(s)
7Q10s used as conservative estimate of 30(Q2.
❑ CHECK TO APPLY MODEL
REQUIRED DATA ENTRY
Par01
Par02
Par03
Par04
Par05
Par06 E
Par07
Par08
Par09
Par10
Par11
Par12
Par13
Par14
Par15
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
1.0250
FW
6.1449
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
214.2492
FW
1650.4464
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
14.7182
FW
20.9022
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
6.6599
FW
171.3799
ug/L
Mercury
Aquatic Life
NC
12
FW
0.5
-,^"
Molybdenum
Human Health
NC
2000
HH
ug/L
Nickel
Aquatic Life
NC
69.1041
FW
623.4914
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
1.0467
ug/L
Zinc
Aquatic Life
NC
235.4502
FW
234.0360
ug/L
43532 RPA, input
9/5/2023

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Table 1. Project Information
❑ CHECK IF HQW OR ORW WQS
Facility Name
West Stanly WWTP
WWTP/WTP Class
III
NPDES Permit
NCO043532
Outfall
002
Flow, Qw (MGD)
2.500
Receiving Stream
Rocky River
HUC Number
03040105
Stream Class
❑ Apply WS Hardness WQC
C
7Q10s (cfs)
29.000
7Q10w (cfs)
51.00
30Q2 (cfs)
29.00
QA (cfs)
920.00
1 Q10s (cfs)
23.88
Effluent Hardness
62.14 mg/L (Avg)
Upstream Hardness
51.28 mg/L (Avg)
Combined Hardness Chronic
52.56 mg/L
Combined Hardness Acute
52.79 mg/L
Data Source(s)
7Q10s used as conservative estimate of 30(Q2.
❑ CHECK TO APPLY MODEL
REQUIRED DATA ENTRY
Par01
Par02
Par03
Par04
Par05
Par06 E
Par07
Par08
Par09
Par10
Par11
Par12
Par13
Par14
Par15
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
1.0343
FW
6.2201
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
216.3610
FW
1669.4181
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
14.8696
FW
21.1788
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
6.7489
FW
174.0513
ug/L
Mercury
Aquatic Life
NC
12
FW
0.5
-,^"
Molybdenum
Human Health
NC
2000
HH
ug/L
Nickel
Aquatic Life
NC
69.8078
FW
630.8960
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
1.0721
ug/L
Zinc
Aquatic Life
NC
237.8515
FW
236.8197
ug/L
43532 RPA, input
9/5/2023

REASONABLE POTENTIAL ANALYSIS
H1
I Effluent Hardness
Date
1 1/31/2019
2 4/3/2019
3 7/16/2019
4 10/16/2019
5 1 /8/2020
6 4/7/2020
7 7/8/2020
8 10/14/2020
9 1 /13/2021
10 4/7/2021
11 7/21 /2021
12 10/13/2021
13 1 /12/2022
14 4/13/2022
15 7/20/2022
16 10/12/2022
17 1 /17/2023
18 4/11/2023
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
Data
BDL=1/2DL
Results
76
76
Std Dev.
59
59
Mean
59.4
59.4
C.V.
70.5
70.5
n
73
73
10th Per value
62.9
62.9
Average Value
75.4
75.4
Max. Value
57.2
57.2
49.4
49.4
63.8
63.8
68.6
68.6
57.9
57.9
60.4
60.4
57.4
57.4
61
61
63.1
63.1
53.5
53.5
50
50
Use "PASTE SPECIAL
Values" then "COPY"
Maximum data
points = 58
7.9433
62.1389
0.1278
18
52.45 mg/L
62.14 mg/L
76.00 mg/L
H2
Date
1 2/12/2019
2 4/3/2019
3 7/16/2019
4 10/16/2019
5 1 /8/2020
6 4/7/2020
7 7/8/2020
8 10/14/2020
9 1 /13/2021
10 4/7/2021
11 7/21 /2021
12 10/13/2021
13 1 /12/2022
14 4/13/2022
15 10/12/2022
16 1 /17/2023
17 4/11/2023
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
Upstream Hardness
Data
BDL=1/2DL
Results
71
71
Std Dev.
55
55
Mean
62.5
62.5
C.V.
79.6
79.6
n
39.3
39.3
10th Per value
40
40
Average Value
61
61
Max. Value
38.5
38.5
37.1
37.1
38.2
38.2
51.5
51.5
48.2
48.2
43.3
43.3
36.7
36.7
95.2
95.2
42.6
42.6
32
32
Use "PASTE SPECIAL
Values" then "COPY"
Maximum data
points = 58
17.4878
51.2765
0.3410
17
36.94 mg/L
51.28 mg/L
95.20 mg/L
43532 RPA, data
- 1 - 9/5/2023

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
Date Data
1/12/2022 <
4/25/2022 <
7/13/2022 <
Arsenic
BDL=1/2DL
10 5
10 5
30 15
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
5.7735
8.3333
0.6000
3
3.00
15.0 ug/L
45.0 ug/L
-2-
43532 RPA, data
9/5/2023

REASONABLE POTENTIAL ANALYSIS
Par03
Date Data
1 1/12/2022 <
2 4/25/2022 <
3 7/13/2022 <
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
Par04
Use "PASTE SPECIAL
Use "PASTE SPECIAL
Beryllium
Values" then "COPY"
Cadmium
Values" then "COPY"
Maximum data
. Maximum data
points = 58
points = 58
BDL=1/2DL
Results
Date
Data
BDL=1/2DL
Results
1 0.5
Std Dev.
2.5981
1
1/12/2022
<
1 0.5
Std Dev.
2.5981
1 0.5
Mean
2.0000
2
4/25/2022
<
1 0.5
Mean
2.0000
10 5
C.V. (default)
0.6000
3
7/13/2022
<
10 5
C.V. (default)
0.6000
n
3
4
n
3
5
Mult Factor =
3.00
6
Mult Factor =
3.00
Max. Value
5.00 ug/L
7
Max. Value
5.000 ug/L
Max. Pred Cw
15.00 ug/L
8
Max. Pred Cw
15.000 ug/L
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
<
ERR
53
<
ERR
54
<
ERR
55
<
ERR
56
<
ERR
57
<
ERR
58
<
ERR
43532 RPA, data
-3- 9/5/2023

REASONABLE POTENTIAL ANALYSIS
Par07
Total Phenolic Compounds
Use "PASTE SPECIAL -
Values" then "COPY".
Part O
Maximum data points =
58
Date
Data BDL=1/2DL
Results
Date Data
1
1/26/2022
< 20 10
Std Dev.
0.0000
1
1/12/2022 <
2
4/19/2022
< 20 10
Mean
10.0000
2
4/25/2022 <
3
7/13/2022
< 20 10
C.V. (default)
0.6000
3
7/13/2022 <
4
n
3
4
5
5
6
Mult Factor =
3.00
6
7
Max. Value
10.0 ug/L
7
8
Max. Pred Cw
30.0 ug/L
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
Use "PASTE SPECIAL
Chromium, Total
Values" then "COPY"
Maximum data
points = 58
BDL=1/2DL
Results
5 2.5
Std Dev.
1.4434
5 2.5
Mean
3.3333
10 5
C.V. (default)
0.6000
n
3
Mult Factor =
3.00
Max. Value
5.0 pg/L
Max. Pred Cw
15.0 dig/L
-4-
43532 RPA, data
9/5/2023

REASONABLE POTENTIAL ANALYSIS
Pal
Date Data
1 1 /2/2019 <
2 1 / 15/2019 <
3 4/3/2019
4 7/16/2019
5 10/16/2019
6 1 /8/2020 <
7 4/7/2020 <
8 7/8/2020
9 10/14/2020 <
10 1/13/2021 <
11 4/7/2021
12 7/21 /2021 <
13 10/13/2021
14 1 /12/2022
15 4/13/2022
16 7/20/2022 <
17 10/12/2022 <
18 1/17/2023 <
19 4/11/2023 <
20 4/25/2022 <
21 7/13/2022 <
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
Par12
Use "PASTE SPECIAL
Copper Values" then "COPY"
Maximum data
points = 58
BDL=1/2DL
Results
10
5
Std Dev.
10
5
Mean
17
17
C.V.
5
5
n
7
7
5
2.5
Mult Factor =
5
2.5
Max. Value
5
5
Max. Pred Cw
5
2.5
5
2.5
6
6
5
2.5
6
6
5
5
6
6
5
2.5
5
2.5
5
2.5
5
2.5
5
2.5
20
10
Cyanide
Date
Data BDL=1/2DL
Results
3.4502
1
1 /20/2022
45 45
Std Dev.
4.8571
2
4/25/2022
29 29
Mean
0.7103
3
7/19/2022
240 240
C.V. (default)
21
4
n
5
1.41 6
17.00 ug/L 7
23.97 ug/L 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
Mult Factor =
Max. Value
Max. Pred Cw
Use "PASTE SPECIAL
Values" then "COPY"
Maximum data
points = 58
117.4748
104.67
0.6000
3
3.00
240.0 ug/L
720.0 ug/L
-5-
43532 RPA, data
9/5/2023

REASONABLE POTENTIAL ANALYSIS
Par14
Date
1 1/12/2022 <
2 4/25/2022 <
3 7/13/2022 <
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
Par17 & Par18
use "PASTE
Use "PASTE SPECIAL
SPECIAL -
Lead
values" then "COPY"
Nickel
values" then
Maximum data
"COPY".
points = 58
Maximum data
BDL=1/2DL
Results
Date Data
BDL=1/2DL
Results
points = 58
5 2.5
Std Dev.
5.7735
1
1/12/2022 <
5 2.5
Std Dev.
4.3301
5 2.5
Mean
5.8333
2
4/25/2022 <
5 2.5
Mean
5.0000
25 12.5
C.V. (default)
0.6000
3
7/13/2022 <
20 10
C.V. (default)
0.6000
n
3
4
n
3
5
Mult Factor =
3.00
6
Mult Factor =
3.00
Max. Value
12.500 ug/L
7
Max. Value
10.0 pg/L
Max. Pred Cw
37.500 ug/L
8
Max. Pred Cw
30.0 pg/L
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
43532 RPA, data
-6- 9/5/2023

REASONABLE POTENTIAL ANALYSIS
Par19
Date Data
1 1/12/2022 <
2 4/25/2022 <
3 7/13/2022 <
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
Par20
Use "PASTE SPECIAL-
Use "PASTE SPECIAL
Selenium
Values" then "COPY".
Silver
Values" then "COPY"
Maximum data points
. Maximum data
= 58
points = 58
BDL=1/2DL
Results
Date Data
BDL=1/2DL
Results
10 5
Std Dev.
8.6603
1
1/12/2022 <
5 2.5
Std Dev.
1.4434
10 5
Mean
10.0000
2
4/25/2022 <
5 2.5
Mean
3.3333
40 20
C.V. (default)
0.6000
3
7/13/2022 <
10 5
C.V. (default)
0.6000
n
3
4
n
3
5
Mult Factor =
3.00
6
Mult Factor =
3.00
Max. Value
20.0 ug/L
7
Max. Value
5.000 ug/L
Max. Pred Cw
60.0 ug/L
8
Max. Pred Cw
15.000 ug/L
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
43532 RPA, data
-7- 9/5/2023

REASONABLE POTENTIAL ANALYSIS
Par21
Use "PASTE SPECIAL
Zinc
Values" then "COPY"
Maximum data
points = 58
Date
Data
BDL=1/2DL
Results
1
1 /4/2019
14
14
Std Dev.
20.4252
2
4/3/2019
82
82
Mean
39.6071
3
7/16/2019
59
59
C.V.
0.5157
4
10/16/2019
36
36
n
21
5
1 /8/2020
35
35
6
4/7/2020
48
48
Mult Factor =
1.29
7
7/8/2020
79
79
Max. Value
82.0 ug/L
8
10/14/2020
20
20
Max. Pred Cw
105.8 ug/L
9
1/13/2021
29
29
10
4/7/2021
33
33
11
7/21 /2021
70
70
12
10/13/2021
19
19
13
1/12/2022
36
36
14
4/13/2022
47
47
15
7/20/2022
44
44
16
10/12/2022
18
18
17
1/17/2023
34
34
18
4/11/2023
14
14
19
1/12/2022
< 32.7
16.35
20
4/25/2022
47.9
47.9
21
7/13/2022
50.5
50.5
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
43532 RPA, data
- 8 - 9/5/2023

