NC0025721_Fact Sheet_20230403

Fact Sheet
NPDES Permit No. NCOO25721
Permit Writer/Email Contact Nick Coco,[e-mail]
Date: February 21,2023
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: Town of Weldon/Weldon Wastewater Treatment Plant(WWTP)
Applicant Address: PO Box 551,Weldon,NC 27890
Facility Address: 525 River Road,Weldon,NC 27890
Permitted Flow: 1.2 MGD
Facility Type/Waste: MAJOR Municipal; 100%domestic
Facility Class: Grade III Biological Water Pollution Control System
Treatment Units: influent bar screening and pH adjustment with caustic as needed,
influent pumps, dual oxidation ditches,two secondary clarifiers, one
aerobic digester for sludge, one aerated sludge holding tank, 30 degree
V notch weir with continuous flow measurement, chlorinator, chlorine
contact chamber, dechlorination, cascade aeration, four sludge drying
beds,485,000 gallon positive displacement air blower sludge tank, 450
KW standby generator, and polymer addition to the clarifiers.
Pretreatment Program(Y/N) Y,Inactive
County: Halifax
Region Raleigh
Briefly describe the proposed permitting action and facility background: The Town of Weldon has
applied for an NPDES permit renewal at 1.2 MGD for the Weldon WWTP. The Town initially submitted
a renewal application on June 28,2022,but upon review of the application on September 22,2022, it was
identified that the incorrect form,Modified Form 2A,was used. Shortly thereafter,the Town submitted a
revised application using EPA Form 2A was submitted to the Division. This facility serves a population
of approximately 5,700 residents from the Town of Weldon,Halifax County,Northampton County, and
the Town of Halifax. Treated domestic wastewater is discharged via Outfall 001 into the Roanoke River,
a class C waterbody in the Roanoke River Basin. The Town's significant industrial user(SIU) closed in
2018 and the Town's pretreatment program was placed on an inactive status at that time.
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Sludge disposal: Synagro is permitted to haul sludge under permit WQ0002368. Sludge was last hauled
from the facility spring of 2021.
2. Receiving Waterbody Information:
Receiving Waterbody Information
Outfalls/Receiving Stream(s): Outfall 001 —Roanoke River
Stream Segment: 23-(26)
Stream Classification: C
Drainage Area(mi2): 8,420
Summer 7Q10(cfs) 1,100
Winter 7Q10(cfs): -
30Q2 (cfs): 2,400
Average Flow(cfs): 6,000
IWC (%effluent): 0.17
2022 303(d) listed/parameter: Not listed; Meeting criteria for all parameters in 2022
Integrated Report
Subject to TMDL/parameter: Yes- Statewide Mercury TMDL implementation
Basin/Sub-basin/HUC: Roanoke River/03-02-08/HUC: 03010107
USGS Topo Quad: B28NE
3. Effluent Data Summary
Effluent data for Outfall 001 is summarized below for the period of June 2018 through December 2022.
Table 1. Effluent Data Summary Outfall 001
Parameter Units Average Max Min Permit Limit
Flow MGD 0.57 2.456 0.107 MA 1.2
BOD mg/l 2.8 26.4 <2 WA 22.5
MA 15.0
NH3-N mg/1 0.3 7 0.1 Monitor&
Report
TSS mg/1 5.9 44 <2 WA 45.0
MA 30.0
pH SU 6.4 8 6 6.0>pH<9.0
(geometric)
Fecal coliform #/100 ml (geo .bean) 600 < 1 WA 400
MA 200
DM 28.0
TRC µg/1 14.8 36 < 10 (<50
compliance)
Temperature ° C 20.0 28 10 Monitor&
Report
TN mg/l 8.6 29.8 1.25 Monitor&
Report
TP mg/1 1.9 28.9 0.21 Monitor&
Report
Total Hardness mg1I 4 5 56 28 Monitor&
Report
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MA-Monthly Average,WA-Weekly Average,DM-Daily Maximum,DA=Daily Average
4. Instream Data Summary
Instream monitoring may be required in certain situations, for example: 1)to verify model predictions
when model results for instream DO are within 1 mg/l of instream standard at full permitted flow; 2)to
verify model predictions for outfall diffuser; 3)to provide data for future TMDL; 4)based on other
instream concerns. Instream monitoring may be conducted by the Permittee, and there are also
Monitoring Coalitions established in several basins that conduct instream sampling for the Permittee(in
which case instream monitoring is waived in the permit as long as coalition membership is maintained).
If applicable, summarize any instream data and what instream monitoring will be proposed for this
permit action: The current permit requires instream sampling for total hardness 100 feet upstream of the
discharge. Upstream total hardness reported from June 2018 to December 2022 ranged from 16 mg/L to
36 mg/L,with an average of 30.4 mg/L. PF
While 15A NCAC 02B .0508 requirements specify Grade III facilities under SIC code 4952 shall sample
upstream and downstream for dissolved oxygen, fecal coliform,temperature and conductivity, instream
monitoring for these parameters has not been required throughout the history of the permit. Inclusion of
such requirements has been assessed with this renewal. As the stream is neither classified B waters nor
impaired for fecal coliform,no changes are proposed to instream fecal coliform monitoring requirements
at this time.As the facility does not accept industrial wastewater,no changes are proposed to instream
conductivity monitoring requirements at this time. As the dilution factor for this discharge as calculated in
the attached WLA spreadsheet is 592.4, any impact the effluent could have on the receiving stream(e.g.
DO decreases or temperature fluctuation)would be captured via an effluent violation. As such,no
changes are proposed for instream DO or temperature requirements.
Is this facility a member of a Monitoring Coalition with waived instream monitoring(Y/N):NO
Name of Monitoring Coalition: NA
5. Compliance Summary
Summarize the compliance record with permit effluent limits (past 5 years): The facility reported weekly
geometric mean exceedances for fecal coliform in 2018 and 2020. Both violations resulted in Notices of
Violation(NOV). Additionally,the facility reported one monthly average flow exceedance in 2021
resulting in an NOV.
Summarize the compliance record with aquatic toxicity test limits and any second species test results
(past 5 years): The facility passed 20 of 21 quarterly acute toxicity tests from January 2018 to October
2022. The failed test occurred in October 2020 but was followed by a passing result in November 2020.
The Town had not conducted WET testing on an additional species at the time of submittal of their
renewal application. The Town worked with the Division to develop a testing schedule and conducted
testing as instructed. The facility passed all 4 second species (Ceriodaphnia dubia) chronic toxicity tests
conducted in October 2022,November 2022,December 2022, and January 2023.
Summarize the results from the most recent compliance inspection: The last facility inspection conducted
in November 2021 reported that the facility was compliant with NPDES permit NC0025721.
6. Water Quality-Based Effluent Limitations (WQBELs)
Dilution and Mixing
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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/l for Municipals)may be appropriate if deemed more stringent based on dilution and
model results.
If permit limits are more stringent than TBELs, describe how limits were developed: The current permit
limitations for BOD are based on a 1992 Streeter Phelps model(Level B) for instream DO protection. No
changes are proposed from the previous permit limits. In addition to the setting of BOD limits, the 1992
Level B model concluded that no DO limits or monitoring were required for this discharger.
Ammonia and Total Residual Chlorine Limitations
Limitations for ammonia are based on protection of aquatic life utilizing an ammonia chronic criterion of
1.0 mg/l (summer) and 1.8 mg/1(winter). Acute ammonia limits are derived from chronic criteria,
utilizing a multiplication factor of 3 for Municipals and a multiplication factor of 5 for Non-Municipals.
Limitations for Total Residual Chlorine(TRC) are based on the NC water quality standard for protection
of aquatic life(17 ug/1)and capped at 28 ug/1(acute impacts). Due to analytical issues, all TRC values
reported below 50 ug/1 are considered compliant with their permit limit.
Describe any proposed changes to ammonia and/or TRC limits for this permit renewal: TRC limits have
been reviewed in the attached WLA and have been found to be protective.No changes are proposed.
There are currently no limits set for ammonia. Consideration of ammonia limitations has been assessed in
the attached WLA for toxicity. As the calculated allowable discharge concentrations for ammonia based
on the toxicity-based calculations are>35 mg/L,no limit has been imposed. Monitoring for ammonia
shall continue at a frequency of 3/week.
Reasonable Potential Analysis(RPA) for Toxicants
If applicable, conduct RPA analysis and complete information below.
The need for toxicant limits is based upon a demonstration of reasonable potential to exceed water quality
standards, a statistical evaluation that is conducted during every permit renewal utilizing the most recent
effluent data for each outfall. The RPA is conducted in accordance with 40 CFR 122.44(d) (i). The NC
RPA procedure utilizes the following: 1)95% Confidence Level/95%Probability; 2)assumption of zero
background; 3)use of%detection limit for"less than"values; and 4) streamflows used for dilution
consideration based on 15A NCAC 2B.0206. Effective April 6,2016,NC began implementation of
dissolved metals criteria in the RPA process in accordance with guidance titled NPDES Implementation of
Instream Dissolved Metals Standards, dated June 10,2016.
A reasonable potential analysis was conducted on effluent toxicant data collected between June 2018 and
July 2022. 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:
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• Effluent Limit with Monitoriniz. 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:None
• POTW Effluent Pollutant Scan Review: Three effluent pollutant scans (2019,2020, 2021) data
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: None
o The following parameter(s)will receive a monitor-only requirement, since as part of a
limited data set, one sample exceeded the allowable discharge concentration: None
o The following parameters will not receive a limit or monitoring, since they did not
demonstrate reasonable potential to exceed applicable water quality standards/criteria and
the maximum predicted concentration was<50%of the allowable concentration: Total
Beryllium, Total Arsenic, Total Cadmium, Total Copper, Total Lead, Total Zinc, Total
Chromium, Total Cyanide, Total Lead, Total Phenolic Compounds, Total Nickel,Total
Selenium, Total Silver, Chlorodibromomethane,Dichlorobromomethane, Chloroform
Note: Chlorodibromomethane, dichlorobromomethane and chloroform were detected in the 2019, 2020
and 2021 effluent pollutant scans,but were not observed at levels> 50%of the respective allowable
discharge concentrations.
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.
Toxici , Testing Limitations
Permit limits and monitoring requirements for Whole Effluent Toxicity(WET)have been established in
accordance with Division guidance(per WET Memo, 8/2/1999). Per WET guidance, all NPDES permits
issued to Major facilities or any facility discharging"complex"wastewater(contains anything other than
domestic waste)will contain appropriate WET limits and monitoring requirements,with several
exceptions. The State has received prior EPA approval to use an Alternative WET Test Procedure in
NPDES permits,using single concentration screening tests,with multiple dilution follow-up upon a test
failure.
Describe proposed toxicity test requirement: This is a Major POTW, and acute WET testing at a limit of
90% effluent is required on a quarterly frequency. The facility conducts this testing using the fathead
minnow. As the calculated IWC is only 0.17%, acute WET testing at 90%effluent is required in the
permit,per the WET guidance. The facility consistently passes its acute toxicity requirements(see
Compliance Summary above).No changes are proposed for WET testing.
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
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industrial facilities with known mercury discharges. Given the small contribution of mercury from point
sources(^2%of total load),the TMDL emphasizes mercury minimization plans(MMPs) for point source
control. Municipal facilities>2 MGD and discharging quantifiable levels of mercury(>1 ng/1)will
receive an MMP requirement. Industrials are evaluated on a case-by-case basis, depending if mercury is a
pollutant of concern. Effluent limits may also be added if annual average effluent concentrations exceed
the WQBEL value(based on the NC WQS of 12 ng/1) and/or if any individual value exceeds a TBEL
value of 47 ng/l.
Describe proposed permit actions based on mercury evaluation:
Table 2. Mercu Effluent Data Summary
2018 2019 2020 2021 2022
#of Samples 2 4 4 2 4
Annual Average Conc.n /L 4.0 4.2 16.0 4.2 3.5
Maximum Conc.,n /L 4.66 7.98 44.00 5.07 5.81
TBEL,n /L 47
WQBEL,n /L 7108.8
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 MGD,no mercury minimization plan(MMP)has been added to
the permit.
Other TMDL/Nutrient Management Strategy Considerations
If applicable, describe any other TMDLs/Nutrient Management Strategies and their implementation
within this permit: NA
Other WQBEL Considerations
If applicable, describe any other parameters of concern evaluated for WQBELs: As required by Session
Law 2018-5, Senate Bill 99, Section 13.1(r), every applicant shall submit documentation of any additional
pollutants for which there are certified methods with the permit application if their discharge is
anticipated. The list of pollutants may be found in 40 CFR Part 136,which is incorporated by reference.
Additional pollutants with certified methods to be reported are submitted with the NPDES permit
application via the Chemical Addendum to NPDES Application table This requirement applies to all
NPDES facilities. The Town of Weldon informed the Division that no monitoring for additional
pollutants has been conducted(see attached chemical addendum) and therefore no additional pollutants of
concern have been identified.
Effluent fecal coliform is currently limited at a monthly geometric mean of 200/100mL and a weekly
geometric mean of 400/100mL due to the facility having grant-funded chlorination facilities and the
accessibility of the discharge to the public (per the 1992 Wasteload Allocation). The facility does not
appear to have difficulty maintaining compliance with these permit limits.No changes are proposed to
fecal coliform requirements.
If applicable, describe any special actions (HQW or ORW) this receiving stream and classification shall
comply with in order to protect the designated waterbody:NA
If applicable, describe any compliance schedules proposed for this permit renewal in accordance with
1 SA NCAC 2H 0107(c)(2)(B), 40CFR 122.47, and EPA May 2007 Memo:NA
If applicable, describe any water quality standards variances proposed in accordance with NCGS 143-
215.3(e) and 1 SA NCAC 2B.0226 for this permit renewal:NA
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7. Technology-Based Effluent Limitations (TBELs)
Municipals (if not applicable,delete and skip to Industrials)
Are concentration limits in the permit at least as stringent as secondary treatment requirements (30 mg/l
BODS/TSS for Monthly Average, and 45 mg/l for BODS/TSS for Weekly Average). YES
If NO,provide a justification for alternative limitations (e.g., waste stabilization pond). NA
Are 85%removal requirements for BODS/TSS included in the permit? YES; Overall BOD and TSS
removal were>85%. 85%BOD removal was not met in February 2021. 85%TSS removal was not met
in November 2018,January and December 2019,January,February and October 2020, February 2021
and January and February 2022. This suggests difficulties meeting 85%TSS removal in the winter
months.
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 21-1.0105(c)(2). In all
cases, existing instream water uses and the level of water quality necessary to protect the existing use is
maintained and protected.
If applicable, describe the results of the antidegradation review, including the Engineering Alternatives
Analysis (EAA) and any water quality modeling results:NA
9. Antibacksliding Review:
Sections 402(o)(2) and 303(d)(4)of the CWA and federal regulations at 40 CFR 122.44(1)prohibit
backsliding of effluent limitations in NPDES permits. These provisions require effluent limitations in a
reissued permit to be as stringent as those in the previous permit,with some exceptions where limitations
may be relaxed(e.g.,based on new information, increases in production may warrant less stringent TBEL
limits, or WQBELs may be less stringent based on updated RPA or dilution).
Are any effluent limitations less stringent than previous permit(YES/NO): NO
If YES, confirm that antibacksliding provisions are not violated.•NA
10. Monitoring Requirements
Monitoring frequencies for NPDES permitting are established in accordance with the following
regulations and guidance: 1) State Regulation for Surface Water Monitoring, 15A NCAC 213.0500;2)
NPDES Guidance,Monitoring Frequency for Toxic Substances(7/15/2010 Memo); 3)NPDES Guidance,
Reduced Monitoring Frequencies for Facilities with Superior Compliance(10/22/2012 Memo); 4)Best
Professional Judgement(BPJ). Per US EPA(Interim Guidance, 1996),monitoring requirements are not
considered effluent limitations under Section 402(o)of the Clean Water Act, and therefore anti-
backsliding prohibitions would not be triggered by reductions in monitoring frequencies.
For instream monitoring,refer to Section 4.
To better understand the contribution of PFAS compounds from the Weldon WWTP,monitoring of PFAS
chemicals will be added to the permit at a frequency of 2/year. The frequency of 2/year was chosen due to
the amount of dilution experienced and the distance from the nearest WS water(approximately 78 stream
miles). 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
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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.
Based on discussion with the DWR Basin Planning Branch,to support planning efforts, and as the two
parameters are used in calculating TN,monthly monitoring and reporting for TKN and NO2+NO3 has
been added to the permit.
11. Electronic Reporting Requirements
The US EPA NPDES Electronic Reporting Rule was finalized on December 21, 2015. Effective
December 21, 2016,NPDES regulated facilities are required to submit Discharge Monitoring Reports
(DMRs) electronically. While NPDES regulated facilities would initially be required to submit additional
NPDES reports electronically effective December 21, 2020, EPA extended this deadline from December
21,2020,to December 21,2025. The current compliance date, effective January 4,2021,was extended as
a final regulation change published in the November 2, 2020 Federal Register. This permit contains the
requirements for electronic reporting, consistent with Federal requirements.
12.Summary of Proposed Permitting Actions:
Table 4. Current Permit Conditions and Proposed Changes Outfall 001
Parameter Current Permit Proposed Change Basis for Condition/Change
Flow MA 1.2 MGD No change 15A NCAC 2B .0505
BOD5 MA 15.0 mg/l No change WQBEL. 1992 Level B model; Surface
WA 22.5 mg/l Water Monitoring, 15A NCAC 2B. 0500
Monitor and report 3/Week
NH3-N Monitor and report 3/Week No change Surface Water Monitoring, 15A NCAC
2B. 0500; 1992 Level B model,2023
WLA review
TSS MA 30.0 mg/l No change TBEL. Secondary treatment standards/40
WA 45.0 mg/l CFR 133 / 15A NCAC 2B .0406; 1992
Monitor and report 3/Week Level B Model; Surface Water
Monitoring, 15A NCAC 2B. 0500
Fecal coliform MA 200/100ml 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
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
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. Surface
Chlorine Monitor and report 3/Week Water Monitoring, 15A NCAC 2B. 0500
Total Monitor and report No change Surface Water Monitoring, 15A NCAC
Nitrogen Monthly 2B. 0500
TKN No requirement Monitor effluent For calculation of Total Nitrogen
and report Monthly
NO2+NO3 No requirement Monitor effluent For calculation of Total Nitrogen
and report Monthly
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Total Monitor and report No change Surface Water Monitoring, 15A NCAC
Phosphorus Monthly 2B. 0500
Total Quarterly upstream and No change Hardness-dependent dissolved metals
Hardness effluent monitoring water quality standards approved in 2016
Add 2/year Evaluation of PFAS contribution;
PFAS No requirement monitoring with Implementation delayed until after EPA
delayed certified method becomes available.
implementation
Toxicity Test Acute limit, 90%effluent No change WQBEL.No toxics in toxic amounts.
15A NCAC 213.0200 and 15A NCAC
213.0500
Effluent Three times per permit No change; 40 CFR 122
Pollutant Scan cycle conducted in 2025,
2026, 2027
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
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(919) 707-3609 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
• WET Testing and Self-Monitoring Summary
• Compliance Inspection Report
• Requested Additional Information
• Chemical Addendum
Page 9 of 9

