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HomeMy WebLinkAboutNC0003433_Correspondence_20240105 (2)Fact Sheet NPDES Permit No. NCO003433 Permit Writer/Email Contact: Sergei Chernikov, Ph.D., sergei.chernikov@deq.nc.gov Date: May 27, 2020 Division/Branch: NC Division of Water Resources/NPDES Complex Permitting Fact Sheet Template: Version 09Jan2017 Permitting Action: ❑X Renewal ❑ Renewal with Expansion ❑ New Discharge ❑ Modification (Fact Sheet should be tailored to mod request) Note: A complete application should include the following: • For New Dischargers, EPA Form 2A or 2D requirements, Engineering Alternatives Analysis, Fee • For Existing Dischargers (POTW), EPA Form 2A, 3 effluent pollutant scans, 4 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: Duke Energy Progress LLC — Cape Fear Steam Electric Plant Applicant Address: 500 CP&L Road, Moncure, NC 27599 Facility Address: 500 CP&L Road, Moncure, NC 27599 Permitted Flow: Outfall 007 — 0.73 MGD Daily Maximum Outfall 008 — 0.72 MGD Daily Maximum Outfall 009 — 0.005 MGD Daily Maximum Facility Type/Waste: 100% Industrial (Ash basin clean up, remediation) Facility Class: Grade I Physical Chemical WPCS County: Chatham Region Raleigh Briefly describe the proposed permitting action and facility background.- This is a renewal of the NPDES permit for Progress Duke Energy Progress 400 megawatt (Mwe) steam electric power plant on the Cape Fear River in Moncure, North Carolina. The facility operated two coal fired units with a total net generating capacity of 316 Mwe, two waste heat recovery units with a total net capacity of 28 MWe, and four internal combustion turbines with a total net capacity of 56 MWe. The facility retired in 2011. Page 1 of 12 This facility withdrew water from the Cape Fear River just downstream of the confluence of the Deep and Haw Rivers. Outfalls discharge to a channel (designated as an unnamed tributary to the Cape Fear River) just upstream of Buckhom Dam in Chatham County. The facility operated three internal wastewater outfalls (001, 003, and 005) and one outfall that is the combination of the three (outfall 007). Outfall 008 was the stormwater discharged from an abandoned ash pond south of the plant. Ash disposal to this pond was terminated in the late 1970s. A majority of this area is covered with grass and trees with a small pool of approximately 3 acres of standing water. No industrial activities are performed in this pond. This pond last discharged in 1998. Currently, the following outfalls are operational: Internal Outfall 005 Emergency discharge only. Outfall 007 This outfall discharges collected flows from the effluent channel consisting of storm water, commingled ash basin wastewater that discharges to Outfall 008, and episodic emergency flow from Internal Outfall 005. This outfall has not discharged since late 2018. Outfall 008 This outfall discharges combined flows of treated wastewater from the on -site treatment facility, if necessary, to assure state Water Quality Standards are not contravened in the receiving stream. 1963/1970 Ash Basins (Outfall 008A). This new outfall is designated as an emergency discharge only and will consist of ash basin decanting wastewater. This is limited to discharging excess wastewater above the available treatment plant capacity during an eminent threat of 1963/1970 Ash Basin overflow. 1963/1970 Ash Basins (Outfall 008B). This new outfall is designated as an emergency spillway only and designed to safely pass a design storm event. This Outfall (lat. - 35034'57.37"; long.