West Stanly WWTP
NCO043532
Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Qw (MGD) =
1.2000
1Q10S (cfs) =
23.88
7Q10S (cfs) =
29.00
7Q10W (cfs) =
51.00
30Q2 (cfs) =
29.00
Avg. Stream Flow, QA (cfs) =
920.00
Receiving Stream:
Rocky River HUC 03040105
WWTP/WTP Class: III
IWC% @ 1Q10S = 7.226107226
IWC% @ 7Q10S = 6.027219702
IWC% @ 7Q10W = 3.518728717
IWC% @ 30Q2 = 6.027219702
IW%C @ QA = 0.201765995
Stream Class: C
Outfall 002
Qw = 1.2 MGD
COMBINED HARDNESS (mg/L)
Acute = 52.06 mg/L
Chronic = 51.93 mg/L
PARAMETER
NC STANDARDS OR EPA CRITERIA
CO
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
TYPE
J
Applied
Chronic Acute
M
n # Det. Max Pred Cw Allowable Cw
Standard
Acute (FW): 4,705.2
Arsenic
C
150 FW(7Q10s) 340
ug/L
3 0
45.0
Chronic (FW):---2,488.7 -
----------------------------
C.V. (default)
Max MDL30
Arsenic
C
10 HH/WS(Qavg)
ug/L
Note: n < 9
NO DETECTS
_=
Chronic (HH): 4,956.2
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
Max MDL = 30
Monitoring required
Acute: 899.52
Beryllium
NC
6.5 FW(7Q10s) 65
ug/L
3 0
15.00
Note: n < 9
C.V. (default)
Chronic: 107.84
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
NO DETECTS
Max MDL = 10
Monitoring required
Acute: 85.037
Cadmium
NC
1.0250 FW(7Q10s) 6.1449
ug/L
3 0
15.000
Note: n < 9
C.V. (default)
Chronic: 17.006
All non -detect < 10 ug/L and < 1 ug/L; No monitoring
required - Permittee shall report to PQL < 1 ug/L
Limited data set
NO DETECTS
Max MDL 10
during all PPAs.
Acute: NO WQS
Total Phenolic Compounds
NC
300 A(30Q2)
ug/L
3 0
30.0
Note: n < 9
C.V. (default)
Chronic: 4,977.4
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
NO DETECTS
Max MDL = 20
Monitoring required
Acute: 22,840.0
Chromium III
NC
214.25 FW(7Q10s) 1650.45
µg/L
0 0
N/A
Chronic: -----3 554.7 -
----------------------------
Acute: 221.4
Chromium VI
NC
11 FW(7Q10s) 16
µg/L
0 0
N/A
Chronic:----- 182.5--
----------------------------
Chromium, Total
NC
µg/L
3 0
15.0
Max reported value = 5
a: No monitoring required if all Total Chromium
Note: n < 9
C.V. (default)
samples are < 5 pg/L or Pred. max for Total Cr is <
allowable Cw for Cr VI.
Limited data set
NO DETECTS
Max MDL = 10
Acute: 289.26
Copper
NC
14.7182 FW(7Q 1 Os) 20.9022
ug/L
21 8
23.97
Chronic: 244.20
No RP, Predicted Max < 50% of Allowable Cw - No
No value > Allowable Cw
Monitoring required
Acute: 304.5
Cyanide
NC
5 FW(7010s) 22
10
u2/L
3 3
720.0
_ _____ __
____________________________
Note: n < 9
C.V. (default)
Chronic: 83.0
RP for Limited Dataset (n<8 samples) - apply
Limited data set
1 value(s) > Allowable Cw
Quarterly Monitoring
43532 RPA, rpa
Page 1 of 2 9/5/2023

West Stanly WWTP
NCO043532
Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
Outfall 002
Qw = 1.2 MGD
Acute: 2,371.677
Lead
NC
6.6599 FW(7Q1Os) 171.3799
ug/L
3 0
37.500
Note: n <_ 9
C.V. (default)
Chronic: 110.497
All value non -detect < 25 ug/L and < 5 ug/L; No
Limited data set
NO DETECTS
Max MDL = 25
monitoring required.
Acute (FW): 8,628.3
Nickel
NC
69.1041 FW(7Q10s) 623.4914
µg/L
3 0
30.0
Chronic (FW): 1,146.5
No RP, Predicted Max < 50% of Allowable Cw - No
Note: n < 9
C.V. (default)
Max MDL_= 20
Monitoring required
Nickel
NC
25.0000 WS(7Q10s)
µg/L
Limited data set
NO DETECTS
Chronic (WS): 414.8
Max MDL = 20
Acute: 775.0
Selenium
NC
5 FW(7Q10s) 56
ug/L
3 0
60.0
Note: n < 9
C.V. (default)
Chronic: 83.0
All value non -detect < 40 ug/L and < 10 ug/L; No
Limited data set
NO DETECTS
Max MDL = 40
monitoring required.
Acute: 14.485
Silver
NC
0.06 FW(7Q10s) 1.0467
ug/L
3 0
15.000
Note: n < 9
C.V. (default)
Chronic: 0.995
All non -detect < 10 ug/L and < 5 ug/L; No monitoring
Limited data set
NO DETECTS
Max MDL 10
required - Permittee shall report to PQL < 1 ug/L
during all PPAs.
Acute: 3,238.8 No RP, Predicted Max < 50% of Allowable Cw - No
Zinc
NC
####### FW(7Q10s) 234.0360 ug/L
21 20 105.8 Monitoring required
-----3,9-- - --- — - — - — - — - — - — - — - — - — - — - — - — - — - —
Chronic:
No value > Allowable Cw
43532 RPA, rpa
Page 2 of 2 9/5/2023

West Stanly WWTP
NCOO43532
Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Qw (MGD) =
2.5000
1Q10S (cfs) =
23.88
7Q10S (cfs) =
29.00
7Q10W (cfs) =
51.00
30Q2 (cfs) =
29.00
Avg. Stream Flow, QA (cfs) =
920.00
Receiving Stream:
Rocky River HUC 03040105
WWTP/WTP Class: III
IWC% @ 1Q10S =
13.96144839
IWC% @ 7Q10S =
11.78707224
IWC% @ 7Q10W =
7.061503417
IWC% @ 30Q2 =
11.78707224
IW%C @ QA =
0.419429035
Stream Class: C
Outfall 002
Qw = 2.5 MGD
COMBINED HARDNESS (mg/L)
Acute = 52.79 mg/L
Chronic = 52.56 mg/L
PARAMETER
NC STANDARDS OR EPA CRITERIA
CO
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
TYPE
J
Applied
Chronic Acute
M
n # Det. Max Pred Cw Allowable Cw
Standard
Acute (FW): 2,435.3
Arsenic
C
150 FW(7Q10s) 340
ug/L
3 0
45.0
Chronic (FW): ---1,272.E -
----------------------------
C.V. (default)
Max MDL30
Arsenic
C
10 HH/WS(Qavg)
ug/L
Note: n < 9
NO DETECTS
_=
Chronic (HH): 2,384.2
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
Max MDL = 30
Monitoring required
Acute: 465.57
Beryllium
NC
6.5 FW(7Q10s) 65
ug/L
3 0
15.00
Note: n < 9
C.V. (default)
Chronic: 55.15
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
NO DETECTS
Max MDL = 10
Monitoring required
Acute: 44.552
Cadmium
NC
1.0343 FW(7Q10s) 6.2201
ug/L
3 0
15.000
Note: n < 9
C.V. (default)
Chronic: 8.775
All non -detect < 10 ug/L and < 1 ug/L; No monitoring
required - Permittee shall report to PQL < 1 ug/L
Limited data set
NO DETECTS
Max MDL 10
during all PPAs.
Acute: NO WQS
Total Phenolic Compounds
NC
300 A(30Q2)
ug/L
3 0
30.0
Note: n < 9
C.V. (default)
Chronic: 2,545.2
No RP, Predicted Max < 50% of Allowable Cw - No
Limited data set
NO DETECTS
Max MDL = 20
Monitoring required
Acute: 11,957.3
Chromium III
NC
216.36 FW(7Q10s) 1669.42
µg/L
0 0
N/A
Chronic: -----1 835.E -
----------------------------
Acute: 114.6
Chromium VI
NC
11 FW(7Q10s) 16
µg/L
0 0
N/A
Chronic:----- 93.3---
----------------------------
Chromium, Total
NC
µg/L
3 0
15.0
Max reported value = 5
a: No monitoring required if all Total Chromium
Note: n < 9
C.V. (default)
samples are < 5 pg/L or Pred. max for Total Cr is <
allowable Cw for Cr VI.
Limited data set
NO DETECTS
Max MDL = 10
Acute: 151.70
Copper
NC
14.8696 FW(7Q I Os) 21.1788
ug/L
21 8
23.97
Chronic: 126.15
No RP, Predicted Max < 50% of Allowable Cw - No
No value > Allowable Cw
Monitoring required
Acute: 157.6
Cyanide
NC
5 FW(7010s) 22
10
u2/L
3 3
720.0
__ _ ______ __
____________________________
Note: n < 9
C.V. (default)
Chronic: 42.4
RP for Limited Dataset (n<8) but 2 values > Allowable
Limited data set
2 value(s) > Allowable Cw
Cw - apply Monthly Monitoring with Limit
43532 RPA, rpa
Page 1 of 2 9/5/2023

West Stanly WWTP
NCO043532
Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
Outfall 002
Qw = 2.5 MGD
Acute: 1,246.657
Lead
NC
6.7489 FW(7Q10s) 174.0513
ug/L
3 0
37.500
Note: n < 9
C.V. (default)
Chronic: 57.257
All value non -detect < 25 ug/L and < 5 ug/L; No
Limited data set
NO DETECTS
Max MDL = 25
monitoring required.
Acute (FW): 4,518.8
Nickel
NC
69.8078 FW(7Q10s) 630.8960
µg/L
3 0
30.0
Chronic (FW): 592.2
No RP, Predicted Max < 50% of Allowable Cw - No
Note: n < 9
C.V. (default)
Max MDL_= 20
Monitoring required
Nickel
NC
25.0000 WS(7Q10s)
µg/L
Limited data set
NO DETECTS
Chronic (WS): 212.1
Max MDL = 20
Acute: 401.1
Selenium
NC
5 FW(7Q10s) 56
ug/L
3 0
60.0
Note: n < 9
C.V. (default)
Chronic: 42.4
All value non -detect < 40 ug/L and < 10 ug/L; No
Limited data set
NO DETECTS
Max MDL = 40
monitoring required.
Acute: 7.679
Silver
NC
0.06 FW(7Q10s) 1.0721
ug/L
3 0
15.000
Note: n < 9
C.V. (default)
Chronic: 0.509
All non -detect < 10 ug/L and < 5 ug/L; No monitoring
Limited data set
NO DETECTS
Max MDL 10
required - Permittee shall report to PQL < 1 ug/L
during all PPAs.
Acute: 1,696.2 No RP, Predicted Max < 50% of Allowable Cw - No
Zinc
NC
####### FW(7Q10s) 236.8197
ug/L
21 20 105.8 Monitoring required
-----2,0-- - --- — - — - — - — - — - — - — - — - — - — - — - — - — - —
Chronic:
No value > Allowable Cw
43532 RPA, rpa
Page 2 of 2 9/5/2023

Date: 9/5/2023
Dissolved to Total Metal Calculator
Do NOT enter anv data directly into this spreadsheet.
Enter data onto "Table 1" under the Input Sheet and enter
"Effluent Hardness" under the Data Sheet.
In accordance with 40 CFR 122.45 (c ), permits are, have and
must be written as total metals.
This calculator has been inserted into the RPA to calculate
Total Metal allowable allocations once Table 1 has been
completed (Input Sheet) and Effluent hardness has been
entered (Data Sheet).
1) Following the spreadsheet from left to right. First
the allowable allocations for the dissolved metals will
appear for all the metals listed once Table 1 is complete
and effluent hardness entered. Use a default value of 25
FACILITY: West Stanly WWTP Outfall 002
NPDES PERMIT: NCO043532
Dissolved to Total Metal Calculator
In accordance with Federal Regulations, permit limitations must be written as Total Metals per 40 CFR 122.45(c)
PARAMETER
mg/L if no hardness data is available. Second,
the Dissolved Metal allocations are divided by the
Translators to determine the Total Metals that can be
allocated to the Permittee. These Total Metals values are
automatically inserted into Table 2 and are the allowable
Total Metal allocations determined for the Permittee prior
to allowing for dilution. See Input sheet Table 2. The final
acute and chronic values shown under the RPA sheet are
the Total Metal values listed in Table 2 divided by the acute
and chronic IWC, respectively.
2) The Translators used in the freshwater RPA are the
Partition Coefficients published by US EPA in 1984. They
are TSS dependent equations and can be found listed with
Cadmium (d)
Cd -Trout streams
Chromium III (d)(h)
Chromium VI (d)
Chromium, Total (t)
Copper (d)(h)
Lead (d)(h)
Nickel (d)(h)
Ni - WS streams (t)
Silver (d)(h,acute)
Zinc (d)(h)
Beryllium
Arsenic (d)
Receiving
Receiving
Rec. Stream
NPDES
Total Suspended
Combined
Combined
Instream
Instream
Effluent
Upstream
Stream
Stream
Solids
Hardness
Hardness
Wastewater
Wastewater
Hardness
summer
summer 7Q10
1Q10
Flow Limit
-Fixed Value-
chronic
Acute
Concentration
Concentration
Hardness
Average
7Q10 (CFS)
(MGD)
[MGD]
[MGD]
(mg/L)
(mg/L)
(mg/L)
(Chronic)
(Acute)
Average (mg/L)
(mg/L)
29.0000
18.7097
15.4065
1 1.2000
10 11
51.931
52.061
6.0272
7.2261
151.2764706
162.13889
after applying hardness I Translators- using
equation
Default Partition
Coefficients
(streams)
Chronic
Acute
[u /1]
[u /1]
0.26
1.55
0.252
0.26
0.96
0.252
43
334
0.202
11
16
1.000
5.1
7.3
0.348
1.22
32
0.184
30
270
0.432
1.000
0.288
0.06 1.05
68 67
Upstream Hard Avg (mg/L) = 51.27647
EFF Hard Avg (mg/L) = 62.13889
Total Metal Criteria Total Metal = (COMMENTS (identify parameters to PERCS Branch to maintain in facility's LTMP/STMP):
Dissolved Metal = Translator
Chronic I Acute
1.03
6.14
3.82
1650.45
1.03
214.25
11.00
-------------
16.00
N/A
N/A
14.72
20.90
6.66
171.38
69.10
623.49
25 N/A
0.06 1.05
235.45 234.04
6.51 651 1.0001 6.51 65
1501 3401 1.0001 1501 340
(d) =dissolved metal standard. See 15A NCAC 02B .0211 for more information.
the WQS hardness dependent equations under the sheet (h) = hardness -dependent dissolved metal standard. See 15A NCAC 02B .0211 for more information.
labeled Equations. A fixed TSS value of 10 mg/L is used to (t) = based upon measurement of total recoveable metal. See 15A NCAC 02B .0211 for more information.
calculate the Translator values. The Human Health standard for Nickel in Water Supply Streams is 25 mg/L which is Total Recoverable metal standard.
3) Pretreatment Facilities - PERCS will need a copy of the The Human Health standard for Arsenic is 10 µg/L which is Total Recoverable metal standard.
Dissolved to Total Metal Calculator spreadsheet and the
RPA sheet along with the Final Permit. Pretreatment
Facilities are required to renew their Headwords Analysis
after renewal of their permits. Since all their metal
allocations are likely to change PERCS needs to see any new
metal permit limits and the allowable allocations for the
dissolved metals to assess Maximum Allowable Headworks
Loading (MAHL) numbers for each metal based on the
Combined Hardness values used in the permit writers RPA
calculations.
4) For Cadmium, Lead, Nickel, Chromium and Beryllium, if all
the effluent sampling data for the last three to five years
shows the pollutant at concentrations less than the
Practical Quantitative Level (PQL), it is not likely a limit or
monitoring will be put in the permit. However, if the
estimated NPDES permit limit is less than the Practical
Quantitative Limit (particularly, Cadmium and Lead) and
the pollutant is believed to be present, to assess
compliance with the new standards and for future permit
limit development, monitoring for the pollutant will be
required. If the facility is monitoring for the pollutant in its
Pretreatment LTMP, no monitoring is needed in the permit.
5) For monitoring and compliance purposes if Total
Chromium < the Chromium VI chronic Total Metal
ACAH 52.0614
ACCH 51.93117