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
REQUIRED DATA ENTRY
Table 1. Project Information Table 2. Parameters of Concern
❑ CHECK IF HQW OR ORW WQS Name WQs Type Chronic Modifier Acute PQL Units
Facility Name Weldon WWTP Par01 Arsenic Aquactic Life C 150 FW 340 ug/L
WWTP/WTP Class III Par02 Arsenic Human Health C 10 HH/WS N/A ug/L
Water Supply
NPDES Permit Nc0025721 Par03 Beryllium Aquatic Life NC 6.5 FW 65 ug/L
Outfall 001 Par04 Cadmium Aquatic Life NC 0.6838 FW 3.8427 ug/L
Flow, Qw (MGD) 1.200 Par05 Chlorides Aquatic Life NC 230 FW mg/L
Receiving Stream Roanoke River Par06 Chlorinated Phenolic Compounds Water Supply NC 1 A ug/L
HUC Number 03010107 Par07 Total Phenolic Compounds Aquatic Life NC 300 A ug/L
Stream Class C Par08 Chromium III Aquatic Life NC 138.1604 FW 1062.2549 ug/L
❑ Apply WS Hardness WQC Par09 Chromium VI Aquatic Life NC 11 FW 16 pg/L
7Q10s (cfs) 1100.000 Par10 Chromium, Total Aquatic Life NC N/A FW N/A pg/L
7Q10w (cfs) 1100.00 Par11 Copper Aquatic Life NC 9.3124 FW 12.5902 ug/L
30Q2 (cfs) 2400.00 Par12 Cyanide Aquatic Life NC 5 FW 22 10 ug/L
QA(cfs) 6000.00 Par13 Fluoride Aquatic Life NC 1,800 FW ug/L
1Q10s (cfs) 882.94 Par14 Lead Aquatic Life NC 3.6641 FW 94.0418 ug/L
Effluent Hardness 41.47 mg/L (Avg) Par15 Mercury Aquatic Life NC 12 FW 0.5 ng/L
------------- ----------------------
Upstream Hardness 30.38 mg/L (Avg) Par16 Molybdenum Human Health NC 2000 HH ug/L
------------- ----------------------
Combined Hardness Chronic 30.39 mg/L Par17 Nickel Aquatic Life NC 43.9225 FW 395.5020 pg/L
Combined Hardness Acute 30.4 mg/L -I Par18 Nickel Water Supply NC 25.0000 WS N/A pg/L
Data Source(s) Par19 Selenium Aquatic Life NC 5 FW 56 ug/L
❑ CHECK TO APPLY MODEL Par20 Silver Aquatic Life NC 0.06 FW 0.4149 ug/L
Par21 Zinc Aquatic Life NC 149.5476 FW 148.3533 ug/L
Par22 Chlorodibromomethane Human Health C 21 HH pg/L
Par23 Dichlorobromomethane Human Health C 27 HH pg/L
Par24 Chloroform Human Health NC 2000 HH pg/L
25721 RPA, input
2/3/2023