-79002'57.50") discharges to Cape Fear River. Sampling of this spillway is waived due to unsafe conditions associated with sampling during overflow events. Ash Beneficiation Retention Pond Wastewater (Outfall 009). This new outfall will discharge episodic wastewater collected from isolated areas of the beneficiation operation consisting of ash storage runoff, truck loading spills, and dust suppression. Page 2 of 12 2. Receiving Waterbody Information: Table 3. Receiving Stream Index 7Q10s (cfs) QA (cfs) IWC (7Q10s) Outfall 007 — Unnamed tributary to Cape Fear River 18-(1) 0 0 100% Outfalls 008 — Cape Fear River 18-(1) 65 3,170 1.7% Outfall 009 — Cape Fear River 18-(1) 65 3,170 0.012% Outfall 008A/008B — Cape Fear River Outfall 005— Internal Outfall Stream Classification: WS-IV Regional Office: Raleigh 303(d) Listed?: No USGS Topo Quad: E22SE Moncure, NC I UC No.: 03030002 Permit Writer: Sergei Chernikov, Ph.D. Subbasin: 03-06-07 Date: November 2, 2023 Cape Fear River Stream Statistics — 2016 Drainage (mi2): - Summer — 7Q 10 (cfs): 65 ' Winter — 7Q 10 (cfs): 89, 30Q2 (cfs): 150' QA (cfs): 3,170 1. Based on USGS recommendation and data 3. Instream Monitoring Instream monitoring may be required in certain situations, for example: 1) to verify model predictions when model results for instream DO are within 1 mg/1 of instream standard at full permitted flow; 2) to verify model predictions for outfall diffuser; 3) to provide data for future TMDL; 4) based on other instream concerns. Instream monitoring may be conducted by the Permittee, and there are also Monitoring Coalitions established in several basins that conduct instream sampling for the Permittee (in which case instream monitoring is waived in the permit as long as coalition membership is maintained). If applicable, summarize what instream monitoring will be proposed for this permit action: The current permit requires instream monitoring for total arsenic, total selenium, total mercury, total chromium, dissolved lead, dissolved cadmium, dissolved copper, dissolved zinc, total bromide, total hardness (as CaCO3), temperature, turbidity, and total dissolved solids (TDS) at locations specified in Table 4: Instream sampling location descriptions are shown in Table 4. Table 4. Instream Sampling Locations Description Instream Sample Description Location Upstream Outfall 008 0.9 miles upstream from Outfall 008A in Cape Fear River Downstream Outfall 008 Approximately 250 meters downstream from Outfall 008 in Cape Fear River Is this facility a member of a Monitoring Coalition with waived instream monitoring (YIN): Y Name of Monitoring Coalition: Middle Cape Fear Basin Association Page 3 of 12 Instream monitoring is provisionally waived considering the permittee's participation in the Middle Cape Fear River Basin Association provided the Association agrees to sample for all the parameters listed in this condition and at the specified locations. Instream monitoring shall be conducted as stated in this permit should the permittee end its participation in the Association. Review of the instream monitoring data indicates that all the monitoring parameters are well below water quality standards at upstream and downstream monitoring locations. The permit also requires annual fish tissue monitoring for arsenic, selenium, and mercury. The following fish species were sampled at two upstream locations and one downstream location: Largemouth Bass, Spotted Bass, Bluegill, Hybrid Sunfish, Redbreast Sunfish, Redear Sunfish, and Warmouth. The concentration of arsenic and selenium at all three locations were below EPA screening values. Between 33% and 50% of individual mercury concentrations in some Bass species were above EPA screening values at upstream and downstream locations. The fish tissue data indicates that discharge from this facility has no measurable impact on the instream accumulation of trace elements in fish species. 