Date: 9/5/2023
Dissolved to Total Metal Calculator
Do NOT enter anv data directly into this spreadsheet.
Enter data onto "Table 1" under the Input Sheet and enter
"Effluent Hardness" under the Data Sheet.
In accordance with 40 CFR 122.45 (c ), permits are, have and
must be written as total metals.
This calculator has been inserted into the RPA to calculate
Total Metal allowable allocations once Table 1 has been
completed (Input Sheet) and Effluent hardness has been
entered (Data Sheet).
1) Following the spreadsheet from left to right. First
the allowable allocations for the dissolved metals will
appear for all the metals listed once Table 1 is complete
and effluent hardness entered. Use a default value of 25
FACILITY: West Stanly WWTP Outfall 002
NPDES PERMIT: NCO043532
Dissolved to Total Metal Calculator
In accordance with Federal Regulations, permit limitations must be written as Total Metals per 40 CFR 122.45(c)
PARAMETER
mg/L if no hardness data is available. Second,
the Dissolved Metal allocations are divided by the
Translators to determine the Total Metals that can be
allocated to the Permittee. These Total Metals values are
automatically inserted into Table 2 and are the allowable
Total Metal allocations determined for the Permittee prior
to allowing for dilution. See Input sheet Table 2. The final
acute and chronic values shown under the RPA sheet are
the Total Metal values listed in Table 2 divided by the acute
and chronic IWC, respectively.
2) The Translators used in the freshwater RPA are the
Partition Coefficients published by US EPA in 1984. They
are TSS dependent equations and can be found listed with
Cadmium (d)
Cd -Trout streams
Chromium III (d)(h)
Chromium VI (d)
Chromium, Total (t)
Copper (d)(h)
Lead (d)(h)
Nickel (d)(h)
Ni - WS streams (t)
Silver (d)(h,acute)
Zinc (d)(h)
Beryllium
Arsenic (d)
Receiving
Receiving
Rec. Stream
NPDES
Total Suspended
Combined
Combined
Instream
Instream
Effluent
Upstream
Stream
Stream
Solids
Hardness
Hardness
Wastewater
Wastewater
Hardness
summer
summer 7Q10
1Q10
Flow Limit
-Fixed Value-
chronic
Acute
Concentration
Concentration
Hardness
Average
7Q10 (CFS)
(MGD)
[MGD]
[MGD]
(mg/L)
(mg/L)
(mg/L)
(Chronic)
(Acute)
Average (mg/L)
(mg/L)
29.0000
18.7097
15.4065
1 2.5000
10 11
52.557
52.793
11.7871
13,9614
151.2764706
162.13889
after applying hardness I Translators- using
equation
Default Partition
Coefficients
(streams)
Chronic
Acute
[u /1]
[u /1]
0.26
1.57
0.252
0.26 0.98
44 338
11: 16
0.252
0.202
1.000
5.2
1.24
7.4
32
0.348
0.184
30
273
0.432
0.06
1.07
1.000
68
68
0.288
Upstream Hard Avg (mg/L) = 51.27647
EFF Hard Avg (mg/L) = 62.13889
Total Metal Criteria Total Metal = (COMMENTS (identify parameters to PERCS Branch to maintain in facility's LTMP/STMP):
Dissolved Metal = Translator
Chronic I Acute
1.03
6.22
3.87
1669.42
1.03
216.36
11.00
-------------
16.00
N/A
N/A
14.87
21.18
6.75
174.05
630.90
69.81
25 N/A
0.06 1.07
237.85 236.82
6.51 651 1.0001 6.51 65
1501 3401 1.0001 1501 340
(d) =dissolved metal standard. See 15A NCAC 02B .0211 for more information.
the WQS hardness dependent equations under the sheet (h) = hardness -dependent dissolved metal standard. See 15A NCAC 02B .0211 for more information.
labeled Equations. A fixed TSS value of 10 mg/L is used to (t) = based upon measurement of total recoveable metal. See 15A NCAC 02B .0211 for more information.
calculate the Translator values. The Human Health standard for Nickel in Water Supply Streams is 25 mg/L which is Total Recoverable metal standard.
3) Pretreatment Facilities - PERCS will need a copy of the The Human Health standard for Arsenic is 10 µg/L which is Total Recoverable metal standard.
Dissolved to Total Metal Calculator spreadsheet and the
RPA sheet along with the Final Permit. Pretreatment
Facilities are required to renew their Headwords Analysis
after renewal of their permits. Since all their metal
allocations are likely to change PERCS needs to see any new
metal permit limits and the allowable allocations for the
dissolved metals to assess Maximum Allowable Headworks
Loading (MAHL) numbers for each metal based on the
Combined Hardness values used in the permit writers RPA
calculations.
4) For Cadmium, Lead, Nickel, Chromium and Beryllium, if all
the effluent sampling data for the last three to five years
shows the pollutant at concentrations less than the
Practical Quantitative Level (PQL), it is not likely a limit or
monitoring will be put in the permit. However, if the
estimated NPDES permit limit is less than the Practical
Quantitative Limit (particularly, Cadmium and Lead) and
the pollutant is believed to be present, to assess
compliance with the new standards and for future permit
limit development, monitoring for the pollutant will be
required. If the facility is monitoring for the pollutant in its
Pretreatment LTMP, no monitoring is needed in the permit.
5) For monitoring and compliance purposes if Total
Chromium < the Chromium VI chronic Total Metal
ACAH 52.79302
ACCH 52.55683

Permit No. NCO043532
NPDES Implementation of Instream Dissolved Metals Standards - Freshwater Standards
The NC 2007-2015 Water Quality Standard (WQS) Triennial Review was approved by the NC
Environmental Management Commission (EMC) on November 13, 2014. The US EPA subsequently
approved the WQS revisions on April 6, 2016, with some exceptions. Therefore, metal limits in draft
permits out to public notice after April 6, 2016 must be calculated to protect the new standards - as
approved.
Table 1. NC Dissolved Metals Water Q ality Standards/A uatic Life Protection
Parameter
Acute FW, µg/l
(Dissolved)
Chronic FW, µg/l
(Dissolved)
Acute SW, µg/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. 136672-[ln hardness](0.041838)} e^10.9151 [ln hardness]-3.1485}
Cadmium, Acute Trout waters
WER* {1. 136672-[ln hardness](0.041838)} e^{0.9151[In hardness]-3.62361
Cadmium, Chronic
WER*{1.101672-[ln hardness](0.041838)} • e^{0.7998[ln hardness] -4.445 11
Chromium III, Acute
WER*0.316 e^{0.8190[ln hardness]+3.7256}
Chromium III, Chronic
WER*0.860 e^{0.8190[ln hardness]+0.6848}
Copper, Acute
WER*0.960 e^{0.9422[ln hardness]-1.700}
Copper, Chronic
WER*0.960 e^{0.8545[ln hardness]-1.702}
Lead, Acute
WER*{1.46203-[ln hardness](0.145712)} • e^{1.273[ln hardness]-1.460}
Lead, Chronic
WER*{1.46203-[ln hardness](0.145712)} • e^{1.273[ln hardness]-4.705)
Nickel, Acute
WER*0.998 e^{0.8460[ln hardness]+2.255}
Nickel, Chronic
WER*0.997 e^{0.8460[ln hardness]+0.0584}
Page 1 of 4

Permit No. NCO043532
Silver, Acute
WER*0.85 • e"O.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. NCO043532
The overall hardness value used in the water quality calculations is calculated as follows:
Combined Hardness (chronic)
_ (Permitted Flow, cfs *Avg. Effluent Hardness, mg/L)+s7Q10, cfs *Avg. Upstream Hardness, mg/L)
(Permitted Flow, cfs + s7Q 10, cfs)
The Combined Hardness for acute is the same but the calculation uses the IQ 10 flow.
3. The permit writer converts the numeric standard for each metal of concern to a total recoverable
metal, using the EPA Default Partition Coefficients (DPCs) or site -specific translators, if any
have been developed using federally approved methodology.
EPA default partition coefficients or the "Fraction Dissolved" converts the value for
dissolved metal at laboratory conditions to total recoverable metal at in -stream
ambient conditions. This factor is calculated using the linear partition coefficients
found in The Metals Translator: Guidance for Calculating a Total Recoverable
Permit Limit from a Dissolved Criterion (EPA 823-B-96-007, June 1996) and the
equation:
Cdiss = 1
Ctotal I + { [Kp.] [ss('+a)] [10 6] }
Where:
ss = in -stream suspended solids concentration [mg/1], minimum of 10 mg/L used,
and
Kpo and a = constants that express the equilibrium relationship between dissolved
and adsorbed forms of metals. A list of constants used for each hardness -dependent
metal can also be found in the RPA program under a sheet labeled DPCs.
4. The numeric standard for each metal of concern is divided by the default partition coefficient (or
site -specific translator) to obtain a Total Recoverable Metal at ambient conditions.
In some cases, where an EPA default partition coefficient translator does not exist (ie. silver), the
dissolved numeric standard for each metal of concern is divided by the EPA conversion factor to
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) — (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 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. NC0043532
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)
62.14
Average from 112019 to 412023
[Total as, CaCO3 or (Ca+Mg)]
samples
Average Upstream Hardness (mg/L)
51.28
Average from 212019 to 412023
[Total as, CaCO3 or (Ca+Mg)]
samples
7Q10 summer (cfs)
29.0
Historical; Previous Fact Sheet
1Q10 (cfs)
23.88
Calculated in RPA
Permitted Flow (MGD)
1.2 with
NPDES Files
expansion to
2.5
Date: 8/3/2023
Permit Writer: Nick Coco
Page 4 of 4

NC Division of Water Resources
Planning Section, Basin Planning Branch
September 7, 2022
Memorandum
To: Nick Coco
Cc: Mark Vander Borgh, Michelle Raquet, Nora Dreamer, Pam Behm
From: Ginny Baker
Subject: West Stanly WWTP (NC0043532) Permit Review and Instream Monitoring
DWR Basin Planning Branch supports the changes to instream monitoring as outlined in the West Stanly Draft
Permit including all parameter additions and adjustments to upstream and downstream station locations.
Moving the current YPDRBA station, Q8480000, to the inactive DWR AMS station Q8510000 location, will
change the upstream monitoring from 7.4 to 2.2 miles above the outfall while adding a new instream
monitoring station to the location of the inactive AMS station Q8740000 will change the downstream
monitoring from 10 miles below the outfall, where AMS station Q9120000 is located, to just 3 miles below
the outfall. These upstream and downstream monitoring location changes will provide much better
representative information on the condition of the Rocky River above and below the West Stanly WWTP (See
Map Figure 1). Richland Creek and Lanes Creek, two large tributaries with known water quality issues, drain
to the Rocky River between the West Stanly outfall and AMS station Q9120000 (see Map Figure 1).
The Rocky River watershed (HUC8 03040105) has many pollutant sources contributing to water quality
problems, including several WWTPs, like the West Stanly WWTP, that have needed to pursue expansions to
meet the needs of their communities. There are also several other potential pollution sources that DWR has
limited information on such as animal waste management, failing septic tanks, and commercial fertilizer
rates. Close to 60% of monitored rivers, creeks, and streams and nearly 70% of the lakes in the Rocky River
watershed were impaired on the 2022 Integrated Report (IR).
The majority of the Rocky River mainstem was impaired for turbidity and metals, mainly copper and some
zinc, including the Assessment Unit (AU) where station Q8480000 and the West Stanly outfall is located, 13-
176, a large 36-mile stretch of the Rocky River from Anderson Creek to Lanes Creek (see Map Figure 1). The
metals data for this AU is based on the old total metals standard using data collected over 10 years ago, and
not the new dissolved metals standard. However, the next lower section of the Rocky River, AU 13-17d (from
the mouth of Island Creek to the Pee Dee River; see Map Figure 1), where station Q9120000 is located, was
also impaired for turbidity and copper, using the new dissolved metals standard. Both AUs rated 3a, data
inconclusive, on the 2022 IR, because 5-in-30 fecal samples were not collected at either Q4840000 or
Q9120000. However, screening level monitoring data indicates exceedances over the 400 colonies/100 mL
standard was 43% at the current upstream station (Q8480000) and 28% at the current downstream station
(Q9120000) for data collected over the previous five years, 2018-2022 indicating there are existing issues
with fecal coliform in the lower Rocky River mainstem.