REASONABLE POTENTIAL ANALYSIS
H1 H2 Use"PASTE SPECIAL Use"PASTE SPECIAL
Effluent Hardness Values"then"COPY" Upstream Hardness Values"then"COPY"
Maximum data .Maximum data
points=58 points=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 4/2/2019 34 34 Std Dev. 9.0227 1 1/8/2019 30 30 Std Dev. 5.4268
2 7/10/2019 52 52 Mean 41.4667 2 4/2/2019 16 16 Mean 30.3750
3 10/1/2019 56 56 C.V. 0.2176 3 7/10/2019 36 36 C.V. 0.1787
4 1/7/2020 36 36 n 15 4 10/1/2019 36 36 n 16
5 4/2/2020 40 40 10th Per value 29.60 mg/L 5 1/2/2020 36 36 10th Per value 26.00 mg/L
6 7/7/2020 44 44 Average Value 41.47 mg/L 6 4/2/2020 24 24 Average Value 30.38 mg/L
7 10/6/2020 44 44 Max. Value 56.00 mg/L 7 7/7/2020 36 36 Max. Value 36.00 mg/L
8 1/5/2021 28 28 8 10/6/2020 28 28
9 4/6/2021 56 56 9 1/5/2021 28 28
10 7/6/2021 40 40 10 4/6/2021 32 32
11 10/5/2021 40 40 11 7/6/2021 28 28
12 1/6/2022 32 32 12 10/5/2021 32 32
13 4/5/2022 28 28 13 1/6/2022 28 28
14 7/6/2022 48 48 14 4/5/2022 28 28
15 10/4/2022 44 44 15 7/6/2022 32 32
16 16 10/4/2022 36 36
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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
25721 RPA, data
- 1 - 2/3/2023

REASONABLE POTENTIAL ANALYSIS
Par01 & Par02
Use"PASTE SPECIAL
Arsenic Values"then"COPY"
Maximum data
points=58
Date Data BDL=1/2DL Results
1 7/17/2019 < 10 5 Std Dev. 0.0000
2 10/27/2020 < 10 5 Mean 5.0000
3 7/29/2021 < 10 5 C.V. (default) 0.6000
4 n 3
5
6 Mult Factor= 3.00
7 Max. Value 5.0 ug/L
8 Max. Pred Cw 15.0 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
25721 RPA, data
-2 - 2/3/2023

REASONABLE POTENTIAL ANALYSIS
Par03 Par04
Use"PASTE SPECIAL Use"PASTE SPECIAL
Beryllium Values"then"COPY" Cadmium Values"then"COPY"
Maximum data .Maximum data
points=58 points=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 7/17/2019 < 5 2.5 Std Dev. 0.0000 1 7/17/2019 < 2 1 Std Dev. 0.0000
2 10/27/2020 < 5 2.5 Mean 2.5000 2 10/27/2020 < 2 1 Mean 1.0000
3 7/29/2021 < 5 2.5 C.V. (default) 0.6000 3 7/29/2021 < 2 1 C.V. (default) 0.6000
4 n 3 4 n 3
5 5
6 Mult Factor= 3.00 6 Mult Factor= 3.00
7 Max. Value 2.50 ug/L 7 Max. Value 1.000 ug/L
8 Max. Pred Cw 7.50 ug/L 8 Max. Pred Cw 3.000 ug/L
9 9
10 10
11 11
12 12
13 13
14 14
15 15
16 16
17 17
18 18
19 19
20 20
21 21
22 22
23 23
24 24
25 25
26 26
27 27
28 28
29 29
30 30
31 31
32 32
33 33
34 34
35 35
36 36
37 37
38 38
39 39
40 40
41 41
42 42
43 43
44 44
45 45
46 46
47 47
48 48
49 49
50 50
51 51
52 52
53 53
54 54
55 55
56 56
57 57
58 58
25721 RPA, data
-3- 2/3/2023

REASONABLE POTENTIAL ANALYSIS
Par07 Part O
Use"PASTE SPECIAL Use"PASTE SPECIAL
Total Phenolic Compounds Values"then"COPY" Chromium' Total Values"then"COPY"
Maximum data Maximum data
points=58 points=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 7/17/2019 < 10 5 Std Dev. 13.0512 1 7/17/2019 < 5 2.5 Std Dev. 0.0000
2 10/27/2020 16 16 Mean 17.3333 2 10/27/2020 < 5 2.5 Mean 2.5000
3 7/29/2021 31 31 C.V. (default) 0.6000 3 7/29/2021 < 5 2.5 C.V. (default) 0.6000
4 n 3 4 n 3
5 5
6 Mult Factor= 3.00 6 Mult Factor= 3.00
7 Max. Value 31.0 ug/L 7 Max. Value 2.5 pg/L
8 Max. Pred Cw 93.0 ug/L 8 Max. Pred Cw 7.5 pg/L
9 9
10 10
11 11
12 12
13 13
14 14
15 15
16 16
17 17
18 18
19 19
20 20
21 21
22 22
23 23
24 24
25 25
26 26
27 27
28 28
29 29
30 30
31 31
32 32
33 33
34 34
35 35
36 36
37 37
38 38
39 39
40 40
41 41
42 42
43 43
44 44
45 45
46 46
47 47
48 48
49 49
50 50
51 51
52 52
53 53
54 54
55 55
56 56
57 57
58 58
25721 RPA, data
-4- 2/3/2023

REASONABLE POTENTIAL ANALYSIS
Pal Par12
Use"PASTE SPECIAL Use"PASTE SPECIAL
Copper Values"then"COPY" Cyanide Values"then"COPY"
pp .Maximum data y .Maximum data
points=58 points=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 7/17/2019 4 4 Std Dev. 2.4083 1 7/17/2019 9 5 Std Dev. 0.0000
2 10/27/2020 8 8 Mean 6.6000 2 10/27/2020 < 5 5 Mean 5.00
3 7/29/2021 6 6 C.V. (default) 0.6000 3 7/29/2021 < 5 5 C.V. (default) 0.6000
4 7/3/2018 5 5 n 5 4 n 3
5 10/2/2018 10 10 5
6 Mult Factor= 2.32 6 Mult Factor= 3.00
7 Max. Value 10.00 ug/L 7 Max. Value 5.0 ug/L
8 Max. Pred Cw 23.20 ug/L 8 Max. Pred Cw 15.0 ug/L
9 9
10 10
11 11
12 12
13 13
14 14
15 15
16 16
17 17
18 18
19 19
20 20
21 21
22 22
23 23
24 24
25 25
26 26
27 27
28 28
29 29
30 30
31 31
32 32
33 33
34 34
35 35
36 36
37 37
38 38
39 39
40 40
41 41
42 42
43 43
44 44
45 45
46 46
47 47
48 48
49 49
50 50
51 51
52 52
53 53
54 54
55 55
56 56
57 57
58 58
25721 RPA, data
- 5- 2/3/2023