4. Antidegradation Review (New/Expanding Discharge): The objective of an antidegradation review is to ensure that a new or increased pollutant loading will not degrade water quality. Permitting actions for new or expanding discharges require an antidegradation review in accordance with 15A NCAC 2B.0201. Each applicant for a new/expanding NPDES permit must document an effort to consider non -discharge alternatives per 15A NCAC 2H.0105(c)(2). In all cases, existing instream water uses and the level of water quality necessary to protect the existing use is maintained and protected. If applicable, describe the results of the antidegradation review, including the Engineering Alternatives Analysis (EAA) and any water quality modeling results: NA 5. 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 (YESINO): NO If YES, confirm that antibacksliding provisions are not violated: NA 6.Summary of Proposed Permitting Actions: Outfall 007 This outfall discharges at the end of the effluent channel and to an unnamed tributary with a "zero" 7Q10 summer flow, thus, has an IWC=100%. A reasonable potential analysis was not conducted for this outfall since it has not discharged wastewater since late 2018 and is not expected to discharge in the future. Page 4 of 12 Therefore, effluent requirements largely remained unchanged since the last renewal. For the list of all changes, please see page 11 of this Fact Sheet. Table 5: Outfall 007 — Episodic discharge Parameter Monitoring DMR Monitoring Basis Requirements Frequency Flow 0.72 MGD DM Daily 15A NCAC 213 .0505 6.0 < pH < 9.0 S.U. pH Continuous Monthly 15A NCAC 213.0200 monitoring/auto shutoff TSS 30.0 mg/L MA Monthly EPA requirement, 100 m /L DM 40 CFR 423 Oil & Grease 15.0 mg/L MA Monthly 40 CFR 423 20.0 m /L DM Total Antimony 5.6 µg/L MA Monthly RP to exceed NC WQS and 5.6 /L DM EPA criteria Total Arsenic 10.0 µg/L MA Monthly RP to exceed NC WQS and 340.0 /L DM EPA criteria Total Molybdenum 160 µg/L MA Monthly RP to exceed NC WQS and 160 /L DM EPA criteria Total Lead Monitor & Report, /L Monthly Pollutant of concern Total Nickel 25.0 µg/L MA Monthly RP to exceed NC WQS and 335.2 /L DM EPA criteria Total Selenium 5.0 µg/L MA Monthly RP to exceed NC WQS and 56.0 /L DM EPA criteria Total Zinc 125.7 µg/L MA Monthly RP to exceed NC WQS and 125.7 /L DM EPA criteria Total Mercury 12 n /L, annual average Monthly Dewatering strategy Total Cadmium Monitor & Report, µg/L Monthly No RP, predicted value > 50% of the Allowable Cw Total Copper Monitor & Report, µg/L Monthly No RP, predicted value > 50% of the Allowable Cw Fluoride Monitor & Report, mg/L Monthly No RP, predicted value > 50% of the Allowable Cw Sulfates Monitor & Report, mg/L Monthly No RP, predicted value > 50% of the Allowable Cw Total Dissolved Monitor & Report, mg/L Monthly No RP, predicted value > 50% Solids of the Allowable Cw Total Thallium Monitor & Report, µg/L Monthly No RP, predicted value > 50% of the Allowable Cw Turbidity Net Turbidity <— 50 NTU Monthly Decanting strategy, EPA requirement Effluent Hardness Monitor & Report, mg/L Quarterly Required to assess dissolved metal limitations Chronic Toxicity 90% concentration, P/F Quarterly DEQ Toxicity Policy Nitrate/Nitrite as N Monitor & Report, m /L Quarterly Needed to calculate TN Total Kjeldahl Monitor & Report, mg/L Quarterly Needed to calculate TN Nitrogen Total Nitrogen Monitor & Report, m /L Quarterly 15A NCAC 02B .0500 Total Phosphorus Monitor & Report, m /L Quarterly 15A NCAC 02B .0500 Page 5 of 12 MGD — Million gallons per day, MA — Monthly Average, DM — Daily Max Outfall 008 - Dewatering Dewatering at this outfall was initiated on 11/11/2019. This outfall will discharge to a segment of the Cape Fear River and based on stream flow data has a 7Q10 summer -based IWC = 1.7%. A reasonable potential analysis was conducted using the 0.72 MGD capacity of the treatment system as the estimated flow and using the highest 1985 (East) and 1978 (West) Ash Basins interstitial water concentration data collected in January 2015. 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: Selenium. Arsenic and Mercury will be monitored in accordance with the dewatering strategy. 