101
Figure 1: Lower Rocky River, Richland Creek, Lanes Creek, Pee Dee River Monitoring Stations
Stanl AU 13-17c3
�t
38
est Stanly
IITP Outfall
Q8510000�
0Q8480000 QS7`
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• YPDRBA
2022 IR Overall Category
\ i
AMS Monitoring Stations — No Data
O Active
Data Inconclusive
1
0 Inactive
Exceeding Criteria
1
NPDESWWTPPermits (Cat.4)
Exceeding Criteria
Major
(Cat. 5)
Minor
_ Exceeding Criteria
NPDES Outfalls
(Cat. 5r)
74
Minor
Meeting Criteria
aid Major

Water quality monitoring data collected over the last several years indicates that the Rocky River
mainstem and several tributaries, including Richardson Creek, have some of the highest levels of nutrients
in the state. Figure 2 compares the mainstem Rocky River station dataset collected from eight long-term
monitoring stations (including Q8480000 and Q9120000) to the entire North Carolina Piedmont ecoregion
dataset using yearly box and whisker plots. Total nitrogen, nitrite -nitrates, and phosphorus levels were
notably higher at the Rocky River stations than at the Piedmont ecoregion stations. Only TKN was
comparable in most years. The USGS SPARROW (SPAtially Referenced Regression On Watershed
Attributes) model results also show that the Rocky River has the second -highest total nitrogen yield and
third -highest total phosphorus yield of all HUC8 watersheds in the state (USGS 2019). Nutrients from the
Rocky River watershed are affecting downstream waterbodies, including Blewett Falls Lake, the lowest of
the Yadkin -Pee Dee River chain lakes located below the Rocky River confluence (see Map Figure 1), which
has been impaired for chlorophyll -a since 2018.
Water quality data indicates nutrient levels increase along Q7150000 Pee Dee R. Upstream
the Pee Dee River below the confluence with the Rocky Q2480000 Rocky River Upstream
River. Figure 3 displays nutrient yearly water quality data
using box and whisker graphs by station in hydrologic � ��� 20000 Rocky River Downstream
order: Q7150000 (light blue) on the Pee Dee mainstem Q9160000 pee Dee R. Downstream
below Lake Tillery and above the Rocky River confluence, Q8480000 (light gray) on the Rocky River above
the West Stanly WWTP, Q9120000 (black) on the Rocky River below the WWTP, and Q7160000 (dark blue)
on the Pee Dee mainstem below the Rocky River confluence (also see Map Figure 1 color -coded stations).
Water quality data also indicates nutrient levels in the two StatiorlD
tributaries, Richland and Lanes creeks, located between
the West Stanly WWTP outfall and lower Rocky River QPee Dee R. Upstream
Q8848480000 0000 Rocky River, Upstream
station Q9120000 are influencing nutrient levels in the Q8800000 Richland Creek, Upstream
Rocky. A comparison of yearly water quality data from the Q8820000 Richland Creek, MidStream
Rocky River stations above and below West Stanly WWTP, Q8917000 Richland Creek, Downstream
the tributary stations, and the Pee Dee River stations above Q9021300 Lanes Creek
and below the Rocky confluence highlight the extremely 09120000 Rocky River, Downstream
concentrated nutrient levels that are draining to the Rocky 09160000 pee Dee R. Downstream
River from these tributaries, particularly Richland Creek.
Figure 4 displays nutrient yearly water quality data using box and whisker graphs by station in hydrologic
order: Q7150000 (light blue) located on the Pee Dee mainstem below Lake Tillery and above the Rocky
River confluence, Q8480000 (light gray) on the Rocky River above the West Stanly WWTP, Q8800000
(pink) the most upstream Richland Creek station, Q8820000 (red) the next lower station (mid -stream) on
Richland Creek, Q89170000 (burgundy) the lowest Richland Creek station, Q9021300 (lime green) the
Lanes Creek station, Q9120000 (black) the downstream Rocky River station below the WWTP and Richland
and Lanes creeks, and Q7160000 (dark blue) located on the Pee Dee mainstem below the Rocky River
confluence (also see Map Figure 1 color -coded stations). See Figure 5 for assistance in interpreting Box
and Whisker plots. Also, note the scaling differences of the nutrients in Figures 4 and 5.
The extremely high levels of nutrients in these tributaries and other water quality issues demonstrate the
need for monitoring closer to the West Stanly WWTP. Richland Creek has multiple impairments on
different sections for benthos, dissolved copper, and dissolved oxygen while Lanes Creek is entirely
impaired for benthos and partially impaired for dissolved oxygen. Screening level fecal coliform data for
exceedances of the 400 colonies/100 mL standard over the last five years have ranged from 22% to 37%
at Richland and Lanes Creek stations.

Figure 2: Rocky River Mainstem and Piedmont Ambient Monitoring Stations (Piedmont Yearly Mean — "+", Rock River Yearly Mean — "X")
Piedmont
R Fuve(
IOtal NI
,7.0
,&0
15.0
T
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13.0
12.4
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an
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Figure 3: Nutrient Monitoring for Rocky River Stations Q8480000 (gray) & Q9120000 (Black) and Pee Dee River Q7150000
(light blue above Rocky River confluence) & Q9160000 (dark blue below Rocky River confluence)
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Figure 4: Nutrient Monitoring in the Rocky River (gray Q8480000 upstream & black Q9120000 downstream), Richland
Creek (pink Q8800000 upstream, red Q8820000 midstream, burgundy Q8917000), Lanes Creek (lime green Q9021300),
and Pee Dee River (light blue Q7160000 upstream of Rocky River & dark blue Q9160000 downstream of Rocky River)
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Figure 5: How to Read Box and Whisker Plots
■ N
NONE
■■■■■■■ ■
■■■■■N■■■■■■
■■■■■■■■■■■■■■■■■ ■
■■■■■■■■■■■■■■■■■■■■■■■ ■
■■■■■■■■■���■■■■■■■N■■■■■■■■ ■■
(25%) (25%) [25%) (25%)
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- Q3 + 1 5(IQR)
is
V
(Ouillers)
DWR also recognizes that the Rocky River watershed is likely nutrient -sensitive and in need of a
comprehensive management strategy to address growing water quality issues resulting in
degraded aquatic habitat and negative water quality impacts to downstream waterbodies. DWR
has identified multiple limitations in the current Rocky River model used to understand point
source impacts to the watershed and would like to update this model in the future. Obtaining
current monitoring data for the mainstem is essential. Any future applications of the model will at a
minimum need to address these limitations. They include:
• Full calibration of the model at multiple points in the watershed to address the need for water
quality monitoring at or near 7Q10 conditions;
• Updated to ensure that all the tributary and point source inputs along the Rocky River are accurate
and current;
• Updated to ensure that the simulated longitudinal patterns of water quality variables are
consistent with recent available observations; and
• Calibration is done in such a way that all portions of the watershed are equally represented.
It would benefit all entities involved if these improvements could lead to the development of a regional
Rocky River model extending to the end of the Rocky River (i.e., Pee Dee River confluence). A dynamic
model, rather than a steady-state model, would be preferred so that the complexities of this river system
are properly represented, and all the available monitoring data can be readily incorporated, increasing
the model confidence.

USGS, (2019), SPARROW modeling: Estimating nutrient, sediment, and dissolved solids transport.
Retrieved from https://www.usgs.gov/mission-areas/water-resources/science/sparrow-modeling-
estimating-nutrient-sediment-and-dissolved?qt-science center objects=0#qt-science center objects,
Accessed June 23, 2020.

Cya- n71 RPA Procedures
Subject: Cyanide RPA Procedures
Date: Thu, 03 Oct 200211:22:47 -0400
From: Tom Belnick <[e-mail]>
To: "DENR.NPDES.DWQ" <[e-mail]>
Here's something to print and retain in your Guidance Manual. Based on
recent negotiations with EPA, NPDES is considering a cyanide PQL of 10
ug/1 to be appropriate due to the analytical variability near this
concentration range. While many labs are currently reporting values
below this PQL, we will not treat those values as valid numbers for RPA
purposes. Below are some RPA examples:.
Example 1). All data reported are below 10 ug/l (e.g., <5, <10, 7, 9,
<5). In this instance, we consider all values to be non -detects, since
there are no positive detections above 10 ug/l. There is no need to do
RPA, and there should be no limit. If this is a municipal with
pretreatment program, cyanide monitoring could be delegated to the
pretreatment program (LIMP/STMP).
Example 2). There are some detections above 10 ug/1 (e.g., <2, <5, <10,
14, <5, 7, 3). Lets assume the allowable effluent concentration is 20
ug/l. In this instance, we would need to conduct RPA since there is a
positive detection above 10 ug/l. For all reported values below 10 ug/1
'(<2, <5, <10, 7, 3), substitute a modified value of 5 ug/1 in the RPA
(based on 1/2 of the accepted PQL). Then include the positive values
above 10 ug/1 and run the RPA.
Mailto:tom.belnick9nr_mail.net
N.0 DENR-DWQ/NPDES Unit
1617 Mail Service Center, Raleigh NC 27699-1617
Work: [phone] ext. 543
Fax: [phone]
0
1 of 1 6/6/03 3:34 PM

DWQ - Determining Cyanide Compliance
Permit Footnote - Cyanide 2009 — Due to difficulties quantifying cyanide
in a wastewater matrix, the Division shall consider all values reported
below 10 tag/L to be "compliant" with this permit. However, the Permittee
shall submit to DWQ all values reported by a North Carolina -certified test
method (even if values fall below 10 lag/L), and the Permittee shall
consider all reported values when calculating averages, if any, as required
under this permit.
Although the Division argues "poor test consistency below 10 lag/L," some labs assert better
accuracy. Therefore, the Permittee shall report on the DMR the lab's test method PQL (practical
quantitation level/minimum verifiable method quantitation level. The Permittees shall not
report just "<PQL," but report the lab's asserted test method result (example: <5 lig/L).
CALCULATING AVERAGES — from values reported below 10 ua/L
EXAMPLES: Facility X's permit says, Weekly Average = 5.0 pg/L
Daily Max = 15.0 lag/L
Given a week's CN data (lag/L), calculate the averages: [* = values below PQL = 0]
a. 9 * b. 14 C. 9 *
13 9 18
7 * 13 7 *
+ 8 +. 7 + 6 .*
13 27 18
13=4=3.25 27:4=6.75 18+4=4.5
Weekly Avg: Compliant Weekly Avg: Noncompliant Weekly Avg: Compliant
Daily Max: Compliant Daily Max: Compliant Daily Max: Noncompliant
d. 9 * e. 9
10 8
18 7
8 * + 6
�y
28 0
28:4=7.0 0=4=0
Weekly Avg: Noncompliant Weekly Avg: Compliant
Daily Max: Noncompliant Daily Max: Compliant
Notes:
1. Apply the PQL to individually reported values only - not to the calculated result. If the
calculated result exceeds the permit's Weekly Average limit, the Permittee has violated
its limit (even if that value is less than the method PQL).
2. The guidance "PQL = 0" also applies to Daily Max < 10 lag/L (or other PQL value).

