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HomeMy WebLinkAboutNC0024970_Fact Sheet_20230516 Fact Sheet NPDES Permit No. NCO024970 Permit Writer/Email Contact Nick Coco,nick.coco@ncdenr.gov Date: May 2,2023 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: Charlotte Water/McAlpine Creek Wastewater Management Facility (WWMF) Applicant Address: 5100 Brookshire Blvd., Charlotte,NC 28216 Facility Address: 12701 Lancaster Highway,Pineville,NC 28134 Permitted Flow: 64.0 MGD Facility Type/Waste: MAJOR Municipal; 90%domestic, 10% industrial* Facility Class: Grade IV Biological Water Pollution Control System Treatment Units: Flow equalization, screening,grit removal,primary clarifiers, aeration basins, secondary clarifiers,biological and chemical phosphorus removal, alkaline addition for nitrification, chlorination, dichlorination, anaerobic sludge digestion, centrifuges and gravity sludge thickeners, rapid sand filters Pretreatment Program(Y/N) Y,LTMP County: Mecklenburg Region Mooresville *Based on permitted flows. Briefly describe the proposed permitting action and facility background: Charlotte Water has applied for an NPDES permit renewal at 64.0 MGD for the McAlpine Creek WWMF. This facility serves a population of approximately 574,100 residents, as well as 17 significant industrial users (SIUs), including 6 categorical industrial users (CIUs),via an approved pretreatment program. Treated domestic and industrial wastewater is discharged via Outfall 001 into McAlpine Creek, a class C waterbody in the Page 1 of 13 Catawba River Basin. Outfall 001 is located approximately 2.0 miles upstream of the North Carolina- South Carolina border. Additionally,the City is scheduling improvements to the facility, including an upgrade to the headworks to fine barscreen and grit pump/vortex grit classifier,upgrade to their SCADA system, and upgrade from coarse bubble diffused air to fine bubble diffused air. The reliability and process improvements are anticipated to be completed in early 2023,biosolids treatment facilities rehabilitation is projected to complete construction by the end of 2024 and preliminary and primary treatment facilities improvements are expected to be completed shortly thereafter in early 2025. Sludge disposal: Biosolids residuals are permitted,managed, and disposed under a contract with Synagro. Land application and land filling are the means for ultimate use of the residuals. This is managed under permit WQ0000057. 2. Receiving Waterbody Information: Receiving Waterbody Information Outfalls/Receiving Stream(s): Outfall 001 McAlpine Creek Stream Segment: 11-137-9 Stream Classification: C Drainage Area(mi2): 92.4 Summer 7Q10(cfs) 2 Winter 7Q10(cfs): 10 30Q2 (cfs): 13.5 Average Flow(cfs): 62.4 IWC (%effluent): 98% 2022 303(d) listed/parameter: Yes; listed as exceeding criteria for benthos and fish community Subject to TMDL/parameter: Yes- State wide Mercury TMDL implementation; Fecal coliform TMDL for McAlpine Creek(DM 1000/100 ml); SC DHEC ongoing development on nutrient TMDL in the Catawba basin* Basin/Sub-basin/HUC: Catawba River/03-08-34/HUC: 0305010301 USGS Topo Quad: G15SE *Please see attached for the 2020 SCDHEC Lower Catawba River Basin—2020 Nutrient Study. 3. Effluent Data Summary Effluent data for Outfall 001 is summarized below for the period of January 2018 through August 2022. Table 1. Effluent Data Summary Outfall 001 Parameter Units Average Max Min Permit Limit Flow MGD 46.2 104.9 28.3 MA 64.0 CBOD summer mg/l 2.1 5.3 < 2 WA 6.0 MA 4.0 CBOD winter mg/1 2.1 3.9 < 2 WA 12.0 MA 8.0 Page 2 of 13 NH3N summer mg/1 0.1 0.4 <0.1 WA 3.0 MA 1.0 NH3N winter mg/l 0.1 10 <0.1 WA 5.7 MA 1.9 TSS mg/l 2.6 11.7 2.5 WA 22.5 MA 15.0 0>pH< pH SU 7.0 7.6 6.4 6. 9.0 (geometric) Fecal coliform #/100 ml 7.1 403 < I WA 400 MA 200 DM 1000 DO mg/l 8.8 10.1 7.2 DA>6.0 DM 28.0 TRC µg/1 < 15 < 15 < 15 WA 17.0 (<50 compliance) Conductivity umhos/cm 593.7 739 387 Monitor& Report Temperature ° C 21.6 27.2 15.3 Monitor& Report TN mg/l 19.8 28.1 9.4 Monitor& Report TP mg/I 0.4 0.92 0.16 Monitor& Report TP Load lbs/day 163.1 311.18 100.05 1067 TP Load* lbs/day 451.7 656.31 288.68 826.0 Total Silver ug/1 < 1 < I < I Monitor& Report Total Phenolic Monitor& Compounds ug/1 50.6 70 <50 Report Dichlorobromomethane ug/l 6.1 10.1 3.2 Monitor& Report Total Hardness mg/l 152.5 180 120 Monitor& Report MA-Monthly Average,WA-Weekly Average,DM-Daily Maximum,DA=Daily Average *annual rolling average of combined discharge of 3 WWTPs: Sugar Creek WWTP,Irwin Creek WWTP,and McAlpine Creek WWTP 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). Page 3 of 13 If applicable, summarize any instream data and what instream monitoring will be proposed for this permit action: The current permit requires instream monitoring for several locations: Irwin Creek, McAlpine Creek, Sugar Creek, and Little Sugar Creek. All of these receiving streams are a part of the facility and facility owner's(Charlotte Water) instream monitoring program for Sugar Creek WWTP, Irwin Creek WWTP, and McAlpine WWMF. For the McAlpine Creek WWMF renewal,instream data for MC 1(upstream)and MC2 (downstream), were analyzed for the period of January 2018 through August 2022 (see stream map attached in factsheet attachments for locations of MCI and MC2). Instream monitoring at the McAlpine Creek stations,MCI upstream of McAlpine Creek WWMF and MC2 downstream of McAlpine Creek WWMF is required for dissolved oxygen,temperature, conductivity, and total copper. Total hardness monitoring is also required upstream at MCI on a quarterly basis. The data has been summarized in Table 2 below. Table 2. Instream Monitoring Data Summary McAlpine Creek Upstream Downstream Parameter Units Average Max Min Average Max Min Temperature ° C 20.3 27.1 3.7 22.2 27.3 10 DO mg/1 6.9 12 4.9 7.5 10.5 5.6 Conductivity µmhos/cm 198.7 320 84 472.9 653 101 Total Copper mg/1 2.6 11 2 3.8 18 2.3 Total hardness mg/1 80.7 120 1 23 1 - I - I - Students t-tests were run at a 95% confidence interval to analyze relationships between instream samples.A statistically significant difference is determined when the t-test p-value result is<0.05 Downstream temperature was not greater than 29 degrees Celsius [per 15A NCAC 02B .0211 (18)] during the period reviewed. Downstream temperature was greater than upstream temperature by more than 2.8 degrees Celsius on 31 occasions during the period reviewed. Review of concurrent effluent temperature for these 31 occasions demonstrated a consistent relationship between elevated effluent temperatures and elevated downstream temperature. Additionally, it was concluded that a statistically significant difference exists between upstream and downstream temperature. Effluent temperature does appear to have the potential to influence instream temperature. Downstream DO did not drop below 5 mg/L [per 15A NCAC 02B .0211 (6)] during the period reviewed. While it was concluded that a statistically significant difference exists between upstream and downstream DO,this does not appear to create any instances of noncompliance with DO standards. It was concluded that a statistically significant difference exists between upstream and downstream conductivity with downstream conductivity consistently higher than upstream conductivity. It was concluded that a statistically significant difference exists between upstream and downstream copper with downstream copper concentrations consistently higher than upstream copper concentrations. Upon review of concurrent effluent total copper demonstrating effluent concentrations at levels generally greater than upstream concentrations, it does appear that the effluent may have an influence on downstream total copper. However,both upstream and downstream total copper were not observed at levels greater than the standard of 21.4 ug/L(calculated based on average reported upstream hardness of 80.7 mg/L and EPA Default Partition Coefficient of 0.348) during the period reviewed. In addition to the instream monitoring requirements in the permit, Charlotte Water conducted sampling at the two McAlpine Creek stations for pH,TKN,nitrate+nitrite, Orthophosphate,total chromium,total Page 4 of 13 zinc, fecal coliform and total phosphorous. Data from January 2018 through August 2022 has been summarized below. Table 3. Additional Instream Monitoring Data Summary McAlpine Creek Upstream Downstream Parameter Units Average Max Min Average Max Min pH S.U. 7.1 7.5 6.4 7.1 7.4 6.5 Orthophosphate mg/l 0.05 0.05 0.05 0.2 0.65 0.1 Total mg/l 0.1 0.1 0.1 0.3 0.7 0.2 Phosphorous TKN mg/l 0.5 1 0.3 0.7 2 0.3 NO3+NO2 mg/1 0.4 0.7 0.1 15.5 26 4.7 Fecal Coliform #/100ml (geomean) 61000 19 (geomean) 36000 45 569 438 Total µg/l 5.0 6.7 5 5.2 15 5 Chromium Total Zinc µg/1 10.7 32 10 18.1 28 12 No changes are proposed to McAlpine Creek instream monitoring requirements. All instream monitoring for all parameters for Irwin Creek WWTP's receiving streams,Irwin Creek and Sugar Creek, and Sugar Creek WWTP's receiving stream, Little Sugar Creek,will be maintained in McAlpine Creek WWMF's permit(NC0024970)along with McAlpine Creek instream monitoring requirements. Please note that, while no changes have been made to the instream monitoring requirements listed in the permit for Irwin Creek, Sugar Creep and Little Sugar Creek, instream summaries will be provided for the other receiving streams in the applicable permit reviews. Is this facility a member of a Monitoring Coalition with waived instream monitoring(YIN):NO Name of Monitoring Coalition: NA 5. Compliance Summary Summarize the compliance record with permit effluent limits (past 5 years): The facility did not report any limit violations during the period reviewed. Summarize the compliance record with aquatic toxicity test limits and any second species test results (past 5 years): The facility passed 18 of 18 quarterly chronic toxicity tests, as well as all 4 second species chronic toxicity tests from March 2018 to June 2022. Summarize the results from the most recent compliance inspection: The last facility inspection conducted in February 2022 reported that the facility was compliant. 6. Water Quality-Based Effluent Limitations (WQBELs) Dilution and Mixing Zones Page 5 of 13 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 CBOD are based on a 1995 Streeter-Phelps model(Level B)for instream DO protection. No changes are proposed from the previous permit limits. 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: The current TRC limits are expressed as a daily maximum of 28 ug/L and a weekly average of 17 ug/L. TRC limits have been reviewed in the attached WLA. Based on the 15A NCAC 02B .0211(3) TRC standard of 17 ug/L and accounting for instream wasteload concentration/dilution, a daily maximum limit of 17 ug/L was calculated. Additionally,while the 2003 Total Residual Chlorine Policy for NPDES permits(attached) states that"Facilities discharging to streams with a 7Q 10<0.05 cfs(zero-flow streams)will receive a limit of 17 µg/L,"it does not state that limit calculations based on the aquatic life standard of 17 ug/L cannot be applied if they result in a limit of 17 ug/L. As the calculated limit is more stringent than the current permit limits,a daily maximum limit of 17 ug/L has been proposed. The current limitations for ammonia are based on protection of aquatic life utilizing an ammonia chronic criterion of 1.0 mg/1(summer) and 1.8 mg/1(winter). Acute ammonia limits are derived from chronic criteria,utilizing a multiplication factor of 3 for Municipals and a multiplication factor of 5 for Non- Municipals. The ammonia limits have been reviewed in the attached WLA for toxicity and have been found to be protective.No changes are proposed. Reasonable Potential Analysis(RPA)for Toxicants If applicable, conduct RPA analysis and complete information below. The need for toxicant limits is based upon a demonstration of reasonable potential to exceed water quality standards, a statistical evaluation that is conducted during every permit renewal utilizing the most recent effluent data for each outfall. The RPA is conducted in accordance with 40 CFR 122.44(d) (i). The NC RPA procedure utilizes the following: 1) 95%Confidence Level/95%Probability; 2)assumption of zero Page 6 of 13 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 January 2018 and August 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: • 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 Arsenic, Total Cadmium, Total Phenolic Compounds, Total Chromium, Total Copper, Total Cyanide, Total Lead, Total Molybdenum, Total Nickel, Total Selenium, Total Silver, Total Zinc, Dichlorobromomethane • POTW Effluent Pollutant Scan Review: Three effluent pollutant scans were evaluated for additional pollutants of concern. o The following parameter(s)will receive a water quality-based effluent limit(WQBEL) with monitoring, since as part of a limited data set,two samples exceeded the allowable discharge concentration: 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 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 a chronic WET limit at 90% effluent will continue on a quarterly frequency. Mercury Statewide TMDL Evaluation Page 7 of 13 There is a statewide TMDL for mercury approved by EPA in 2012. The TMDL target was to comply with EPA's mercury fish tissue criteria(0.3 mg/kg) for human health protection. The TMDL established a wasteload allocation for point sources of 37 kg/year(81 lb/year), and is applicable to municipals and industrial facilities with known mercury discharges. Given the small contribution of mercury from point sources(-2%of total load),the TMDL emphasizes mercury minimization plans (MMPs)for point source control. Municipal facilities>2 MGD and discharging quantifiable levels of mercury(>1 ng/1)will receive an MMP requirement. Industrials are evaluated on a case-by-case basis, depending if mercury is a pollutant of concern. Effluent limits may also be added if annual average effluent concentrations exceed the WQBEL value(based on the NC WQS of 12 ng/1) and/or if any individual value exceeds a TBEL value of 47 ng/1 Table 4. Mercury Effluent Data Summary 2018 2019 2020 2021 2022 #of Samples 11 13 13 13 7 Annual Average Conc.n /L 1.1 1.4 0.7 0.81 0.66 Maximum Conc.,n /L 3.9 9.8 0.9 1.16 0.93 TBEL,n /L 47 WQBEL,n /L 12.2 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 and reported quantifiable levels of mercury(> 1 ng/1), the mercury minimization plan(MMP) condition has been maintained. Charlotte Water submitted their MMP with their 2022 Pretreatment Annual Report. Other TMDL/Nutrient Management Strategy Considerations If applicable, describe any other TMDLs/Nutrient Management Strategies and their implementation within this permit: A fecal coliform TMDL was established in February 2002 and the permit contains a 1000/100 mL fecal coliform daily maximum. A bubble limit for total phosphorus is included for Irwin Creek WWTP, Sugar Creek WWTP, and McAlpine Creek WWMF. As stipulated by the 2002 Settlement Agreement between Charlotte-Mecklenburg Utilities(CMU),the South Carolina Department of Health and Environmental Control(SC DHEC)and the North Carolina Division of Water Quality(NC-DWQ), now North Carolina Division of Water Resources, Charlotte Water's McAlpine Creek WWMF, Sugar Creek WWTP and Irwin Creek WWTP must comply with a combined 12 month rolling average limit of 826.0 lbs/day as of February 28,2006. Charlotte Water has asked the Division to revise the Sugar, Irwin, and McAlpine Creek permits to improve the uniformity of their nutrient conditions. As outlined in the 2021 internal Memorandum "Charlotte Water Permits—Proposed Uniform Nutrient Conditions"(attached),changes are proposed to the nutrient language and permit conditions for each of these permits to apply more consistent terminology,units of measure, and parameter codes for the various measures of TP, apply consistent methods for calculation of TN and TP loads and require reporting of interim calculation results,to make it easier to see how the final results were derived. Proposed changes include: • Section A.(L): Added Total Monthly Flow(TMF)reporting, created separate rows for TP concentration and mass, applied new parameter names in the table and footnotes to improve clarity,provided clearer linkage between the limits page, footnotes, and the other TP special conditions. Page 8 of 13 • Special Condition A.(7.): Applied the new parameter names and added linkage to the limits page and calculations condition. • Special Condition A.(8.): Applied the new terminology and described the calculations for each measure of TP used on the limits page. Clarified how the combined TP loads would be calculated and where they would be reported. The changes will not affect the TN and TP limits or monitoring requirements for the facilities. Other WQBEL Considerations If applicable, describe any other parameters of concern evaluated for WQBELs: The bubble limit for total phosphorus was analyzed for Irwin Creek WWTP, Sugar Creek WWTP, and McAlpine Creek WWMF. There were no compliance concerns for the period analyzed(January 2018-August 2022) and the three facilities stayed below their total phosphorus rolling average bubble limit. 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. Charlotte Water informed the Division that no monitoring for additional pollutants has been conducted(see attached email exchange) and therefore no additional pollutants of concern have been identified. If applicable, describe any special actions (HQW or ORW) this receiving stream and classification shall comply with in order to protect the designated waterbody:NA If applicable, describe any compliance schedules proposed for this permit renewal in accordance with 15A NCAC 2H 0107(c)(2)(B), 40CFR 122.47, and EPA May 2007 Memo:NA If applicable, describe any water quality standards variances proposed in accordance with NCGS 143- 215.3(e) and 15A NCAC 2B.0226 for this permit renewal:NA 7. Technology-Based Effluent Limitations (TBELs) Municipals (if not applicable,delete and skip to Industrials) Are concentration limits in the permit at least as stringent as secondary treatment requirements (30 mg/l CBODS/TSS for Monthly Average, and 45 mg/l for CBODS/TSS for Weekly Average). YES If NO,provide a justification for alternative limitations (e.g., waste stabilization pond). NA Are 85%removal requirements for CBOD51TSS included in the permit? YES If NO,provide a justification (e.g., waste stabilization pond). NA 8. Antidegradation Review (New/Expanding Discharge): The objective of an antidegradation review is to ensure that a new or increased pollutant loading will not degrade water quality. Permitting actions for new or expanding discharges require an antidegradation review in accordance with 15A NCAC 213.0201. Each applicant for a new/expanding NPDES permit must document an effort to consider non-discharge alternatives per 15A NCAC 2H.0105(c)(2). In all cases, existing instream water uses and the level of water quality necessary to protect the existing use is maintained and protected. If applicable, describe the results of the antidegradation review, including the Engineering Alternatives Analysis (EAA) and any water quality modeling results:NA Page 9 of 13 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. Charlotte Water was granted 2/week monitoring for CBOD, ammonia,TSS and fecal coliform based on 2012 DWR Guidance Regarding the Reduction of Monitoring Frequencies in NPDES Permits for Exceptionally Performing Facilities during their 2017 renewal. Charlotte Water has requested continuation of this monitoring frequency reduction as part of their renewal application. The last three years of the facility's data for these parameters have been reviewed in accordance with the criteria outlined in the guidance. Based on this review, 2/week monitoring frequency has been maintained for CBOD, ammonia,TSS and fecal coliform. To identify PFAS concentrations in waters classified as Water Supply(WS)waters,monitoring requirements are to be implemented in permits with pretreatment programs that discharge to WS waters. While there are no WS waters designated by the Division downstream of the discharge,the discharge point is upstream of the border between North Carolina and South Carolina. Since all waters in South Carolina are deemed suitable for drinking water uses with appropriate treatment,and to ensure PFAS contamination does not cross State lines, and as the McAlpine Creek WWMF has a pretreatment program, monitoring of PFAS 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 CFR136 published in the Federal Register. This date may be extended upon request and if there are no NC-certified labs. As the McAlpine Creek WWMF accepts influent wastewater from several industrial facilities that are potential sources of 1,4-dioxane via the approved pretreatment program, as no additional sampling has been conducted for 1,4-dioxane at this facility as identified in the chemical addendum submitted by Charlotte Water, and as the facility discharges above the NC/SC state border line,monthly effluent monitoring for 1,4-dioxane as well as a 1,4-dioxane reopener condition have been added to the permit. The statement, "There shall be no discharge of floating solids or visible foam in other than trace amounts,"was removed during the 2017 renewal. This statement has been standard language in NPDES Page 10 of 13 permits since the program's inception and is still used widely by state and federal permitting authorities. Because it is subjective, it is hardly suitable as the basis for an enforcement action; instead,we would rely on the permittee's monitoring reports to establish and quantify any limits exceedances. Part of its value is that it provides a quick measure of effluent quality and possible water quality impacts. A DWR inspector who notices such an issue at a discharge can address the matter while on site rather than waiting days or weeks for effluent monitoring to be reported. In addition,there is also a concern of the presence of emerging contaminants in visible foams. Therefore,this condition should be maintained in NPDES permits. As such,the statement has been added back into the permit in Section A.