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: Chromium III, Chromium VI, Total Chromium, Beryllium, Total Phenolic Compounds, Copper, Cyanide, Fluoride, Lead, Nickel, Silver, Zinc, Aluminum, Thallium, and Sulfate. Table 6: Outfall 008 - Ash Basin Dewatering Monitoring DMR Parameter Requirements Monitoring Basis Frequency Flow 0.72 MGD DM Dail y Dewatering strategy, 15A NCAC 2B .0505 6.0 < pH < 9.0 S.U. Dewatering strategy, pH Continuous Weekly 15A NCAC 2B monitoring/auto /auto shutoff .0200 30.0 mg/L MA Dewatering strategy, TSS 100 mg/L DM Weekly EPA requirement, Continuous 40 CFR 423 monitoring/auto shutoff Oil & Grease 15.0 mg/L MA Weekly Dewatering strategy, 20.0 m /L DM 40 CFR 423 Total Arsenic Monitor & Report, /L Monthly Dewatering strategy Total Mercury Monitor & Report, n /L Monthly Dewaterin Strategy Total Selenium Monitor & Report, µg/L Monthly No RP, predicted Cw > 50% of Allowable Cw Turbidity Net Turbidity < 50 NTU Weekly Dewatering strategy Effluent Hardness Monitor & Report, mg/L Quarterly Required to assess dissolved metal limitations Chronic Toxicity 1.7% concentration, P/F Monthly Dewatering strategy, DEQ Toxicity Policy Nitrate/Nitrite as N Monitor & Report, m /L Quarterly Needed to calculate TN Page 6 of 12 Total Keldahl Nitrogen Monitor & Report, mg/L Quarterly Needed to calculate TN Total Nitrogen Monitor & Report, mg/L Quarterly 15A NCAC 02B .0500 Total Phosphorus Monitor & Report, mg/L Quarterly 15A NCAC 02B .0500 MGD — Million gallons per day, MA — Monthly Average, DM — Daily Max Outfall 008 — Dewatering/Ground Water Remediation As requested by the Permittee this new outfall will discharge to a segment of the Cape Fear River, and based on stream flow data and a maximum 0.72 MGD treatment system capacity has a 7Q 10 summer -based IWC = 1.7%. A reasonable potential analysis was conducted during the last renewal using the 1.7% and using two source data points if available, one data point from the highest 1985 (East) and 1978 (West) Ash Basins interstitial water concentration data collected in January 2015 and a second data point from the highest ground water monitoring wells data collected in 2015 and 2016. 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: TDS, Aluminum, Copper, Lead, Nickel, Selenium, Silver, Sulfates, Zinc Arsenic and Mercury will be monitored in accordance with the dewatering s trategIL • 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: Beryllium, Copper, Cadmium. No Limit or Monitoring: The following parameters will not receive a limit or monitoring, since they did not demonstrate reasonable potential to exceed applicable water quality standards/criteria and the maximum predicted concentration was <50% of the allowable concentration: Antimony, Chlorides, Chromium III, Chromium VI, Total Chromium, Fluoride, Barium, Thallium The Permittee shall notify the Raleigh Regional Office and the Division seven (7) calendar days prior to the introduction of remediation ground water with the dewatering wastewater. Table 7: Outfall 008 - Ash Basin Dewatering/Ground Water Remediation DMR Parameter Monitoring Requirements Monitoring Basis Frequency Flow 0.72 MGD DM Daily Dewatering strategy, 15A NCAC 213 .0505 Temperature, °C Monitor & Report Weekly Ground Water Remediation NCG510000 6.0 < pH < 9.0 S.U. Dewatering strategy, pH Continuous monitoring/auto Weekly 15A NCAC 213 shutoff .0200 30.0 mg/L MA Dewatering strategy, TSS 100 mg/L DM Weekly EPA requirement, Continuous monitoring/auto 40 CFR 423 shutoff Oil & Grease 15.0 mg/L MA Weekly Dewatering strategy, 20.0 mg/L DM 40 CFR 423 Total Aluminum 385.1 mg/L MA Monthly RP to exceed NC WQS and 385.1 mg/L DM EPA criteria Page 7 of 12 Total Arsenic Monitor & Report, µg/L Monthly Dewatering strategy, EPA requirement Total Beryllium Monitor & Report, µg/L Monthly No RP, predicted Cw > 50% of Allowable Cw Total Cadmium Monitor & Report, µg/L Monthly No