REASONABLE POTENTIAL ANALYSIS
Par14 Use"PASTE SPECIAL Par17 & Par18 use"PASTE
Values"then"COPY" SPECIAL-Values"
Lead .Maximum data Nickel then"COPY".
points=58 Maximum data
Date BDL=1/2DL Results Date Data BDL=1/2DL Results points=58
1 7/17/2019 < 10 5 Std Dev. 0.0000 1 7/17/2019 < 10 5 Std Dev. 0.0000
2 10/27/2020 < 10 5 Mean 5.0000 2 10/27/2020 < 10 5 Mean 5.0000
3 7/29/2021 < 10 5 C.V. (default) 0.6000 3 7/29/2021 < 10 5 C.V. (default) 0.6000
4 n 3 4 n 3
5 5
6 Mult Factor= 3.00 6 Mult Factor= 3.00
7 Max. Value 5.000 ug/L 7 Max. Value 5.0 tag/L
8 Max. Pred Cw 15.000 ug/L 8 Max. Pred Cw 15.0 tag/L
9 9
10 10
11 11
12 12
13 13
14 14
15 15
16 16
17 17
18 18
19 19
20 20
21 21
22 22
23 23
24 24
25 25
26 26
27 27
28 28
29 29
30 30
31 31
32 32
33 33
34 34
35 35
36 36
37 37
38 38
39 39
40 40
41 41
42 42
43 43
44 44
45 45
46 46
47 47
48 48
49 49
50 50
51 51
52 52
53 53
54 54
55 55
56 56
57 57
58 58
25721 RPA, data
-6- 2/3/2023

REASONABLE POTENTIAL ANALYSIS
Par19 use"PASTE Par20
SPECIAL-Values" Use"PASTE SPECIAL-
Selenium then"COPY". Silver Values"then"COPY".
Maximum data Maximum data points=
points=58 58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 7/17/2019 < 10 5 Std Dev. 0.0000 1 7/17/2019 < 5 2.5 Std Dev. 0.0000
2 10/27/2020 < 10 5 Mean 5.0000 2 10/27/2020 < 5 2.5 Mean 2.5000
3 7/29/2021 < 10 5 C.V. (default) 0.6000 3 7/29/2021 < 5 2.5 C.V. (default) 0.6000
4 n 3 4 n 3
5 5
6 Mult Factor= 3.00 6 Mult Factor= 3.00
7 Max. Value 5.0 ug/L 7 Max. Value 2.500 ug/L
8 Max. Pred Cw 15.0 ug/L 8 Max. Pred Cw 7.500 ug/L
9 9
10 10
11 11
12 12
13 13
14 14
15 15
16 16
17 17
18 18
19 19
20 20
21 21
22 22
23 23
24 24
25 25
26 26
27 27
28 28
29 29
30 30
31 31
32 32
33 33
34 34
35 35
36 36
37 37
38 38
39 39
40 40
41 41
42 42
43 43
44 44
45 45
46 46
47 47
48 48
49 49
50 50
51 51
52 52
53 53
54 54
55 55
56 56
57 57
58 58
25721 RPA, data
- 7- 2/3/2023

REASONABLE POTENTIAL ANALYSIS
Par21 Par22 use"PASTE
Use"PASTE SPECIAL
Values"then"COPY" SPECIAL-Values"
Zinc Maximum data Chlorodibromomethane then"COPY".
.
points=58 Maximum data points
=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 7/17/2019 79 79 Std Dev. 17.2143 1 7/17/2019 4.43 4.43 Std Dev. 1.4967
2 10/27/2020 52 52 Mean 59.3333 2 10/27/2020 1.44 1.44 Mean 2.9767
3 7/29/2021 47 47 C.V. (default) 0.6000 3 7/29/2021 3.06 3.06 C.V. (default) 0.6000
4 n 3 4 n 3
5 5
6 Mult Factor= 3.00 6 Mult Factor= 3.00
7 Max. Value 79.0 ug/L 7 Max. Value 4.430000 pg/L
8 Max. Pred Cw 237.0 ug/L 8 Max. Pred Cw 13.290000 pg/L
9 9
10 10
11 11
12 12
13 13
14 14
15 15
16 16
17 17
18 18
19 19
20 20
21 21
22 22
23 23
24 24
25 25
26 26
27 27
28 28
29 29
30 30
31 31
32 32
33 33
34 34
35 35
36 36
37 37
38 38
39 39
40 40
41 41
42 42
43 43
44 44
45 45
46 46
47 47
48 48
49 49
50 50
51 51
52 52
53 53
54 54
55 55
56 56
57 57
58 58
25721 RPA, data
-8- 2/3/2023

REASONABLE POTENTIAL ANALYSIS
Par23 use"PASTE Par24
SPECIAL-Values" Use"PASTE SPECIAL
Values"
Dichlorobromomethane then"COPY". Chloroform es"then"COPY"
Maximum data
Maximum data .
points=58 points=58
Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results
1 7/17/2019 22.1 22.1 Std Dev. 7.5839 1 7/17/2019 58.4 58.4 Std Dev. 23.0983
2 10/27/2020 6.94 6.94 Mean 14.3800 2 10/27/2020 12.7 12.7 Mean 33.6000
3 7/29/2021 14.1 14.1 C.V. (default) 0.6000 3 7/29/2021 29.7 29.7 C.V. (default) 0.6000
4 n 3 4 n 3
5 5
6 Mult Factor= 3.00 6 Mult Factor= 3.00
7 Max. Value 22.100000 pg/L 7 Max. Value 58.400000 pg/L
8 Max. Pred Cw 66.30000 fag/L 8 Max. Pred Cw 175.200000 pg/L
9 9
10 10
11 11
12 12
13 13
14 14
15 15
16 16
17 17
18 18
19 19
20 20
21 21
22 22
23 23
24 24
25 25
26 26
27 27
28 28
29 29
30 30
31 31
32 32
33 33
34 34
35 35
36 36
37 37
38 38
39 39
40 40
41 41
42 42
43 43
44 44
45 45
46 46
47 47
48 48
49 49
50 50
51 51
52 52
53 53
54 54
55 55
56 56
57 57
58 58
25721 RPA, data
-9- 2/3/2023

Weldon WWTP > Outfall 001
Nc0025721 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators QW = 1 .2 MGD
MAXIMUM DATA POINTS = 58
Qw (MGD) = 1.2000 WWTP/WTP Class: III COMBINED HARDNESS (mg/L)
1Q10S (cfs) = 882.94 IWC% @ 1Q10S = 0.210216998 Acute = 30.4 mg/L
7Q10S (cfs) = 1100.00 IWC% @ 7Q10S = 0.168805474 Chronic= 30.39 mg/L
7Q10W (cfs) = 1100.00 IWC% @ 7Q10W= 0.168805474
30Q2 (cfs) = 2400.00 IWC% @ 30Q2 = 0.077439984
Avg. Stream Flow, QA(cfs) = 6000.00 IW%C @ QA= 0.030990393
Receiving Stream: Roanoke River HUC 03010107 Stream Class: C
PARAMETER NC STANDARDS OR EPA CRITERIA J REASONABLE POTENTIAL RESULTS RECOMMENDED ACTION
CY
TYPE Aplied
Chronic Standard Acute D n #Det. Max Pred Cw Allowable Cw
Acute (FW): 161.737.6
Arsenic C 150 FW(7Q10s) 340 u@
3 0 15.0 Chronic (FW): 88,859.7 No RP, Predicted Max< 50% of Allowable Cw- No
C.V. (default) Max MDL= 10 Monitoring required
--------- -----------------------------
Arsenic C 10 HH/WS(Qavg) ug/L Note: n<9 NO DETECTS Chronic (HH) 32,268.1
Limited data set Max MDL= 10
Acute: 30,920.43
Beryllium NC 6.5 FW(7Q10s) 65 ug/L 3 0 7.50
------------------- -----------------------------
Note: n<9 C.V. (default) Chronic: 3,850.59 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set NO DETECTS Max MDL= 5 Monitoring required
Acute: 1,827.957
Cadmium NC 0.6838 FW(7Q10s) 3.8427 uWL 3 0 3.000
Note: n< 9 C.V. (default) Chronic: 405.087 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set NO DETECTS Max MDL= 2 Monitoring required
Acute: NO WQS
Total Phenolic Compounds NC 300 A(30Q2) ug/L 3 2 93.0
Note: n<9 C.V. (default) Chronic: 387,396.8 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: 505,313.5
Chromium III NC 138.1604 FW(7010s) 1062.2549 up-/L 0 0 N/A
Chronic: 81,845.9
Acute: 7,611.2
Chromium VI NC 11 FW(7010s) 16 ua/L 0 0 N/A
--Chronic: ----6 516.4 -- ---------------------------
a: No monitoring required if all Total Chromium
Chromium, Total NC µg/L 3 0 7.5 Max reported value = 2.5 samples are < 5 pg/L or Pred. max for Total Cr is <
Note: n<9 C.V. (default) allowable Cw for Cr Vl.
Acute: 5,989.12
Copper NC 9.3124 FW(7Q10s) 12.5902 ug/L 5 5 23.20
Note: n<9 C.V. (default) Chronic: 5,516.63 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: 10,465.4
Cyanide NC 5 FW(7Q1Os) 22 10 ug/L 3 1 15.0
Note: n<9 C.V. (default) Chronic: 2,962.0 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set I jNo value >Allowable Cw Monitoring required
Acute: 44,735.573
Lead NC 3.6641 FW(7Q10s) 94.0418 ug/L 3 0 15.000
------------------ ----------------------------
56863 RPA, rpa
Page 1 of 2 2/3/2023