(1.). 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 5. Current Permit Conditions and Proposed Changes Outfall 001 Parameter Current Permit Proposed Change Basis for Condition/Change Flow MA 64.0 MGD No change 15A NCAC 2B .0505 CBOD5 Summer: No change WQBEL. 1995 Level B model, MA 4.0 mg/l Surface Water Monitoring, 2012 WA 6.0 mg/l DWR Guidance Regarding the Winter: Reduction of Monitoring MA 8.0 mg/1 Frequencies in NPDES Permits for WA 12.0 mg/1 Exceptionally Performing Facilities Monitor and report 2/Week NH3-N Summer: No change WQBEL. 2022 WLA review; MA 1.0 mg/1 Surface Water Monitoring, 2012 WA 3.0 mg/l DWR Guidance Regarding the Winter: Reduction of Monitoring MA 1.9 mg/1 Frequencies in NPDES Permits for WA 5.7 mg/1 Exceptionally Performing Facilities Monitor and report 2/Week TSS MA 15.0 mg/l No change WQBEL. 1995 Level B model, WA 22.5 mg/1 Surface Water Monitoring, 2012 Monitor and report 2/Week DWR Guidance Regarding the Reduction of Monitoring Frequencies in NPDES Permits for Exceptionally Performing Facilities Fecal coliform MA 200/100ml No change WQBEL. State WQ standard, 15A WA 400/100ml NCAC 213 .0200; 2002 TMDL for DM 1000/100ml fecal,results in DM; Surface Water Monitor and report 2/Week Monitoring, 2012 DWR Guidance Regarding the Reduction of Page 11 of 13 Monitoring Frequencies in NPDES Permits for Exceptionally Performing Facilities DO >6 mg/1 No change WQBEL. 1995 Level B model; Monitor and report Daily Surface Water Monitoring, 15A NCAC 2B. 0500 pH 6—9 SU No change WQBEL. State WQ standard, 15A Monitor and report Daily NCAC 213 .0200; Surface Water Monitoring, 15A NCAC 2B. 0500 Conductivity Monitor and report Daily No change Surface Water Monitoring, 15A NCAC 2B. 0500 Temperature Monitor and report Daily No change Surface Water Monitoring, 15A NCAC 2B. 0500 Total Residual WA 17 ug/L DM 17 ug/L WQBEL. 2022 WLA review and Chlorine DM 28 ug/L Monitor and report Surface Water Monitoring, 15A Monitor and report Daily Daily NCAC 2B. 0500 Total Nitrogen Monitor and report Monthly No change Surface Water Monitoring, 15A NCAC 2B. 0500 TKN No requirement Monitor and report For calculation of Total Nitrogen Monthly NO3+NO2 No requirement Monitor and report For calculation of Total Nitrogen Monthly Total 826.0 lbs/day bubble limit for No change WQBEL. Required TP nutrient Phosphorus Irwin Creek WWTP, Sugar limits per 2002 permitting strategy Creek WWTP, and McAlpine agreement with Charlotte- Creek WWTP Mecklenburg Utilities(CMU),the MA 1,0671bs/day South Carolina Department of Monitor and report Monthly Health and Environmental Control (SC DHEC) and the North Carolina Division of Water Quality(NC- DWQ); Surface Water Monitoring, 15A NCAC 2B. 0500 Total Hardness Quarterly monitoring No change Hardness-dependent dissolved Upstream and in Effluent metals water quality standards approved in 2016 Total Silver Monitor and report Quarterly Remove Based on results of RPA; All values requirement non-detect< 1 ug/L-no monitoring required Dichlorobromo- Monitor and report Quarterly Remove Based on results of RPA;No RP, methane requirement Predicted Max< 50%of Allowable Cw-No Monitoring required Total Phenolic Remove Based on results of RPA;No RP, Compounds Monitor and report Quarterly requirement Predicted Max< 50%of Allowable Cw-No Monitoring required Monitor and Report Based on PT Program—industrial 1,4-dioxane No requirement Monthly and facilities linked to 1,4-dioxane reo ener condition PFAS No requirement Add Quarterly Evaluation of PFAS contribution: monitoring with pretreatment facility; Page 12 of 13 delayed Implementation delayed until after implementation EPA certified method becomes available. Toxicity Test Chronic 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 cycle No change; 40 CFR 122 Pollutant Scan conducted in 2024, 2025, 2026 Mercury MMP Special Condition No change; revise WQBEL. Consistent with 2012 Minimization wording towards its Statewide Mercury TMDL Plan(MMP) maintenance Implementation. Electronic Electronic Reporting Special No change In accordance with EPA Electronic Reporting 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 nick.coco@ncdenr.gov. 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 • Compliance Inspection Report • 2003 TRC Policy • 2021 Internal Memo Charlotte Water Permits—Proposed Uniform Nutrient Conditions • Requested Additional Information • Email Correspondence Page 13 of 13 Permit No. NCO024970 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. NCO024970 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. NCO024970 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. NC0024970 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) 152.6 Average from January 2018 to [Total as, CaCO3 or(Ca+Mg)] August 2022 samples Average Upstream Hardness (mg/L) 80.7 Average from January 2018 to [Total as, CaCO3 or(Ca+Mg)] August 2022 samples 7Q10 summer(cfs) 2.0 Historical;Previous Fact Sheet 1Q10(cfs) 1.68 Calculated in RPA Permitted Flow(MGD) 64.0 NPDES Files Date: 12/19/2022 Permit Writer: Nick Coco Page 4 of 4 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 McAlpine Creek WWMF Par01 Arsenic Aquactic Life C 150 FW 340 ug/L WWTP/WTP Class IV Par02 Arsenic Human Health C 10 HH/WS N/A ug/L Water Supply NPDES Permit NCO024970 Par03 Beryllium Aquatic Life NC 6.5 FW 65 ug/L Outfall 001 Par04 Cadmium Aquatic Life NC 2.2941 FW 15.5700 ug/L Flow, Qw (MGD) 64.000 Par05 Chlorides Aquatic Life NC 230 FW mg/L Receiving Stream McAlpine Creek Par06 Chlorinated Phenolic Compounds Water Supply NC 1 A ug/L HUC Number 03050103 Par07 Total Phenolic Compounds Aquatic Life NC 300 A ug/L Stream Class C Par08 Chromium III Aquatic Life NC 513.9885 FW 3956.1300 ug/L ❑ Apply WS Hardness WQC Par09 Chromium VI Aquatic Life NC 11 FW 16 pg/L 7Q10s (cfs) 2.00 Par10 Chromium, Total Aquatic Life NC N/A FW N/A pg/L 7Q10w (cfs) 10.00 Par11 Copper Aquatic Life NC 36.6743 FW 57.1443 ug/L 30Q2 (cfs) 13.50 Par12 Cyanide Aquatic Life NC 5 FW 22 10 ug/L QA(cfs) 62.40 Par13 Fluoride Aquatic Life NC 1,800 FW ug/L 1Q10s (cfs) 1.68 Par14 Lead Aquatic Life NC 21.3941 FW 549.8819 ug/L Effluent Hardness 152.59 mg/L (Avg) Par15 Mercury Aquatic Life NC 12 FW 0.5 ng/L ------------- ---------------------- Upstream Hardness 80.65 mg/L (Avg) Par16 Molybdenum Human Health NC 2000 HH ug/L ------------- ---------------------- Combined Hardness Chronic 151.16 mg/L Par17 Nickel Aquatic Life NC 170.6343 FW 1538.2117 pg/L ------------- ---------------------- Combined Hardness Acute 151.39 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 6.5641 ug/L Par21 Zinc Aquatic Life NC 582.1902 FW 578.1905 ug/L Par22 Dichlorobromomethane Human Health C 17 HH pg/L Par23 Par24 24970 rpa, input 9/14/2022 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 2/20/2018 150 150 Std Dev. 15.3966 1 1/16/2018 66 66 Std Dev. 18.8996 2 3/20/2018 140 140 Mean 152.5862 2 2/21/2018 94 94 Mean 80.6545 3 4/17/2018 150 150 C.V. 0.1009 3 3/14/2018 73 73 C.V. 0.2343 4 5/22/2018 160 160 n 58 4 4/11/2018 94 94 n 55 5 6/19/2018 170 170 10th Per value 137.00 mg/L 5 5/14/2018 110 110 10th Per value 59.80 mg/L 6 7/24/2018 130 130 Average Value 152.59 mg/L 6 6/13/2018 92 92 Average Value 80.65 mg/L 7 8/21/2018 150 150 Max. Value 180.00 mg/L 7 7/23/2018 120 120 Max. Value 120.00 mg/L 8 9/12/2018 160 160 8 8/6/2018 59 59 9 9/25/2018 150 150 9 9/5/2018 75 75 10 10/16/2018 140 140 10 10/15/2018 74 74 11 11/20/2018 140 140 11 11/19/2018 69 69 12 12/18/2018 130 130 12 12/13/2018 68 68 13 1/14/2019 120 120 13 1/14/2019 59 59 14 2/9/2019 160 160 14 2/14/2019 65 65 15 3/10/2019 140 140 15 3/19/2019 86 86 16 4/8/2019 140 140 16 4/16/2019 73 73 17 5/7/2019 140 140 17 5/21/2019 110 110 18 6/5/2019 160 160 18 6/17/2019 73 73 19 7/11/2019 160 160 19 7/18/2019 90 90 20 8/9/2019 180 180 20 8/7/2019 61 61 21 9/7/2019 170 170 21 9/12/2019 110 110 22 10/6/2019 150 150 22 10/8/2019 120 120 23 11/18/2019 170 170 23 11/14/2019 50 50 24 12/4/2019 180 180 24 12/19/2019 67 67 25 12/10/2019 170 170 25 1/9/2020 94 94 26 1/8/2020 160 160 26 2/4/2020 75 75 27 2/6/2020 170 170 27 3/16/2020 100 100 28 3/6/2020 170 170 28 4/6/2020 110 110 29 3/11/2020 170 170 29 5/11/2020 100 100 30 4/4/2020 160 160 30 6/1/2020 75 75 31 5/10/2020 140 140 31 7/7/2020 91 91 32 6/8/2020 140 140 32 8/3/2020 76 76 33 7/14/2020 170 170 33 9/15/2020 84 84 34 8/5/2020 150 150 34 10/5/2020 91 91 35 9/17/2020 160 160 35 11/2/2020 63 63 36 10/9/2020 140 140 36 12/8/2020 74 74 37 11/7/2020 130 130 37 1/11/2021 71 71 38 12/6/2020 140 140 38 2/3/2021 77 77 39 1/11/2021 120 120 39 3/8/2021 92 92 40 2/9/2021 120 120 40 4/12/2021 87 87 41 3/10/2021 140 140 41 5/17/2021 91 91 42 4/8/2021 150 150 42 6/14/2021 74 74 43 5/14/2021 160 160 43 7/6/2021 68 68 44 6/5/2021 160 160 44 8/9/2021 92 92 45 6/9/2021 140 140 45 9/7/2021 78 78 46 7/11/2021 170 170 46 10/4/2021 110 110 47 8/16/2021 160 160 47 11/9/2021 95 95 48 9/14/2021 160 160 48 12/14/2021 63 63 49 10/13/2021 150 150 49 1/19/2022 56 56 50 11/18/2021 140 140 50 2/9/2022 56 56 51 12/17/2021 180 180 51 3/2/2022 66 66 52 1/8/2022 160 160 52 4/13/2022 85 85 53 2/6/2022 160 160 53 5/9/2022 70 70 54 3/7/2022 150 150 54 6/1/2022 91 91 55 4/5/2022 140 140 55 7/20/2022 23 23 56 5/11/2022 170 170 56 57 6/9/2022 170 170 57 58 7/22/2022 140 140 58 24970 rpa, data - 1 - 9/14/2022 REASONABLE POTENTIAL ANALYSIS Par01 & Par02 Use"PASTE SPECIAL Arsenic Values"then"COPY" Maximum data points=58 Date Data BDL=1/2DL Results 1 8/24/2021 < 5 2.5 Std Dev. 0.0000 2 8/31/2021 < 5 2.5 Mean 2.5000 3 9/8/2021 < 5 2.5 C.V. 0.0000 4 9/14/2021 < 5 2.5 n 58 5 9/21/2021 < 5 2.5 6 9/28/2021 < 5 2.5 Mult Factor= 1.00 7 10/5/2021 < 5 2.5 Max. Value 2.5 ug/L 8 10/12/2021 < 5 2.5 Max. Pred Cw 2.5 ug/L 9 10/13/2021 < 5 2.5 10 10/19/2021 < 5 2.5 11 10/26/2021 < 5 2.5 12 11/2/2021 < 5 2.5 13 11/9/2021 < 5 2.5 14 11/16/2021 < 5 2.5 15 11/18/2021 < 5 2.5 16 11/23/2021 < 5 2.5 17 11/30/2021 < 5 2.5 18 12/7/2021 < 5 2.5 19 12/14/2021 < 5 2.5 20 12/17/2021 < 5 2.5 21 12/21/2021 < 5 2.5 22 12/29/2021 < 5 2.5 23 1/4/2022 < 5 2.5 24 1/8/2022 < 5 2.5 25 1/11/2022 < 5 2.5 26 1/19/2022 < 5 2.5 27 1/25/2022 < 5 2.5 28 2/1/2022 < 5 2.5 29 2/6/2022 < 5 2.5 30 2/8/2022 < 5 2.5 31 2/15/2022 < 5 2.5 32 2/22/2022 < 5 2.5 33 3/1/2022 < 5 2.5 34 3/7/2022 < 5 2.5 35 3/9/2022 < 5 2.5 36 3/15/2022 < 5 2.5 37 3/22/2022 < 5 2.5 38 3/29/2022 < 5 2.5 39 4/5/2022 < 5 2.5 40 4/12/2022 < 5 2.5 41 4/19/2022 < 5 2.5 42 4/26/2022 < 5 2.5 43 5/3/2022 < 5 2.5 44 5/10/2022 < 5 2.5 45 5/11/2022 < 5 2.5 46 5/17/2022 < 5 2.5 47 5/24/2022 < 5 2.5 48 6/1/2022 < 5 2.5 49 6/7/2022 < 5 2.5 50 6/9/2022 < 5 2.5 51 6/14/2022 < 5 2.5 52 6/21/2022 < 5 2.5 53 6/28/2022 < 5 2.5 54 7/6/2022 < 5 2.5 55 7/12/2022 < 5 2.5 56 7/19/2022 < 5 2.5 57 7/22/2022 < 5 2.5 58 7/26/2022 < 5 2.5 24970 rpa, data -2 - 9/14/2022 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 9/12/2018 < 2 1 Std Dev. 0.0000 1 8/24/2021 < 0.5 0.25 Std Dev. 0.0000 2 12/4/2019 < 2 1 Mean 1.0000 2 8/31/2021 < 0.5 0.25 Mean 0.2500 3 3/11/2020 < 2 1 C.V. (default) 0.6000 3 9/8/2021 < 0.5 0.25 C.V. 0.0000 4 6/9/2021 < 2 1 n 4 4 9/14/2021 < 0.5 0.25 n 58 5 5 9/21/2021 < 0.5 0.25 6 Mult Factor= 2.59 6 9/28/2021 < 0.5 0.25 Mult Factor= 1.00 7 Max. Value 1.00 ug/L 7 10/5/2021 < 0.5 0.25 Max. Value 0.250 ug/L 8 Max. Pred Cw 2.59 ug/L 8 10/12/2021 < 0.5 0.25 Max. Pred Cw 0.250 ug/L 9 9 10/13/2021 < 0.5 0.25 10 10 10/19/2021 < 0.5 0.25 11 11 10/26/2021 < 0.5 0.25 12 12 11/2/2021 < 0.5 0.25 13 13 11/9/2021 < 0.5 0.25 14 14 11/16/2021 < 0.5 0.25 15 15 11/18/2021 < 0.5 0.25 16 16 11/23/2021 < 0.5 0.25 17 17 11/30/2021 < 0.5 0.25 18 18 12/7/2021 < 0.5 0.25 19 19 12/14/2021 < 0.5 0.25 20 20 12/17/2021 < 0.5 0.25 21 21 12/21/2021 < 0.5 0.25 22 22 12/29/2021 < 0.5 0.25 23 23 1/4/2022 < 0.5 0.25 24 24 1/8/2022 < 0.5 0.25 25 25 1/11/2022 < 0.5 0.25 26 26 1/19/2022 < 0.5 0.25 27 27 1/25/2022 < 0.5 0.25 28 28 2/1/2022 < 0.5 0.25 29 29 2/6/2022 < 0.5 0.25 30 30 2/8/2022 < 0.5 0.25 31 31 2/15/2022 < 0.5 0.25 32 32 2/22/2022 < 0.5 0.25 33 33 3/1/2022 < 0.5 0.25 34 34 3/7/2022 < 0.5 0.25 35 35 3/9/2022 < 0.5 0.25 36 36 3/15/2022 < 0.5 0.25 37 37 3/22/2022 < 0.5 0.25 38 38 3/29/2022 < 0.5 0.25 39 39 4/5/2022 < 0.5 0.25 40 40 4/12/2022 < 0.5 0.25 41 41 4/19/2022 < 0.5 0.25 42 42 4/26/2022 < 0.5 0.25 43 43 5/3/2022 < 0.5 0.25 44 44 5/10/2022 < 0.5 0.25 45 45 5/11/2022 < 0.5 0.25 46 46 5/17/2022 < 0.5 0.25 47 47 5/24/2022 < 0.5 0.25 48 48 6/1/2022 < 0.5 0.25 49 49 6/7/2022 < 0.5 0.25 50 50 6/9/2022 < 0.5 0.25 51 51 6/14/2022 < 0.5 0.25 52 52 6/21/2022 < 0.5 0.25 53 53 6/28/2022 < 0.5 0.25 54 54 7/6/2022 < 0.5 0.25 55 55 7/12/2022 < 0.5 0.25 56 56 7/19/2022 < 0.5 0.25 57 57 7/22/2022 < 0.5 0.25 58 58 7/26/2022 < 0.5 0.25 24970 rpa, data -3- 9/14/2022 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 1/17/2018 < 50 25 Std Dev. 9.1140 1 8/24/2021 < 5 2.5 Std Dev. 0.0000 2 3/14/2018 < 50 25 Mean 27.2581 2 8/31/2021 < 5 2.5 Mean 2.5000 3 5/14/2018 70 70 C.V. 0.3344 3 9/8/2021 < 5 2.5 C.V. 0.0000 4 7/9/2018 < 50 25 n 31 4 9/14/2021 < 5 2.5 n 58 5 9/12/2018 < 50 25 5 9/21/2021 < 5 2.5 6 11/13/2018 < 50 25 Mult Factor= 1.11 6 9/28/2021 < 5 2.5 Mult Factor= 1.00 7 1/14/2019 < 50 25 Max. Value 70.0 ug/L 7 10/5/2021 < 5 2.5 Max. Value 2.5 pg/L 8 3/6/2019 < 50 25 Max. Pred Cw 77.7 ug/L 8 10/12/2021 < 5 2.5 Max. Pred Cw 2.5 pg/L 9 5/13/2019 < 50 25 9 10/13/2021 < 5 2.5 10 7/8/2019 < 50 25 10 10/19/2021 < 5 2.5 11 9/11/2019 < 50 25 11 10/26/2021 < 5 2.5 12 11/12/2019 < 50 25 12 11/2/2021 < 5 2.5 13 12/4/2019 < 50 25 13 11/9/2021 < 5 2.5 14 1/6/2020 < 50 25 14 11/16/2021 < 5 2.5 15 3/2/2020 < 50 25 15 11/18/2021 < 5 2.5 16 3/11/2020 < 50 25 16 11/23/2021 < 5 2.5 17 5/4/2020 < 50 25 17 11/30/2021 < 5 2.5 18 7/6/2020 50 50 18 12/7/2021 < 5 2.5 19 9/23/2020 < 50 25 19 12/14/2021 < 5 2.5 20 11/2/2020 < 50 25 20 12/17/2021 < 5 2.5 21 1/12/2021 < 50 25 21 12/21/2021 < 5 2.5 22 3/3/2021 < 50 25 22 12/29/2021 < 5 2.5 23 5/11/2021 < 50 25 23 1/4/2022 < 5 2.5 24 6/9/2021 < 50 25 24 1/8/2022 < 5 2.5 25 7/7/2021 < 50 25 25 1/11/2022 < 5 2.5 26 9/8/2021 < 50 25 26 1/19/2022 < 5 2.5 27 11/9/2021 < 50 25 27 1/25/2022 < 5 2.5 28 1/11/2022 < 50 25 28 2/1/2022 < 5 2.5 29 3/9/2022 < 50 25 29 2/6/2022 < 5 2.5 30 5/3/2022 < 50 25 30 2/8/2022 < 5 2.5 31 7/12/2022 < 50 25 31 2/15/2022 < 5 2.5 32 32 2/22/2022 < 5 2.5 33 33 3/1/2022 < 5 2.5 34 34 3/7/2022 < 5 2.5 35 35 3/9/2022 < 5 2.5 36 36 3/15/2022 < 5 2.5 37 37 3/22/2022 < 5 2.5 38 38 3/29/2022 < 5 2.5 39 39 4/5/2022 < 5 2.5 40 40 4/12/2022 < 5 2.5 41 41 4/19/2022 < 5 2.5 42 42 4/26/2022 < 5 2.5 43 43 5/3/2022 < 5 2.5 44 44 5/10/2022 < 5 2.5 45 45 5/11/2022 < 5 2.5 46 46 5/17/2022 < 5 2.5 47 47 5/24/2022 < 5 2.5 48 48 6/1/2022 < 5 2.5 49 49 6/7/2022 < 5 2.5 50 50 6/9/2022 < 5 2.5 51 51 6/14/2022 < 5 2.5 52 52 6/21/2022 < 5 2.5 53 53 6/28/2022 < 5 2.5 54 54 7/6/2022 < 5 2.5 55 55 7/12/2022 < 5 2.5 56 56 7/19/2022 < 5 2.5 57 57 7/22/2022 < 5 2.5 58 58 7/26/2022 < 5 2.5 24970 rpa, data -4- 9/14/2022 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 8/24/2021 3 3 Std Dev. 0.3620 1 1/10/2022 < 10 5 Std Dev. 0.0000 2 8/31/2021 3.2 3.2 Mean 2.9741 2 1/11/2022 < 10 5 Mean 5.00 3 9/8/2021 3 3 C.V. 0.1217 3 1/18/2022 < 10 5 C.V. 0.0000 4 9/14/2021 3.5 3.5 n 58 4 1/19/2022 < 10 5 n 58 5 9/21/2021 3.8 3.8 5 1/24/2022 < 10 5 6 9/28/2021 3.4 3.4 Mult Factor= 1.00 6 1/25/2022 < 10 5 Mult Factor= 1.00 7 10/5/2021 3.8 3.8 Max. Value 3.90 ug/L 7 1/31/2022 < 10 5 Max. Value 5.0 ug/L 8 10/12/2021 3.1 3.1 Max. Pred Cw 3.90 ug/L 8 2/1/2022 < 10 5 Max. Pred Cw 5.0 ug/L 9 10/13/2021 2.7 2.7 9 2/7/2022 < 10 5 10 10/19/2021 3 3 10 2/8/2022 < 10 5 11 10/26/2021 3.1 3.1 11 2/14/2022 < 10 5 12 11/2/2021 2.9 2.9 12 2/15/2022 < 10 5 13 11/9/2021 3.2 3.2 13 2/21/2022 < 10 5 14 11/16/2021 3.4 3.4 14 2/22/2022 < 10 5 15 11/18/2021 3.5 3.5 15 2/28/2022 < 10 5 16 11/23/2021 3.4 3.4 16 3/1/2022 < 10 5 17 11/30/2021 3.3 3.3 17 3/8/2022 < 10 5 18 12/7/2021 3.1 3.1 18 3/9/2022 < 10 5 19 12/14/2021 3.6 3.6 19 3/14/2022 < 10 5 20 12/17/2021 2.7 2.7 20 3/15/2022 < 10 5 21 12/21/2021 2.5 2.5 21 3/21/2022 < 10 5 22 12/29/2021 2.6 2.6 22 3/22/2022 < 10 5 23 1/4/2022 2.7 2.7 23 3/28/2022 < 10 5 24 1/8/2022 2.6 2.6 24 3/29/2022 < 10 5 25 1/11/2022 2.8 2.8 25 4/6/2022 < 10 5 26 1/19/2022 2.8 2.8 26 4/7/2022 < 10 5 27 1/25/2022 2.7 2.7 27 4/11/2022 < 10 5 28 2/1/2022 3 3 28 4/12/2022 < 10 5 29 2/6/2022 2.8 2.8 29 4/18/2022 < 10 5 30 2/8/2022 2.8 2.8 30 4/19/2022 < 10 5 31 2/15/2022 2.9 2.9 31 4/25/2022 < 10 5 32 2/22/2022 2.6 2.6 32 4/26/2022 < 10 5 33 3/1/2022 2.7 2.7 33 5/2/2022 < 10 5 34 3/7/2022 2.6 2.6 34 5/3/2022 < 10 5 35 3/9/2022 2.9 2.9 35 5/9/2022 < 10 5 36 3/15/2022 3.1 3.1 36 5/12/2022 < 10 5 37 3/22/2022 2.7 2.7 37 5/16/2022 < 10 5 38 3/29/2022 3.2 3.2 38 5/17/2022 < 10 5 39 4/5/2022 2.8 2.8 39 5/23/2022 < 10 5 40 4/12/2022 3 3 40 5/24/2022 < 10 5 41 4/19/2022 2.9 2.9 41 5/31/2022 < 10 5 42 4/26/2022 3.2 3.2 42 6/1/2022 < 10 5 43 5/3/2022 3.3 3.3 43 6/6/2022 < 10 5 44 5/10/2022 3 3 44 6/7/2022 < 10 5 45 5/11/2022 3.2 3.2 45 6/13/2022 < 10 5 46 5/17/2022 3.1 3.1 46 6/14/2022 < 10 5 47 5/24/2022 3.9 3.9 47 6/20/2022 < 10 5 48 6/1/2022 2.7 2.7 48 6/21/2022 < 10 5 49 6/7/2022 3 3 49 6/27/2022 < 10 5 50 6/9/2022 2.8 2.8 50 6/28/2022 < 10 5 51 6/14/2022 2.6 2.6 51 7/5/2022 < 10 5 52 6/21/2022 2.5 2.5 52 7/6/2022 < 10 5 53 6/28/2022 2.8 2.8 53 7/11/2022 < 10 5 54 7/6/2022 2.7 2.7 54 7/12/2022 < 10 5 55 7/12/2022 2.1 2.1 55 7/18/2022 < 10 5 56 7/19/2022 3 3 56 7/19/2022 < 10 5 57 7/22/2022 2.3 2.3 57 7/25/2022 < 10 5 58 7/26/2022 2.9 2.9 58 7/26/2022 < 10 5 24970 rpa, data - 5- 9/14/2022 REASONABLE POTENTIAL ANALYSIS Par14 Par16 Use"PASTE SPECIAL Use"PASTE SPECIAL Lead Values"then"COPY" Molybdenum Values"then"COPY" Maximum data .Maximum data points=58 points=58 Date BDL=1/2DL Results Date Data BDL=1/2DL Results 1 8/24/2021 < 5 2.5 Std Dev. 0.0000 1 8/24/2021 < 5 2.5 Std Dev. 0.0000 2 8/31/2021 < 5 2.5 Mean 2.5000 2 8/31/2021 < 5 2.5 Mean 2.5000 3 9/8/2021 < 5 2.5 C.V. 0.0000 3 9/8/2021 < 5 2.5 C.V. 0.0000 4 9/14/2021 < 5 2.5 n 58 4 9/14/2021 < 5 2.5 n 58 5 9/21/2021 < 5 2.5 5 9/21/2021 < 5 2.5 6 9/28/2021 < 5 2.5 Mult Factor= 1.00 6 9/28/2021 < 5 2.5 Mult Factor= 1.00 7 10/5/2021 < 5 2.5 Max. Value 2.500 ug/L 7 10/5/2021 < 5 2.5 Max. Value 2.5 ug/L 8 10/12/2021 < 5 2.5 Max. Pred Cw 2.500 ug/L 8 10/12/2021 < 5 2.5 Max. Pred Cw 2.5 ug/L 9 10/13/2021 < 5 2.5 9 10/13/2021 < 5 2.5 10 10/19/2021 < 5 2.5 10 10/19/2021 < 5 2.5 11 10/26/2021 < 5 2.5 11 10/26/2021 < 5 2.5 12 11/2/2021 < 5 2.5 12 11/2/2021 < 5 2.5 13 11/9/2021 < 5 2.5 13 11/9/2021 < 5 2.5 14 11/16/2021 < 5 2.5 14 11/16/2021 < 5 2.5 15 11/18/2021 < 5 2.5 15 11/18/2021 < 5 2.5 16 11/23/2021 < 5 2.5 16 11/23/2021 < 5 2.5 17 11/30/2021 < 5 2.5 17 11/30/2021 < 5 2.5 18 12/7/2021 < 5 2.5 18 12/7/2021 < 5 2.5 19 12/14/2021 < 5 2.5 19 12/14/2021 < 5 2.5 20 12/17/2021 < 5 2.5 20 12/17/2021 < 5 2.5 21 12/21/2021 < 5 2.5 21 12/21/2021 < 5 2.5 22 12/29/2021 < 5 2.5 22 12/29/2021 < 5 2.5 23 1/4/2022 < 5 2.5 23 1/4/2022 < 5 2.5 24 1/8/2022 < 5 2.5 24 1/8/2022 < 5 2.5 25 1/11/2022 < 5 2.5 25 1/11/2022 < 5 2.5 26 1/19/2022 < 5 2.5 26 1/19/2022 < 5 2.5 27 1/25/2022 < 5 2.5 27 1/25/2022 < 5 2.5 28 2/1/2022 < 5 2.5 28 2/1/2022 < 5 2.5 29 2/6/2022 < 5 2.5 29 2/6/2022 < 5 2.5 30 2/8/2022 < 5 2.5 30 2/8/2022 < 5 2.5 31 2/15/2022 < 5 2.5 31 2/15/2022 < 5 2.5 32 2/22/2022 < 5 2.5 32 2/22/2022 < 5 2.5 33 3/1/2022 < 5 2.5 33 3/1/2022 < 5 2.5 34 3/7/2022 < 5 2.5 34 3/7/2022 < 5 2.5 35 3/9/2022 < 5 2.5 35 3/9/2022 < 5 2.5 36 3/15/2022 < 5 2.5 36 3/15/2022 < 5 2.5 37 3/22/2022 < 5 2.5 37 3/22/2022 < 5 2.5 38 3/29/2022 < 5 2.5 38 3/29/2022 < 5 2.5 39 4/5/2022 < 5 2.5 39 4/5/2022 < 5 2.5 40 4/12/2022 < 5 2.5 40 4/12/2022 < 5 2.5 41 4/19/2022 < 5 2.5 41 4/19/2022 < 5 2.5 42 4/26/2022 < 5 2.5 42 4/26/2022 < 5 2.5 43 5/3/2022 < 5 2.5 43 5/3/2022 < 5 2.5 44 5/10/2022 < 5 2.5 44 5/10/2022 < 5 2.5 45 5/11/2022 < 5 2.5 45 5/11/2022 < 5 2.5 46 5/17/2022 < 5 2.5 46 5/17/2022 < 5 2.5 47 5/24/2022 < 5 2.5 47 5/24/2022 < 5 2.5 48 6/1/2022 < 5 2.5 48 6/1/2022 < 5 2.5 49 6/7/2022 < 5 2.5 49 6/7/2022 < 5 2.5 50 6/9/2022 < 5 2.5 50 6/9/2022 < 5 2.5 51 6/14/2022 < 5 2.5 51 6/14/2022 < 5 2.5 52 6/21/2022 < 5 2.5 52 6/21/2022 < 5 2.5 53 6/28/2022 < 5 2.5 53 6/28/2022 < 5 2.5 54 7/6/2022 < 5 2.5 54 7/6/2022 < 5 2.5 55 7/12/2022 < 5 2.5 55 7/12/2022 < 5 2.5 56 7/19/2022 < 5 2.5 56 7/19/2022 < 5 2.5 57 7/22/2022 < 5 2.5 57 7/22/2022 < 5 2.5 58 7/26/2022 < 5 2.5 58 7/26/2022 < 5 2.5 24970 rpa, data -6- 9/14/2022 REASONABLE POTENTIAL ANALYSIS Par17 & Par18 Par19 use"PASTE Use"PASTE SPECIAL Values"then"COPY" SPECIAL-Values" Nickel Maximum data Selenium then"COPY". . points=58 Maximum data Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results points=58 1 8/24/2021 3.8 3.8 Std Dev. 0.4937 1 8/24/2021 < 5 2.5 Std Dev. 0.0000 2 8/31/2021 4.1 4.1 Mean 4.2259 2 8/31/2021 < 5 2.5 Mean 2.5000 3 9/8/2021 4.3 4.3 C.V. 0.1168 3 9/8/2021 < 5 2.5 C.V. 0.0000 4 9/14/2021 4.6 4.6 n 58 4 9/14/2021 < 5 2.5 n 58 5 9/21/2021 5 5 5 9/21/2021 < 5 2.5 6 9/28/2021 4.2 4.2 Mult Factor= 1.00 6 9/28/2021 < 5 2.5 Mult Factor= 1.00 7 10/5/2021 5.5 5.5 Max. Value 5.5 pg/L 7 10/5/2021 < 5 2.5 Max. Value 2.5 ug/L 8 10/12/2021 4 4 Max. Pred Cw 5.5 pg/L 8 10/12/2021 < 5 2.5 Max. Pred Cw 2.5 ug/L 9 10/13/2021 4 4 9 10/13/2021 < 5 2.5 10 10/19/2021 4.2 4.2 10 10/19/2021 < 5 2.5 11 10/26/2021 4.2 4.2 11 10/26/2021 < 5 2.5 12 11/2/2021 3.8 3.8 12 11/2/2021 < 5 2.5 13 11/9/2021 3.6 3.6 13 11/9/2021 < 5 2.5 14 11/16/2021 4.2 4.2 14 11/16/2021 < 5 2.5 15 11/18/2021 4.1 4.1 15 11/18/2021 < 5 2.5 16 11/23/2021 3.7 3.7 16 11/23/2021 < 5 2.5 17 11/30/2021 3.4 3.4 17 11/30/2021 < 5 2.5 18 12/7/2021 3.2 3.2 18 12/7/2021 < 5 2.5 19 12/14/2021 4.4 4.4 19 12/14/2021 < 5 2.5 20 12/17/2021 4.3 4.3 20 12/17/2021 < 5 2.5 21 12/21/2021 3.7 3.7 21 12/21/2021 < 5 2.5 22 12/29/2021 3.7 3.7 22 12/29/2021 < 5 2.5 23 1/4/2022 3.5 3.5 23 1/4/2022 < 5 2.5 24 1/8/2022 4.9 4.9 24 1/8/2022 < 5 2.5 25 1/11/2022 4.4 4.4 25 1/11/2022 < 5 2.5 26 1/19/2022 4.3 4.3 26 1/19/2022 < 5 2.5 27 1/25/2022 4.5 4.5 27 1/25/2022 < 5 2.5 28 2/1/2022 4.7 4.7 28 2/1/2022 < 5 2.5 29 2/6/2022 4.5 4.5 29 2/6/2022 < 5 2.5 30 2/8/2022 4.4 4.4 30 2/8/2022 < 5 2.5 31 2/15/2022 4.5 4.5 31 2/15/2022 < 5 2.5 32 2/22/2022 4 4 32 2/22/2022 < 5 2.5 33 3/1/2022 3.8 3.8 33 3/1/2022 < 5 2.5 34 3/7/2022 4 4 34 3/7/2022 < 5 2.5 35 3/9/2022 4.4 4.4 35 3/9/2022 < 5 2.5 36 3/15/2022 4.8 4.8 36 3/15/2022 < 5 2.5 37 3/22/2022 4.1 4.1 37 3/22/2022 < 5 2.5 38 3/29/2022 4.7 4.7 38 3/29/2022 < 5 2.5 39 4/5/2022 4.6 4.6 39 4/5/2022 < 5 2.5 40 4/12/2022 4.1 4.1 40 4/12/2022 < 5 2.5 41 4/19/2022 4.1 4.1 41 4/19/2022 < 5 2.5 42 4/26/2022 3.3 3.3 42 4/26/2022 < 5 2.5 43 5/3/2022 4.5 4.5 43 5/3/2022 < 5 2.5 44 5/10/2022 4.3 4.3 44 5/10/2022 < 5 2.5 45 5/11/2022 4.8 4.8 45 5/11/2022 < 5 2.5 46 5/17/2022 5 5 46 5/17/2022 < 5 2.5 47 5/24/2022 4.5 4.5 47 5/24/2022 < 5 2.5 48 6/1/2022 5 5 48 6/1/2022 < 5 2.5 49 6/7/2022 4.7 4.7 49 6/7/2022 < 5 2.5 50 6/9/2022 4.5 4.5 50 6/9/2022 < 5 2.5 51 6/14/2022 4.3 4.3 51 6/14/2022 < 5 2.5 52 6/21/2022 4.3 4.3 52 6/21/2022 < 5 2.5 53 6/28/2022 5 5 53 6/28/2022 < 5 2.5 54 7/6/2022 3.7 3.7 54 7/6/2022 < 5 2.5 55 7/12/2022 3.3 3.3 55 7/12/2022 < 5 2.5 56 7/19/2022 3.4 3.4 56 7/19/2022 < 5 2.5 57 7/22/2022 4.4 4.4 57 7/22/2022 < 5 2.5 58 7/26/2022 3.8 3.8 58 7/26/2022 < 5 2.5 24970 rpa, data -7- 9/14/2022 REASONABLE POTENTIAL ANALYSIS Par20 Par21 Use"PASTE SPECIAL Use"PASTE SPECIAL Silver Values"then"COPY" Zinc Values"then"COPY" Maximum data .Maximum data points=58 points=58 Date Data BDL=1/2DL Results Date Data BDL=1/2DL Results 1 8/24/2021 < 1 0.5 Std Dev. 0.0000 1 8/24/2021 19 19 Std Dev. 3.1848 2 8/31/2021 < 1 0.5 Mean 0.5000 2 8/31/2021 23 23 Mean 23.1207 3 9/8/2021 < 1 0.5 C.V. 0.0000 3 9/8/2021 20 20 C.V. 0.1377 4 9/14/2021 < 1 0.5 n 58 4 9/14/2021 26 26 n 58 5 9/21/2021 < 1 0.5 5 9/21/2021 24 24 6 9/28/2021 < 1 0.5 Mult Factor= 1.00 6 9/28/2021 21 21 Mult Factor= 1.00 7 10/5/2021 < 1 0.5 Max. Value 0.500 ug/L 7 10/5/2021 25 25 Max. Value 34.0 ug/L 8 10/12/2021 < 1 0.5 Max. Pred Cw 0.500 ug/L 8 10/12/2021 19 19 Max. Pred Cw 34.0 ug/L 9 10/13/2021 < 1 0.5 9 10/13/2021 22 22 10 10/19/2021 < 1 0.5 10 10/19/2021 24 24 11 10/26/2021 < 1 0.5 11 10/26/2021 24 24 12 11/2/2021 < 1 0.5 12 11/2/2021 21 21 13 11/9/2021 < 1 0.5 13 11/9/2021 22 22 14 11/16/2021 < 1 0.5 14 11/16/2021 26 26 15 11/18/2021 < 1 0.5 15 11/18/2021 24 24 16 11/23/2021 < 1 0.5 16 11/23/2021 25 25 17 11/30/2021 < 1 0.5 17 11/30/2021 30 30 18 12/7/2021 < 1 0.5 18 12/7/2021 34 34 19 12/14/2021 < 1 0.5 19 12/14/2021 27 27 20 12/17/2021 < 1 0.5 20 12/17/2021 26 26 21 12/21/2021 < 1 0.5 21 12/21/2021 25 25 22 12/29/2021 < 1 0.5 22 12/29/2021 22 22 23 1/4/2022 < 1 0.5 23 1/4/2022 19 19 24 1/8/2022 < 1 0.5 24 1/8/2022 24 24 25 1/11/2022 < 1 0.5 25 1/11/2022 20 20 26 1/19/2022 < 1 0.5 26 1/19/2022 22 22 27 1/25/2022 < 1 0.5 27 1/25/2022 24 24 28 2/1/2022 < 1 0.5 28 2/1/2022 25 25 29 2/6/2022 < 1 0.5 29 2/6/2022 25 25 30 2/8/2022 < 1 0.5 30 2/8/2022 23 23 31 2/15/2022 < 1 0.5 31 2/15/2022 25 25 32 2/22/2022 < 1 0.5 32 2/22/2022 22 22 33 3/1/2022 < 1 0.5 33 3/1/2022 24 24 34 3/7/2022 < 1 0.5 34 3/7/2022 20 20 35 3/9/2022 < 1 0.5 35 3/9/2022 23 23 36 3/15/2022 < 1 0.5 36 3/15/2022 23 23 37 3/22/2022 < 1 0.5 37 3/22/2022 21 21 38 3/29/2022 < 1 0.5 38 3/29/2022 23 23 39 4/5/2022 < 1 0.5 39 4/5/2022 22 22 40 4/12/2022 < 1 0.5 40 4/12/2022 20 20 41 4/19/2022 < 1 0.5 41 4/19/2022 20 20 42 4/26/2022 < 1 0.5 42 4/26/2022 21 21 43 5/3/2022 < 1 0.5 43 5/3/2022 22 22 44 5/10/2022 < 1 0.5 44 5/10/2022 21 21 45 5/11/2022 < 1 0.5 45 5/11/2022 24 24 46 5/17/2022 < 1 0.5 46 5/17/2022 20 20 47 5/24/2022 < 1 0.5 47 5/24/2022 21 21 48 6/1/2022 < 1 0.5 48 6/1/2022 18 18 49 6/7/2022 < 1 0.5 49 6/7/2022 20 20 50 6/9/2022 < 1 0.5 50 6/9/2022 20 20 51 6/14/2022 < 1 0.5 51 6/14/2022 27 27 52 6/21/2022 < 1 0.5 52 6/21/2022 21 21 53 6/28/2022 < 1 0.5 53 6/28/2022 23 23 54 7/6/2022 < 1 0.5 54 7/6/2022 23 23 55 7/12/2022 < 1 0.5 55 7/12/2022 22 22 56 7/19/2022 < 1 0.5 56 7/19/2022 27 27 57 7/22/2022 < 1 0.5 57 7/22/2022 34 34 58 7/26/2022 < 1 0.5 58 7/26/2022 23 23 24970 rpa, data -8- 9/14/2022 REASONABLE POTENTIAL ANALYSIS Par22 Use"PASTE SPECIAL Dichlorobromomethane Values"then"COPY" Maximum data points=58 Date Data BDL=1/2DL Results 1 1/17/2018 < 5 2.5 Std Dev. 2.3073 2 3/14/2018 < 5 2.5 Mean 5.6129 3 5/14/2018 6.5 6.5 C.V. 0.4111 4 7/9/2018 6.9 6.9 n 31 5 9/12/2018 5.8 5.8 6 11/13/2018 < 5 2.5 Mult Factor= 1.13 7 1/14/2019 < 5 2.5 Max. Value 10.100000 tag/L 8 3/6/2019 < 5 2.5 Max. Pred Cw 11.413000 tag/L 9 5/13/2019 < 5 2.5 10 7/8/2019 6.8 6.8 11 9/11/2019 9.7 9.7 12 11/12/2019 5.7 5.7 13 12/4/2019 5.4 5.4 14 1/6/2020 3.2 3.2 15 3/2/2020 4 4 16 3/11/2020 6.7 6.7 17 5/4/2020 5.4 5.4 18 7/6/2020 6.4 6.4 19 9/23/2020 4.3 4.3 20 11/2/2020 5.9 5.9 21 1/12/2021 4.3 4.3 22 3/3/2021 6 6 23 5/11/2021 5.6 5.6 24 6/9/2021 8.1 8.1 25 7/7/2021 9.3 9.3 26 9/8/2021 9.1 9.1 27 11/9/2021 7.8 7.8 28 1/11/2022 7.9 7.9 29 3/9/2022 4 4 30 5/3/2022 4.1 4.1 31 7/12/2022 10.1 10.1 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 24970 rpa, data -9- 9/14/2022 McAlpine Creek WWMF > Outfall 001 NCO024970 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 64 MGD MAXIMUM DATA POINTS = 58 Qw (MGD) = 64.0000 WWTP/WTP Class: IV COMBINED HARDNESS (mg/L) 1Q10S (cfs) = 1.68 IWC% @ 1Q10S = 98.33465504 Acute = 151.39 mg/L 7Q10S (cfs) = 2.00 IWC% @ 7QIOS = 98.02371542 Chronic= 151.16 mg/L 7QIOW (cfs) = 10.00 IWC% @ 7Q10W= 90.84249084 30Q2 (cfs) = 13.50 IWC% @ 30Q2 = 88.02129547 Avg. Stream Flow, QA(cfs) = 62.40 IW%C @ QA= 61.38613861 Receiving Stream: McAlpine Creek HUC 03050103 Stream Class: C PARAMETER NC STANDARDS OR EPA CRITERIA J co REASONABLE POTENTIAL RESULTS RECOMMENDED ACTION TYPE Aplied Chronic Standa d Acute D n #Det. Max Pred Cw Allowable Cw Acute (FW): 345.8 Arsenic C 150 FW(7Q1Os) 340 ug/L _ 58 0 2.5 Chronic (FW) 153.0 No RP, Predicted Max< 50% of Allowable Cw- No Max MDL= 5 Monitoring required ---------- ----------------------------- Arsenic C 10 HH/WS(Qavg) ug/L NO DETECTS Chronic (HH) 16.3 Max MDL 5 Acute: 66.10 Beryllium NC 6.5 FW(7Q10s) 65 ug/L 4 0 2.59 Note: n< 9 C.V. (default) Chronic: 6.63 No RP, Predicted Max< 50% of Allowable Cw- No Limited data set NO DETECTS Max MDL= 2 Monitoring required Acute: 15.834 Cadmium NC 2.2941 FW(7Q10s) 15.5700 ug/L 58 0 0.250 Chronic: 2.340 No RP, Predicted Max< 50% of Allowable Cw- No NO DETECTS Max MDL= 0.5 Monitoring required Acute: NO WQS Total Phenolic Compounds NC 300 A(30Q2) ug/L 31 2 77.7 Chronic: 340.8 No RP, Predicted Max< 50% of Allowable Cw- No No value >Allowable Cw Monitoring required Acute: 4,023.1 Chromium III NC 513.9885 FW(7Q10s) 3956.1300 µg/L 0 0 N/A --Chronic: -----524.4--- --------------------------- Acute: 16.3 Chromium VI NC I 1 FW(7Q10s) 16 µg/L 0 0 N/A --Chronic: ----- 11.2 --- --------------------------- Chromium, Total NC µg/L 58 0 2.5 Max reported value = 2.5 a: No monitoring required if all Total Chromium samples are < 5 pg/L or Pred. max for Total Cr is < allowable Cw for Cr VI. NO DETECTS Max MDL 5 Acute: 58.11 Copper NC 36.6743 FW(7Q10s) 57.1443 ug/L 58 58 3.90 Chronic: 37.41 No RP, Predicted Max< 50% of Allowable Cw- No No value > Allowable Cw [All onitoring required Acute: 22.4 Cyanide NC 5 FW(7Q10s) 22 10 ug/L 58 0 5.0 ____ Chronic: 5.1 values non-detect< 10 ug/L- no monitoring NO DETECTS Max MDL 10 required 24970 rpa, rpa Page 1 of 2 9/14/2022 McAlpine Creek WWMF > Outfall 001 NCO024970 Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators Qw = 64 MGD Acute: 559.194 Lead NC 21.3941 FW(7Q1Os) 549.8819 ug/L 58 0 2.500 Chronic: 21.825 No RP, Predicted Max< 50% of Allowable Cw- No NO DETECTS Max MDL= 5 Monitoring required Acute: NO WQS Molybdenum NC 2000 HH(7Q10s) ug/L 58 0 2.5 Chronic: 2,040.3 No RP, Predicted Max< 50% of Allowable Cw- No NO DETECTS Max MDL= 5 Monitoring required Acute (FW): 1,564.3 Nickel NC 170.6343 FW(7Q 1 Os) 1538.2117 µg/L _ _ _ _____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 58 58 5.5 Chronic (FW) 174.1 [Monitoring o RP, Predicted Max< 50% of Allowable Cw- No No value >Allowable Cw required Nickel NC 25.0000 WS(7Q10s) µg/L Chronic (WS) 25.5 No value >Allowable Cw Acute: 56.9 Selenium NC 5 FW(7Q10s) 56 ug/L 58 0 2.5 Chronic: 5.1 No RP, Predicted Max< 50% of Allowable Cw- No NO DETECTS Max MDL= 5 Monitoring required Acute: 6.675 Silver NC 0.06 FW(7Q10s) 6.5641 ug/L 58 0 0.500 Chronic: 0.061 All values non-detect < 1 ug/L - no monitoring NO DETECTS Max MDL 1 required Acute: 588.0 Zinc NC 582.1902 FW(7Q10s) 578.1905 ug/L 58 58 34.0 Chronic: 593.9 No RP, Predicted Max< 50% of Allowable Cw- No No value >Allowable Cw Monitoring required Acute: NO WQS Dichlorobromomethane C 17 HH(Qavg) µg/L 31 25 11.41300 Chronic: 27.69355 No RP, Predicted Max< 50% of Allowable Cw- No No value >Allowable Cw Monitoring required 24970 rpa, rpa Page 2 of 2 9/14/2022 Date:9/14/2022 Dissolved to Total Metal Calculator FACILITY:McAlpine Creek WWMF Outfall 001 NPDES PERMIT:NCO024970 Dissolved to Total Metal Calculator Do NOT enter any data directly into this spreadsheet. Enter data onto"Table 1"under the Input Sheet and enter In accordance with Federal Regulations,permit limitations must be written as Total Metals per 40 CFR 122.45(c) "Effluent Hardness"under the Data Sheet. In accordance with 40 CFR 122.45 c permits are,have and ReceivingReceivin Rec.Stream NPDES Total Suspended Combined Combined eam nstream Effluent ( ) P 9 P Upstream must be written as total metals. stream Stream Solids Hardness Hardness Wastewater Wastewater Hardness 1Q10 Flow Limit Hardness summer summer 7Q10 -Fixed Value- chronic Acute Concentration Concentration Average This calculator has been inserted into the RPA to calculate 7Q10(CFS) (MGD) [MGD] [MGD] (mg/L) (mg/L) (mg/L) Chronic) Acute) Average(mg y (mg/L) Total Metal allowable allocations once Table 1 has been 2.0000 1.2903 1.0839 sa.0000 0 51.1ss s1.3s8 98.0237 98.3317 80.6545455 152.5862 completed(Input Sheet)and Effluent hardness has been Upstream Hard Avg(mg/L)= 80.65455 ACAH 151.3883 entered(Data Sheet). EFF Hard Avg(mg/L)= 152.5862 ACCH 151.1646 1) Following the spreadsheet from left to right. First Dissolved Metals Criteria US EPA Total Metal Criteria Total Metal= COMMENTS(identify parameters to PERCS Branch to maintain in facility's LTMP/STMP): the allowable allocations for the dissolved metals will after applying hardness Translators-using Dissolved Metal+Translator appear for all the metals listed once Table 1 is complete PARAMETER equation Defoe[Partition PP P Chronic Acute Coefficients Chronic Acute and effluent hardness entered.Use a default value of 25 u/I u/I streams u/I u I mg/L if no hardness data is available. Second,Cadmium(d) 0.58 3.93 0.252 2.29 15.57 the Dissolved Metal allocations are divided by the Cd-Trout streams 0.58 2.44 0.252 2.29 9.68 Chromium III(d)(h) 104 800 0.202 513.99 3956.13 Translators to determine the Total Metals that can be Chromium VI(d) 11 16 1.0001 11.00 16.00 allocated to the Permittee.These Total Metals values are Chromium,Total(t) N/A N/A automatically inserted into Table 2 and are the allowable Copper(d)(h) 12.7 19.9 0.348 36.67 57.14 Total Metal allocations determined for the Permittee prior Lead(d)(h) 3.931 101 0.184 21.39 549.88 to allowing for dilution.See Input sheet Table 2.The final Nickel(d)(h) 74 665 0.432 170.63 1538.21 Ni-WS streams(t) 2 N/A acute and chronic values shown under the RPA sheet are Silver(d)(h,acute) 0.06 6.56 1.000 0.06 6.56 the Total Metal values listed in Table 2 divided by the acute Zinc(d)(h) 168 167 0.288 582.19 578.19 and chronic IWC,respectively. 2) The Translators used in the freshwater RPA are the Beryllium 6.51 651 1.0001 6.5 65 Partition Coefficients published by US EPA in 1984.They Arsenic(d) 1501 E 3401 1.0001 d1i 1501 d1i 340 are TSS dependent equations and can be found listed with (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 1SA NCAC 02B.0211 for more information. labeled Equations.A fixed TSS value of 10 mg/L is used to (t)=based upon measurement oftotal recoveable metal.See 1SA 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 NCO024970 McAlpine Creek WWMF 9/14/2022 CBOD monthly removal rate TSS monthly removal rate Month RR(%) Month RR (%) Month RR(%) Month RR(%) January-18 99.33 July-20 99.30 January-18 99.26 July-20 99.31 February-18 99.28 August-20 99.16 February-18 99.29 August-20 99.10 March-18 99.21 September-20 99.28 March-18 99.19 September-20 99.30 April-18 99.23 October-20 99.28 April-18 99.22 October-20 99.19 May-18 99.28 November-20 99.32 May-18 99.35 November-20 99.28 June-18 99.21 December-20 99.31 June-18 99.27 December-20 99.23 July-18 99.27 January-21 99.30 July-18 99.25 January-21 99.21 August-18 99.19 February-21 99.20 August-18 99.21 February-21 99.14 September-18 99.14 March-21 99.28 September-18 99.17 March-21 99.25 October-18 99.23 April-21 99.33 October-18 99.27 April-21 99.22 November-18 99.16 May-21 99.40 November-18 99.20 May-21 99.28 December-18 99.10 June-21 99.42 December-18 99.20 June-21 99.36 January-19 99.09 July-21 99.35 January-19 99.13 July-21 99.29 February-19 99.21 August-21 99.38 February-19 99.20 August-21 99.33 March-19 99.17 September-21 99.47 March-19 99.23 September-21 99.43 April-19 99.24 October-21 99.54 April-19 99.20 October-21 99.50 May-19 99.29 November-21 99.57 May-19 99.38 November-21 99.45 June-19 99.24 December-21 99.47 June-19 99.30 December-21 99.45 July-19 99.31 January-22 99.37 July-19 99.28 January-22 99.36 August-19 99.23 February-22 99.41 August-19 99.17 February-22 99.37 September-19 99.36 March-22 99.31 September-19 99.30 March-22 99.36 October-19 99.36 April-22 99.31 October-19 99.28 April-22 99.38 November-19 99.20 May-22 99.37 November-19 99.15 May-22 99.38 December-19 99.30 June-22 99.31 December-19 99.36 June-22 99.39 January-20 99.17 July-22 99.28 January-20 99.18 July-22 99.30 February-20 99.15 August-22 February-20 99.23 August-22 March-20 99.17 September-22 March-20 99.15 September-22 April-20 99.20 October-22 April-20 99.26 October-22 May-20 98.91 November-22 May-20 98.76 November-22 June-20 99.17 December-22 June-20 99.07 December-22 Overall CBOD removal rate 99.27 Overall TSS removal rate 99.26 Reduction in Frequency Evalaution Facility: McAlpine Creek WWMF Permit No. NC0024970 Review period(use 8/2019-8/2022 3 yrs) Approval Criteria: Y/N? 1. Not currently under SOS Y 2. Not on EPA Quarterly noncompliance y report 3. Facility or employees convicted of CWA N violations #of non- Weekly Monthly 50� 200% monthly #civil penalty 3-yr mean #daily 200% #daily Reduce Data Review Units average (geo mean <50%? samples <15? samples <20? >2? >1? Frequency? average limit limit MA for FC) MA >200% WA >200% limit asessment (Yes/No) violations CBOD(summer) mg/L 6 4 2 1.3497436 Y 8 0 Y 0 N 0 N Y CBOD(winter) mg/L 12 8 4 1.4146154 Y 16 0 Y 0 N 0 N Y TSS mg/L 22.5 15 7.5 1.600627 Y 30 0 Y 0 N 0 N Y Ammonia(summer) mg/L 3 1 0.5 0.0535354 Y 2 0 Y 0 N 0 N Y Ammonia(winter) mg/L 5.7 1.9 1 0.0549618 Y 3.8 0 Y IF 0 N 0 N Y Fecal Coliform #/100 400 200 100 8.2229499 Y 800 1 0 1 Y 0 N 0 N Y NH3/TRC WLA Calculations Facility: McAlpine Creek WWMF PermitNo. NC0024970 Prepared By: Nick Coco Enter Design Flow (MGD): 64 Enter s7Q10 (cfs): 2 Enter w7Q10 (cfs): 10 Total Residual Chlorine (TRC) Ammonia (Summer) Daily Maximum Limit (ug/1) Monthly Average Limit(mg NH3-N/1) s7Q10 (CFS) 2 s7Q10 (CFS) 2 DESIGN FLOW (MGD) 64 DESIGN FLOW (MGD) 64 DESIGN FLOW (CFS) 99.2 DESIGN FLOW (CFS) 99.2 STREAM STD (UG/L) 17.0 STREAM STD (MG/L) 1.0 Upstream Bkgd (ug/1) 0 Upstream Bkgd (mg/1) 0.22 IWC (%) 98.02 IWC (%) 98.02 Allowable Conc. (ug/1) 17 Allowable Conc. (mg/1) 1.0 More stringent than current limit. Consistent with current limit.Maintain limit. Apply limit. Ammonia (Winter) Monthly Average Limit(mg NH3-N/1) Fecal Coliform w7Q10 (CFS) 10 Monthly Average Limit: 200/100ml DESIGN FLOW (MGD) 64 (If DF >331; Monitor) DESIGN FLOW (CFS) 99.2 (If DF<331; Limit) STREAM STD (MG/L) 1.8 Dilution Factor(DF) 1.02 Upstream Bkgd (mg/1) 0.22 IWC (%) 90.84 Allowable Conc. (mg/1) 2.0 Less stringent than current limit.Maintain limit. Total Residual Chlorine 1. Cap Daily Max limit at 28 ug/l to protect for acute toxicity Ammonia (as NH3-N) 1. If Allowable Conc > 35 mg/l, Monitor Only 