RP, predicted Cw > 50% of Allowable Cw Total Copper Monitor & Report, µg/L Monthly No RP, predicted Cw > 50% of Allowable Cw Total Lead Monitor & Report, µg/L Monthly No RP, predicted Cw > 50% of Allowable Cw Total Mercury Monitor & Report, n L Monthly Dewatering strategy Total Nickel 1.48 mg/L MA Monthly RP to exceed NC WQS and 16.3 mg/L DM EPA criteria Total Selenium 0.30 mg/L MA Monthly RP to exceed NC WQS and 2.73 mg/L DM EPA criteria Total Silver Monitor & Report, µg/L Monthly No RP, predicted Cw > 50% of Allowable Cw Total Zinc Monitor & Report, µg/L Monthly No RP, predicted Cw > 50% of Allowable Cw TDS Monitor & Report, mg/L Weekly No RP, predicted Cw > 50% of Allowable Cw Sulfates Monitor & Report, mg/L Monthly No RP, predicted Cw > 50% of Allowable Cw Turbidity Net Turbidity < 50 NTU Weekly Dewatering strategy, EPA requirement Effluent Hardness Monitor & Report, mg/L Quarterly Required to assess dissolved metal limitations Chronic Toxicity 1.7% concentration, P/F Monthly Dewatering strategy, DEQ Toxicity Policy Conductivity, µmhos/cm Monitor and Report Quarterly Ground Water Remediation, NCG510000 Nitrate/Nitrite as N Monitor & Report, mg/L Quarterly Needed to calculate TN Total Keldahl Nitrogen Monitor & Report, mg/L Quarterly Needed to calculate TN Total Nitrogen Monitor & Report, mg/L Quarterly 15A NCAC 02B .0500 Total Phosphorus Monitor & Report, mg/L Quarterly 15A NCAC 02B .0500 MGD — Million gallons per day, MA — Monthly Average, DM — Daily Max In addition, a special condition will be added to require the Permittee to submit EPA Form 2C to update the ground water remediation characterization 180 days after its initial introduction to the treatment system. The Division may reopen the permit to assign additional limits or conditions. Outfall 008 — Ground Water Remediation As requested by the Permittee this new outfall will discharge to a segment of the Cape Fear River, and based on stream flow data and a maximum 0.72 MGD treatment system capacity has a 7Q 10 summer -based IWC = 1.7%. The reasonable potential analysis was conducted during the last renewal using only the highest ground water monitoring wells data toxicant concentration collected in 2015 and 2016 yielded the same results as the reasonable potential analysis conducted for comingled dewatering and groundwater remediation waste sources. Therefore, the only changes will be the removal of conditions related to dewatering activity, and a reduction in various parameters monitoring frequency and TSS limits to comply with Division ground water remediation permitting strategy. Page 8 of 12 The Permittee shall notify the Raleigh Regional Office and the Division seven (7) calendar days prior to the completion of dewatering activities and the continuation of remediation ground water treatment. Table 8: Outfall 008 - Ground Water Remediation Monitoring DMR Parameter Requirements Monitoring Basis Frequency Flow 0.72 MGD DM Weekly 15A NCAC 2B .0400 et seq., 02B .0500 et seq. Temperature, C Monitor & Report Weekly Ground Water Remediation, NCG510000 H 6.0 < H < 9.0 S.U. Weekly 15A NCAC 2B .0200 TSS 30.0 mg/L MA WeeklyGround Water Remediation, 45.0 m /L DM NCG510000 Oil & Grease 15.0 mg/L MA Weekly 40 CFR 423 20.0 m /L DM Total Aluminum 385.1 mg/L MA 2/Month RP to exceed NC WQS and 385.1 m /L DM EPA criteria Total Arsenic Monitor & Report, µg/L 2/Month No RP, predicted Cw > 50% of Allowable Cw Total Beryllium Monitor & Report, µg/L 2/Month No RP, predicted Cw > 50% of Allowable Cw Total Lead Monitor & Report, µg/L 2/Month No RP, predicted Cw > 50% of Allowable Cw Total Mercury Monitor & Report, µg/L 2/Month No RP, predicted Cw > 50% of Allowable Cw Total Nickel 1.48 mg/L MA 2/Month RP to exceed NC WQS and 16.3 m /L DM EPA criteria Total Selenium Monitor & Report, µg/L 2/Month No RP, predicted Cw > 50% of Allowable Cw Total Silver Monitor & Report, µg/L 2/Month No RP, predicted