NCO043532 West Stanly WWTP
BOD monthly removal rate
Month
January-19
February-19
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
RR (%)
90.31
68.49
82.23
89.65
97.68
98.31
98.24
96.74
97.85
98.40
95.48
93.35
95.70
94.43
94.47
98.51
92.69
98.00
98.16
96.95
95.63
97.63
98.31
95.14
91.11
95.85
93.54
97.34
97.63
95.54
Month
July-21
August-21
September-21
October-21
November-21
December-21
January-22
February-22
March-22
April-22
May-22
June-22
July-22
August-22
September-22
October-22
November-22
December-22
January-23
February-23
March-23
April-23
May-23
June-23
July-23
August-23
September-23
October-23
November-23
December-23
Overall BOD removal rate
RR (%)
98.38
97.44
97.50
81.36
93.23
94.77
96.20
97.66
95.16
96.18
98.86
99.00
97.87
98.83
98.09
96.37
96.11
95.98
94.38
95.00
93.95
95.51
94.87
95.02
8/3/2023
TSS monthly removal rate
Month
January-19
February-19
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
Apri I-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
RR (%)
90.95
49.20
78.24
75.00
98.00
98.44
97.97
95.66
97.49
97.86
95.36
92.51
93.76
88.25
92.71
98.10
90.28
98.32
97.06
97.42
94.64
97.67
97.52
95.70
92.53
92.41
94.13
97.29
98.28
96.19
Month
July-21
August-21
September-21
October-21
November-21
December-21
January-22
February-22
March-22
April-22
May-22
June-22
July-22
August-22
September-22
October-22
November-22
December-22
January-23
February-23
March-23
April-23
May-23
June-23
July-23
August-23
September-23
October-23
November-23
December-23
Overall TSS removal rate
RR (%)
98.59
96.48
97.64
79.85
86.10
93.08
96.42
98.29
96.23
96.97
98.99
99.25
98.20
98.90
98.02
96.38
97.63
97.20
92.03
95.66
95.72
97.14
96.84
93.92

9/5/23 WQS = 12 ng/L
Facility Name West Stanly WWTP/NC0043532
/Permit No. :
Total Mercury 1631E PQL = 0.5 ng/L
Date
Modifier Data Entry
Value
1/14/22
2.27
2.27
4/13/22
< 1
0.5
8/8/22
< 0.5
0.5
MERCURY WQBEL/TBEL EVALUATION
No Limit Required
No MMP Required
7Q10s = 29.000 cfs WQBEL =
Permitted Flow = 2.500
V:2013-6
101.81 ng/L
47 ng/L
1.1 ng/L - Annual Average for 2022

9/5/23 WQS = 12 ng/L
Facility Name West Stanly WWTP/NC0043532
/Permit No. :
Total Mercury 1631E PQL = 0.5 ng/L
Date
Modifier Data Entry
Value
1/14/22
2.27
2.27
4/13/22
< 1
0.5
8/8/22
< 0.5
0.5
MERCURY WQBEL/TBEL EVALUATION
No Limit Required
No MMP Required
7Q10s = 29.000 cfs WQBEL =
Permitted Flow = 1.200
V:2013-6
199.10 ng/L
47 ng/L
1.1 ng/L - Annual Average for 2022

West Stanly WWTP/NC0043532
Mercury Data Statistics (Method 1631E)
2022
# of Samples
3
Annual Average, ng/L
1.1
Maximum Value, ng/L
2.27
TBEL, ng/L
47
WQBEL, ng/L
101.8

West Stanly WWTP/NC0043532
Mercury Data Statistics (Method 1631E)
2022
# of Samples
3
Annual Average, ng/L
1.1
Maximum Value, ng/L
2.27
TBEL, ng/L
47
WQBEL, ng/L
199.1

NH3/TRC WLA Calculations
Facility: West Stanly WWTP
PermitNo. NC0043532
Prepared By: Nick Coco
Enter Design Flow (MGD): 1.2
Enter s7Q10 (cfs): 29
Enter w7Q10 (cfs): 51
Total Residual Chlorine (TRC)
Daily Maximum Limit (ug/1)
Ammonia (Summer)
Monthly Average Limit (mg NH3-N/1)
s7Q10 (CFS)
29
s7Q10 (CFS)
29
DESIGN FLOW (MGD)
1.2
DESIGN FLOW (MGD)
1.2
DESIGN FLOW (CFS)
1.86
DESIGN FLOW (CFS)
1.86
STREAM STD (UG/L)
17.0
STREAM STD (MG/L)
1.0
Upstream Bkgd (ug/1)
0
Upstream Bkgd (mg/1)
0.22
IWC (%)
6.03
IWC (%)
6.03
Allowable Conc. (ug/1)
282
Allowable Conc. (mg/1)
13.2
Cap at 28 uq/L. Consistent with current limit.
Less stringent than current limit. Maintain limit.
Maintain limit.
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/1)
Fecal Coliform
w7Q10 (CFS)
51
Monthly Average Limit:
200/100mI DESIGN FLOW (MGD)
1.2
(If DF >331; Monitor)
DESIGN FLOW (CFS)
1.86
(If DF<331; Limit)
STREAM STD (MG/L)
1.8
Dilution Factor (DF)
16.59 Upstream Bkgd (mg/1)
0.22
IWC (%)
3.52
Allowable Conc. (mg/1)
45.1
Less stringent than current limit. 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)

NH3/TRC WLA Calculations
Facility: West Stanly WWTP
PermitNo. NC0043532
Prepared By: Nick Coco
Enter Design Flow (MGD): 2.5
Enter s7Q10 (cfs): 29
Enter w7Q10 (cfs): 51
Total Residual Chlorine (TRC) Ammonia (Summer)
Daily Maximum Limit (ug/1) Monthly Average Limit (mg NH3-N/1)
s7Q10 (CFS)
29
s7Q10 (CFS)
29
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 (%)
11.79
IWC (%)
11.79
Allowable Conc. (ug/1)
144
Allowable Conc. (mg/1)
6.8
Cap at 28 ug/L.
Less stringent than speculative
limit. Apply spec limit.
Apply limit.
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/1)
Fecal Coliform
w7Q10 (CFS)
51
Monthly Average Limit:
200/100mI 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)
8.48 Upstream Bkgd (mg/1)
0.22
IWC (%)
7.06
Allowable Conc. (mg/1)
22.6
Apply summer year-round until modeling demonstrates winter limits.
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)

MONITORING REPORT(MR) VIOLATIONS for:
Permit: NCO043532 MRS Betweei 7 - 2018 and 7 - 2023 Region: %
Facility Name: % Param Nam(% County: %
Major Minor: %
Report Date: 07/31/22 Page 1 of 27
Violation Category:Limit Violation Program Category:
Subbasin: % Violation Action: %
PERMIT: NCO043532
FACILITY: Stanly County -West Stanly WWTP
COUNTY: Stanly
REGION: Mooresville
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) -
05/31/20
3 X week
mg/I
9
9.9
10
Monthly Average
Proceed to NOV
Concentration
Exceeded
05-2020
001
Effluent
Chlorine, Total Residual
05/22/20
3 X week
mg/I
28
49
75
Daily Maximum
No Action, BPJ
Exceeded
05-2020
001
Effluent
Chlorine, Total Residual
05/28/20
3 X week
mg/I
28
49
75
Daily Maximum
No Action, BPJ
Exceeded
05-2020
001
Effluent
Coliform, Fecal MF, MFC
05/30/20
3 X week
#/100ml
400
600
50
Weekly Geometric Mean
Proceed to NOV
Broth, 44.5 C
Exceeded
05-2020
001
Effluent
Coliform, Fecal MF, MFC
05/31/20
3 X week
#/100ml
200
600
200
Monthly Geometric Mean
Proceed to NOV
Broth, 44.5 C
Exceeded
05-2020
001
Effluent
Flow, in conduit orthru
05/31/20
Continuous
mgd
0.9
1.37
52.6
Monthly Average
Proceed to NOV
treatment plant
Exceeded
05 -2020
001
Effluent
Nitrogen, Ammonia Total (as
05/31/20
3 X week
mg/I
2.8
4.3
53.6
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
09 - 2018
002
Effluent
BOD, 5-Day (20 Deg. C) -
09/22/18
3 X week
mg/I
13.5
25
85.2
Weekly Average
No Action, BPJ
Concentration
Exceeded
01 -2019
002
Effluent
BOD, 5-Day (20 Deg. C) -
01/05/19
3 X week
mg/I
27
27.47
1.7
Weekly Average
Proceed to NOV
Concentration
Exceeded
01 -2019
002
Effluent
BOD, 5-Day (20 Deg. C) -
01/12/19
3 X week
mg/I
27
42.67
58.0
Weekly Average
Proceed to NOV
Concentration
Exceeded
02 - 2019
002
Effluent
BOD, 5-Day (20 Deg. C) -
02/16/19
3 X week
mg/I
27
40.03
48.3
Weekly Average
Proceed to
Concentration
Exceeded
Enforcement Case
02 - 2019
002
Effluent
BOD, 5-Day (20 Deg. C) -
02/23/19
3 X week
mg/I
27
120
344.4
Weekly Average
Proceed to
Concentration
Exceeded
Enforcement Case
02 - 2019
002
Effluent
BOD, 5-Day (20 Deg. C) -
02/28/19
3 X week
mg/I
18
47.06
161.4
Monthly Average
Proceed to
Concentration
Exceeded
Enforcement Case
03 - 2019
002
Effluent
BOD, 5-Day (20 Deg. C) -
03/09/19
3 X week
mg/I
27
45.33
67.9
Weekly Average
Proceed to
Concentration
Exceeded
Enforcement Case
03 - 2019
002
Effluent
BOD, 5-Day (20 Deg. C) -
03/16/19
3 X week
mg/I
27
44.33
64.2
Weekly Average
Proceed to
Concentration
Exceeded
Enforcement Case

MONITORING REPORT(MR) VIOLATIONS for:
Permit: NCO043532 MRS Betweel 7 - 2018 and 7 - 2023 Region: %
Facility Name: % Param Nam(% County: %
Major Minor: %
Report Date: 07/31/2� Page 2 of 27
Violation Category:Limit Violation Program Category: %
Subbasin: % Violation Action: %
PERMIT: NCO043532
FACILITY: Stanly County -West Stanly WWTP
COUNTY: Stanly
REGION: Mooresville
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
03 - 2019
002
Effluent
BOD, 5-Day (20 Deg. C) -
03/31 /19
3 X week
mg/I
18
27.97
55.4
Monthly Average
Proceed to
Concentration
Exceeded
Enforcement Case
04 - 2019
002
Effluent
BOD, 5-Day (20 Deg. C) -
04/13/19
3 X week
mg/I
13.5
45.67
238.3
Weekly Average
Proceed to
Concentration
Exceeded
Enforcement Case
04 - 2019
002
Effluent
BOD, 5-Day (20 Deg. C) -
04/30/19
3 X week
mg/I
9
15.95
77.3
Monthly Average
Proceed to
Concentration
Exceeded
Enforcement Case
05 - 2020
002
Effluent
BOD, 5-Day (20 Deg. C) -
05/23/20
3 X week
mg/I
13.5
48
255.6
Weekly Average
Proceed to NOV
Concentration
Exceeded
05 - 2020
002
Effluent
BOD, 5-Day (20 Deg. C) -
05/31/20
3 X week
mg/I
9
16.13
79.3
Monthly Average
Proceed to NOV
Concentration
Exceeded
09 - 2020
002
Effluent
BOD, 5-Day (20 Deg. C) -
09/05/20
3 X week
mg/I
13.5
14.33
6.2
Weekly Average
Proceed to NOV
Concentration
Exceeded
10 - 2020
002
Effluent
BOD, 5-Day (20 Deg. C) -
10/03/20
3 X week
mg/I
13.5
16.4
21.5
Weekly Average
Proceed to NOV
Concentration
Exceeded
01 - 2021
002
Effluent
BOD, 5-Day (20 Deg. C) -
01/30/21
3 X week
mg/I
27
45
66.7
Weekly Average
Proceed to NOV
Concentration
Exceeded
06 - 2021
002
Effluent
BOD, 5-Day (20 Deg. C) -
06/12/21
3 X week
mg/I
13.5
22.73
68.4
Weekly Average
Proceed to
Concentration
Exceeded
Enforcement Case
06 - 2021
002
Effluent
BOD, 5-Day (20 Deg. C) -
06/30/21
3 X week
mg/I
9
10.44
16.0
Monthly Average
Proceed to
Concentration
Exceeded
Enforcement Case
10 - 2021
002
Effluent
BOD, 5-Day (20 Deg. C) -
10/16/21
3 X week
mg/I
13.5
43.33
221.0
Weekly Average
Proceed to NOV
Concentration
Exceeded
10 - 2021
002
Effluent
BOD, 5-Day (20 Deg. C) -
10/23/21
3 X week
mg/I
13.5
45
233.3
Weekly Average
Proceed to NOV
Concentration
Exceeded
10 - 2021
002
Effluent
BOD, 5-Day (20 Deg. C) -
10/30/21
3 X week
mg/I
13.5
72.33
435.8
Weekly Average
Proceed to NOV
Concentration
Exceeded
10 - 2021
002
Effluent
BOD, 5-Day (20 Deg. C) -
10/31/21
3 X week
mg/I
9
42.83
375.9
Monthly Average
Proceed to NOV
Concentration
Exceeded
12 - 2021
002
Effluent
BOD, 5-Day (20 Deg. C) -
12/04/21
3 X week
mg/I
27
31.33
16.0
Weekly Average
Proceed to NOV
Concentration
Exceeded
12 - 2021
002
Effluent
BOD, 5-Day (20 Deg. C) -
12/11/21
3 X week
mg/I
27
36.67
35.8
Weekly Average
Proceed to NOV
Concentration
Exceeded