2. Monthly Avg limit x 3 = Weekly Avg limit (Municipals) 3. Monthly Avg limit x 5 = Daily Max limit(Non-Munis) If the allowable ammonia concentration is > 35 mg/L, no limit shall be imposed Fecal Coliform 1. Monthly Avg limit x 2 =400/100 ml = Weekly Avg limit (Municipals) = Daily Max limit (Non-Muni) 9/13/22 WQS= 12 ng/L MERCURY WQBEL/TBEL EVALUATION V:2013-6 Facility Name McAlpine Creek WWMF/NC0024970 No Limit Required /Permit No. MMP Required Total Mercury 1631E PQL=0.5 ng/L 7Q10s = 2.000 cfs WQBEL= 12.24 ng/L Date Modifier Data Entry Value Permitted Flow= 64.000 47 ng/L 1/6/18 < 1 0.5 2/4/18 < 1 0.5 3/5/18 1 1 4/3/18 < 1 0.5 5/9/18 < 1 0.5 6/7/18 2.5 2.5 7/13/18 1.2 1.2 8/11/18 3.9 3.9 10/8/18 < 1 0.5 11/6/18 < 1 0.5 12/5/18 < 1 0.5 1.1 ng/L-Annual Average for 2018 1/10/19 < 1 0.5 2/8/19 1.3 1.3 3/9/19 < 1 0.5 4/7/19 < 1 0.5 5/6/19 < 1 0.5 6/4/19 9.8 9.8 7/10/19 0.7 0.7 8/8/19 0.8 0.8 9/6/19 0.9 0.9 1 0/5/19 0.6 0.6 11/17/19 0.7 0.7 1 2/3/19 0.8 0.8 12/9/19 0.7 0.7 1.4 ng/L-Annual Average for 2019 1/7/20 0.9 0.9 2/5/20 0.6 0.6 3/5/20 0.8 0.8 3/10/20 0.7 0.7 4/3/20 0.9 0.9 5/9/20 0.7 0.7 6/7/20 0.6 0.6 7/13/20 0.6 0.6 8/4/20 < 0.5 0.5 9/16/20 0.8 0.8 10/8/20 0.6 0.6 11/6/20 0.8 0.8 12/5/20 0.8 0.8 0.7 ng/L-Annual Average for 2020 1/10/21 1.1 1.1 2/8/21 1 1 3/9/2 1 0.7 0.7 4/7/21 1 1 5/13/21 < 0.5 0.5 6/4/21 0.76 0.76 6/8/21 0.79 0.79 7/10/21 0.66 0.66 8/15/21 1.16 1.16 9/13/21 0.66 0.66 10/12/21 0.69 0.69 11/17/21 0.97 0.97 12/16/21 0.54 0.54 0.8 ng/L-Annual Average for 2021 1/7/22 0.79 0.79 2/5/22 0.93 0.93 3/6/22 0.54 0.54 4/4/22 0.69 0.69 5/10/22 0.65 0.65 6/8/22 < 0.5 0.5 7/21/22 < 0.5 0.5 0.7 ng/L-Annual Average for 2022 McAlpine Creek WWMF/NC0024970 Mercury Data Statistics (Method 1631E) 2018 2019 2020 2021 2022 #of Samples 11 13 13 13 7 Annual Average, ng/L 1.1 1.4 0.7 0.81 0.657143 Maximum Value, ng/L 3.90 9.80 0.90 1.16 0.93 TBEL, ng/L 47 WQBEL, ng/L 12.2 Coco, Nick A From: Sypolt, Shannon <Shannon.Sypolt@charlottenc.gov> Sent: Monday, February 13, 2023 4:08 PM To: Coco, Nick A Cc: Montebello, Michael J; Macomber, Maggie; Lockler,Joseph Subject: RE: [EXT]RE: [External] RE:Additional Information Request: Irwin &Sugar Creek NPDES Permit Renewal Applications Follow Up Flag: Follow up Flag Status: Flagged CAUTION: External email. Do not click links or open attachments unless you verify.Send all suspicious email as an attachment to Report Spam. Hi Nick, Per you request below and pertaining to confirmation that our application remains accurate,to the best of our knowledge, no additional parameters have been sampled for since our original application was submitted. Therefore no additional parameters have been identified in the effluent and no chemical addendum sheets are necessary. Thank you. Shannon Sypolt Water Quality Program Administrator Environmental Management CHARLOTTE WLTER 4222 Westmont Drive/Charlotte, NC 28217 P: 704-336-4581 /C: 704-634-6984/ charlottewater.org From: Coco, Nick A<Nick.Coco@ncdenr.gov> Sent: Monday, February 6, 2023 3:59 PM To:Sypolt, Shannon <Shannon.Sypolt@charlottenc.gov> Cc: Montebello, Michael J <Michael.Montebello@ncdenr.gov>; Macomber, Maggie <Maggie.Macomber@charlottenc.gov>; Lockler,Joseph <Joseph.Lockler@charlottenc.gov> Subject: [EXT]RE: [External] RE: Additional Information Request: Irwin &Sugar Creek NPDES Permit Renewal Applications Hi Shannon, Thank you for getting this to us and thank you for the call last week to discuss the status of these permits. To justify that the application remains accurate with regard to which parameters have been sampled for at each of these facilities, please verify that no additional parameters have been sampled for, before or after the application was submitted, and therefore no additional parameters have been identified in the effluents of each plant and no chemical addendum sheets are necessary. Thanks again, 1 Nick Coco, PE (he/him/his) Engineer 111 NPDES Municipal Permitting Unit NC DEQ/Division of Water Resources/Water Quality Permitting Office: (919) 707-3609 nick.coco@ncdenr.gov "Email is preferred but 1 am available to talk by via Microsoft Teams" Physical Address: 512 North Salisbury St.,Raleigh, NC, 27604 Mailing Address: 1617 Mail Service Center, Raleigh, NC, 27699-1617 tr.���D7 E NORTH CAROLINA :.� Q Department of Environmental Quality Email correspondence to and from this address is subject to the North Carolina Public Records Law and may be disclosed to third parties. From: Sypolt, Shannon <Shannon.Sypolt@charlottenc.gov> Sent: Friday, February 3, 2023 4:57 PM To: Coco, Nick A<Nick.Coco@ncdenr.gov> Cc: Montebello, Michael J <Michael.Montebello@ncdenr.goy>; Macomber, Maggie <Maggie.Macomber@charlottenc.gov>; Lockler,Joseph <Joseph.Lockler@charlottenc.gov> Subject: [External] RE:Additional Information Request: Irwin &Sugar Creek NPDES Permit Renewal Applications CAUTION: External email. Do not click links or open attachments unless you verify.Send all suspicious email as an attachment to Report Spam. Hi Nick, Per your request below please see the following additional information: 1) Please see the attached monitoring frequency reduction request summary for Irwin and Sugar Creek 2) 1 have confirmed with our Pretreatment Program Supervisor that no SIU's in our Pretreatment Program have been sampled for 1,4 Dioxane. Additionally, we have not collected any 1,4 Dioxane samples from Irwin, Sugar, or McAlpine. 3) Regarding the chemical addendum submission, Charlotte Water believes we have met the requirement needed to properly submit this information as outlined on NCDWR's website and we have previously certified our application as being true, accurate, and complete. Please see the information below that we are referring to: z )ES Individual Permit Applice X I SL 2018-5(SB 99) X I + C Q deq.nc.gov/about/divisions/water-resources/water-quality-permitting/npdes-wastewater/npdes-permitting-process/npdes-indiv Manuracruring,waxer I reatmenr Fiants,etc.). IT you are apptying ror a NFUt.)kieneral click the link found on side bar to the right. Please make sure your application is comr submission. Please submit 1 original and 2 copies of your application package to the following mai Division of Water Resources Water Quality Permitting Section - NPDES 1617 Mail Service Center Raleigh, NC 27699-1617 EPA Updates-All EPA applications below have been updated.As of February 1,2020, P any previous versions and use the updated forms below.Tips for filling out the new ap can be found here. If you completed an application prior to Feburary 1,2020, please cc and attach it as an addendum to your application. Chemical Addendum Form-As required by Session Law 2018-5, Senate Bill 99, Sectio applicant shall now submit documentation of any additional pollutants for which ther methods with the permit application if their discharge is anticipated.The list of pollut< found in 40 CFR Part 136,which is incorporated by reference. If there are additional po certified methods to be reported, please submit the Chemical Addendum to NPDES AF with your application and, if applicable, list the selected certified analytical method u! no additional pollutants to report,this form is not required to be included with your al requirement applies to all NPDES facilities. The Chemical Addendum to NPDES Appli( required for any type of facility with an NPDES permit,depending on whether those ty are found in your wastewater. 3 6.2 Certification Statement 1 certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate,and complete. l am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. Name(print or type first and last name) Official title --i'gc E121ZL DL-Pv1XI IJ� YZG-Cty .. Signature Date signed - 30 Z,-A If you have any questions concerning the information contained in this email, or if you need any further information,just let me know. Thank you for the opportunity to provide this additional information. Happy Friday!!! Respectfully, Shannon Sypolt Water Quality Program Administrator Environmental Management CHARLOTTE W` TER 4222 Westmont Drive/Charlotte, NC 28217 P: 704-336-4581 /C: 704-634-6984/ charlottewater.org From: Coco, Nick A<Nick.Coco@ncdenr.gov> Sent: Friday,January 13, 2023 1:50 PM To:Sypolt, Shannon <Shannon.Sypolt@charlottenc.gov> Cc: Montebello, Michael J <Michael.Montebello@ncdenr.gov> Subject: [EXT]RE: [External] RE: [EXT]Additional Information Request: NCO024970 McAlpine Creek NPDES Permit Application Hi Shannon, I hope all is well. I'm making good progress on the 3 renewals for McAlpine Creek WWMF, Irwin Creek WWTP and Sugar Creek WWTP. I was hoping you could just provide me with the monitoring frequency reduction request and criteria check for the Irwin and Sugar Creek plants. I also wanted to clarify the chemical addendum. We will need the addendum for each of these facilities. I know that you had mentioned that the addendum was not necessary since no additional monitoring had been conducted, but we will need that written on the chemical addendum form and signed (anywhere on the form will do). If no additional sampling was conducted,you can just note that no additional sampling was conducted and therefore no additional parameters were identified. 4 One last question I have is related to 1,4-dioxane. Has Charlotte Water conducted any monitoring of 1,4-dioxane at these 3 plants? It appears that each facility has at least one industry type linked to use of 1,4-dioxane in their pretreatment programs. Thanks in advance for your time and help on this, Nick Coco, PE (he/him/his) Engineer 111 NPDES Municipal Permitting Unit NC DEQ/Division of Water Resources/Water Quality Permitting Office: (919) 707-3609 nick.coco@ncdenr.gov "Email is preferred but 1 am available to talk by via Microsoft Teams" Physical Address: 512 North Salisbury St.,Raleigh, NC, 27604 Mailing Address: 1617 Mail Service Center, Raleigh, NC, 27699-1617 D- E NORTH CAROLINA7d� Q kl ; Department of Environmental Quality Email correspondence to and from this address is subject to the North Carolina Public Records Law and may be disclosed to third parties. From: Sypolt, Shannon <Shannon.Sypolt@charlottenc.gov> Sent:Tuesday, October 4, 2022 10:00 AM To: Coco, Nick A<Nick.Coco@ncdenr.gov> Cc: Macomber, Maggie<Maggie.Macomber@charlottenc.gov>; Lockler,Joseph <Joseph.Lockler@charlottenc.gov>; Montebello, Michael J <Michael.Montebello@ncdenr.gov>;Jarrell,Jackie<Jackie.Jarrell@charlottenc.gov>; Smith, Reid <Terrell.Smith@charlottenc.gov> Subject: [External] RE: [EXT]Additional Information Request: NCO024970 McAlpine Creek NPDES Permit Application CAUTION: External email. Do not click links or open attachments unless you verify.Send all suspicious email as an attachment to Report Spam. Good morning Nick, Please see the following responses, and their associated attached documents,for the information that you have requested in your email below: 1. Please see the five attached PPA's that were completed since McAlpine's last permit renewal. Although McAlpine's permit only required three PPA's be performed during the last permit cycle, CLTWater conducts PPA's annually at all of our facilities. 2. Our biosolids permit number is WQ0000057. 3. The estimated average daily volume of I&I is 4.176 MGD. 4. McAlpine WWMF would like to continue reduced monitoring frequencies (2x/week)for conventional parameters. Please see the attached spreadsheet that demonstrates McAlpine WWMF has met all the requirements for reduced monitoring frequencies as an "Exceptionally Performing Facility". 5 5. To the best of our knowledge, all samples collected at McAlpine WWMF that are covered under a method listed in 40 CFR Part 136 and run by a state certified lab, have been reported to NCDWR on our monthly DMR's. No additional pollutants with methods listed in 40 CFR Part 136 have been analyzed,therefore,the Chemical Addendum form was not submitted in our application. 6. Per your request, please see the attached CLTWater Mercury Minimization Plan. 7. The treatment unit components list submitted in our permit application is accurate and represents all permanent treatment units currently present at McAlpine. If you have any questions concerning the information contained in this email, or if you need any additional information, please feel free to contact me directly. Thank you for your assistance with the renewal of McAlpine's NPDES permit. Respectfully, Shannon Sypolt Water Quality Program Administrator Environmental Management CHARLOTTE WLTER 4222 Westmont Drive/Charlotte, NC 28217 P: 704-336-4581 /C: 704-634-6984/ charlottewater.org From: Coco, Nick A<Nick.Coco@ncdenr.gov> Sent:Tuesday, September 13, 2022 11:47 AM To: kneels@charlottenc.gov Cc:Jarrell,Jackie<Jackie.Jarrell@charlottenc.gov>; Montebello, Michael J <Michael.Montebello@ncdenr.gov> Subject: [EXT]Additional Information Request: NCO024970 McAlpine Creek NPDES Permit Application Hi Kim, I hope all is well on your end. I have begun reviewing the NPDES renewal application for NCO024970 McAlpine Creek WWTP and have the following comments: 1. Please provide the 3 effluent pollutant scans taken during this permit period. 2. Please provide the permit number associated with Charlotte Water's sludge disposal agreement with Synagro. 3. Please provide the estimated average daily volume of I&I. It appears this wasn't noted on the attachment or in the application. 4. Charlotte Water was granted 2/week monitoring for BOD, ammonia,TSS and fecal coliform based on 2012 DWR Guidance Regarding the Reduction of Monitoring Frequencies in NPDES Permits for Exceptionally Performing Facilities.The renewal application does not include a request for continuation of this monitoring frequency reduction. If this is a mistake, and Charlotte Water would like to continue 2/week monitoring for these parameters, please submit a request to continue this requirement and include confirmation of the approval criteria outlined in the attached guidance document. 5. As required by Session Law 2018-5, Senate Bill 99, Section 13.1(r), every applicant shall now 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. If there are additional pollutants with certified methods to be reported, please submit the Chemical Addendum to NPDES Application table with your application and, if applicable, list the selected certified analytical method used. If there are no additional pollutants to report, this form is not required to be included with your application. This requirement applies to all NPDES facilities.The Chemical Addendum to NPDES 6 Application will be required for any type of facility with an NPDES permit, depending on whether those types of pollutants are found in your wastewater. Please fill out, sign and submit the Chemical Addendum to NPDES Application. 6. Please provide a copy of the Mercury Minimization Plan prepared for this facility, per Special Condition A.(10) of the current permit. 7. Please verify the accuracy of this component list for the McAlpine Creek WWTP: • Elena equalisation • Scrocuing • Grit mmoval • Primary clanfirn • Aeration hasinc • Secondary clarifiers • Liiological and chemical phosphorus removal • Alkulinc addition for nitrificiihon • Chlurinatiun • Dechlonnation • Anaerobic sludge digestion • Centrifuges and gravity sludge thickeners • Rapid sand filtern Thank you in advance for all of your help with this. If you have any questions for me along the way, please do not hesitate to reach out. Best, Nick Coco, PE (he/him/his) Engineer 111 NPDES Municipal Permitting Unit NC DEQ/Division of Water Resources/Water Quality Permitting Office: (919) 707-3609 nick.coco@ncdenr.gov "Email is preferred but 1 am available to talk by via Microsoft Teams" Physical Address: 512 North Salisbury St.,Raleigh, NC, 27604 Mailing Address: 1617 Mail Service Center, Raleigh, NC, 27699-1617 ka ;NORTH CAROLINA Department of Environmental Quality Email correspondence to and from this address is subject to the North Carolina Public Records Law and may be disclosed to third parties. 7 Whole Effluent Toxicity Testing and Self Monitoring Summary CMUD-McAlpine WWTP NCO024970/001 County: Mecklenburg Region: MRO Basin: CTB34 Mar Jun Sep Dec SOC JOC: Ceri7dPF Begin: 10/1/2017 chr lim:90% NonComp: Single 70,10: 0.3 PF: 64.0 IWC: 99.35 Freq: Q J F M A M J J A S O N D 2018 - - Pass(s)>100(P) - - Pass(s) - - Pass - - Pass(s) 2019 - - Pass(s) - - >100(P)Pass(s) - - Pass(s) - - Pass(s) 2020 - - Pass(s) - - Pass(s) - - >100(P)Pass - - Pass 2021 - - Pass - - Pass(s) - - Pass(S)Pass(5) - - Pass>100(P) 2022 - - Pass(S)Pass(S)>100(F - - Pass(s)Pass(S) - - - - - - CMUD-McDowell Cr.WWTP NCO036277/001 County: Mecklenburg Region: MRO Basin: CTB33 Jan Apr Jul Oct SOC JOC: Ceri7dPF Begin: 1/1/2014 chr lim.: 90% NonComp: Single 70.10: 1.80 PF: 12.0 IWC: 85 Freq: Q J F M A M J J A S O N D 2018 Pass(s)92.5(P) - - Pass(s) - - Pass(s) - - Pass(s) - - 2019 Pass(s) - - Pass(s)>100(P) - - Pass(s) - - Pass(s) - - 2020 Pass(s) - - Pass(s) - - 97.5 Pass Pass - - Pass - - 2021 Pass - - Pass(s)Pass(s) - - Pass(5)Pass(S) - - >100(P)Pass(5)Pass - 2022 Pass(S)Pass(S)>100(P) - - Pass(S)Pass(S) - - - - - - - - Coats American-Sevier Plant NC0004243/001 County: McDowell Region: ARO Basin: CTB30 Feb May Aug Nov SOC JOC: Ceri7dPF Begin: 12/1/2017 chr lim:15% NonComp: Single 701,10: 18.0 PF: 2.0 IWC: 14.7 Freq: Q I 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 - Fail 5.3(NC) 21.2 10.6(NC) >60 >60 - - - - - Coddle Creek WTP NCO083119/001 County: Cabarrus Region: MRO Basin: YAD11 Jan Apr Jul Oct SOC JOC: Ceri7dPF Begin: 12/1/2013 90%chr mont NonComp: 7Q10: PF: 0.30 IWC: Freq: Q J F M A M J J A S O N D 2018 Pass - - Pass - - Fail - - Pass - - 2019 Pass - - Pass - - Pass - - Pass - - 2020 Pass - - Pass - - Fail Pass - Pass - - 2021 Pass - - Pass - - Pass - - Pass - - 2022 Pass - - Pass - - Pass - - - - - Cofield Facility(RO&Cooling Water) NCO089516/001 County: Hertford Region: WARO Basin: CH001 Jan Apr Jul Oct SOC JOC: Ceri7dPF Begin: 9/1/2020 Chr Limit: 90% NonComp: 7Q10: PF: IWC: Freq: Q J F M A M J J A S O N D 2018 Fail - - Fail - Fail Fail - - Pass - - 2019 Pass - - Pass - - Pass - - Fail H - 2020 Pass - - Pass - - Pass - - Pass - - 2021 Pass - - Pass - - Pass - - Fail Fail 94.9>100 2022 Pass - - Pass - - Pass - - - - - LeEend: P=Fathead minnow(Pimohales oromelas).H=No Flow(facility is active).s=Split test between Certified Labs Page 24 of 117 „,STATE c,A' r✓ >A �P r1V..