Weldon WWTP > Outfall 001
Nc0025721 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators _ _ _ _ _ _ _QW_ _= 1 .2_ MGD
Note: n<9 C.V. (default) Chronic: 2,170.576 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set NO DETECTS Max MDL= 10 Monitoring required
Acute (FW): 188,139.9
Nickel NC 43.9225 FW(7Q10s) 395.5020 µg/L __
3 0 15.0 Chronic (FW) 26,019.6 No RP, Predicted Max< 50% of Allowable Cw- No
Note: n<9 C.V. (default) Max_MD_L= 10 Monitoring required
--------- -----------------------------
Nickel NC 25.0000 WS(7Q10s) µg/L Limited data set NO DETECTS Chronic (WS) 14,809.9
Max MDL= 10
Acute: 26,639.1
Selenium NC 5 FW(7Q10s) 56 ug/L 3 0 15.0
Note: n<9 C.V. (default) Chronic: 2,962.0 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set NO DETECTS Max MDL= 10 Monitoring required
Acute: 197.357
Silver NC 0.06 FW(7Q10s) 0.4149 ug/L 3 0 7.500 ___ _ ____ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _
Note: n<9 C.V. (default) Chronic: 35.544 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set NO DETECTS Max MDL= 5 Monitoring required
Acute: 70,571.5 No RP, Predicted Max< 50% of Allowable Cw- No
Zinc NC 149.5476 FW(7Q10s) 148.3533 ug/L 3 3 237.0 Monitoring required
Note: n<9 C.V. (default) Chronic: 88,591.7
Limited data set No value >Allowable Cw
Acute: NO WQS
Chlorodibromomethane C 21 HH(Qavg) µg/L 3 3 13.29000 ------------------- -----------------------------
Note: n<9 C.V. (default) Chronic: 67762.935 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: NO WQS
Dichlorobromomethane C 27 HH(Qavg) µg/L 3 3 66.30000 _
Note: n<9 C.V. (default) Chronic: 87123 77419 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value >Allowable Cw Monitoring required
Acute: NO WQS
Chloroform NC 2000 HH(7Q10s) µg/L 3 3 175.20000
Note: n<9 C.V. (default) Chronic: 1184795.70 No RP, Predicted Max< 50% of Allowable Cw- No
Limited data set No value > Allowable Cw Monitoring required
56863 RPA, rpa
Page 2 of 2 2/3/2023

Permit No. NCO025721
NPDES Implementation of Instream Dissolved Metals Standards-Freshwater Standards
The NC 2007-2015 Water Quality Standard(WQS)Triennial Review was approved by the NC
Environmental Management Commission(EMC)on November 13,2014. The US EPA subsequently
approved the WQS revisions on April 6,2016,with some exceptions. Therefore,metal limits in draft
permits out to public notice after April 6,2016 must be calculated to protect the new standards - as
approved.
Table 1.NC Dissolved Metals Water Q ality Standards/A uatic Life Protection
Parameter Acute FW, µg/l Chronic FW, µg/l Acute SW, µg/1 Chronic SW, µg/1
(Dissolved) (Dissolved) (Dissolved) (Dissolved)
Arsenic 340 150 69 36
Beryllium 65 6.5 --- ---
Cadmium Calculation Calculation 40 8.8
Chromium III Calculation Calculation --- ---
Chromium VI 16 11 1100 50
Copper Calculation Calculation 4.8 3.1
Lead Calculation Calculation 210 8.1
Nickel Calculation Calculation 74 8.2
Silver Calculation 0.06 1.9 0.1
Zinc Calculation Calculation 90 81
Table 1 Notes:
1. FW=Freshwater, SW= Saltwater
2. Calculation=Hardness dependent standard
3. Only the aquatic life standards listed above are expressed in dissolved form. Aquatic life
standards for Mercury and selenium are still expressed as Total Recoverable Metals due to
bioaccumulative concerns (as are all human health standards for all metals). It is still necessary
to evaluate total recoverable aquatic life and human health standards listed in 15A NCAC
2B.0200(e.g., arsenic at 10 µg/1 for human health protection; cyanide at 5 µg/L and fluoride at
1.8 mg/L for aquatic life protection).
Table 2.Dissolved Freshwater Standards for Hardness-Dependent Metals
The Water Effects Ratio(WER)is equal to one unless determined otherwise under 15A
NCAC 02B .0211 Subparagraph(11)(d)
Metal NC Dissolved Standard, µg/I
Cadmium,Acute WER*{1.136672-[ln hardness](0.041838)} e^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. NCO025721
Silver,Acute WER*0.85 •e^{1.72[ln hardness]-6.59}
Silver,Chronic Not applicable
Zinc,Acute WER*0.978 e^{0.8473[ln hardness]+0.884}
Zinc,Chronic WER*0.986 e^{0.8473[ln hardness]+0.884}
General Information on the Reasonable Potential Analysis (RPA)
The RPA process itself did not change as the result of the new metals standards. However, application of
the dissolved and hardness-dependent standards requires additional consideration in order to establish the
numeric standard for each metal of concern of each individual discharge.
The hardness-based standards require some knowledge of the effluent and instream(upstream)hardness
and so must be calculated case-by-case for each discharge.
Metals limits must be expressed as `total recoverable' metals in accordance with 40 CFR 122.45(c). The
discharge-specific standards must be converted to the equivalent total values for use in the RPA
calculations. We will generally rely on default translator values developed for each metal(more on that
below),but it is also possible to consider case-specific translators developed in accordance with
established methodology.
RPA Permitting Guidance/WOBELs for Hardness-Dependent Metals -Freshwater
The RPA is designed to predict the maximum likely effluent concentrations for each metal of concern,
based on recent effluent data, and calculate the allowable effluent concentrations,based on applicable
standards and the critical low-flow values for the receiving stream.
If the maximum predicted value is greater than the maximum allowed value(chronic or acute),the
discharge has reasonable potential to exceed the standard,which warrants a permit limit in most cases. If
monitoring for a particular pollutant indicates that the pollutant is not present(i.e. consistently below
detection level),then the Division may remove the monitoring requirement in the reissued permit.
1. To perform a RPA on the Freshwater hardness-dependent metals the Permit Writer compiles the
following information:
• Critical low flow of the receiving stream, 7Q10(the spreadsheet automatically calculates
the 1 Q 10 using the formula 1 Q 10=0.843 (s7Q 10, cfs)0.993
• Effluent hardness and upstream hardness, site-specific data is preferred
• Permitted flow
• Receiving stream classification
2. In order to establish the numeric standard for each hardness-dependent metal of concern and for
each individual discharge,the Permit Writer must first determine what effluent and instream
(upstream)hardness values to use in the equations.
The permit writer reviews DMR's,Effluent Pollutant Scans, and Toxicity Test results for any
hardness data and contacts the Permittee to see if any additional data is available for instream
hardness values,upstream of the discharge.
If no hardness data is available,the permit writer may choose to do an initial evaluation using a
default hardness of 25 mg/L(CaCO3 or(Ca+Mg)). Minimum and maximum limits on the
hardness value used for water quality calculations are 25 mg/L and 400 mg/L,respectively.
If the use of a default hardness value results in a hardness-dependent metal showing reasonable
potential,the permit writer contacts the Permittee and requests 5 site-specific effluent and
upstream hardness samples over a period of one week. The RPA is rerun using the new data.
Page 2 of 4

Permit No. NCO025721
The overall hardness value used in the water quality calculations is calculated as follows:
Combined Hardness(chronic)
_(Permitted Flow,cfs *Avg. Effluent Hardness,mg/L)+s7Q10, cfs *Avg. Upstream Hardness,mg/L)
(Permitted Flow,cfs+s7Q10,cfs)
The Combined Hardness for acute is the same but the calculation uses the IQ 10 flow.
3. The permit writer converts the numeric standard for each metal of concern to a total recoverable
metal,using the EPA Default Partition Coefficients(DPCs)or site-specific translators, if any
have been developed using federally approved methodology.
EPA default partition coefficients or the"Fraction Dissolved"converts the value for
dissolved metal at laboratory conditions to total recoverable metal at in-stream
ambient conditions. This factor is calculated using the linear partition coefficients
found in The Metals Translator: Guidance for Calculating a Total Recoverable
Permit Limit from a Dissolved Criterion (EPA 823-B-96-007, June 1996)and the
equation:
Cdiss - 1
Ctotal I + { [Kpo] [ss('+a)] [10-6] }
Where:
ss=in-stream suspended solids concentration [mg/1],minimum of 10 mg/L used,
and
Kpo and a=constants that express the equilibrium relationship between dissolved
and adsorbed forms of metals. A list of constants used for each hardness-dependent
metal can also be found in the RPA program under a sheet labeled DPCs.
4. The numeric standard for each metal of concern is divided by the default partition coefficient(or
site-specific translator)to obtain a Total Recoverable Metal at ambient conditions.
In some cases,where an EPA default partition coefficient translator does not exist(ie. silver),the
dissolved numeric standard for each metal of concern is divided by the EPA conversion factor to
obtain a Total Recoverable Metal at ambient conditions. This method presumes that the metal is
dissolved to the same extent as it was during EPA's criteria development for metals. For more
information on conversion factors see the June, 1996 EPA Translator Guidance Document.
5. The RPA spreadsheet uses a mass balance equation to determine the total allowable concentration
(permit limits)for each pollutant using the following equation:
Ca=(s7Q 10+Qw)(Cwgs)—(s7Q 10) (Cb)
Qw
Where: Ca=allowable effluent concentration(µg/L or mg/L)
Cwqs=NC Water Quality Standard or federal criteria(µg/L or mg/L)
Cb=background concentration: assume zero for all toxicants except NH3* (µg/L or mg/L)
Qw=permitted effluent flow(cfs,match s7Q 10)
s7Q 10=summer low flow used to protect aquatic life from chronic toxicity and human
health through the consumption of water, fish, and shellfish from noncarcinogens (cfs)
* Discussions are on-going with EPA on how best to address background concentrations
Flows other than s7Q 10 may be incorporated as applicable:
IQ 10=used in the equation to protect aquatic life from acute toxicity
Page 3 of 4