Cw > 50% of Allowable Cw Total Zinc Monitor & Report, µg/L 2/Month No RP, predicted Cw > 50% of Allowable Cw TDS Monitor & Report, mg/L 2/Month No RP, predicted Cw > 50% of Allowable Cw Sulfates 14,811 mg/L MA 2/Month RP to exceed NC WQS and 14,811m /L DM EPA criteria Turbidity Net Turbidi < 50 NTU 2/Month 15 NCAC 2B .0500 Effluent Hardness Monitor & Report, mg/L Quarterly Required to assess dissolved metal limitations Chronic Toxicity 1.7% concentration, P/F Quarterly Dewatering strategy, DEQ Toxicity Policy Conductivity, µmhos/cm Monitor and Report Quarterly Ground Water Remediation, NCG510000 Nitrate/Nitrite as N Monitor & Report, m /L Quarterly Needed to calculate TN Total Keldahl Nitrogen Monitor & Report, m /L Quarterly Needed to calculate TN Total Nitrogen Monitor & Report, m /L Quarterly 15A NCAC 02B .0500 Total Phosphorus Monitor & Report, m /L Quarterly 15A NCAC 02B .0500 MGD — Million gallons per day, MA — Monthly Average, DM — Daily Max Page 9 of 12 Outfall 008A — 1963/1970 Ash Basins Emergency Outfall This new outfall is designated as an emergency discharge only and will consist of ash basin decanting wastewater. This is limited to discharging excess wastewater above the available treatment plant capacity during an eminent treat of 1963/1970 Ash Basin overflow. Table 9: Outfall 008A - 1963/1970 Ash Basins Emeraencv Parameter Monitoring DMR Monitoring Frequency Basis Re uirements Monitor and report Daily during Episodic Event NCAC 2B et 15AFlow seeq.q. et se, 02B .0500 et seq. H 6.0 < H < 9.0 S.U. Daily during Episodic Event 15A NCAC 2B .0200 TSS 30.0 mg/L MA Daily during Episodic Event Ground Water Remediation, 100.0 m /L DM NCG510000 Oil & Grease 15.0 mg/L MA Daily during Episodic Event 40 CFR 423 20.0 m /L DM Outfall 009 — Beneficiation Miscellaneous Wastewater As requested by the Permittee this new outfall will discharge to a segment of the Cape Fear River, and based on stream flow data and a maximum 0.005 MGD discharge has a 7Q10 summer -based IWC = 0.012%. The expected sources of wastewater from the Beneficiation process area are ash pile run off, truck washing and ash dust spills. Data from an existing similar operation which included 21 toxicants was provided to characterize the proposed Beneficiation waste stream, and used to conducted a reasonable potential analysis during the last renewal. 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: Aluminum, Antimony, Cadmium, Chlorides, Barium, Beryllium, Total Chromium, Copper, Fluoride, Lead, Molybdenum, Nickel, Silver, Thallium, Zinc, Sulfates, TDS Monitoring for Arsenic and Selenium will be required as they are toxicants of concern. Table 10: Outfall 009 — Beneficiation Miscellaneous Wastewater Parameter Monitoring DMR Monitoring Requirements FrequencyBasis Flow 0.005 MGD DM Weekly 15A NCAC 2B .0400 et seq., 02B .0500 et seq. Temperature, °C Monitor & Report Monthly BPJ (untreated waste stream) H 6.0 < H < 9.0 S.U. Monthly 15A NCAC 2B .0200 TSS 30.0 mg/L MA Monthly BPJ (untreated waste 100.0 m /L DM stream) Oil & Grease 15.0 mg/L MA Monthly 40 CFR 423 20.0 m /L DM Total Mercury 47 n /L, annual average Monthly Mercury TMDL Total Arsenic Monitor & Report Monthly Toxicant of concern, BPJ (coal ash source) Total Selenium Monitor & Report Monthly Toxicant of concern, BPJ (coal ash source) Turbidity Net Turbidity < 50 NTU Monthly 15 NCAC 2B .0500 Page 10 of 12 MGD — Million gallons per day, MA — Monthly Average, DM — Daily Max Internal Outfall 005- Ash Basins Emergency Overflow Discharge As requested by the Permittee internal outfall will be permitted for an existing 1985 (East) Ash Basin to address potential emergency overflow only events. An emergency discharge is defined as the ash basin decanting wastewater that is in excess of the facility 0.72 MGD treatment capacity that will overflow. Table 11: Ash Basin Emergency Overflow Outfall 005 Parameter Monitoring Sample Requirements 2 Type Flow Monitor & Report, MGD Estimate Outfall 005 (Internal) Monitor & Report Outfall 007 per A. (3.) 