�ry f1 ROY COOPER v Governor u O ELIZABETH S.BISER _A , a2 Secretary $`°”" S.DANIEL SMITH NORTH CAROLINA Director Environmental Quality September 28, 2021 MEMORANDUM TO: Permit Files: NCO024937, Sugar Creek WWTP NCO024945, Irwin Creek WWTP NCO024970, McAlpine Creek WWTP NCO036277, McDowell Creek WWTP NCO089630, Joe C. Stowe, Jr., RWRRF FROM: Mike Templeton SUBJECT: Charlotte Water Permits—Proposed Uniform Nutrient Conditions Charlotte Water owns and operates five wastewater facilities that are subject to nutrient limits. Charlotte has pointed out that the nutrient conditions in four of the five permits contain minor but not insignificant differences in terminology and content. These permits should be modified at the first opportunity to improve clarity and uniformity. This memo provides a brief overview of the nutrient conditions. This memo and a markup copy of each facility's permit has been added to its LaserFiche folder for 2021, and the Word file for each permit has been saved to its"NPDES Permits"folder on the S: drive. The five facilities are currently subject to the following nutrient requirements: • The Sugar, Irwin, and McAlpine Creek facilities are subject to a single, collective Total Phosphorus (TP) limit. The TP limit is the result of an agreement with SC DHEC that implements a downstream phosphorus TMDL. The"bubble"limit is included in the McAlpine Creek permit for internal outfall TPO1, and the other permits include a cross-reference to that permit and limit. One source of confusion is the inconsistent use of terms within each permit and among the three. • The McAlpine Creek facility is the largest of Charlotte's plants (64 MGD). Its permit also includes an individual TP limit,based on the same settlement agreement, to ensure a certain level of performance. Another source of confusion is the inconsistent use of terms and methods between the collective and individual requirements in the permit. • The McDowell Creek permit includes seasonal Monthly Average mass limits for Total Nitrogen (TN) and Total Phosphorus. The limits were based on modeling of Mountain Island Lake and McDowell Creek Cove to protect for the chlorophyll-a water quality standard. The nutrient requirements are clear enough within the permit,but terms and methods differ from the other permits. • The Joe Stowe permit includes total seasonal limits for TN and TP in accordance with the Lake Wylie Nutrient TMDL. The new facility has not yet been built, and the Cities of Belmont and Mount Holly will connect to Charlotte's collection system and decommission their own treatment plants. The timing of those connections is uncertain and will affect the amount of nutrient �FQ_ North Carolina Department of Environmental Quality I Division of Water Resources _ 512 North Salisbury Street 11617 Mail Service Center I Raleigh,North Carolina 27699-1617 919.707.9000 Charlotte Water Permits—Proposed Uniform Nutrient Conditions September 28, 2021 Page 2 allocations available to Charlotte for the Stowe discharge. Thus,the permit includes limits for several connection sequences. We are not proposing changes to the Stowe permit at this time. The various nutrient limits and permit conditions were established at different times to implement different control strategies. As a result,the terminology, reporting requirements, and mass calculation methods vary among the permits and, in some cases,within a given permit. Charlotte Water has asked the Division to revise the Sugar, Irwin, and McAlpine Creek permits to improve the uniformity of their nutrient conditions. We propose to modify the McDowell Creek permit, as well, so that the conditions are more consistent across all of the permits. The changes will not affect the TN and TP limits or monitoring requirements for the facilities. The Joe Stowe permit does not require changes at this time; instead, it is being used, as much as possible, as the template for conditions in the other permits. (NOTE: It may be possible to perform minor mods for some facilities rather than wait for their upcoming renewals. In that case,when the first of the permits is renewed,the mods for the others could be issued at the same time. So permit writers should note that the nutrient updates described here for a particular facility may have already been made by the time its permit comes up for renewal.) Let me know if you have any questions regarding these modifications. Attachments: Summary of Proposed Changes Permits,including proposed nutrient revisions NC0024937,Sugar Creek WWTP NC0024945,Irwin Creek WWTP NC0024970,McAlpine Creek WWTP NC0036277,McDowell Creek WWTP NC0089630,Joe C.Stowe,Jr.,RWRRF eCopy(w/o attachments): Mike Montebello,Municipal Permitting Memo to file-proposed changes to Charlotte Water permits 20210928 412712023 1:45 PM Charlotte Water Permits-Proposed Uniform Nutrient Conditions September 28, 2021 Page 3 Summary of Proposed Changes -for Discussion with Charlotte Water All four permits: McAlpine,Sugar,Irwin, and McDowell Creek • Applied more consistent terminology,units of measure, and parameter codes for the various measures of TP. • Applied consistent methods for calculation of TN and TP loads (see figure on next page). • Required reporting of interim calculation results,to make it easier to see how the final results were derived. The"bubble" permits: McAlpine,Sugar, and Irwin Creek • Updated the"Combined Limitations" condition and edited to include the revised terminology,etc. The same language is used in all three permits. • Applied a uniform method for TN and TP calculations, as shown in this figure. Each plant would report its own results up through the 12-Month TP Loads,and McAlpine would continue to report the Combined TP Load for the three. McAlpine Creek • A.(1.): Added Total Monthly Flow (TMF) reporting,created separate rows for TP concentration and mass,applied new parameter names in the table and footnotes to improve clarity,provided clearer linkage between the limits page,footnotes,and the other TP special conditions. • A.(7.): Applied the new parameter names and added linkage to the limits page and calculations condition. • A.(8.): Applied the new terminology and described the calculations for each measure of TP used on the limits page. Clarified how the combined TP loads would be calculated and where they would be reported. Sugar Creek,Irwin Creek • Similar to McAlpine Creek except that the limits pages do not include the bubble limit, and the TP special conditions do not repeat the requirements for calculation and reporting of the combined 12-month TP load. McDowell Creek • A.(1.): Separated concentration and mass requirements for clarity, applied new TP terms. Linked the limits page to the mass calculations condition. • Added a version of the calculations condition tailored to this permits requirements. Memo to file-proposed changes to Charlotte Water permits 20210928 412712023 1:45 PM Charlotte Water Permits—Proposed Uniform Nutrient Conditions September 28, 2021 Page 4 Calculation of Combined Nutrient Loads -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Monthly Flow(MG)y X Monthly TP Load(lb/mo) > 12-Month TP Load(lb/yr) Average TP(mg/L) Sugar,NC002 37 r Monthly Flow(MG) + X yMonthly TP Load(lb/mo) —> 12-Month TP Load(lb/yr) Combined TP Load(lb/day) Average TP(mg/L) �7 + @ Outfall TPOI,McAlpine NCO024970 Irwin,NC0024945 Monthly Flow(MG) X Monthly TPLoad(lb/mo) > 12-Month TP Load(lb/yr) Average TP(mg/L) �7 '-------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------I McAlpine,NC0024970 r--------- --------------------------------------------------------------------------------------------------- Days Daily TP Load(lb/day) @ Outfall 001,McAlpine NC0024970 McAlpine,NC0024970 Memo to file-proposed changes to Charlotte Water permits 20210928 412712023 1:45 PM MONITORING REPORT(MR)VIOLATIONS for: Report Date: 09/13/22 Page 1 of 1 Permit: NCO024970 MRS Betweel 9 - 2017 and 9 - 2022 Region: % Violation Category:Limit Violation Program Category: Facility Name:% Param Nam(% County: % Subbasin:% Violation Action:% Major Minor: PERMIT: FACILITY: COUNTY: REGION: MONITORING VIOLATION UNIT OF CALCULATED % REPORT LOCATION PARAMETER DATE FREQUENCY MEASURE LIMIT VALUE Over VIOLATION TYPE VIOLATION ACTION 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 NCO024970 111 121 22/02/25 I17 18 LC]I 19 I G 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 2.0 70L 71 I„ I 72 73 LJ74 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) 09:15AM 22/02/25 17/10/01 McAlpine Creek WWTP 12701 Lancaster Hwy Exit Time/Date Permit Expiration Date Pineville NC 28134 01:35PM 22/02/25 21/06/30 Name(s)of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s) Other Facility Data Keith Allen Purgason/ORC/704-542-0736/ Name,Address of Responsible Official/Title/Phone and Fax Number Contacted Angela D Charles,5100 Brookshire Blvd Charlotte NC 282163371/Di rector/704-336-5911/ 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 Wes Bell DWR/MRO WQ/704-663-1699 Ext.2192/ 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# 1 NPDES yr/mo/day Inspection Type 1 31 NC0024970 I11 12I 22/02/25 117 18 i c i Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary) On-site Representatives: The following Charlotte Water personnel were in attendance during the inspection: Mr. Keith Purgason, Mr. Reid Smith, Mr. Joseph Lockler and Mr. Shannon Sypolt. Page# 2 Permit: NCO024970 Owner-Facility: McAlpine Creek WWTP Inspection Date: 02/25/2022 Inspection Type: Compliance Evaluation Permit Yes No NA NE (If the present permit expires in 6 months or less). Has the permittee submitted a new ■ ❑ ❑ ❑ application? Is the facility as described in the permit? ■ ❑ ❑ ❑ #Are there any special conditions for the permit? ■ ❑ ❑ ❑ Is access to the plant site restricted to the general public? ■ ❑ ❑ ❑ Is the inspector granted access to all areas for inspection? ■ ❑ ❑ ❑ Comment: Charlotte Water implements a Division approved Industrial Pretreatment Program. The Division received Charlotte Water's renewal package on 1/4/20. Construction activities associated with the approved Reliability and Process Improvements projects are ongoing. The last compliance inspection (bio-monitoring) at this facility was performed by DWR staff on 9/22/20. 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? ❑ ❑ ❑ ■ Page# 3 Permit: NCO024970 Owner-Facility: McAlpine Creek WWTP Inspection Date: 02/25/2022 Inspection Type: Compliance Evaluation Record Keeping Yes No NA NE Comment: The records reviewed during the inspection were organized and well maintained. Discharge monitoring reports (eDMRs)were reviewed for the period January 2021 through December 2021. No limit and/or monitoring violations were reported. Laboratory Yes No NA NE Are field parameters performed by certified personnel or laboratory? 0 ❑ ❑ ❑ Are all other parameters(excluding field parameters) performed by a certified lab? 0 ❑ ❑ ❑ # Is the facility using a contract lab? 0 ❑ ❑ ❑ # Is proper temperature set for sample storage (kept at less than or equal to 6.0 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: Influent and effluent analyses (including field) are performed under Charlotte Water's Environmental Services Laboratory Certification #192. ETT and ETS (chronic toxicity) have also been contracted to provide analytical support. 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 ❑ ❑ ❑ # 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? 0 ❑ ❑ ❑ Comment: The subject permit requires influent BOD and TSS composite samples. Facility staff check the sampler aliquot volumes on a daily basis. 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? ■ ❑ ❑ ❑ # 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 0 ❑ ❑ ❑ representative)? Page# 4 Permit: NCO024970 Owner-Facility: McAlpine Creek WWTP Inspection Date: 02/25/2022 Inspection Type: Compliance Evaluation Effluent Sampling Yes No NA NE Comment: The subject permit requires composite and grab effluent samples. Facility staff check the sampler aliquot volumes on a daily basis. Upstream / Downstream Sampling Yes No NA NE Is the facility sampling performed as required by the permit (frequency, sampling type, ■ ❑ ❑ ❑ and sampling location)? Comment: 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: The wastewater treatment facility appeared to be properly operated and well maintained. Facility staff incorporate a comprehensive process control program with all measurements being properly documented and maintained on-site. In-depth operation and maintenance records are also maintained on-site. Approximately Fourteen (14) SCADA stations are located throughout the treatment plant site. Odor control systems are connected to the influent pump station, primary clarifiers, sludge thickening/dewatering and bio-solids storage facility. Bar Screens Yes No NA NE Type of bar screen a.Manual ❑ b.Mechanical Are the bars adequately screening debris? ■ ❑ ❑ ❑ Is the screen free of excessive debris? 0 ❑ ❑ ❑ Is disposal of screening in compliance? 0 ❑ ❑ ❑ Is the unit in good condition? 0 ❑ ❑ ❑ Comment: 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? ■ ❑ ❑ ❑ Page# 5 Permit: NC0024970 Owner-Facility: McAlpine Creek WWTP Inspection Date: 02/25/2022 Inspection Type: Compliance Evaluation Grit Removal Yes No NA NE Comment: Screenings and grit are disposed at a permitted landfill. 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? 0 ❑ ❑ ❑ Are all pumps present? 0 ❑ ❑ ❑ Are all pumps operable? 0 ❑ ❑ ❑ Are float controls operable? 0 ❑ ❑ ❑ Is SCADA telemetry available and operational? 0 ❑ ❑ ❑ Is audible and visual alarm available and operational? ❑ ❑ 0 ❑ Comment: Equalization Basins Yes No NA NE Is the basin aerated? ■ ❑ ❑ ❑ Is the basin free of bypass lines or structures to the natural environment? 0 ❑ ❑ ❑ Is the basin free of excessive grease? ■ ❑ ❑ ❑ Are all pumps present? 0 ❑ ❑ ❑ Are all pumps operable? ■ ❑ ❑ ❑ Are float controls operable? 0 ❑ ❑ ❑ Are audible and visual alarms operable? ❑ ❑ ■ ❑ # Is basin size/volume adequate? 0 ❑ ❑ ❑ Comment: The facility is equipped with an eighty-five (85) million gallon equalization basin. Primary 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? 0 ❑ ❑ ❑ Are weirs level? 0 ❑ ❑ ❑ Is the site free of weir blockage? ■ ❑ ❑ ❑ Is the site free of evidence of short-circuiting? 0 ❑ ❑ ❑ Is scum removal adequate? 0 ❑ ❑ ❑ Is the site free of excessive floating sludge? ■ ❑ ❑ ❑ Is the drive unit operational? 0 ❑ ❑ ❑ Is the sludge blanket level acceptable? 0 ❑ ❑ ❑ Page# 6 Permit: NCO024970 Owner-Facility: McAlpine Creek WWTP Inspection Date: 02/25/2022 Inspection Type: Compliance Evaluation Primary Clarifier Yes No NA NE Is the sludge blanket level acceptable? (Approximately '/4 of the sidewall depth) 0 ❑ ❑ ❑ Comment: All eight (8) primary clarifiers (4— North Train and 4—South Train)were in service. Nutrient Removal Yes No NA NE # Is total nitrogen removal required? 0 ❑ ❑ ❑ # Is total phosphorous removal required? 0 ❑ ❑ ❑ Type Biological # Is chemical feed required to sustain process? ❑ ❑ 0 ❑ Is nutrient removal process operating properly? 0 ❑ ❑ ❑ Comment: The facility continues to operate two converted aeration basins (North Train) as fermenters to enhance nutrient reductions. Ferric chloride can also be added into the final clarifier effluent to reduce nutrient levels. Aeration Basins Yes No NA NE Mode of operation Ext. Air Type of aeration system Diffused Is the basin free of dead spots? 0 ❑ ❑ ❑ Are surface aerators and mixers operational? 0 ❑ ❑ ❑ Are the diffusers operational? 0 ❑ ❑ ❑ Is the foam the proper color for the treatment process? 0 ❑ ❑ ❑ Does the foam cover less than 25% of the basin's surface? ❑ 0 ❑ ❑ Is the DO level acceptable? 0 ❑ ❑ ❑ Is the DO level acceptable?(1.0 to 3.0 mg/1) 0 ❑ ❑ ❑ Comment: The facility is equipped with twenty-six (26) aeration basins (10 — North Train and 16— South Train). All aeration basins were in service except two aeration basins being rehabbed in the South Train. Magnesium hydroxide is added to maintain appropriate alkalinity/pH levels. The foam was greater than 25% of the basin's surface; however, no foam carryover was observed in the final clarifiers. Chemical Feed Yes No NA NE Is containment adequate? ■ ❑ ❑ ❑ Is storage adequate? ■ ❑ ❑ ❑ Are backup pumps available? 0 ❑ ❑ ❑ Is the site free of excessive leaking? 0 ❑ ❑ ❑ Page# 7 Permit: NCO024970 Owner-Facility: McAlpine Creek WWTP Inspection Date: 02/25/2022 Inspection Type: Compliance Evaluation Chemical Feed Yes No NA NE Comment: Secondary Clarifier Yes No NA NE 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: The facility is equipped with sixteen (16)final clarifiers (6 — North Train and 10—South Train). All final clarifiers were in service except for one clarifier per train being rehabbed. Pumps-RAS-WAS Yes No NA NE Are pumps in place? ■ ❑ ❑ ❑ Are pumps operational? ■ ❑ ❑ ❑ Are there adequate spare parts and supplies on site? ❑ ❑ ❑ ■ Comment: Filtration (High Rate Tertiary) Yes No NA NE Type of operation: Down flow Is the filter media present? ■ ❑ ❑ ❑ Is the filter surface free of clogging? ■ ❑ ❑ ❑ Is the filter free of growth? ■ ❑ ❑ ❑ Is the air scour operational? ■ ❑ ❑ ❑ Is the scouring acceptable? ■ ❑ ❑ ❑ Is the clear well free of excessive solids and filter media? ■ ❑ ❑ ❑ Comment: All nineteen 09)tertiary filters were in service. Page# 8 Permit: NC0024970 Owner-Facility: McAlpine Creek WWTP Inspection Date: 02/25/2022 Inspection Type: Compliance Evaluation 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? ❑ ❑ ❑ Comment: Both chlorine contact chambers were in service. 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 ❑ ❑ ❑ Are the tablets the proper size and type? ❑ ❑ ❑ Comment: Aqueous sodium bisulfite is used for dechlorination. Are tablet de-chlorinators operational? ❑ ❑ ❑ Number of tubes in use? Comment: Flow Measurement - Effluent Yes No NA NE # Is flow meter used for reporting? 0 ❑ ❑ ❑ Is flow meter calibrated annually? 0 ❑ ❑ ❑ Is the flow meter operational? 0 ❑ ❑ ❑ (If units are separated) Does the chart recorder match the flow meter? ❑ ❑ 0 ❑ Comment: The flow meter is calibrated twice per year and was last calibrated on 1/24/22 by CITI, LLC. Facility staff must ensure effluent flows account for the non-potable flows used on-site. Effluent Pipe Yes No NA NE Is right of way to the outfall properly maintained? 0 ❑ ❑ ❑ Are the receiving water free of foam other than trace amounts and other debris? 0 ❑ ❑ ❑ If effluent (diffuser pipes are required) are they operating properly? ❑ ❑ ■ ❑ Page# 9 Permit: NCO024970 Owner-Facility: McAlpine Creek WWTP Inspection Date: 02/25/2022 Inspection Type: Compliance Evaluation Effluent Pipe Yes No NA NE Comment: The effluent appeared clear with no floatable solids and foam (entrained air). The foam dissipated prior to the Lancaster Highway bridge. The receiving stream did not appear to be negatively impacted. Anaerobic Digester Yes No NA NE Type of operation: Fixed cover Is the capacity adequate? 0 ❑ ❑ ❑ # Is gas stored on site? 0 ❑ ❑ ❑ Is the digester(s)free of tilting covers? 0 ❑ ❑ ❑ Is the gas burner operational? ■ ❑ ❑ ❑ Is the digester heated? 0 ❑ ❑ ❑ Is the temperature maintained constantly? 0 ❑ ❑ ❑ Is tankage available for properly waste sludge? 0 ❑ ❑ ❑ Comment: The facility is equipped with eight (8) digesters and two (2) storage tanks (floating cover). Seven (7) digesters and one storage tank were in service. The facility continues to use the Combine Heat & Power facility using methane gas as the fuel source. Solids Handling Equipment Yes No NA NE Is the equipment operational? ■ ❑ ❑ ❑ Is the chemical feed equipment operational? 0 ❑ ❑ ❑ 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? ■ ❑ ❑ ❑ Is the site free of excessive moisture in belt filter press sludge cake? N ❑ ❑ ❑ The facility has an approved sludge management plan? 0 ❑ ❑ ❑ Comment: The facility is equipped with four(4) gravity thickeners (three in service) and six (6) centrifuges (3—thickening and 3—dewatering). All thickening centrifuges and two (2) dewatering centrifuges were in service. The primary and waste activated sludges from the Sugar Creek WWTP are processed at this facility. Dewatered bio-solids are stored under cover and are land applied by a contracted company (Synagro) under the authority of Permit No. WQ0000057. 