Permit No. NC0025721
QA=used in the equation to protect human health through the consumption of water,
fish, and shellfish from carcinogens
30Q2=used in the equation to protect aesthetic quality
6. The permit writer enters the most recent 2-3 years of effluent data for each pollutant of concern.
Data entered must have been taken within four and one-half years prior to the date of the permit
application(40 CFR 122.21). The RPA spreadsheet estimates the 95th percentile upper
concentration of each pollutant. The Predicted Max concentrations are compared to the Total
allowable concentrations to determine if a permit limit is necessary. If the predicted max exceeds
the acute or chronic Total allowable concentrations,the discharge is considered to show
reasonable potential to violate the water quality standard, and a permit limit(Total allowable
concentration)is included in the permit in accordance with the U.S. EPA Technical Support
Document for Water Quality-Based Toxics Control published in 1991.
7. When appropriate,permit writers develop facility specific compliance schedules in accordance
with the EPA Headquarters Memo dated May 10,2007 from James Hanlon to Alexis Strauss on
40 CFR 122.47 Compliance Schedule Requirements.
8. The Total Chromium NC WQS was removed and replaced with trivalent chromium and
hexavalent chromium Water Quality Standards. As a cost savings measure,total chromium data
results may be used as a conservative surrogate in cases where there are no analytical results
based on chromium III or VI. In these cases,the projected maximum concentration(95th%) for
total chromium will be compared against water quality standards for chromium III and
chromium VI.
9. Effluent hardness sampling and instream hardness sampling,upstream of the discharge, are
inserted into all permits with facilities monitoring for hardness-dependent metals to ensure the
accuracy of the permit limits and to build a more robust hardness dataset.
10. Hardness and flow values used in the Reasonable Potential Analysis for this permit included:
Parameter Value Comments (Data Source)
Average Effluent Hardness(mg/L) 41.47 Average from 2019-2022 DMR
[Total as, CaCO3 or(Ca+Mg)] data
Average Upstream Hardness (mg/L) 30.38 Average from 2019-2022 DMR
[Total as, CaCO3 or(Ca+Mg)] data
7Q10 summer(cfs) 1,100 NPDES Files
1Q10(cfs) 882.94 Calculated in RPA
Permitted Flow(MGD) 1.20 NPDES Files
Date: 2/3/2023
Permit Writer: Nick Coco
Page 4 of 4

NCO025721 Weldon WWTP 2/3/2023
BOD monthly removal rate TSS monthly removal rate
Month RR(%) Month RR(%) Month RR(%) Month RR(%)
June-18 96.91 December-20 94.97 June-18 97.77 December-20 90.87
July-18 96.58 January-21 96.07 July-18 95.17 January-21 89.48
August-18 95.26 February-21 60.81 August-18 90.78 February-21 32.79
September-18 96.88 March-21 93.68 September-18 94.17 March-21 88.76
October-18 97.26 April-21 96.12 October-18 92.03 April-21 86.62
November-18 95.99 May-21 97.00 November-18 84.81 May-21 94.46
December-18 94.94 June-21 97.98 December-18 85.28 June-21 94.69
January-19 95.94 July-21 97.70 January-19 84.76 July-21 95.14
February-19 94.57 August-21 95.18 February-19 87.11 August-21 90.53
March-19 95.20 September-21 95.94 March-19 88.21 September-21 93.32
April-19 95.49 October-21 96.56 April-19 92.35 October-21 94.69
May-19 97.72 November-21 97.65 May-19 96.96 November-21 94.11
June-19 97.34 December-21 96.97 June-19 96.85 December-21 94.65
July-19 97.17 January-22 95.14 July-19 97.08 January-22 80.97
August-19 97.60 February-22 96.29 August-19 96.39 February-22 75.55
September-19 97.49 March-22 95.83 September-19 96.30 March-22 89.92
October-19 97.73 April-22 97.10 October-19 94.05 April-22 93.54
November-19 96.83 May-22 95.82 November-19 92.73 May-22 93.56
December-19 92.42 June-22 98.02 December-19 80.19 June-22 96.37
January-20 95.32 July-22 98.00 January-20 82.65 July-22 96.54
February-20 94.27 August-22 97.38 February-20 82.68 August-22 96.14
March-20 95.61 September-22 96.94 March-20 86.80 September-22 95.31
April-20 95.71 October-22 97.42 April-20 91.30 October-22 94.49
May-20 96.38 November-22 97.35 May-20 95.27 November-22 95.72
June-20 95.46 December-22 96.64 June-20 89.44 December-22 86.78
July-20 97.51 January-23 July-20 96.22 January-23
August-20 95.09 February-23 August-20 93.72 February-23
September-20 96.72 March-23 September-20 91.77 March-23
October-20 96.53 April-23 October-20 83.21 April-23
November-20 96.22 May-23 November-20 91.05 May-23
Overall BOD removal rate 95.69 Overall TSS removal rate 90.28

NH3/TRC WLA Calculations
Facility: Weldon WWTP
PermitNo. NC0025721
Prepared By: Nick Coco
Enter Design Flow (MGD): 1.2
Enter s7Q10 (cfs): 1100
Enter w7Q10 (cfs): 1100
Total Residual Chlorine (TRC) Ammonia (Summer)
Daily Maximum Limit(ug/1) Monthly Average Limit (mg NH3-N/1)
s7Q10 (CFS) 1100 s7Q10 (CFS) 1100
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 (%) 0.17 IWC (%) 0.17
Allowable Conc. (ug/1) 10071 Allowable Conc. (mg/1) 462.3
Cap at 28 ug/L.Maintain limit. Allowable>35.0 mg/L;Monitor only.
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/1)
Fecal Coliform w7Q10 (CFS) 1100
Monthly Average Limit: Not Required 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) 592.40 Upstream Bkgd (mg/1) 0.22
Maintain Limit for antibacksliding. IWC (%) 0.17
Allowable Conc. (mg/1) 936.2
Allowable>35.0 mg/L;Monitor only.
Total Residual Chlorine
1. Cap Daily Max limit at 28 ug/I to protect for acute toxicity
Ammonia (as NH3-N)
1. If Allowable Conc > 35 mg/l, Monitor Only
2. Monthly Avg limit x 3 = Weekly Avg limit (Municipals)
3. Monthly Avg limit x 5 = Daily Max limit (Non-Munis)
If the allowable ammonia concentration is > 35 mg/L, no limit shall be imposed
Fecal Coliform
1. Monthly Avg limit x 2 = 400/100 ml = Weekly Avg limit (Municipals) = Daily Max limit (Non-Muni)

2/2/23 WQS= 12 ng/L MERCURY WQBEL/TBEL EVALUATION V:2013-6
Facility Name
Weldon WWTP/NC0025721 No Limit Required
/Permit No.
No MMP Required
Total Mercury 1631E PQL=0.5 ng/L 7Q10s = 1100.000 cfs WQBEL= 7108.77 ng/L
Date Modifier Data Entry Value Permitted Flow= 1.200 47 ng/L
7/18/18 3.38 3.38
10/10/18 4.66 4.66 4.0 ng/L-Annual Average for 2018
1/16/19 7.98 7.98
4/23/19 2.15 2.15
7/17/19 4.4 4.4
10/15/19 2.16 2.16 4.2 ng/L-Annual Average for 2019
2/12/20 4.87 4.87
4/14/20 2.3 2.3
7/22/20 13 13
10/6/20 44 44 16.0 ng/L-Annual Average for 2020
3/3/21 3.29 3.29
7/22/21 5.07 5.07 4.2 ng/L-Annual Average for 2021
1/12/22 5.81 5.81
4/5/22 3.13 3.13
7/13/22 2.81 2.81
10/11/22 2.29 2.29 3.5 ng/L-Annual Average for 2022

Weldon WWTP/NC0025721
Mercury Data Statistics (Method 1631E)
2018 2019 2020 2021 2022
#of Samples 2 4 4 2 4
Annual Average, ng/L 4.0 4.2 16.0 4.18 3.51
Maximum Value, ng/L 4.66 7.98 44.00 5.07 5.81
TBEL, ng/L 47
WQBEL, ng/L 7108.8

MONITORING REPORT(MR)VIOLATIONS for: Report Date: 02/02/22 Page 1 of 1
Permit: NCO025721 MRS Betweei 1 - 2018 and 1 - 2023 Region: % Violation Category:Limit Violation Program Category:
Facility Name:% Param Nam(% County: % Subbasin:% Violation Action:%
Major Minor: %
PERMIT: NCO025721 FACILITY: Town of Weldon-Weldon WWTP COUNTY: Halifax REGION: Raleigh
Limit Violation
MONITORING VIOLATION UNIT OF CALCULATED %
REPORT OUTFALL LOCATION PARAMETER DATE FREQUENCY MEASURE LIMIT VALUE Over VIOLATION TYPE VIOLATION ACTION
08-2019 001 Effluent Chlorine,Total Residual 08/01/19 3 Xweek ug/I 28 34 21.4 Daily Maximum No Action, BPJ
Exceeded
12-2020 001 Effluent Chlorine,Total Residual 12/02/20 3 X week ug/I 28 32 14.3 Daily Maximum No Action, BPJ
Exceeded
12-2020 001 Effluent Chlorine,Total Residual 12/03/20 3 X week ug/I 28 36 28.6 Daily Maximum No Action, BPJ
Exceeded
12-2020 001 Effluent Chlorine,Total Residual 12/08/20 3 X week ug/I 28 29 3.6 Daily Maximum No Action, BPJ
Exceeded
12-2020 001 Effluent Chlorine,Total Residual 12/09/20 3 X week ug/I 28 35 25 Daily Maximum No Action, BPJ
Exceeded
05-2018 001 Effluent Coliform, Fecal MF, MFC 05/26/18 3 X week #/100ml 400 600 50.0 Weekly Geometric Mean Proceed to NOV
Broth,44.5 C Exceeded
05-2020 001 Effluent Coliform, Fecal MF, MFC 05/16/20 3 X week #/100ml 400 600 50.0 Weekly Geometric Mean Proceed to NOV
Broth,44.5 C Exceeded
02-2021 001 Effluent Flow,in conduit or thru 02/28/21 Continuous mgd 1.2 1.37 14.6 Monthly Average Proceed to NOV
treatment plant Exceeded