MONITORING REPORT(MR) VIOLATIONS for:
Permit: NCO043532 MRS Betweel 7 - 2018 and 7 - 2023 Region: %
Facility Name: % Param Nam(% County: %
Major Minor: %
Report Date: 07/31/2� Page 3 of 27
Violation Category:Limit Violation Program Category: %
Subbasin: % Violation Action: %
PERMIT: NCO043532
FACILITY: Stanly County -West Stanly WWTP
COUNTY: Stanly
REGION: Mooresville
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
04 - 2022
002
Effluent
BOD, 5-Day (20 Deg. C) -
04/09/22
3 X week
mg/I
13.5
27.4
103.0
Weekly Average
Proceed to NOV
Concentration
Exceeded
04 - 2022
002
Effluent
BOD, 5-Day (20 Deg. C) -
04/30/22
3 X week
mg/I
9
9.7
7.8
Monthly Average
Proceed to NOV
Concentration
Exceeded
01 - 2023
002
Effluent
BOD, 5-Day (20 Deg. C) -
01/07/23
3 X week
mg/I
15
21.67
44.4
Weekly Average
None
Concentration
Exceeded
03 - 2023
002
Effluent
BOD, 5-Day (20 Deg. C) -
03/31 /23
3 X week
mg/I
10
13.84
38.4
Monthly Average
Proceed to NOV
Concentration
Exceeded
04 - 2023
002
Effluent
BOD, 5-Day (20 Deg. C) -
04/01/23
3 X week
mg/I
15
25
66.7
Weekly Average
Proceed to NOV
Concentration
Exceeded
04 - 2023
002
Effluent
BOD, 5-Day (20 Deg. C) -
04/30/23
3 X week
mg/I
10
11.41
14.1
Monthly Average
Proceed to NOV
Concentration
Exceeded
06 - 2023
002
Effluent
BOD, 5-Day (20 Deg. C) -
06/10/23
3 X week
mg/I
15
16.67
11.1
Weekly Average
None
Concentration
Exceeded
06 - 2023
002
Effluent
BOD, 5-Day (20 Deg. C) -
06/17/23
3 X week
mg/I
15
27
80
Weekly Average
None
Concentration
Exceeded
06 - 2023
002
Effluent
BOD, 5-Day (20 Deg. C) -
06/24/23
3 X week
mg/I
15
45.33
202.2
Weekly Average
None
Concentration
Exceeded
06 - 2023
002
Effluent
BOD, 5-Day (20 Deg. C) -
06/30/23
3 X week
mg/I
10
32.08
220.8
Monthly Average
None
Concentration
Exceeded
07-2018
002
Effluent
Chlorine, Total Residual
07/24/18
3 X week
ug/I
28
32
14.3
Daily Maximum
No Action, BPJ
Exceeded
10-2018
002
Effluent
Chlorine, Total Residual
10/11/18
3 Xweek
ug/I
28
38
35.7
Daily Maximum
No Action, BPJ
Exceeded
10-2018
002
Effluent
Chlorine, Total Residual
10/30/18
3 X week
ug/I
28
32
14.3
Daily Maximum
No Action, BPJ
Exceeded
11 -2018
002
Effluent
Chlorine, Total Residual
11/07/18
3 X week
ug/I
28
42
50
Daily Maximum
No Action, BPJ
Exceeded
12-2018
002
Effluent
Chlorine, Total Residual
12/12/18
3 X week
ug/I
28
31
10.7
Daily Maximum
No Action, BPJ
Exceeded
04-2019
002
Effluent
Chlorine, Total Residual
04/08/19
3 X week
ug/I
28
29
3.6
Daily Maximum
No Action, BPJ
Exceeded

MONITORING REPORT(MR) VIOLATIONS for:
Permit: NCO043532 MRS Betweel 7 - 2018 and 7 - 2023 Region: %
Facility Name: % Param Nam(% County: %
Major Minor: %
Report Date: 07/31/2� Page 23 of 27
Violation Category:Limit Violation Program Category: %
Subbasin: % Violation Action: %
PERMIT: NCO043532
FACILITY: Stanly County -West Stanly WWTP
COUNTY: Stanly
REGION: Mooresville
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
06-2023
002
Effluent
Chlorine, Total Residual
06/15/23
3 X week
ug/I
28
35
25
Daily Maximum
No Action, BPJ
Exceeded
06-2023
002
Effluent
Chlorine, Total Residual
06/22/23
3 X week
ug/I
28
43
53.6
Daily Maximum
No Action, BPJ
Exceeded
06-2023
002
Effluent
Chlorine, Total Residual
06/23/23
3 X week
ug/I
28
35
25
Daily Maximum
No Action, BPJ
Exceeded
06-2023
002
Effluent
Chlorine, Total Residual
06/29/23
3 X week
ug/I
28
42
50
Daily Maximum
No Action, BPJ
Exceeded
06-2023
002
Effluent
Chlorine, Total Residual
06/30/23
3 X week
ug/I
28
48
71.4
Daily Maximum
No Action, BPJ
Exceeded
09-2018
002
Effluent
Coliform, Fecal MF, MFC
09/22/18
3 X week
#/100ml
400
2,083.68
420.9
Weekly Geometric Mean
No Action, BPJ
Broth, 44.5 C
Exceeded
11 -2018
002
Effluent
Coliform, Fecal MF, MFC
11/10/18
3 X week
#/100ml
400
819.76
104.9
Weekly Geometric Mean
Proceed to NOV
Broth, 44.5 C
Exceeded
11 -2018
002
Effluent
Coliform, Fecal MF, MFC
11/17/18
3 X week
#/100ml
400
2,737.74
584.4
Weekly Geometric Mean
Proceed to NOV
Broth, 44.5 C
Exceeded
11 -2018
002
Effluent
Coliform, Fecal MF, MFC
11/30/18
3 X week
#/100ml
200
332.38
66.2
Monthly Geometric Mean
Proceed to NOV
Broth, 44.5 C
Exceeded
12-2018
002
Effluent
Coliform, Fecal MF, MFC
12/15/18
3 X week
#/100ml
400
866.68
116.7
Weekly Geometric Mean
Proceed to NOV
Broth, 44.5 C
Exceeded
12-2018
002
Effluent
Coliform, Fecal MF, MFC
12/29/18
3 X week
#/100ml
400
1,871.22
367.8
Weekly Geometric Mean
Proceed to NOV
Broth, 44.5 C
Exceeded
12-2018
002
Effluent
Coliform, Fecal MF, MFC
12/31/18
3 X week
#/100ml
200
293.17
46.6
Monthly Geometric Mean
Proceed to NOV
Broth, 44.5 C
Exceeded
01 -2019
002
Effluent
Coliform, Fecal MF, MFC
01/05/19
3 X week
#/100ml
400
832.03
108.0
Weekly Geometric Mean
Proceed to NOV
Broth, 44.5 C
Exceeded
01 -2019
002
Effluent
Coliform, Fecal MF, MFC
01/12/19
3 X week
#/100ml
400
605.5
51.4
Weekly Geometric Mean
Proceed to NOV
Broth, 44.5 C
Exceeded
02-2019
002
Effluent
Coliform, Fecal MF, MFC
02/23/19
3 X week
#/100ml
400
1,358.65
239.7
Weekly Geometric Mean
Proceed to
Broth, 44.5 C
Exceeded
Enforcement Case
03-2019
002
Effluent
Coliform, Fecal MF, MFC
03/09/19
3 X week
#/100ml
400
1,829.15
357.3
Weekly Geometric Mean
Proceed to
Broth. 44.5 C
Exceeded
Enforcement Case

MONITORING REPORT(MR) VIOLATIONS for:
Permit: NCO043532 MRS Betweel 7 - 2018 and 7 - 2023 Region: %
Facility Name: % Param Nam(% County: %
Major Minor: %
Report Date: 07/31/2� Page 24 of 27
Violation Category:Limit Violation Program Category: %
Subbasin: % Violation Action: %
PERMIT: NCO043532
FACILITY: Stanly County -West Stanly WWTP
COUNTY: Stanly
REGION: Mooresville
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
03-2019
002
Effluent
Coliform, Fecal MF, MFC
03/30/19
3 X week
#/100ml
400
970.61
142.7
Weekly Geometric Mean
Proceed to
Broth, 44.5 C
Exceeded
Enforcement Case
03-2019
002
Effluent
Coliform, Fecal MF, MFC
03/31/19
3 X week
#/100ml
200
291.36
45.7
Monthly Geometric Mean
Proceed to
Broth, 44.5 C
Exceeded
Enforcement Case
05-2020
002
Effluent
Coliform, Fecal MF, MFC
05/23/20
3 X week
#/100ml
400
2,784.95
596.2
Weekly Geometric Mean
Proceed to NOV
Broth, 44.5 C
Exceeded
08-2018
002
Effluent
Flow, in conduit or thru
08/31/18
Continuous
mgd
0.9
13.44
1,393.0
Monthly Average
Proceed to NOV
treatment plant
Exceeded
12-2018
002
Effluent
Flow, in conduit or thru
12/31/18
Continuous
mgd
0.9
1.04
15.9
Monthly Average
Proceed to NOV
treatment plant
Exceeded
02 - 2020
002
Effluent
Flow, in conduit or thru
02/29/20
Continuous
mgd
0.9
0.93
3.0
Monthly Average
Proceed to NOV
treatment plant
Exceeded
01 -2021
002
Effluent
Flow, in conduit or thru
01/31/21
Continuous
mgd
0.9
0.9
0.5
Monthly Average
Proceed to NOV
treatment plant
Exceeded
02 - 2021
002
Effluent
Flow, in conduit or thru
02/28/21
Continuous
mgd
0.9
1.11
23.4
Monthly Average
Proceed to NOV
treatment plant
Exceeded
01 -2019
002
Effluent
Nitrogen, Ammonia Total (as
01/31/19
3 X week
mg/I
6
7.31
21.9
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
01 -2020
002
Effluent
Nitrogen, Ammonia Total (as
01/18/20
3 X week
mg/I
18
19.12
6.3
Weekly Average
Proceed to NOV
N) - Concentration
Exceeded
01 -2020
002
Effluent
Nitrogen, Ammonia Total (as
01/25/20
3 X week
mg/I
18
23.67
31.5
Weekly Average
Proceed to NOV
N) - Concentration
Exceeded
01 -2020
002
Effluent
Nitrogen, Ammonia Total (as
01/31/20
3 X week
mg/I
6
13.32
122.0
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
02 - 2020
002
Effluent
Nitrogen, Ammonia Total (as
02/22/20
3 X week
mg/I
18
23.67
31.5
Weekly Average
Proceed to NOV
N) - Concentration
Exceeded
02 - 2020
002
Effluent
Nitrogen, Ammonia Total (as
02/29/20
3 X week
mg/I
6
17.99
199.9
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
03 - 2020
002
Effluent
Nitrogen, Ammonia Total (as
03/07/20
3 X week
mg/I
18
25.67
42.6
Weekly Average
Proceed to NOV
N) - Concentration
Exceeded
03 -2020
002
Effluent
Nitrogen, Ammonia Total (as
03/31/20
3 X week
mg/I
6
12.38
106.4
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded

MONITORING REPORT(MR) VIOLATIONS for:
Permit: NCO043532 MRS Betweel 7 - 2018 and 7 - 2023 Region: %
Facility Name: % Param Nam(% County: %
Major Minor: %
Report Date: 07/31/2� Page 25 of 27
Violation Category:Limit Violation Program Category: %
Subbasin: % Violation Action: %
PERMIT: NCO043532
FACILITY: Stanly County -West Stanly WWTP
COUNTY: Stanly
REGION: Mooresville
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
04 - 2020
002
Effluent
Nitrogen, Ammonia Total (as
04/30/20
3 X week
mg/I
3
3.11
3.8
Monthly Average
Proceed to NOD
N) - Concentration
Exceeded
05 - 2020
002
Effluent
Nitrogen, Ammonia Total (as
05/23/20
3 X week
mg/I
9
20
122.2
Weekly Average
Proceed to NOV
N) - Concentration
Exceeded
05 -2020
002
Effluent
Nitrogen, Ammonia Total (as
05/31/20
3 X week
mg/I
3
6.54
117.9
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
06 - 2020
002
Effluent
Nitrogen, Ammonia Total (as
06/27/20
3 X week
mg/I
9
15.33
70.4
Weekly Average
Proceed to NOV
N) - Concentration
Exceeded
06 - 2020
002
Effluent
Nitrogen, Ammonia Total (as
06/30/20
3 X week
mg/I
3
7.58
152.8
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
09 - 2020
002
Effluent
Nitrogen, Ammonia Total (as
09/30/20
3 X week
mg/I
3
3.22
7.4
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
10 -2020
002
Effluent
Nitrogen, Ammonia Total (as
10/31/20
3 X week
mg/I
3
3.58
19.3
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
03 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
03/31 /21
3 X week
mg/I
6
13.7
128.3
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
04 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
04/03/21
3 X week
mg/I
9
11.3
25.6
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
04 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
04/10/21
3 X week
mg/I
9
14.67
63.0
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
04 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
04/17/21
3 X week
mg/I
9
21
133.3
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
04 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
04/24/21
3 X week
mg/I
9
18
100
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
04 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
04/30/21
3 X week
mg/I
3
17.38
479.5
Monthly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
05 -2021
002
Effluent
Nitrogen, Ammonia Total (as
05/01/21
3 X week
mg/I
9
17.33
92.6
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
05 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
05/08/21
3 X week
mg/I
9
18.67
107.4
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
05 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
05/15/21
3 X week
mg/I
9
12.33
37.0
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case