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 ❑ ❑ ❑ Page# 10 Permit: NC0024970 Owner-Facility: McAlpine Creek WWTP Inspection Date: 02/25/2022 Inspection Type: Compliance Evaluation Standby Power Yes No NA NE Was generator tested & operational during the inspection? ❑ ❑ ❑ Do the generator(s) have adequate capacity to operate the entire wastewater site? ■ ❑ ❑ ❑ Is there an emergency agreement with a fuel vendor for extended run on back-up 0 ❑ ❑ ❑ power? Is the generator fuel level monitored? ❑ ❑ ❑ Comment: The facility is equipped with six (6) backup generators. The generators are serviced on a quarterly basis by a contracted company (Cummings). Page# 11 NORTH CAROLINA 2022 303(D) LIST Lower Catawba Catawba River Basin AU Name AU Number Classification AU_LengthArea AU—Units AU ID Description McAlpine Creek(Waverly Lake) 11-137-9b C 6.3 FW Miles 667 From SR 3356 to NC 51 PARAMETER IR CATEGORY CRITERIA STATUS REASON FOR RATING 303D YEAR Benthos(Nar,AL, FW) 5 Exceeding Criteria Fair, Poor or Severe Bioclassification Fish Community(Nar,AL, FW) 5 Exceeding Criteria Fair, Poor or Severe Bioclassification McAlpine Creek(Waverly Lake) 11-137-9c C 4.6 FW Miles 668 From NC 51 to NC 521 PARAMETER IR CATEGORY CRITERIA STATUS REASON FOR RATING 303D YEAR Benthos(Nar,AL, FW) 5 Exceeding Criteria Fair, Poor or Severe Bioclassification Fish Community(Nar,AL, FW) 5 Exceeding Criteria Fair, Poor or Severe Bioclassification McAlpine Creek(Waverly Lake) 11-137-9d C 1.0 FW Miles 666 From NC 521 to North Carolina-South Carolina State Line PARAMETER IR CATEGORY CRITERIA STATUS REASON FOR RATING 303D YEAR Benthos(Nar,AL, FW) 5 Exceeding Criteria Fair, Poor or Severe Bioclassification 1998 Fish Community(Nar,AL, FW) 5 Exceeding Criteria Fair, Poor or Severe Bioclassification 2000 Twelvemile Creek 11-138 C FW Miles 676 From source to North Carolina-South Carolina State Line PARAMETER IR CATEGORY CRITERIA STATUS REASON FOR RATING 303D YEAR Fish Community(Nar,AL, FW) 5 Exceeding Criteria Fair, Poor or Severe Bioclassification Sixmile Creek 11-138-3 C 8.8 FW Miles 691 From source to North Carolina-South Carolina State Line PARAMETER IR CATEGORY CRITERIA STATUS REASON FOR RATING 303D YEAR Fish Community(Nar,AL, FW) 5 Exceeding Criteria Fair, Poor or Severe Bioclassification 6/7/2022 NC 2022 303d List-Approved by EPA 4/30/2022 Page 37 of 192 CHARLOTTE W4JER MERCURY MINIMIZATION PLAN Charlotte Water(CLTWater) serves approximately 276,498 households and businesses in Mecklenburg County that discharge wastewater directly to the sanitary sewer(Wastewater Performance Report, 2021). Customers are categorized as either commercial or residential in the billing system. Dentists, once considered the only major contributor of mercury to the wastewater collection system, have the potential to pollute the sanitary sewer with waste from the installation or removal of dental amalgam. However, other industries are also potential contributors of this pollutant. This Mercury Minimization Plan is an outline to facilitate a minimization in the levels of mercury entering the sanitary sewer system. In the data analysis for the wastewater system, the goal is to target areas of concern as the basin-specific data experiences an upward trend in relation to the Baseline Study. METHODOLOGY The MMP focus is on the individual basin trends. The five wastewater plants operated by CLTWater are Mallard Creek, McDowell Creek, Irwin Creek, Sugar Creek and McAlpine Creek wastewater treatment plants. Additional monitoring sites are located strategically throughout the collection system. When upward trends of five percent above the baseline influent data for the basin occur, further action may be taken to minimize the potential impact of the pollutant on the ecosystem. The baseline was determined by averaging three calendar years' data for each plant. Some other industries, such as laboratories, hospitals, schools and factories could affect the wastewater collection system with mercury. Although they may not hold an SIU permit, an annual chemical inventory may be required if upward trends warrant increased action. THE PLAN Mercury comes from a variety of sources. Identifying these sources is the key to a successful minimization plan. Depending upon the data trends in each wastewater basin, an annual review of the following steps will determine the level of action for the upcoming year: 1. The Assessment—Annual Report generated by CLTWater, including the removal rates for the wastewater treatment plants. 2. Monitoring—Periodic wastewater data review for the wastewater treatment plants, continuous industrial waste survey process, sampling and increased inspection frequencies as trends dictate. 3. Dental Amalgam Program—A dental amalgam plan developed by CLTWater in response to the promulgation of 40 CFR 441. The plan outlines the general oversight of dental practices in Mecklenburg county. 4. Educational Outreach - Oral and written communication to the community about findings and increased efforts to reduce mercury pollution. 5. Internal Assessments— Including but not limited to, review of Spill Control Plans, Chemical Hygiene Plans and safety for employees periodically in Laboratory Services. For more information about mercury, please refer to the 2022 Mercury Assessment. 1 I MERCURY MINIMIZATION PLAN Rev. 02/02/2022 CHARLOTTE W6TER THE ASSESSMENT Annually, CLTWater performs an assessment of the potential contributors of mercury to the collection system and publishes the findings. The assessment includes newly identified potential contributors, as well as known contributors of any level of mercury to the wastewater collection system. Known contributors that have a Significant Industrial User(SIU) permit limit should take the necessary actions outlined in their permit if their discharge exceeds the permit limit for mercury. These facilities are inspected once annually and the Compliance Specialist assigned to that industry should be notified if changes in the chemical inventory or process have the potential to affect the wastewater effluent of the facility. From the reported information, it can be determined if any changes need to be made to the permit limits. Industries that hold an SIU permit should also respond to the wastewater survey provided them by their designated Compliance Specialist once every five years and keep track of any chemicals that contain mercury by performing a comprehensive chemical inventory, using Safety Data Sheets housed onsite. The annual inspection sheet has one new question concerning mercury to keep the industry mindful of the potential impact the pollutant could have on the collection system. MONITORING Based on data from 2021, CLTWater's five wastewater plants currently average a 99.03% removal rate for mercury from the influent stage of treatment to the effluent stage. The data from each wastewater basin will be reviewed periodically for trending. If the data is in an upward trend for any of the five basins, additional measures may be activated to curb those trends. These measures may include additional inspections or sampling in the collection system to determine the contributors. Once it is determined the level of contribution by the industries, then a plan of action may include methods of reducing the mercury levels leaving the facility, implementation of Best Management Practices to prevent reoccurrence of the pollutant discharge and monitoring onsite at the expense of the industry, as needed. To verify that the efforts are working, a routine sampling program may be required for the facilities found to have elevated levels of mercury in their wastewater effluent. DENTAL AMALGAM PROGRAM On July 14, 2017, the EPA promulgated 40 CFR Part 441. This rule requires dental offices that place and/or remove amalgam to install an amalgam separator in accordance with the requirements in the rule, to implement two best management practices, to submit a one-time compliance report to the POTW, and to conduct on-going operation and maintenance of the amalgam separator and maintain associated documentation and records. CLTWater has developed a Dental Amalgam Plan to outline its general oversight of those dental practices that operate in Mecklenburg county. CLTWater will be responsible for receiving, reviewing, and retaining a One-Time Compliance Report (OTCR)submitted by users subject to rule 40 CFR Part 441. CLTWater has developed a OTCR requesting all information required by the EPA. It also contains additional questions asked by CLTWater. A mass email with CLTWater's expectations for dental dischargers along with an attached OTCR and Cover Letter was sent to licensed dentists whose license was registered with a Mecklenburg county 21 MERCURY MINIMIZATION PLAN Rev. 02/02/2022 CHARLOTTE W4)TER address. The list of licensed dentists was purchased from the NC Dental Licensing Board. A section for "Dental Dischargers" has also been added to the CLTWater website. There customers can find additional information about 40 CFR Part 441, a fillable copy of the OTCR, a link to the EPA Dental Effluent Guidelines, and CLTWater pretreatment staff contact information. CLTWater's Enforcement Response Plan was updated to describe CLTWater's response to instances of noncompliance committed by dental dischargers. This update was approved by the Pretreatment, Emergency Response, and Collection Systems Unit (PERCS) of the Division of Water Resources on January 7, 2020. EDUCATIONAL OUTREACH On the mecknc.gov website CLTWater customers can find drop-off locations for common household items that may contain mercury such as compact fluorescent lights (CFLs), old thermostats, button cell batteries, car parts, and household appliances. There are four Recycling Centers across Mecklenburg County. Items such as household appliances, compact fluorescent lights, and batteries can be brought to the recycling centers. CLTWater customers may also find information concerning the proper disposal of household waste by visiting the mecknc.gov website. Any household items found to contain mercury need to go to the nearest drop-off location for disposal. These items should never be discharged to the sanitary sewer system. INTERNAL ASSESSMENT CLTWater has several checks and balances in place to ensure it is doing all it can to prevent the introduction of Mercury into our collection system. Four of the five Wastewater treatment plants disinfect the wastewater with Ultraviolet light. When the UV bulbs are replaced, and if they are still under manufacturer warranty they are returned to the manufacture (Xylem). If the bulbs are spent or no longer under manufacturer warranty the bulbs are packaged and taken one of the four recycling centers located in Mecklenburg county. Any fluorescent or CFL bulbs used by the plants are also taken to the recycling center. The wastewater treatment plants have transitioned from using thermometers and manometers that contain mercury. Property Management and Lab Services assisted the plants in the equipment changeover. Each Plant has an Approved Spill Control Plan and Chemical Hygiene Plan in place. Charlotte Water Laboratory Services Division analyzes over 200,000 wastewater and drinking water samples annually. Lab Services has a contract with CHEMTRON Corporation. CHEMTRON is contacted by Lab Services to collect and dispose of chemical hazards. Different areas within the lab use chemicals for sample preservation and in instrumentation calibration standards. All heavy metals calibration standards are picked up by CHEMTRON. Lab Services uses rechargeable Lithium batteries for select pieces of analytical equipment. There has been a recycling program set in place for the spent rechargeable and spent alkaline batteries. The batteries will be stored in a marked container and stored until a drop-off date has been chosen. A member of the Laboratory Services field staff will drop the batteries off for recycling at a Batteries Plus location within the Charlotte area. 31 MERCURY MINIMIZATION PLAN Rev. 02/02/2022 Lower Catawba River Basin — 2020 Nutrient Study Final Report of the Field Program September 2021 Prepared by Matthew S. Baumann, Ph.D. Pdhec S.C. Department of Health and Environmental Control Bureau of Water 303(d), Modeling&TMDL Section Columbia,SC 29201 Technical Report No. 007-2021 Table of Contents Overview of the 2020 Lower Catawba Study................................................................................................1 Nutrient Study Project/Task Description......................................................................................................2 FieldLogistics............................................................................................................................................2 SensorData...............................................................................................................................................5 SurfaceParameters...............................................................................................................................5 VerticalProfile ......................................................................................................................................6 ContinuousMonitoring.........................................................................................................................6 Fluorometer-Based Chlorophyll-a.............................................................................................................7 Cyanotoxins...............................................................................................................................................7 WaterQuality............................................................................................................................................7 Streams.................................................................................................................................................7 Lakes .....................................................................................................................................................7 Summaryof Findings.....................................................................................................................................8 VerticalProfile...........................................................................................................................................8 ContinuousMonitoring...........................................................................................................................10 Fluorometer-Based Chlorophyll-a...........................................................................................................12 Cyan of ox i n s.............................................................................................................................................14 WaterQuality..........................................................................................................................................15 Conclusion...................................................................................................................................................18 Acknowledgments.......................................................................................................................................18 Appendix A—Vertical Profile Section Graphs.............................................................................................19 List of Figures Figure 1. Grab sampling site LWT-01 at the boat ramp immediately below Lake Wylie dam. ....................3 Figure 2. Sampling sites near and within Fishing Creek Reservoir and Lake Wateree. Grab samples only were collected at river site CW-016 (purple). Continuous monitoring systems were installed, and grab samples were collected at sites LCR-04, LCR-02, LCR-03, CW-208, and CW-207B (blue). Grab sampling only occurred at CW-231 (red).........................................................................................4 Figure 3.Temperature (°C) section plot for CW-208 in the Dutchman Creek arm of Lake Wateree.The vertical profile from 8/24/2020 (Julian Day 237)was lost due to an instrument software malfunction......................................................................................................................................9 Figure 4. Dissolved oxygen (mg/L) section plot for CW-208 in the Dutchman Creek arm of Lake Wateree. The vertical profile from 8/24/2020 (Julian Day 237)was lost due to an instrument software malfunction......................................................................................................................................9 Figure 5. pH section plot for CW-208 in the Dutchman Creek arm of Lake Wateree.The vertical profile from 8/24/2020 (Julian Day 237)was lost due to an instrument software malfunction..............10 Figure 6.Average daily temperature at CW-208 in the Dutchman Creek arm of Lake Wateree. Data loss occurred for June 4-8, 2020...........................................................................................................11 Figure 7. Daily minimum and maximum recorded dissolved oxygen concentrations (mg/L) at CW-208 in the Dutchman Creek arm of Lake Wateree. Data loss occurred for June 4-8, 2020.....................11 Figure 8. Hourly average dissolved oxygen concentrations (mg/L)for the April 14 through October 29, 2020, continuous monitoring record at CW-208 in the Dutchman Creek arm of Lake Wateree..12 Figure 9. Daily minimum and maximum recorded dissolved pH values at CW-208 in the Dutchman Creek arm of Lake Wateree. Data loss occurred for May 13-25 and June 4-8, 2020..............................12 Figure 10. Box plot summary of surface (0.3 m)total chlorophyll-a concentrations (µg/L)for each lake station (n = 15).The red line denotes the 40 µg/L ecoregional total chlorophyll-a standard. .....13 Figure 11. Box plot summary of subsurface (1.5 m)total chlorophyll-a concentrations (µg/L) for each lakestation (n = 15). ......................................................................................................................14 Figure 12. Box plot summary of total phosphorus concentrations (mg/L) measured at each stream and lake station.The red line denotes the 0.06 mg/L lake ecoregional total phosphorus standard...16 Figure 13. Box plot summary of total nitrogen concentrations (mg/L) measured at each stream and lake station.The red line denotes the 1.5 mg/L lake ecoregional total nitrogen standard..................17 Figure 14. Box plot summary of total organic carbon concentrations(mg/L) measured at each stream andlake station..............................................................................................................................18 List of Tables Table 1. Field program site coordinates and descriptions............................................................................3 Table 2. Range (minimum and maximum)for each primary field parameter over the 4/7/2020— 10/20/2020 period at the stream and lake sites.............................................................................5 Table 3. Range (minimum and maximum)for additional field parameters at the lake sites surface over the 4/7/2020—10/20/2020 study period........................................................................................6 Table 4.Total chlorophyll-a summary statistics for each lake station and depth along with the percent of observations in which the surface (0.3 m) concentration is greater than the subsurface (1.5 m) measurement. Average is presented as± 1o. All total chlorophyll units in µg/L.........................13 Table 5. Microcystins cyanotoxin summary statistics for each lake station. Samples for microcystins were collected every other field sampling trip at the surface (0.3 m). Average is presented as± 16. All total microcystins concentrations in µg/L. ....................................................................................15 Executive Summary During 2020, South Carolina Department of Health and Environmental Control (DHEC) collected water quality data from two stream sites and six lake sites in the Lower Catawba River Basin located in north- central South Carolina. The field sampling program spanned early April through the end of October and builds on studies conducted in previous years by DHEC and stakeholder partners. This program was designed to address specific questions that remained from studies in prior years including further resolving the seasonal cycle of physical conditions and progression in phototroph ecology in the system and to enhance chemical and physical understandings at key locations in the basin. The 2020 program objective was achieved using a series of five monitoring systems in Lake Wateree and Fishing Creek Reservoir to continuously record physical/hydrographic parameters and biological responses(sensor-based chlorophyll-a and phycocyanin) coupled with biweekly water quality sampling at these lake sites as well as three other strategic locations (one in upper Lake Wateree and two in the Catawba River). The data collected as part of this study will provide insights into the mechanistic links between physical conditions and nutrients and algal responses such as phytoplankton biomass and toxin production. This report discusses the successes and challenges of the field program and briefly summarizes data collected as part of the continuous monitoring and biweekly grab sample project components. Generally, all field program objectives were achieved as nearly all targeted data were successfully collected. Early in the field season, technical