EPA Identification Number NPDES Number Facility Name Outfall Number
NC0025721 Town of Weldon WWTP 001
Method Number Estimated Concentra ion
Pollutant(Required) CAS number {if ApRlicable) Reason Pollutant Believed Present in Discharge Known)
No additional monitoring has been conducted and therefore no additional pollutants have been identified
Signed By:

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 NCO025721 111 121 21/11/09 I17 181�I 19 L!_]I 201 I
21111I I I I I I I II I I I I I I I I I I I I I I I I I I I I I I I II I I I I I r6
Inspection Work Days Facility Self-Monitoring Evaluation Rating B1 QA ----------------------Reserved-------------------
67 70LJ 71Ity 72 L-J 73 1 74 79 I I I I 80
Section B: Facility Data
Name and Location of Facility Inspected(For Industrial Users discharging to POTW,also include Entry Time/Date Permit Effective Date
POTW name and NPDES permit Number) 10:00AM 21/11/09 18/12/01
Weldon WWTP
525 River Rd Exit Time/Date Permit Expiration Date
Weldon NC 27890 11:00AM 21/11/09 22/03/31
Name(s)of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s) Other Facility Data
Bobby Lee Lyons/ORC/252-536-3600/
Donald L Crowder//252-536-3478/2525364104
Donald L Crowder/ORC/252-536-3478/
William Lynwood Hux/ORC/252-536-3478/
Name,Address of Responsible Official/Title/Phone and Fax Number
Contacted
Donald L Crowder,PO Box 551 Weldon NC
278900551/ORC/252-536-3478/2525364935 No
Section C:Areas Evaluated During Inspection (Check only those areas evaluated)
Permit 0 Flow Measurement Operations&Maintenar Records/Reports
Self-Monitoring Progran 0 Sludge Handling Dispo: Facility Site Review Effluent/Receiving Wate
Laboratory
Section D: Summary of Finding/Comments(Attach additional sheets of narrative and checklists as necessary)
(See attachment summary)
Name(s)and Signature(s)of Inspector(s) Agency/Office/Phone and Fax Numbers Date
Mitchell S Hayes DWR/RRO WQ/919-791-4200/
Signature of Management Q A Reviewer Agency/Office/Phone and Fax Numbers Date
EPA Form 3560-3(Rev 9-94)Previous editions are obsolete.
Page# 1

NPDES yr/mo/day Inspection Type (Cont.) 1
31 NCO025721 I11 12I 21/11/09 117 18 i s i
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
The current permit became effective December 1, 2018 and will expire March 31, 2022.
The 1.2 MGD facility consists of the following units: mechanical influent bar screen, caustic feed for
pH adjustment, influent pump station, dual oxidation ditches, two secondary clarifiers, polymer feed
for secondary clarifiers, liquid chlorine disinfection, chlorine contact chamber, liquid dechlorination,
cascade aeration, one aerobic digester, one aerated sludge holding tank (485, 000), four sludge
drying beds, and 450 KW stand-by generator.
At the time of inspection, the influent pump station and automatic bar screen were operating normally.
All aerators were in operation in the oxidation ditches. Color of the influent appeared to be a medium
chocolate brown. Foam covered less than 10% of the surface. Dissolved oxygen content is kept
between 2.6 mg/I and 1.2 mg/I. Sludge blanket in the secondary clarifiers are kept around 3 feet with
a sidewall depth of 12 feet. Effluent flowing off the secondary clarifier weirs and at the cascade
aerator appeared clear with no solids and little foam. The digester was empty and the 485,000
gallons sludge holding tank was approximately one-third full. The back-up generator is operated
under load once weekly.
Synagro is permitted to haul sludge under permit WQ0002368. Sludge was last hauled from the
facility spring of 2021.
Discharge Monitoring Reports (DMR)were reviewed for compliance with permit and monitoring
requirements for the period November 2019 through October 2021. The following were noted: fecal
weekly permit limit for October 2021, aquatic toxicity violation for May 2020, monthly average flow
violation for February 2021, and monthly BOD violation for May 2021.
Commercial lab results, chain of custody records, and bench sheets were compared with data
submitted on the DMR for September 2021. No discrepancies were noted. Weldon Laboratory is field
certified for pH and total residual chlorine. All other permit parameters are analyzed by Meritech
Environmental Laboratories.
The laboratory was checked in a cursory manner. All instruments, meters, probes, photometric cells
are maintained in good condition. Temperatures on all equipment are checked against an NIST
thermometer. All standards, reagents and consumables used are within expiration dates.
Page# 2

Permit: NCO025721 Owner-Facility: Weldon WWTP
Inspection Date: 11/09/2021 Inspection Type: Compliance Sampling
Operations & Maintenance Yes No NA NE
Is the plant generally clean with acceptable housekeeping? 0 ❑ ❑ ❑
Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable ❑ ❑ ❑
Solids, pH, DO, Sludge Judge, and other that are applicable?
Comment:
Permit Yes No NA NE
(If the present permit expires in 6 months or less). Has the permittee submitted a new ❑ ❑ 0 ❑
application?
Is the facility as described in the permit? 0 ❑ ❑ ❑
#Are there any special conditions for the permit? ❑ ■ ❑ ❑
Is access to the plant site restricted to the general public? 0 ❑ ❑ ❑
Is the inspector granted access to all areas for inspection? ❑ ❑ ❑
Comment: No special conditions.
Record Keeping Yes No NA NE
Are records kept and maintained as required by the permit? 0 ❑ ❑ ❑
Is all required information readily available, complete and current? 0 ❑ ❑ ❑
Are all records maintained for 3 years (lab. reg. required 5 years)? ■ ❑ ❑ ❑
Are analytical results consistent with data reported on DMRs? 0 ❑ ❑ ❑
Is the chain-of-custody complete? 0 ❑ ❑ ❑
Dates, times and location of sampling
Name of individual performing the sampling
Results of analysis and calibration
Dates of analysis
Name of person performing analyses
Transported COCs
Are DMRs complete: do they include all permit parameters? ❑ ❑ ❑
Has the facility submitted its annual compliance report to users and DWQ? ❑ ❑ ❑
(If the facility is = or> 5 MGD permitted flow) Do they operate 24/7 with a certified ❑ ❑ ❑
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 M ❑ ❑ ❑
classification?
Page# 3

Permit: NC0025721 Owner-Facility: Weldon WWTP
Inspection Date: 11/09/2021 Inspection Type: Compliance Sampling
Record Keeping Yes No NA NE
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:
Effluent Pipe Yes No NA NE
Is right of way to the outfall properly maintained? ■ ❑ ❑ ❑
Are the receiving water free of foam other than trace amounts and other debris? ■ ❑ ❑ ❑
If effluent (diffuser pipes are required) are they operating properly? ■ ❑ ❑ ❑
Comment: Effluent appeared clear with minimum foam.
Flow Measurement - Effluent Yes No NA NE
# Is flow meter used for reporting? ■ ❑ ❑ ❑
Is flow meter calibrated annually? ■ ❑ ❑ ❑
Is the flow meter operational? ■ ❑ ❑ ❑
(If units are separated) Does the chart recorder match the flow meter? ■ ❑ ❑ ❑
Comment:
Aerobic Digester Yes No NA NE
Is the capacity adequate? ■ ❑ ❑ ❑
Is the mixing adequate? ■ ❑ ❑ ❑
Is the site free of excessive foaming in the tank? ■ ❑ ❑ ❑
# Is the odor acceptable? ■ ❑ ❑ ❑
# Is tankage available for properly waste sludge? ■ ❑ ❑ ❑
Comment: Digester was empty at the time of inspection.
Drying Beds Yes No NA NE
Is there adequate drying bed space? ■ ❑ ❑ ❑
Is the sludge distribution on drying beds appropriate? ■ ❑ ❑ ❑
Are the drying beds free of vegetation? ■ ❑ ❑ ❑
# Is the site free of dry sludge remaining in beds? ■ ❑ ❑ ❑
Is the site free of stockpiled sludge? ■ ❑ ❑ ❑
Is the filtrate from sludge drying beds returned to the front of the plant? ■ ❑ ❑ ❑
# Is the sludge disposed of through county landfill? ■ ❑ ❑ ❑
Page# 4

Permit: NC0025721 Owner-Facility: Weldon WWTP
Inspection Date: 11/09/2021 Inspection Type: Compliance Sampling
Drying Beds Yes No NA NE
# Is the sludge land applied? 0 ❑ ❑ ❑
(Vacuum filters) Is polymer mixing adequate? ❑ ❑ ❑
Comment: There was no sludge in the drying beds.
Solids Handling Equipment Yes No NA NE
Is the equipment operational? ❑ ❑ 0 ❑
Is the chemical feed equipment operational? ❑ ❑ ■ ❑
Is storage adequate? ❑ ❑ 0 ❑
Is the site free of high level of solids in filtrate from filter presses or vacuum filters? ❑ ❑ 0 ❑
Is the site free of sludge buildup on belts and/or rollers of filter press? ❑ ❑ 0 ❑
Is the site free of excessive moisture in belt filter press sludge cake? ❑ ❑ ■ ❑
The facility has an approved sludge management plan? ❑ ❑ ❑
Comment: No sludge equipment.
Chemical Feed Yes No NA NE
Is containment adequate? 0 ❑ ❑ ❑
Is storage adequate? 0 ❑ ❑ ❑
Are backup pumps available? 0 ❑ ❑ ❑
Is the site free of excessive leaking? ■ ❑ ❑ ❑
Comment:
Pump Station - Influent Yes No NA NE
Is the pump wet well free of bypass lines or structures? 0 ❑ ❑ ❑
Is the wet well free of excessive grease? ❑ ❑ ❑ ■
Are all pumps present? 0 ❑ ❑ ❑
Are all pumps operable? 0 ❑ ❑ ❑
Are float controls operable? ❑ ❑ ❑ ■
Is SCADA telemetry available and operational? ❑ ❑ 0 ❑
Is audible and visual alarm available and operational? ❑ ❑ ❑
Comment:
Bar Screens Yes No NA NE
Type of bar screen
Page# 5