MONITORING REPORT(MR) VIOLATIONS for:
Permit: NCO043532 MRS Betweel 7 - 2018 and 7 - 2023 Region: %
Facility Name: % Param Nam(% County: %
Major Minor: %
Report Date: 07/31/2� Page 26 of 27
Violation Category:Limit Violation Program Category: %
Subbasin: % Violation Action: %
PERMIT: NCO043532
FACILITY: Stanly County -West Stanly WWTP
COUNTY: Stanly
REGION: Mooresville
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
05 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
05/22/21
3 X week
mg/I
9
11.9
32.2
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
05 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
05/29/21
3 X week
mg/I
9
32.67
263.0
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
05 -2021
002
Effluent
Nitrogen, Ammonia Total (as
05/31/21
3 X week
mg/I
3
18.89
529.7
Monthly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
06 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
06/05/21
3 X week
mg/I
9
38.33
325.9
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
06 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
06/12/21
3 X week
mg/I
9
14.77
64.1
Weekly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
06 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
06/30/21
3 X week
mg/I
3
12.61
320.4
Monthly Average
Proceed to
N) - Concentration
Exceeded
Enforcement Case
10 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
10/23/21
3 X week
mg/I
9
29.33
225.9
Weekly Average
Proceed to NOV
N) - Concentration
Exceeded
10 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
10/30/21
3 X week
mg/I
9
30.33
237.0
Weekly Average
Proceed to NOV
N) - Concentration
Exceeded
10 -2021
002
Effluent
Nitrogen, Ammonia Total (as
10/31/21
3 X week
mg/I
3
17.17
472.2
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
11 -2021
002
Effluent
Nitrogen, Ammonia Total (as
11/06/21
3 X week
mg/I
18
25.33
40.7
Weekly Average
Proceed to NOV
N) - Concentration
Exceeded
11 -2021
002
Effluent
Nitrogen, Ammonia Total (as
11/30/21
3 X week
mg/I
6
11.93
98.9
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
12 - 2021
002
Effluent
Nitrogen, Ammonia Total (as
12/04/21
3 X week
mg/I
18
18.07
0.4
Weekly Average
Proceed to NOV
N) - Concentration
Exceeded
03 -2023
002
Effluent
Nitrogen, Ammonia Total (as
03/31/23
3 X week
mg/I
4
5.03
25.8
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
04 - 2023
002
Effluent
Nitrogen, Ammonia Total (as
04/30/23
3 X week
mg/I
4
4.4
9.9
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
05 -2023
002
Effluent
Nitrogen, Ammonia Total (as
05/31/23
3 X week
mg/I
4
5.82
45.5
Monthly Average
Proceed to NOV
N) - Concentration
Exceeded
06 - 2023
002
Effluent
Nitrogen, Ammonia Total (as
06/17/23
3 X week
mg/I
12
12.67
5.6
Weekly Average
None
N) - Concentration
Exceeded

MONITORING REPORT(MR) VIOLATIONS for:
Permit: NCO043532 MRS Betweel 7 - 2018 and 7 - 2023 Region: %
Facility Name: % Param Nam(% County: %
Major Minor: %
Report Date: 07/31/2� Page 27 of 27
Violation Category:Limit Violation Program Category: %
Subbasin: % Violation Action: %
PERMIT: NCO043532
FACILITY: Stanly County -West Stanly WWTP
COUNTY: Stanly
REGION: Mooresville
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT
OUTFALL
LOCATION
PARAMETER
DATE
FREQUENCY
MEASURE
LIMIT
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
06 - 2023
002
Effluent
Nitrogen, Ammonia Total (as
06/24/23
3 X week
mg/I
12
12.57
4.7
Weekly Average
None
N) - Concentration
Exceeded
06 - 2023
002
Effluent
Nitrogen, Ammonia Total (as
06/30/23
3 X week
mg/I
4
13.99
249.8
Monthly Average
None
N) - Concentration
Exceeded
09-2018
002
Effluent
Oxygen, Dissolved (DO)
09/20/18
3 X week
mg/I
5
0.09
98.2
Daily Minimum Not
No Action, BPJ
Reached
02 - 2019
002
Effluent
Solids, Total Suspended -
02/16/19
3 X week
mg/I
45
134
197.8
Weekly Average
Proceed to
Concentration
Exceeded
Enforcement Case
02 - 2019
002
Effluent
Solids, Total Suspended -
02/23/19
3 X week
mg/I
45
127
182.2
Weekly Average
Proceed to
Concentration
Exceeded
Enforcement Case
02 - 2019
002
Effluent
Solids, Total Suspended -
02/28/19
3 X week
mg/I
30
70.74
135.8
Monthly Average
Proceed to
Concentration
Exceeded
Enforcement Case
03 - 2019
002
Effluent
Solids, Total Suspended -
03/16/19
3 X week
mg/I
45
76.27
69.5
Weekly Average
Proceed to
Concentration
Exceeded
Enforcement Case
03 -2019
002
Effluent
Solids, Total Suspended -
03/31/19
3 X week
mg/I
30
33.46
11.5
Monthly Average
Proceed to
Concentration
Exceeded
Enforcement Case
04 - 2019
002
Effluent
Solids, Total Suspended -
04/13/19
3 X week
mg/I
45
125.33
178.5
Weekly Average
Proceed to
Concentration
Exceeded
Enforcement Case
04 - 2019
002
Effluent
Solids, Total Suspended -
04/30/19
3 X week
mg/I
30
38.92
29.7
Monthly Average
Proceed to
Concentration
Exceeded
Enforcement Case
02 - 2020
002
Effluent
Solids, Total Suspended -
02/22/20
3 X week
mg/I
45
48.33
7.4
Weekly Average
Proceed to NOV
Concentration
Exceeded
05 - 2020
002
Effluent
Solids, Total Suspended -
05/23/20
3 X week
mg/I
45
59.33
31.9
Weekly Average
Proceed to NOV
Concentration
Exceeded
10 - 2021
002
Effluent
Solids, Total Suspended -
10/30/21
3 X week
mg/I
70
86
22.9
Weekly Average
Proceed to
Concentration
Exceeded
Enforcement Case

Coco, Nick A
From: Genevieve Versteeg <[e-mail]>
Sent: Tuesday, August 29, 2023 2:30 PM
To: Coco, Nick A
Cc: Carl Scharfe
Subject: [External] RE: West Stanly WWTP Narrative Description
Follow Up Flag: Flag for follow up
Flag Status: Flagged
CAUTION: External email. Do not click links or open attachments unless verified. Report suspicious emails with the Report Message
button located on your Outlook menu bar on the Home tab.
Not sure how specific you want it, but here's a narrative of the 1.2-MGD West Stanly WWTP.
Wastewater treatment consists of the McCoy Creek Pump Station (an offsite pump station located in Oakboro),
screening and grit removal headworks, biological treatment via conventional extended aeration basins, clarification, and
disinfection with chlorination followed by de -chlorination. The treated wastewater is pumped via a pressure force main
1.82 miles to Rocky River, Outfall 002. Outfall 001, which historically served as an emergency discharge to Long Creek, is
no longer a permitted discharge. Treated effluent from the West Stanly WWTP is discharged into the Rocky River (class
C) in the Yadkin Pee -Dee drainage basin under NPDES Permit NC0043532. Sludge is treated through aerobic digestion.
Please let me know if you need anything else!
-Genevieve
From: Coco, Nick A <[e-mail]>
Sent: Tuesday, August 29, 2023 2:18 PM
To: Genevieve Versteeg <[e-mail]>
Subject: West Stanly WWTP Narrative Description
Hi Genevieve,
When you have a moment, would you please provide a brief narrative description of the existing West Stanly WWTP
process? I'd missed this earlier when looking through the application, but it's technically required for a complete app. I
see the process flow diagram, but technically there needs to be a written narrative to accompany it.
Thanks,
Nick Coco, PE (he/him/his)
Engineer 111
NPDES Municipal Permitting Unit
NC DEQ / Division of Water Resources / Water Quality Permitting
Office: [phone]
[e-mail]
Physical Address: 512 North Salisbury St.,Raleigh, NC, 27604
Mailing Address: 1617 Mail Service Center, Raleigh, NC, 27699-1617

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 NCO043532 I11 121 22/08/23 I17 18I � I 19 I s I 20L]
21111I I I I I I I II I I I I I I I I I I I I I I I I I I I I I I I II I I I I I r6
Inspection
Work Days Facility Self -Monitoring Evaluation Rating B1 QA ---------------------- Reserved -------------------
67
I 72 I n, I 71 I 74 79 I I I I I I I80
701� I 711 L
LJ L -1 I I
Section B: Facility Data
Name and Location of Facility Inspected (For Industrial Users discharging to POTW, also include
Entry Time/Date
Permit Effective Date
POTW name and NPDES permit Number)
10:05AM 22/08/23
18/12/01
West Stanly WWTP
24939-B Barbees Grove Rd
Exit Time/Date
Permit Expiration Date
Oakboro NC 28129
12:10PM 22/08/23
23/01/31
Name(s) of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s)
Other Facility Data
Tommy Gibbons/ORC/704-486-0285/
Name, Address of Responsible Official/Title/Phone and Fax Number
Contacted
Andy Lucas,1000 N 1st St Ste 12 Albemarle NC 28001/County
Manager/704-986-3601/7049863711 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 Compliance Schedules
Effluent/Receiving Wate 0 Laboratory
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
(See attachment summary)
Name(s) and Signature(s) of Inspector(s) Agency/Office/Phone and Fax Numbers Date
Roberto Scheller DWR/MRO WQ/707-235-2204/
Signature of Management Q A Reviewer Agency/Office/Phone and Fax Numbers Date
Andrew Pitner DWR/MRO WQ/704-663-1699 Ext.2180/
EPA Form 3560-3 (Rev 9-94) Previous editions are obsolete.
Page#

NPDES yr/mo/day Inspection Type
NCO043532 I11 12I 22/08/23 117 18 i s i
(Cont.)
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
The current permit became effective December 1, 2018 and expires on January 31, 2023. Permit is
for the discharge of wastewater into the Rocky River (Outfall #002) and Long Creek (Outfall #001).
Both discharge locations are classified as C waters in the Yadkin -Pee Dee River Basin. This facility
expanded from 0.9 MGD to 1.2 MGD WWTP under Authorization to Construct #043532A01 and SOC
S 19-003.
The subject inspection was conducted as a Compliance Sampling Inspection during which samples
were split with WWTP operator for BOD, NH3 as N, and TSS. Analysis will be sent under seperate
cover.
It was noted during facility review that influent screen had a large amount of solids build-up on screen
and appeared that wash cycle is not operating properly.
Page#

Permit: NCO043532 Owner -Facility: West Stanly WWTP
Inspection Date: 08/23/2022 Inspection Type: Compliance Sampling
Permit
Yes
No
NA NE
(If the present permit expires in 6 months or less). Has the permittee submitted a new
❑
❑
■
❑
application?
Is the facility as described in the permit?
■
❑
❑
❑
# Are there any special conditions for the permit?
■
❑
❑
❑
Is access to the plant site restricted to the general public?
■
❑
❑
❑
Is the inspector granted access to all areas for inspection?
■
❑
❑
❑
Comment:
Record Keeping
Yes
No
NA
NE
Are records kept and maintained as required by the permit?
■
❑
❑
❑
Is all required information readily available, complete and current?
■
❑
❑
❑
Are all records maintained for 3 years (lab. reg. required 5 years)?
■
❑
❑
❑
Are analytical results consistent with data reported on DMRs?
■
❑
❑
❑
Is the chain -of -custody complete?
■
❑
❑
❑
Dates, times and location of sampling
■
Name of individual performing the sampling
■
Results of analysis and calibration
■
Dates of analysis
■
Name of person performing analyses
■
Transported COCs
■
Are DMRs complete: do they include all permit parameters?
■
❑
❑
❑
Has the facility submitted its annual compliance report to users and DWQ?
■
❑
❑
❑
(If the facility is = or > 5 MGD permitted flow) Do they operate 24/7 with a certified
❑
❑
■
❑
operator on each shift?
Is the ORC visitation log available and current?
■
❑
❑
❑
Is the ORC certified at grade equal to or higher than the facility classification?
■
❑
❑
❑
Is the backup operator certified at one grade less or greater than the facility
■
❑
❑
❑
classification?
Is a copy of the current NPDES permit available on site?
■
❑
❑
❑
Facility has copy of previous year's Annual Report on file for review?
❑
❑
❑
■
Comment: 2021-2022 Annual Report on Stanly County Utilities (SCU) website.
Laboratory Yes No NA NE
Are field parameters performed by certified personnel or laboratory? ■ ❑ ❑ ❑
Page# 3