challenges associated with new equipment led to interruptions in the continuous records at three locations. The continuous records at these sites were more complete from early July through the end of record as issues were resolved. Over the course of the field program: • Surface temperatures generally exceeded 30°C by mid-July and persisted through mid-September based on vertical profile and continuous monitoring data. Apparent temperature-based stratification was variable based on the area of the lake. • The upstream lake stations in Lake Wateree exhibited the lowest total chlorophyll-a concentrations and the dissolved oxygen concentrations and pH values in the water column in this area showed little response to algal growth. • The highest total chlorophyll-a concentrations were measured in the Dutchman Creek arm of Lake Wateree. Elevated upper water column dissolved oxygen and pH were also observed in the lake arm. • Generally,total chlorophyll-a concentrations were higher at 1.5 m than at the surface (0.3 m). • Nutrient concentrations (total phosphorus and total nitrogen) in water discharged from Lake Wylie were on average lower than other sites (stream and lake) sampled as part of this project. • Despite returning the highest total chlorophyll-a concentrations, average total phosphorus and total nitrogen in the Dutchman Creek arm were the lowest measured among the lake sites. Average total organic carbon concentration was highest in this lake arm. Overview of the 2020 Lower Catawba Study The Lower Catawba River Basin includes the watershed drainage from the tailrace at Lake Wylie in Fort Mill,South Carolina,to the tailrace at Lake Wateree in Kershaw County,South Carolina.The system is one of the major watersheds for the city of Charlotte, North Carolina, and its south suburbs including rapidly growing York County, South Carolina. More than 30 ambient monitoring locations in the Lower Catawba are included in the State's draft 2018 303(d) list as impaired for total phosphorus, total nitrogen, and/or chlorophyll-a. In addition, blooms of planktonic Microcystis and colonies of Lyngbya wollei, a filamentous, mat-forming algae are commonly present in Lake Wateree during the hot summer months. These cyanobacteria produce toxins known to cause swimmer's itch, respiratory problems, and taste and odor issues in drinking water. In 2016, using an updated version of the WARMF model, South Carolina Department of Health and Environmental Control (DHEC) determined and proposed preliminary total phosphorus and total nitrogen load reductions for point and nonpoint sources as the starting point for Total Maximum Daily Loads (TMDLs). The load reductions included a 66 percent cut in phosphorus and a 55 percent cut in nitrogen from wastewater sources. Reductions from stormwater and human nonpoint sources varied by location, up to 50 percent. DHEC presented these results to stakeholders and proposed that stakeholders conduct an allocation process to determine individual allocations most effectively. DHEC provided a phosphorus allocation tool to assist the process. In response, the dischargers in the Lower Catawba asked DHEC for time to collect additional data and develop more detailed modeling and develop site-specific numeric nutrient (total nitrogen and total phosphorus) and chlorophyll-a standards for the lakes. The standards would be used to develop TMDLs aimed at addressing water quality impairments impacting designated uses. The stakeholders and the National Council for Air and Stream Improvement (NCASI) developed an approved Quality Assurance Project Plan (QAPP) and conducted extensive monitoring in the Catawba basin in 2017 and 2018. The group also initiated a facilitated model review group to select suitable models to support criteria and TMDL development. In 2019, DHEC Bureau of Water (BOW) 303d,TMDL and Modeling group (TMDL group) implemented the Lower Catawba River Basin —Stream and Lake Nutrient Water Quality Study (Nutrient Study) as well as wet-weather watershed studies to produce an enhanced suite of environmental data.The results of these studies may be found in DHEC Bureau of Water Technical Report Nos.009-2020(Nutrient Study) and 014- 2020 (Wet Weather Studies).',' As part of the Nutrient Study, BOW collected biweekly water quality data from six stream sites and 11 lake sites from mid-April through the end of October 2019. Broadly,the objectives of the Nutrient Study were to quantify nutrient loadings from the prevalent land use types in the basin and to resolve the relationship between physical and chemical conditions and ecological responses in Fishing Creek Reservoir and Lake 'South Carolina Department of Health and Environmental Control. 2020. Lower Catawba River Basin—Stream and Lake Nutrient Water Quality Study, Final Report of the 2019 Study. Bureau of Water Technical Report No.009-2020. February 2020. 2South Carolina Department of Health and Environmental Control. 2020. Phase 1-Wet Weather Data Analysis. Bureau of Water Technical Report No.014-2020.June 2020. 1 Wateree. Samples were collected for 18 unique chemical water quality parameters in the streams and at multiple depths in the lakes. In addition, total chlorophyll-a and photosynthetic pigment samples along with sensor-based vertical profiles for physical parameters were collected in the lakes. Monitoring systems to continuously record physical parameters at the surface were also deployed at two locations: one in the mid-lake area of Fishing Creek Reservoir and one in Lake Wateree off the Dutchman Creek lake arm. Further, DHEC partnered with EPA to 1) conduct algal growth potential tests to investigate nutrient limitation on the phytoplankton community, 2) quantify sediment oxygen demand and nutrient fluxes between sediments and the water column, and 3) install two additional continuous monitoring systems at strategic locations in Lake Wateree. DHEC also collaborated with NCASI to quantify grain size and organic carbon content in Lake Wateree sediments. Lastly, DHEC and Coastal Carolina University installed a weather station at Wateree State Park to support modelling efforts. In 2019 and into the winter of 2020, BOW conducted two watershed studies aimed at characterizing nutrient loadings to the Catawba River and lake during wet-weather events in five watersheds of varying land use types. Nutrient loadings during storm events, particularly at the 'first flush' of the event, can be significant due to release of accumulated pollutant mass at the surface and in soil pores associated with high energy runoff of heavy rainfall. Currently, there are no nutrient loading data for the Lower Catawba associated with the wet-weather events. An understanding of these loadings during storm events enhances watershed modeling capability and robustness through verification of nutrient loading export mechanisms. In 2020, the TMDL group conducted the Lower Catawba River Basin —2020 Nutrient Study (2020 Lake Program) program to address specific questions that remained including further resolving the seasonal cycle of physical conditions and progression in phototroph ecology in the system and to enhance chemical and physical understandings at three key locations in the basin that represent important entry points into the system. The new data will be coupled with previous water quality studies by the dischargers and DHEC's ambient water quality monitoring data to develop new watershed, lake hydrodynamic, and lake water quality models to assist in informing site-specific numeric criteria for the Lower Catawba system. The 2020 program objective was achieved using a series of five monitoring systems in Lake Wateree and Fishing Creek Reservoir to continuously record physical/hydrographic parameters and biological responses(sensor-based chlorophyll-a and phycocyanin) coupled with biweekly water quality sampling at these lake sites as well as three other strategic locations (one in upper Lake Wateree and two in the Catawba River). The data collected as part of this study will provide insights into the mechanistic links between physical conditions and nutrients and algal responses such as phytoplankton biomass and toxin production. Together with the results of the earlier studies, these links will help establish site-specific nutrient and chlorophyll-a criteria that are protective of the lakes' designated uses. Nutrient Study Project/Task Description Field Logistics The 2020 Lake Program spanned 30 weeks from the end of March through the end of October 2020.The study focused on a series of eight strategic locations in the Lower Catawba River Basin to meet the objectives described above (Table 1, Figures 1,2): 2 1. LWT-01—Lake Wylie tailrace immediately below dam (stream site) 2. CW-016—Catawba River at Highway 9 bridge (stream site) 3. LCR-04— Fishing Creek Reservoir off Bear Creek arm (lake site) 4. CW-231— Lake Wateree headwater below Cedar Creek Reservoir dam (lake site) 5. LCR-02— Lake Wateree upstream of Wateree Creek arm (lake site) 6. LCR-03— Lake Wateree off Dutchman Creek arm (lake site) 7. CW-208—Dutchman Creek arm of Lake Wateree (lake site) 8. CW-207B—Mid-lake Lake Wateree (lake site) Table 1. Field program site coordinates and descriptions. Station ID Lat./Long. County Site Description Stream Sites LWT-01 35.0213/-81.0038 York Lake Wylie Tailrace Boat Landing CW-016 34.7083/-80.8676 Chester Catawba River at SC-9(Fort Lawn) Lake Sites LCR-04 34.6203/-80.8862 Lancaster Fishing Creek Reservoir off Bear Creek arm CW-231 34.5365/-80.8749 Lancaster Lake Wateree headwater below Cedar Creek Reservoir dam LCR-02 34.4882/-80.9001 Fairfield/Lancaster Lake Wateree upstream of Wateree Creek (near RL-11040) LCR-03 34.4260/-80.8460 Fairfield/Kershaw Lake Wateree off Dutchmans Creek arm CW-208 34.4222/-80.8668 Fairfield Lake Wateree at S-20-101 11 miles east northeast of Winnsboro CW 207B 34.4039/-80.7827 Fairfield Mid-channel Lake Wateree at end of S-20- 291 Lake Wylie Google Earth Figure 1. Grab sampling site LWT-01 at the boat ramp immediately below Lake Wylie dam. 3 .Fishing Creek R servoir LakL-Wateree ELIC. , OLCR-0. 0: Figure 2.Sampling sites near and within Fishing Creek Reservoir and Lake Wateree.Grab samples only were collected at river site CW-016(purple).Continuous monitoring systems were installed and grab samples were collected at sites LCR-04,LCR-02,LCR-03, CW-208,and CW-2078(blue). Grab sampling only occurred at CW-231(red). Biweekly grab sampling was conducted at all sites and continuous monitoring systems were installed at five lake locations (LCR-04 in Fishing Creek Reservoir and LCR-02, LCR-03, CW-208, and CW-207B in Lake Wateree). Continuous monitoring systems were serviced every other week. Surface (nominal 0.3 m)grab sample parameters included: • 5-day biochemical oxygen demand (BOD5; stream sites only), • Turbidity, • Ammonia-nitrogen, • Nitrate/nitrite-nitrogen, • Total Kjeldahl Nitrogen, • Total phosphorus, • Orthophosphate, • Total suspended solids, • Total and filtered total organic carbon, • Total chlorophyll-a (surface and 1.5 m, lake sites only), and • Cyanotoxins (microcystins, lake site only, approximately monthly) Field sensor measurements were recorded at each grab sample site (all sites) along with vertical profiles and photosynthetically active radiation penetration were collected at each lake site: • Water temperature, • Dissolved oxygen, • pH, • Turbidity, • Specific conductance, • Chlorophyll-a fluorescence (lake sites only), and • Phycocyanin fluorescence (lake sites only) 4 Continuous monitoring systems recorded surface measurements (0.5-1.0 m depending on the system) at 15 to 30-minute intervals at the five lake locations.Surface measurements are the same as the field sensor measurements listed above. An attempt was made to collect continuous nitrate data at three locations (LCR-04, LCR-03, and CW-20713), however, technical issues related to Ott EcoN instrument power consumption curtailed the records for this parameter. As such, continuous nitrate data will not be presented here. Further, technical issues related to calibration and manufacturer failings of the In-Situ Aqua Troll 600 phycocyanin sensors used at the same locations limited the usefulness of these measurements and will not be presented here. Sensor Data Surface Parameters Surface physical parameters were collected at a depth of 0.3 m at each stream and lake site using a calibrated Hydrolab DSSX (streams) and YSI EXO2 (lakes). Sampling was conducted from mid-morning through early afternoon (09:00-14:00). Routine physical parameters included pH (SU), optical dissolved oxygen (DO, mg/L), water temperature (°C), specific conductance (µS/cm) (Table 2) Table 2.Range(minimum and maximum)for each primary field parameter over the 41712020-1012012020 period at the stream and lake sites. Field pH Field DO Water Temp. Spec Cond. Station (SU) (mg/L) (°C) (µS/cm) Streams LWT-01 5.63 -7.50 5.12-8.91 17.2 -29.4 55.0-83.0 CW-016 6.85 -7.65 6.72-8.43 16.8-30.5 68.7- 136 Lakes LCR-04 6.96-9.22 7.27- 11.96 19.09 -31.30 73.0- 115.1 CW-231 6.86-7.31 6.82-9.11 17.98-30.05 73.3 - 115.2 LCR-02 6.85 -7.88 7.21-9.43 19.16-31.67 73.8- 115.9 LCR-03 7.00-9.10 7.18- 11.61 19.36-32.44 74.0- 121.3 CW-208 7.44-9.27 7.23 - 12.12 19.78-32.45 79.6- 111.3 CW-207B 7.07-9.23 7.03 - 11.80 20.07 -32.33 72.4- 116.1 An expanded suite of surface measurements was collected at each lake site including sensor-based chlorophyll-a (µg/L) and phycocyanin (µg/L) (Table 3). In addition, upper water column features were measured such as penetration depth of photosynthetically active radiation(PAR,400-700 nm wavelength, µcool m-z s-1) using a LI-COR light meter and a LI-1400 data logger,water clarity expressed as secchi depth (m),and turbidity(FNU). PAR depth was determined as the depth in which PAR decays to 1%of its ambient value.The chlorophyll-a and phycocyanin maximums were determined from the vertical profile downcast and described as either a maximum depth or vertical band where pigment fluorescence was highest. YSI EXO2 sensor-based chlorophyll-a and phycocyanin measurements should be viewed relatively and compared only with 2019 Nutrient Study data. Calibration protocols for the EXO Total Algae sensors were changed to be more consistent with manufacturer recommendations prior to the upper Lake Murray field study in 2021. 5 Table 3.Range(surface minimum and maximum)for additional field parameters at the lake sites over the 41712 02 0-1 012 012 02 0 study period. Station Chl a (µg/L) Chl-a Max Phycocyanin Phycocyanin PAR Depth Secchi Depth Turbidity Depth (m) (µg/L) Max Depth (m) (m) (m) (FNU) LCR-04 1.94-18.23 0.3-1.75 0-6.87 0.3-0.3 1.5-4.7 0.4-0.9 4.30-52.45 CW-231 0-5.27 0.3-0.3 0-1.50 0.3-0.3 1.1-3.0 0.3-0.7 7.62-198.09 LCR-02 0.18-6.69 0.3- 1.0 0-1.74 0.3-0.3 1.3-2.7 0.3-0.7 5.71-154.87 LCR-03 2.60-18.63 0.3-1.75 0-5.03 0.3-1.75 1.3-3.1 0.4-0.9 5.90-81.37 CW-208 5.62-19.50 0.3- 1.5 0-9.52 0.3- 1.5 1.6-3.1 0.5-0.8 4.50-38.94 CW-207B 0.90-13.45 0.3-2.0 0-5.63 0.3-2.0 1.7-4.3 0.4- 1.1 3.02-25.49 Vertical Profile Vertical profiles were collected at each lake site visit using the YSI EXO2. The casts were conducted manually, but data were logged by the instrument every second. The sonde was gradually lowered through the water column (downcast) until contact was made with the lake bottom and then retrieved at a similar rate.An Excel tool was created to process raw vertical profile data.The tool extracts the downcast from the profile record by identifying when instrument descent was initiated and when retrieval began after contacting the lake bottom.The bottom depth for the profile could be manually adjusted to remove the effects of sediment resuspension. The program then averaged the downcast data in half meter intervals. Eight parameters were processed for each profile: water temperature, DO concentration, DO percent saturation, pH, turbidity, specific conductance, chlorophyll-a concentration, and phycocyanin concentration. In total,86 vertical profiles were collected as part of the 2020 Lake Program. Fifteen profiles were targeted at each site. One profile was lost at CW-231, LCR-03, CW-208, and CW-207B on 8/24/2020 due to an instrument software issue. Because profiles are collected on an approximately biweekly schedule, the data can be used to illustrate the evolution of the water column over the course of the field program, but do not capture diel variability. Continuous Monitoring Continuous monitoring systems were deployed at five of the six lake sites (CW-231 excluded) from 4/8/2020 through the end of October 2020. Each deployment was approximately two weeks in duration and data were recorded at 15- or 30-minute intervals depending on the instrument used. YSI EXO2s (15- minute recording interval) were deployed at sites LCR-02 and CW-208 and Hydrolab DSSXs (30-minute recording interval)were installed at LCR-04, LCR-03, and CW-207B. Early in the field season, technical challenges associated with new equipment led to interruptions in the continuous records, particularly at LCR-04, LCR-03, CW-207B. However, end verifications for the primary variables (DO, pH, and specific conductance) were largely successful. A complete end of deployment verification record is stored in the SharePoint Field Log. The following list summarizes end deployment verifications, equipment challenges, and lessons learned: 6 • There are data gaps over the first few months at LCR-04, LCR-03, and CW-207B due to battery strength and data logging/telemetry issues associated with new remote sensing buoys installed at these locations. The buoys were removed in July and the records were more complete in the second half of the field program. • Towards the middle of the campaign,the DO sensors on Hydrolab DSSXs occasionally began failing for periods of time (3-6 hours) midday. These failings typically occurred when DO was highest in the daily cycle and was due to flaking off of the coating on the sensor DO cap. Gentle care, frequent inspection, and replacing the DO cap as necessary is recommended to avoid data loss. • One DO verification failed for an EXO2 at CW-208 in May (Series 2). The record was not immediately discarded as it tracked well with concurrent pH record. • The EXO2 pH modules failed in May and replacements arrived in June.Two Series 3 pH records at LCR-02 and CW-208 were lost. In-Situ Aqua Troll 600 instruments were used to bridge the gap in pH records until EXO2 replacement modules arrived. • A conductivity sensor failed on a Hydrolab DSSX H4472 and was replaced. Fluorometer-Based Chlorophyll-a A total of 165 lake samples were collected for fluorometer-based total chlorophyll-a. Samples were collected at the surface (0.3 m) and at 1.5 m at all lake sites except CW-231 where surface only samples were collected. No samples were lost. Cyanotoxins Samples for microcystins analysis were collected at the surface of each lake site every other field sampling event therefore on an approximately monthly schedule.A total of 48 samples were collected and no samples were lost. Water Quality Grab samples for water quality occurred biweekly from 4/7/2020-10/20/2020. Access Analytical and Rogers and Calcott were used for the first four sampling events (4/7, 4/21, 5/5, and 5/19).The DHEC Central Laboratory analyzed samples from 6/2 through the end of the project. Streams Each stream site was sampled 15 times over the course of the project. Each stream station satisfied the completeness data quality indicator(DQI)as no visits were missed because of human error.Completeness for each station, as assessed by sample opportunities, is determined to be 100%. Further, the project operated under a biweekly sampling schedule,which ensured that the samples collected at each site were evenly distributed across the study timeframe removing any bias towards a specific period of the season. All stream laboratory water quality samples were successfully analyzed except for two ammonia samples at each site due to instrument failure at the Central Laboratory. Lakes Each lake site was sampled 15 times during the field program. Completeness is determined to be 100%as no sample event was omitted due to field team decision or error. As with the stream component, lake sampling followed a biweekly schedule and samples were evenly distributed over the course of the study. All lake laboratory water quality samples were successfully analyzed except for two ammonia samples at each site due to instrument failure at the Central Laboratory. 