Permit: NCO025721 Owner-Facility: Weldon WWTP
Inspection Date: 11/09/2021 Inspection Type: Compliance Sampling
Bar Screens Yes No NA NE
a.Manual ❑
b.Mechanical
Are the bars adequately screening debris? 0 ❑ ❑ ❑
Is the screen free of excessive debris? 0 ❑ ❑ ❑
Is disposal of screening in compliance? 0 ❑ ❑ ❑
Is the unit in good condition? 0 ❑ ❑ ❑
Comment:
Secondary Clarifier Yes No NA NE
Is the clarifier free of black and odorous wastewater? 0 ❑ ❑ ❑
Is the site free of excessive buildup of solids in center well of circular clarifier? ■ ❑ ❑ ❑
Are weirs level? 0 ❑ ❑ ❑
Is the site free of weir blockage? 0 ❑ ❑ ❑
Is the site free of evidence of short-circuiting? 0 ❑ ❑ ❑
Is scum removal adequate? ■ ❑ ❑ ❑
Is the site free of excessive floating sludge? 0 ❑ ❑ ❑
Is the drive unit operational? 0 ❑ ❑ ❑
Is the return rate acceptable (low turbulence)? 0 ❑ ❑ ❑
Is the overflow clear of excessive solids/pin floc? 0 ❑ ❑ ❑
Is the sludge blanket level acceptable? (Approximately '/4 of the sidewall depth) ❑ ❑ ❑
Comment: Sludge blanket was 3 feet with a sidewall depth of 12 feet.
Oxidation Ditches Yes No NA NE
Are the aerators operational? 0 ❑ ❑ ❑
Are the aerators free of excessive solids build up? 0 ❑ ❑ ❑
# Is the foam the proper color for the treatment process? 0 ❑ ❑ ❑
Does the foam cover less than 25% of the basin's surface? 0 ❑ ❑ ❑
Is the DO level acceptable? 0 ❑ ❑ ❑
Are settleometer results acceptable (> 30 minutes)? ❑ ❑ ❑
Is the DO level acceptable?(1.0 to 3.0 mg/1) 0 ❑ ❑ ❑
Are settelometer results acceptable?(400 to 800 ml/I in 30 minutes) ❑ ❑ ❑
Comment:
Page# 6

Permit: NCO025721 Owner-Facility: Weldon WWTP
Inspection Date: 11/09/2021 Inspection Type: Compliance Sampling
De-chlorination Yes No NA NE
Type of system ? Liquid
Is the feed ratio proportional to chlorine amount (1 to 1)? 0 ❑ ❑ ❑
Is storage appropriate for cylinders? ❑ ❑ 0 ❑
# Is de-chlorination substance stored away from chlorine containers? 0 ❑ ❑ ❑
Comment:
Are the tablets the proper size and type? ❑ ❑ ■ ❑
Are tablet de-chlorinators operational? ❑ ❑ 0 ❑
Number of tubes in use?
Comment:
Pumps-RAS-WAS Yes No NA NE
Are pumps in place? 0 ❑ ❑ ❑
Are pumps operational? 0 ❑ ❑ ❑
Are there adequate spare parts and supplies on site? ■ ❑ ❑ ❑
Comment:
Laboratory Yes No NA NE
Are field parameters performed by certified personnel or laboratory? 0 ❑ ❑ ❑
Are all other parameters(excluding field parameters) performed by a certified lab? ■ ❑ ❑ ❑
# Is the facility using a contract lab? 0 ❑ ❑ ❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 ■ ❑ ❑ ❑
degrees Celsius)?
Incubator (Fecal Coliform) set to 44.5 degrees Celsius+/- 0.2 degrees? ❑ ❑ 0 ❑
Incubator (BOD) set to 20.0 degrees Celsius +/- 1.0 degrees? ❑ ❑ 0 ❑
Comment: Weldon Laboratory is field certified for pH and total residual chlorine. All other permit
parameters are analyzed by Meritech Environmental Laboratories.
Disinfection-Liquid Yes No NA NE
Is there adequate reserve supply of disinfectant? 0 ❑ ❑ ❑
(Sodium Hypochlorite) Is pump feed system operational? 0 ❑ ❑ ❑
Is bulk storage tank containment area adequate? (free of leaks/open drains) 0 ❑ ❑ ❑
Is the level of chlorine residual acceptable? 0 ❑ ❑ ❑
Is the contact chamber free of growth, or sludge buildup? 0 ❑ ❑ ❑
Is there chlorine residual prior to de-chlorination? 0 ❑ ❑ ❑
Page# 7

Permit: NCO025721 Owner-Facility: Weldon WWTP
Inspection Date: 11/09/2021 Inspection Type: Compliance Sampling
Disinfection-Liquid Yes No NA NE
Comment:
Influent Sampling Yes No NA NE
# Is composite sampling flow proportional? 0 ❑ ❑ ❑
Is sample collected above side streams? 0 ❑ ❑ ❑
Is proper volume collected? ■ ❑ ❑ ❑
Is the tubing clean? 0 ❑ ❑ ❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 0 ❑ ❑ ❑
degrees Celsius)?
Is sampling performed according to the permit? 0 ❑ ❑ ❑
Comment:
Effluent Sampling Yes No NA NE
Is composite sampling flow proportional? 0 ❑ ❑ ❑
Is sample collected below all treatment units? 0 ❑ ❑ ❑
Is proper volume collected? ■ ❑ ❑ ❑
Is the tubing clean? 0 ❑ ❑ ❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 0 ❑ ❑ ❑
degrees Celsius)?
Is the facility sampling performed as required by the permit (frequency, sampling type ❑ ❑ ❑
representative)?
Comment:
Page# 8

Whole Effluent Toxicity Testing and Self Monitoring Summary
Waynesville WWTP NCO025321/001 County: Haywood Region: ARO Basin: FRB05 Feb May Aug Nov SOC JOC:
Ceri7dPF Begin: 11/1/2021 chr lim:9% NonComp: Single 7Q10: 95.0 PF: 6.0 IWC: 8.91 Freq: Q
J F M A M J J A S O N D
2018 - Pass - - Pass - - Pass - - Pass -
2019 - Pass - - 6.4(F)Pass - - 3.2(F)Fail 6.4(F) >36 >36(P)Pass -
2020 - >12.7(P)Pass - - Pass - - Pass - - Pass -
2021 - Pass - - Pass - - Pass - - Pass -
2022 - Pass - - Pass - - Fail >36 >36 Pass -
Weldon WWTP NCO025721/001 County: Halifax Region: RRO Basin: ROA08 Jan Apr Jul Oct SOC JOC:
Fthd24PF Begin: 8/1/2012 24hr p/f ac lim:90% + NonComp: Single 70.10: 1000 PF: 1.2 IWC: 0.19 Freq: Q
J F M A M J J A S O N D
2018 Pass - - Pass - - Pass - - Pass - -
2019 Pass - - Pass - - Pass - - Pass - -
2020 Pass - - Pass - - Pass - - Fail Pass -
2021 Pass - - Pass - - Pass - - Pass - -
2022 Pass - - Pass - - Pass - - Pass>100 - -
Wells Fargo Bank-Duke Energy Center NCO088226/001 County: Mecklenburg Region: MRO Basin: CTB34 Mar Jun Sep Dec SOC JOC:
Ceri7dPF Begin: 9/1/2020 Chr Lim:P/F 90% NonComp: 7Q10: 1.25 PF: Var IWC: N/A Freq: Q
J F M A M I J A S O N D
2018 - - Pass - - Pass - - Pass - - Pass
2019 - - Fail >100 >100 Pass - - Pass - - Pass
2020 - - Pass - - Pass - - Pass - - Fail
2021 <45(F) <45(F) Fail <45(F) 55.1(F) Pass - - Pass - - Pass
2022 - - Pass - - Pass - - Pass - - -
West Carteret WTP NCO077143/001 County: Carteret Region: WIRO Basin: WOK01 Jan Apr Jul Oct SOC JOC:
Mysd24PF Begin: 11/1/2017 24hr p/f ac monit 90 NonComp: 7Q10: Tidal PF: 0.084 IWC: NA Freq: Q
J F M A M J J A S O N D
2018 Pass - - Pass - - Pass - - Pass - -
2019 Pass - - Pass - - Pass - - Pass - -
2020 Pass - - Pass - - Pass - - Pass - -
2021 Pass - - Pass - - Pass - - Pass - -
2022 Pass - - Pass - - Pass - - Pass - -
West Jefferson WWTP NCO020451/001 County: Ashe Region: WSRO Basin: NEW02 Jan Apr Jul Oct SOC JOC:
Ceri7dPF Begin: 3/1/2018 chr lim:56% NonComp: Single 7Q10: 0.6 PF: 0.5 IWC: 56.32 Freq: Q
J F M A M J J A S O N D
2018 Pass - - Pass - - Pass - - Pass - -
2019 Pass - - Pass>100(P) - - Pass - - Pass - -
2020 >100 Pass - - Pass - - Pass - - Pass - -
2021 Pass - - Pass - - Pass - - Pass - -
2022 Pass - - Pass - - Pass - - Pass - -
Leeend: P=Fathead minnow(Pimphales oromelas).H=No Flow(facility is active).s=Split test between Certified Labs Page 114 of 118