Permit: NCO043532 Owner -Facility: West Stanly WWTP
Inspection Date: 08/23/2022 Inspection Type: Compliance Sampling
Laboratory Yes No NA NE
Are all other parameters(excluding field parameters) performed by a certified lab?
0
❑
❑
❑
# Is the facility using a contract lab?
■
❑
❑
❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0
0
❑
❑
❑
degrees Celsius)?
Incubator (Fecal Coliform) set to 44.5 degrees Celsius+/- 0.2 degrees?
❑
❑
0
❑
Incubator (BOD) set to 20.0 degrees Celsius +/- 1.0 degrees?
❑
❑
❑
Comment: Facility uses contract labs Environmental 1 (Cert.#10), Meritech (Cert.#27), and on site
Field Certification (Cert.#5671).
Bar Screens
Type of bar screen
Yes No NA NE
a.Manual
❑
b.Mechanical
Are the bars adequately screening debris?
❑
❑
❑
Is the screen free of excessive debris?
❑
■
❑
❑
Is disposal of screening in compliance?
0
❑
❑
❑
Is the unit in good condition?
0
❑
❑
❑
Comment: Influent screen has large amount of buildup onscreen and appears
that wash cycle is
not operating properly.
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:
Influent Sampling
Yes
No
NA
NE
# Is composite sampling flow proportional?
0
❑
❑
❑
Is sample collected above side streams?
■
❑
❑
❑
Is proper volume collected?
0
❑
❑
❑
Is the tubing clean?
0
❑
❑
❑
Page# 4

Permit: NCO043532
Inspection Date: 08/23/2022
Owner -Facility: West Stanly WWTP
Inspection Type: Compliance Sampling
Influent Sampling
# 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: At time of inspection influent sampler was recorded at 4 degrees C.
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)
Comment:
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)
Comment:
Pumps-RAS-WAS
Are pumps in place?
Yes No NA NE
■ ❑ ❑ ❑
■ ❑ ❑ ❑
Yes No NA NE
Ext. Air
Surface
■
❑
❑
❑
■
❑
❑
❑
❑
❑
■
❑
■
❑
❑
❑
■
❑
❑
❑
❑
❑
❑
■
❑
❑
❑
■
Yes No NA NE
■ ❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
❑ ❑ ❑ ■
Yes No NA NE
■ ❑ ❑ ❑
Page# 5

Permit: NCO043532
Inspection Date: 08/23/2022
Owner -Facility: West Stanly WWTP
Inspection Type: Compliance Sampling
Pumps-RAS-WAS
Yes
No
NA
NE
Are pumps operational?
0
❑
❑
❑
Are there adequate spare parts and supplies on site?
0
❑
❑
❑
Comment:
Disinfection -Gas
Yes
No
NA
NE
Are cylinders secured adequately?
0
❑
❑
❑
Are cylinders protected from direct sunlight?
0
❑
❑
❑
Is there adequate reserve supply of disinfectant?
0
❑
❑
❑
Is the level of chlorine residual acceptable?
❑
❑
❑
Is the contact chamber free of growth, or sludge buildup?
0
❑
❑
❑
Is there chlorine residual prior to de -chlorination?
0
❑
❑
❑
Does the Stationary Source have more than 2500 Ibs of Chlorine (CAS No.
❑
❑
0
❑
7782-50-5)?
If yes, then is there a Risk Management Plan on site?
❑
❑
0
❑
If yes, then what is the EPA twelve digit ID Number? (1000-
If yes, then when was the RMP last updated?
Comment:
De -chlorination
Yes
No
NA
NE
Type of system ?
Gas
Is the feed ratio proportional to chlorine amount (1 to 1)?
❑
❑
❑
Is storage appropriate for cylinders?
0
❑
❑
❑
# Is de -chlorination substance stored away from chlorine containers?
0
❑
❑
❑
Comment:
Are the tablets the proper size and type? ❑ ❑ ❑
Are tablet de -chlorinators operational? ❑ ❑ ❑
Number of tubes in use?
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?
0
❑
❑
❑
Page# 6

Permit: NCO043532 Owner -Facility: West Stanly WWTP
Inspection Date: 08/23/2022 Inspection Type: Compliance Sampling
Effluent Sampling
Yes
No
NA
NE
Is the tubing clean?
0
❑
❑
❑
# 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)?
Comment: At time of inspection effluent sampler was recorded at 3.0 degrees C.
Pump Station - Effluent
Yes
No
NA
NE
Is the pump wet well free of bypass lines or structures?
■
❑
❑
❑
Are all pumps present?
■
❑
❑
❑
Are all pumps operable?
0
❑
❑
❑
Are float controls operable?
0
❑
❑
❑
Is SCADA telemetry available and operational?
❑
❑
❑
Is audible and visual alarm available and operational?
❑
❑
❑
■
Comment:
Flow Measurement - Effluent
Yes
No
NA
NE
# Is flow meter used for reporting?
■
❑
❑
❑
Is flow meter calibrated annually?
0
❑
❑
❑
Is the flow meter operational?
0
❑
❑
❑
(If units are separated) Does the chart recorder match the flow meter?
M
❑
❑
❑
Comment: Last calibration 11/16/2021.
Standby Power
Yes
No
NA
NE
Is automatically activated standby power available?
0
❑
❑
❑
Is the generator tested by interrupting primary power source?
■
❑
❑
❑
Is the generator tested under load?
0
❑
❑
❑
Was generator tested & operational during the inspection?
❑
❑
❑
Do the generator(s) have adequate capacity to operate the entire wastewater site?
0
❑
❑
❑
Is there an emergency agreement with a fuel vendor for extended run on back-up
■
❑
❑
❑
power?
Is the generator fuel level monitored?
0
❑
❑
❑
Comment:
Page# 7

Permit: NCO043532 Owner -Facility: West Stanly WWTP
Inspection Date: 08/23/2022 Inspection Type: Compliance Sampling
Compliance Schedules
Yes
No
NA
NE
Is there a compliance schedule for this facility?
❑
❑
0
❑
Is the facility compliant with the permit and conditions for the review period?
0
❑
❑
❑
Comment: Facility under SOC S19-003.
Operations & Maintenance Yes No NA NE
Is the plant generally clean with acceptable housekeeping? 0 ❑ ❑ ❑
Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable 0 ❑ ❑ ❑
Solids, pH, DO, Sludge Judge, and other that are applicable?
Comment:
Page# 8

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
LINDA CULPEPPER
Director
Duane Wingo, PE
Stanly County Utilities Director
1000 N. First Street, Suite 12
Albemarle, North Carolina 28001
Dear Mr. Wingo:
NORTH CAROLINA
Environmental Quality
January 27, 2020
Subject: Speculative Effluent Limits
West Stanly WWTP
Permit No. NCO043532
Stanly County
Yadkin -Pee Dee River Basin
This letter provides speculative effluent limits for expansion to 2.5 MGD at the West Stanly
WWTP. The Division received the speculative limits request from the County in a letter dated
November 12, 2019. Please recognize that speculative limits may change based on future water
quality initiatives, and it is highly recommended that the applicant verify the speculative limits
with the Division's NPDES Unit prior to any engineering design work.
Receiving Stream. The Rocky River is located within the Yadkin -Pee Dee River Basin. The
Rocky River has a stream classification of C, and waters with this classification have a best
usage for aquatic life propagation and maintenance of biological integrity, wildlife, secondary
recreation and agriculture. The Rocky River has a summer 7Q 10 flow of 29 cubic feet per
second (cfs), a winter 7Q10 flow of 51 cfs, and an annual average flow of 920 cfs.
The Rocky River is currently listed as an impaired waterbody on the 2018 North Carolina
303(d) Impaired Waters List for dissolved copper and turbidity. This impairment may affect
future effluent limits for these parameters.
Based upon a review of information available from the North Carolina Natural Heritage
Program Online Map Viewer, there are not any Federally Listed threatened or endangered
aquatic species identified within a 5-mile radius of the proposed discharge location. If there
are any identified threatened/endangered species, it is recommended that the applicant discuss
the proposed project with the US Fish and Wildlife Service to determine whether the proposed
discharge location might impact such species.
Speculative Effluent Limits. Based on Division review of receiving stream conditions and
water quality modeling results, speculative limits for the proposed expansion to 2.5 MGD are
presented in Table 1. A complete evaluation of these limits and monitoring requirements for
D North Carolina Department of Environmental Quality I Division of Water Resources
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512 North Salisbury Street 1 1617 Mail Service Center I Raleigh: North Carolina 27699-1617
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^�1� 919.707.9000

metals and other toxicants, as well as potential instream monitoring requirements, will be
addressed upon receipt of a formal NPDES permit application. Some features of the
speculative limit development include the following:
• BOD/NH3 Limits. These speculative limits are based on freezing current permitted
BOD ultimate loading (i.e., facility will not be allowed to discharge oxygen -consuming
waste above what is currently permitted). Requests for seasonal limits in accordance
with 15A NCAC 02B .0404 will need to be supported by a QUAL2K or equivalent
water quality model. The resultant limits at expanded flows are considered
technologically -feasible.
TABLE 1. Speculative Limits for the West Stanly WWTP
Effluent Characteristic
Effluent Limitations
Monthly
Average
Weekly
Average
Daily
Maximum
Flow
2.5 MGD
BOD5
5.0 mg/L
7.5 mg/L
NH3 as N
1.8 mg/L
5.4 mg/L
Dissolved Oxygen
5.0 mg/L Daily Minimum Average
TSS
30.0 mg/L
45.0 mg/L
TRC
28 µg/l
Fecal coliform (geometric
mean)
200/100 ml
400/100 ml
Chronic Toxicity, Pass/Fail
(Quarterly test)
4.6% '
Subject to change. Updated flows will be determined upon receipt of application for
expansion.
Engineering Alternatives Analysis (EAA). Please note that the Division cannot guarantee that
an NPDES permit for a new or expanding discharge will be issued with these speculative limits.
Final decisions can only be made after the Division receives and evaluates a formal permit
application for the new/expanded discharge. In accordance with North Carolina
Administrative Code 15A NCAC 2H.0105(c), the most environmentally sound alternative
should be selected from all reasonably cost effective options. Therefore, as a component of all
NPDES permit applications for new or expanding flow, a detailed engineering alternatives
analysis (EAA) must be prepared. The EAA must justify requested flows and provide an
analysis of potential wastewater treatment alternatives. A copy of the Division guidance for
preparing EAA documents is attached.
State Environmental Policy Act (SEPA) EA/EIS Requirements. A SEPA EA/EIS document
maybe required for projects that: 1) involve $10 Million or more of state funds; or 2) will
significantly and permanently impact 10 or more acres of public lands. Please check with the
DWR SEPA coordinator (David Wainwright, 919-707-9045) as to whether your project
requires SEPA review. For projects that are subject to SEPA, the EAA requirements discussed
above will need to be folded into the SEPA document. Additionally, if subject to SEPA, the
NPDES Unit will not accept an NPDES permit application for a new/expanding discharge until
Page 2 of 3

the Division has approved the SEPA document and sent a Finding of No Significant Impact
(FONSI) to the State Clearinghouse for review and comment.
Should you have any questions about these speculative limits or NPDES permitting
requirements, please feel free to contact David Hill at [phone].
Respectfully,
Jlie Grzyb
pervisor, NPDES Complex Permitting Unit
Attachment: EAA Guidance Document
Hardcopy:
NPDES Permit File
Electronic Copy:
NC WRC, Inland Fisheries, [e-mail]
US Fish and Wildlife Service, [e-mail]
DWR/Mooresville Regional Office/Water Quality Regional Operations/Corey
Basinger
DWR/Modeling and Assessment Branch/Pam Behm
DWR/Basinwide Planning/ Ian McMillan
DWR/NPDES Server>Specs
Page 3 of 3

USDA
United States Department of Agriculture
Rural Development December 9, 2022
North Carolina
(SI 1970-C, Exh. F Att. 5)
State Office
Stanly County Utilities Department
4405 Bland Road
Attn: Mr. Andy Lucas
Suite 260
Raleigh, NC 27609
1000 North First Street, Suite 12
Albemarle, North Carolina 28001
Voice 919.873.2099
Fax [phone]
Dear Mr. Lucas:
Rural Development has completed an Environmental Assessment (EA) on your
proposal requesting financial assistance to construct the West Stanly Wastewater
Treatment Facilities Phase II Expansion. Rural Development has determined that your
proposal will not significantly affect the quality of the human environment, and has
therefore issued a Finding of No Significant Impact (FONSI).
Before further consideration can be given to your proposal, our regulations require
you to publish a notice of the FONSI in a newspaper of general circulation and in any
local or community newspaper in your proposal's vicinity. The notice will be published
once in easily readable type in the non -classified section in the same newspaper(s) where
the NOA was published. It is your responsibility to make the arrangements to publish the
notice. You must also provide our office with a copy of the published notice as it appeared,
the name(s) of the newspapers in which the notice was published, the date(s) of
publication, and an affidavit of publication. A copy of the notice is enclosed. If you have
any questions concerning this letter, please contact Lynn Whittington, Community
Programs Specialist, via email at [e-mail] or by phone at 336-308-
1660.
Sincerely,
HEATHER MURPHY
Environmental Protection Specialist
State Office, Rural Development
United States Department of Agriculture
Enclosure: West Stanly Wastewater Treatment Facilities Phase II Expansion — FONSI
Notice
USDA is an equal opportunity provider, employer, and lender.