7 Summary of Findings The following summary represents a brief discussion of high-level observations of keystone parameters investigated as part of the 2020 Lower Catawba Nutrient Study. It is not meant to be exhaustive of all data collected during the study.The discussion centers on broad features in the vertical and continuous profile records at CW-208 in the Dutchman Creek arm of Lake Wateree and on summary statistics for grab sample total chlorophyll-a, cyanotoxins (microcystins), total phosphorus,total nitrogen, and total organic carbon for all sites. Vertical Profile Section graphs for temperature, dissolved oxygen, pH,temperature, specific conductance, and chlorophyll-a for each station are presented in Appendix A.The plots were interpolated from the 14 or 15 vertical profiles collected on a biweekly basis at each station. Because the plots are collected at approximately two-week intervals at roughly the same time of day,the interpolated data illustrate the seasonal,week over week, evolution of the water column at each site for physical and biological parameters. Section plots for temperature, dissolved oxygen, and pH for station CW-208 located in the Dutchman Creek arm of Lake Wateree are presented in Figures 3-5. Surface water temperature reached a maximum of"32.5°C in mid-to late July. At this point of the season, the water column appeared to demonstrate some thermal stratification (Figure 3), which is supported by enhanced dissolved oxygen concentrations and pH levels near the surface relative to subsurface measurements (Figures 4 and 5). Dissolved oxygen concentrations in bottom waters decreased to less than 2 mg/L during this period. These conditions persisted for at least a month; however, it is not clear if these conditions extended through late August as the 8/24/2020 profile was lost.Similar features occurred at the mid-lake stations (LCR-04, LCR-03, and CW-207B; Appendix A) and coincided with a period of low rainfall in the local area (0.11 inches (2.8 mm)for July and August, PRISM Climate Group). 8 Temperature[Celsius] 0 35 1 32.5 2 30 v 3 27.5 a G1 O 3p 25 4 - 30 a- -22.5 3 5 - \ o- -20 6 ° 100 150 200 7/18/2020 250 300 4/9/2020 5/29/2020 Julian Day 9/6/2020 10/26/2020 Figure 3. Temperature(°C)section plot for CW-208 in the Dutchman Creek arm of Lake Wateree.The vertical profile from 812412020(Julian Day 237)was lost due to an instrument software malfunction. Dissolved Oxygen[mg/L] 0 15 vo 1 — _ 12.5 10� \ 2 ' - -10 10 V7 v 3 _ 1.1 s - -7.5 d O 4 -5 s Q 3 5 >- -2.5 o'I 6 °- -'0 100 150 200 7/18/2020 250 300 4/9/2020 5/29/2020 Julian Day 9/6/2020 10/26/2020 Figure 4.Dissolved oxygen(mg/L)section plot for CW-208 in the Dutchman Creek arm of Lake Wateree.The vertical profile from 812412020(Julian Day 237)was lost due to an instrument software malfunction. 9 pH(su] 0 - -9.5 1 \ — 9 g5 - -08.5 2 w 3 - Q Q 7.5 4 � 7 it a 5 ' 6.5 . _ 6 ° 6 100 150 200 7/18/2020 250 300 4/9/2020 5/29/2020 Julian Day 9/6/2020 10/26/2020 Figure 5.pH section plot for CW-208 in the Dutchman Creek arm of Lake Wateree. The vertical profile from 812412020(Julian Day 237)was lost due to an instrument software malfunction. Continuous Monitoring Continuous monitoring of surface temperature indicated a gradual rise from April through mid-July to a maximum daily average of 32.3°C on July 17, 2020 at CW-208 in the Dutchman Creek arm of Lake Wateree (Figure 6).Temperatures remained above 29°C until the middle of September before decreasing to 12-23°C for the remainder of the monitoring period. During July and August, daily minimum and maximum dissolved oxygen concentrations were generally lower than in the April through June and mid-September through the end of October periods in the Dutchman Creek arm (Figure 7).The mid-summer decrease in dissolved oxygen occurred during the period of warmest ambient temperatures (Figure 6).The observed decrease in daily minimum dissolved oxygen is more pronounced than for the daily maximum concentration as daily differences(daily maximum—daily minimum) were larger during the mid-summer period. For the April through October monitoring period, dissolved oxygen appeared to mirror the pattern of daytime photosynthesis and overnight respiration (Figure 8). On average,the 0800 hour demonstrated the lowest dissolved oxygen concentration (8.54 mg/L) and 1700 produced the highest concentration (10.58 mg/Q. The Dutchman Creek arm consistently demonstrated elevated pH over the monitoring period.The maximum daily pH exceeded 8.5 on 161 of the 181-day record (89%). Further, the minimum daily pH exceeded 8.5 on 18 days, an exceedance of the standard of 10%.The average difference between daily minimum and maximum pH values was 1.42 (range: 0.13-2.52). 10 Average Daily Temperature 35 — - 33 — 31 v 29 KA LU 27 Q 25 Cr a 23 LU 21 .,,.,Aj 19 17 15 4/1/2020 5/1/2020 5/31/2020 6/30/2020 7/30/2020 8/29/2020 9/28/2020 10/28/2020 Figure 6.Average daily temperature at CW-208 in the Dutchman Creek arm of Lake Wateree.Data loss occurred fortune 4-8, 2020. Daily Minimum and Maximum Dissolved Oxygen 16 J 14 — z 12 w O x 10 O 0 > 8 YN e A11A ' fiv Av III 1" .1 Y' AA J O 6 V WT . mw 0 4 4/1/2020 5/1/2020 5/31/2020 6/30/2020 7/30/2020 8/29/2020 9/28/2020 10/28/2020 Min.Daily DO — Max.Daily DO Figure 7.Daily minimum and maximum recorded dissolved oxygen concentrations(mg/L)at CW-208 in the Dutchman Creek arm of Lake Wateree.Data loss occurred fortune 4-8,2020. 11 Hourly Average Dissolved Oxygen 12 J c� 11 L z 10 W X 9 0 0 > 8 J 0 vn 7 6 00 . 00 00 o00 00 00 00 00 00 00 .00 00 00 00 00 00 00 00 00 0 .0 00 ti00 0 0 00 o • 3• h �' do titi titi ti3 do ti� ti� tip' ti� ti� do yti yti ti� Figure 8.Hourly average dissolved oxygen concentrations(mg/L)for the April 14 through October 29,2020,continuous monitoring record at CW-208 in the Dutchman Creek arm of Lake Wateree. Daily Minimum and Maximum pH 10.0 - 9.5 9.0 8.5 D x 8.0 7.5 7.0 6.5 6.0 4/1/2020 5/1/2020 5/31/2020 6/30/2020 7/30/2020 8/29/2020 9/28/2020 10/28/2020 Min.Daily pH Max.Daily pH Figure 9.Daily minimum and maximum recorded dissolved pH values at CW-208 in the Dutchman Creek arm of Lake Wateree. Data loss occurred for May 13-25 and June 4-8,2020. Fluorometer-Based Chlorophyll-a Grab sample total chlorophyll-a distribtions were variable across the system and throughout the study. For the mid-lake stations (LCR-03, LCR-04, CW-208, and CW-207B), the highest average surface total choloropyll-a concentration occurred in early April (31.5 µg/L on 4/7/2020). At these stations, average surface total chlorophyll-a was at least 25 µg/L for five consecutive summer sampling events (6/29, 7/13, 7/27, 8/10, and 8/24/2020). Of these stations, CW-208 demonstrated the highest field program average surface total chlorophyll-a (32.4 µg/L),followed sequentially by CW-207B (21.7 µg/L), LCR-03 (18.5 µg/L), and LCR-04 (17.7 µg/L) (Table 4). Three of the 15 (20%) surface values at CW-208 exceed the 40 µg/L ecoregional standard (Figure 10). Total chlorophyll-a concentrations were typically greater at 1.5 m 12 compared to the 0.3 m surface value (Figure 11). Specifically,the surface concentration was greater than the 1.5 m value 27%of the time at CW-208 and LCR-03 and only 20%of the time at LCR-04 and CW-207B (Table 4). Table 4. Total chlorophyll-a summary statistics for each lake station and depth along with the percent of observations in which the surface(0.3 m)concentration was greater than the subsurface(1.5 m)measurement.Average is presented as±1a. All total chlorophyll units in ug/L. Station Depth (m) Avg.T. Chl-a Minimum Maximum n Surface > 1.5 m LCR-04 0.3 17.7 ± 8.8 4.6 32.7 15 20% 1.5 18.1 ± 9.2 5.4 34.2 15 CW-231 0.3 6.0 ± 2.2 2.5 11.1 15 - LCR-02 0.3 7.4 ± 5.2 3.1 23.9 15 13% 1.5 8.6 ± 4.5 4.2 18.1 15 CW-208 0.3 32.4 ± 7.7 17.7 45.0 15 27% 1.5 35.4 ± 9.2 19.8 47.1 15 LCR-03 0.3 18.5 ± 12.1 4.6 40.7 15 27% 1.5 20.4 ± 15.1 5.7 56.3 15 CW-207B 0.3 21.7 ± 8.0 7.7 37.8 15 20% 1.5 24.8 ± 10.0 8.0 48.5 15 Total Chlorophyll-a at Surface J 60 C O C G1 U C U 40 20 m 0 LCR-04 LCR-02 LCR-03 CW-208 CW-207B Station Figure 10.Box plot summary of surface(0.3 m)total chlorophyll-a concentrations(µg/L)for each lake station(n=15).The red line denotes the 40 µg/L ecoregional total chlorophyll-a standard. 13 Total Chlorophyll-a at 1.5 m J C O N C N � U C O U 40 0 LCR-04 LCR-02 LCR-03 CW-208 CW-207B Station Figure 11.Box plot summary of subsurface(1.5 m)total chlorophyll-a concentrations(µg/L)for each lake station(n=15). Cyanotoxins Microcystins concentrations at the open-lake stations were generally low and below the United States Environmental Protection Agency recreational health advisory value and DHEC recreational standard of 8 µg/L.3,4 These samples were collected routinely at open water sites as part of the 2020 field program. Cyanotoxin concentrations are typically higher within blooms of toxin producing cyanobacteria and in coves or nearshore environments where macrophyte algae tend to accumulate. For more information related to cyanotoxin distributions within South Carolina waters, refer to DHEC Bureau of Water Technical Report No. 001-2021.' 3U.S. Environmental Protection Agency. 2019. Recommended Human Health Recreational Ambient Water Quality Criteria or Swimming Advisories for Microcystins and Cylindrospermopsin. U.S. Environmental Protection Agency, Office of Water, EPA-822-R-19-001. 'South Carolina Department of Health and Environmental Control. Regulations 61-68 Water Classifications and Standards. 'South Carolina Department of Health and Environmental Control. 2021. 2019 South Carolina Cyanotoxin Distribution Project. Bureau of Water Technical Report No. 001-2021. March 2021. 14 Table 5. Microcystins cyanotoxin summary statistics for each lake station.Samples for microcystins were collected every other field sampling trip at the surface(0.3 m).Average is presented as±1a. All total microcystins concentrations in ug/L. Station Avg. Microcystins Minimum Maximum n LCR-04 0.074 ± 0.027 0.029 0.110 8 CW-231 0.080 ± 0.037 0.045 0.150 8 LCR-02 0.060 ± 0.030 0.018 0.097 8 CW-208 0.117 ± 0.063 0.062 0.253 8 LCR-03 0.066 ± 0.036 0.013 0.131 8 CW-207B 0.080 ± 0.038 0.035 0.148 8 Water Quality The water quality data collected as part of this study will be used to support various components of the watershed loading and lake water quality models.The following discussion summarizes the results for total phosphorus (TP) and total nitrogen (TN),two nutrient parameters regulated in lakes by the State, as well as total organic carbon (TOC). Note that TN is not explicitly measured but reported as the sum of Total Kjeldahl Nitrogen (TKN, sum of ammonia/ammonium and organic nitrogen) and nitrate/nitrite. BOW also engaged with Duke Energy Company to conduct split sampling at a series of strategic locations throughout the basin as a measure of laboratory comparability as part of this project.The results of that comparison study are presented in DHEC Bureau of Water Technical Report No. 008-2021.6 The lowest average concentrations for TP,TN, and TOC were measured at the tailrace of Lake Wylie (LWT-01).The downstream Catawba River site, CW-014, demonstrated nutrient concentrations similar to the lake stations.At the lake stations, average surface TP concentrations range from 0.040 mg/L to 0.54 mg/L(Figure 12). Average surface TN concentrations ranged 0.69 mg/L to 1.09 mg/L(Figure 13). The lowest average concentrations for both TP and TN occurred at CW-208 in the Dutchman Creek arm where the highest average total chlorophyll-a concentation was observed. Average lake TOC concentrations ranged from2.76 mg/L to 3.55 mg/L(Figure 14) with the highest average value occuring at CW-208. This disucssion centered on CW-208 as a case study within the project. Notable features observed at this station include: • Surface water temperature reached of maximum of"32.5°C in mid-to late July; possible thermal stratification at this point in the season which is supported. • Enhanced dissolved oxygen concentrations and pH levels observed near the surface in mid-July. • Dissolved oxygen concentrations in bottom waters decreased to less than 2 mg/L in mid-July through at least mid-August. • Daily minimum and maximum dissolved oxygen concentrations were generally lower in July and August than in the April through June and mid-September through the end of October periods. • The lake arm consistently demonstrated elevated pH over the monitoring period. • Dutchman Creek demonstrated the highest field program average surface total chlorophyll-a. 6 South Carolina Department of Health and Environmental Control. 2021.Catawba Basin Split Nutrient Study and Comparability Report. Bureau of Water Technical Report No. 008-2021.September 2021. 15 • Average chlorophyll-a concentration at 1.5 m was higher than at the surface. • The lowest average TP and TN concentrations were observed at CW-208. • Dutchman Creek arm demonstrated the highest average TOC concentration of the lake stations. Total Phosphorus J a020 • . C O N C N U 0 0 1-, • U • 0.00 LWT-01 CW-016 LCR-04 CW-231 LCR-02 LCR-03 CW-208 CW-207B Station Figure 12.Box plot summary of total phosphorus concentrations(mg/L)measured at each stream and lake station. The red line denotes the 0.06 mg/L lake ecoregional total phosphorus standard. 16 Total Nitrogen Q E C f9 U20 C O U 0.0 LWT-01 CW-016 LCR-04 CW-231 LCR-02 LCR-03 CW-208 CW-207B Station Figure 13.Box plot summary of total nitrogen concentrations(mg/L)measured at each stream and lake station. The red line denotes the 1.5 mg/L lake ecoregional total nitrogen standard. 17 Total Organic Carbon J E C � O • f9 C4 U C O ' 0 LWT-01 CW-016 LCR-04 CW-231 LCR-02 LCR-03 CW-208 CW-207B Station Figure 14.Box plot summary of total organic carbon concentrations(mg/L)measured at each stream and lake station. Conclusion As with the 2019 Nutrient Study and the other associated studies,this project is part of a comprehensive effort to resolve the relationship between physical and chemical conditions and ecological responses in the Lower Catawba Basin.Certain ecological responses impair designated uses in the system and degrade water quality as indicated by the cascade of regulatory 303(d) listings in the basin. This project builds on studies conducted in previous years by DHEC and stakeholder partners and is bolstered by years of data collected as part of DHEC's ambient monitoring program. The aggregated results of these programs fill important data gaps and provide a robust data set to develop, calibrate, and validate coupled watershed and river/lake hydrodynamic and water quality models.The calibrated models will be used in setting site- specific numeric nutrient and chlorophyll-a standards that are protective of designated uses for Lower Catawba Basin. Acknowledgments This project was made possible through support from DHEC Bureau of Water(BOW) TMDL group as well as Quality Assurance programs from the DHEC BOW and Bureau of Environmental Health Services (BEHS).The BEHS laboratory processed and analyzed water quality samples from June through the end of the project.Total chlorophyll-a and cyanotoxin samples were processed and analyzed by the BOW Aquatic Science Programs (ASP). Field sampling was conducted by personnel from the BOW TMDL and ASP groups. 18 Appendix A — Vertical Profile Section Graphs Julian Day: 100 is April 9, 2020, 150 is May 29, 2020, 200 is July 18, 2020, 250 is Sept 6, 2020, 300 is October 26, 2020 LCR-04—Fishing Creek Reservoir off Bear Creek arm Dissolved Oxygen[mg/L] 0 15 a I -12.5 2 �s 10 10 w - -7.5 O 4 l 5 5 6 — z -2.5 °- -0 100 150 200 250 300 Julian Day pH(su] 0 - 9.5 9 2 - 8.5 Q � 8.5 -- 7 8s ° ♦ 1— 3 6 > - -' 6.5 - — ' 0016 100 150 200 250 300 Julian Day 19 Temperature[Celsius] 0 35 32.5 2 - 30 e 27.5 Q 30/ 1s N 4 25 QD i 30 o- 22.5 3 6 - g- 20 N O 100 150 200 250 300 Julian Day Specific Conductance[uS/cm] 0 130 100 85 -120 2 110 85 N rr 100 Q 4 1 90 es 80 6 70 100 150 200 250 300 Julian Day 20 Chlorophyll-a 0 17.5 -20 )5 10 2.5 15 2 15 10 4 - 5 10 O '0 5 5 q 6 - a o" 0 100 150 200 250 300 Julian Day 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 • • • • • • • • • • • • • • 6 ' 0 100 150 200 250 300 Julian Day 21 CW-231—Upstream Lake Wateree Headwater, below Cedar Creek Dam Missing 8/24/2020 Dissolved Oxygen[mg/L] 0 15 12.5 1 -10 C 2 - - 7.5 c O 5 i 3 s i -2.5 3 O 4 ° -0 100 150 200 250 300 Julian Day pH[su] 0 - 9.5 s 1 8.5 2 - .. C. d 7.5 0 7- a 7 3 0 3 6.5 O 4 ° _ 6 100 150 200 250 300 Julian Day 22 Temperature[Celsius] 0 30 - -35 -32.5 1 30 30 0 27.5 Q2 30 d a -25 3 0- 22.5 3 g 20 4 ° 100 150 200 250 300 Julian Day Specific Conductance[uS/cm] 0 130 120 1 110 N � O r=.. 2 :.— 100 O, g5 � o 90 3 - 80 qM" 4 70 100 150 200 250 300 Julian Day 23 Chlorophyll-a 0 20 1 15 v v 2 N Q � 10 3 = 5 o' 4 ° 0 100 150 200 250 300 Julian Day 0 . . . . . . . . . . . . . 1 . . . . . . . . . . . . . E m G 3 . s i 0 4 • o 100 150 200 250 300 Julian Day 24 LCR-02—Lake Wateree upstream of Wateree Creek arm Missing 8/24/2020 Dissolved Oxygen[mg/L] 0 - 15 12.5 2 - 10 ti 4 w 7.5 Q N O 6 5 2.5 LL 8 0 100 150 200 250 300 Julian Day pH[su] 9.5 1 9 2 - 8.5 7.5 _ � 4 8 t v.. Q Q 7.5 6 7 s ' 6.5 8 0 ° 6 100 150 200 250 300 Julian Day 25 Temperature[Celsius] 0 35 ^b 8 2 32.5 -30\ - 30 I i 4 a 30 27.5 v Q d + 25 6 i 0 22.5 3 8 0 20 0 100 150 200 250 300 Julian Day Specific Conductance[uS/cm] 0 130 -120 2 110 4 t 100 6 90 80 8 °- 70 100 150 200 250 300 Julian Day 26 Chlorophyll-a 0 ryy - -20 2 s 15 4 - w 0 2s - -10 6 — Aft ° 5 i 8 0 oio 100 150 200 250 300 Julian Day 0 . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 • • • • • • • • • • • • • • 6 • • • s i • s 8 • o' e 100 150 200 250 300 Julian Day 27 LCR-03—Lake Wateree off Dutchmans Creek arm Missing 8/24/2020 Dissolved Oxygen[mg/L] 0 - 15 I i 1 1 12.5 o 10 p V10 7.5 C O 3- 5 0 4 : - 2.5 B 5 ° 0 100 150 200 250 300 Julian Day pH[su] 0 9.5 � s 9 1 8.5 5 .5. 8 w Q 3 7.5 7.5 7 'o 4 -- 3 \ A 6.5 0 5 ° 6 100 150 200 250 300 Julian Day 28 Temperature[Celsius] 0 35 1 32.5 30 2 27.5 v \ a O 3 25 '0 22.5 4 ; I g 20 5 ° 100 150 200 250 300 Julian Day Specific Conductance[uS/cm] 0 130 r 120 110 2 ivs V 0 vim. 85 0 100 d O 3 »s 90 a 0 4 I >$ s 80 0 5 ° 70 100 150 200 250 300 Julian Day 29 Chlorophyll-a 0 s 17.5 10 -20 71 7.5 15 5 5 -AO — 15 2 — M y 7.5 10 2.5 4 5 0 5 °- 0 100 150 200 250 300 Julian Day 0 1 t p 3 4 3 5 o 100 150 200 250 300 Julian Day 30 CW-208—Lake Wateree at S-20-101 (Dutchman Creek arm) Missing 8/24/2020 Dissolved oxygen, pH and temperature section plots included above in main body of report Specific Conductance[uS/cm] 0 - -130 i 85 I 120 ail I 2 a5 11 0 - - I w 3 — — — - -100 i i' 4 i - -90 a I 5 -80 _100 0 6 ° -70 100 150 200 250 300 Julian Day Chlorophyll-a O 17.5 - - 12.5 10 17.5 20 5 17.5 - 10 15 �5. 2 - - -15 -S 3 7.5 - -10 4 10 '1s s 7.5 5 a 5 75 _ 6 �-2.5 12.5 ° -0 100 150 200 250 300 Julian Day 31 0 . . . . . . . . . . . . . 1 2 w 3 4 5 -> 6 • 8 100 150 200 250 300 Julian Day CW-207B—Mid-channel Lake Wateree at end of 5-20-291 Dissolved Oxygen(mg/L] 0 15 f0 o to - -12.5 2 10 1 7.5 q — � 7.5 7.5 N 6 -- 5 2.5 8 i o °- -0 100 150 200 250 300 Julian Day 32 pH(su] 0 7.5 =-- - -9.5 U _ s 2 -- �7.5� erg/ 8.5 � - -8.5 1 � 4 >• - 8 Q Qb <7.5 6 7 7 7.5 a 6.5 ° 6 100 150 200 250 300 Julian Day Temperature[Celsius] 0 35 32 � N 2 24- 32.5 -30 27.5 - -25 6 s a -22.5 a 8 / \ ——01 1 20 I � 0 100 150 200 250 300 Julian Day 33 Specific Conductance(uS/cm] 0 130 120 2 110 4 v 100 Q d O 6 90 a 3 80 8 0 ° 70 100 150 200 250 300 Julian Day Chlorophyll-a 0 --f5, 20 2 15 10 O 6 0 5 3 8 - — _ -•.r o ° 0 100 150 200 250 300 Julian Day 34 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 • • • • • • • • • • 6 s 8 • a 8 100 150 200 280 300 Julian Day 35