3 Notes 1. The Permittee shall notify the Raleigh Regional Office (919) 791 — 4200 no later than the end of the next business day of the occurrence of an emergency discharge event including time of occurrence, duration, and cause. 2. During the duration of a discharge event, the flow shall be reported daily. 3. Effluent monitoring shall commence immediately at the impacted external outfall (Outfall 007) for the limited parameters except for Mercury and Chronic Toxicity. Monitoring parameters and continue weekly during the emergency discharge event. Any external outfall's monitoring requirements in effect prior to an emergency discharge shall remain in effect. Summary of Proposed Changes 1. The description of wastewater types discharged from Outfall 007 was updated to reflect the current operational status. 2. The Internal Outfall 001 was removed from the permit because this outfall was eliminated. 3. The S-05 Outfall was removed from the permit based upon this former seep being dispositioned in accordance with consent order EMC SOC WQ 19-001 and coverage in the Seep Corrective Action Plan. 4. The Division is unable to eliminate Selenium limits for Outfall 007 since this Outfall has not discharged since late 2018 and the RPA cannot be conducted. 5. The monitoring frequency for Arsenic, Selenium, and Mercury was reduced from weekly to monthly based on the review of the effluent data and frequency of discharge. 6. The Division is unable to eliminate the WET testing requirements for Outfall 007 to be consisted with the requirements of 15A NCAC 2B .0500. 7. The requirements associated with decanting and dewatering have been removed from Outfall 007 because decanting has been completed and dewatering discharge is routed through Outfall 008. Page 11 of 12 8. The Effluent page for Outfall 008 decanting was eliminated from the permit since this activity has been completed and dewatering was initiated on 11/11/2019. 9. The limits for Selenium have been removed from the permit based on the results of the RPA (Outfall 008 dewatering). 10. The monitoring frequency for Arsenic, Selenium, and Mercury was reduced from weekly to monthly based on the results of the RPA (Outfall 008 dewatering). 11. The monitoring requirements for Aluminum, Nickel, Lead, and Cadmium were eliminated from the permit based on the results of the RPA (Outfall 008 dewatering). 12. The limits and monitoring requirements for Copper were eliminated from the permit based on the results of the RPA (Outfall 008 dewatering). 13. The Division is unable to reduce frequency of the WET testing requirements for Outfall 008 until dewatering is complete to be consistent with the Division's dewatering strategy. 14. The Division is unable to eliminate requirements associated with dewatering from Outfall 008 until dewatering is completed. 15. The Division is unable to eliminate Selenium limits for Outfall 008 (dewatering and groundwater remediation) since this phase of the operation has not been initiated and the RPA cannot be conducted. 16. The monitoring frequency for Arsenic, Selenium, Mercury, Aluminum, Nickel, Beryllium, Copper, Lead, Silver, and Zinc was reduced from weekly to monthly based on the results of the RPA (Outfall 008 dewatering and groundwater remediation). 17. The monitoring frequency for instream monitoring was reduced from Monthly and Quarterly based on the review of the instream data. 18. The monitoring frequency for fish tissue instream monitoring was reduced from Annually to once per permit term based on the review of the fish tissue data. 7. Public Notice Schedule: Permit to Public Notice: ?????/2023 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 parry filing such request and the reasons why a hearing is warranted. Page 12 of 12