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HomeMy WebLinkAboutNC0004979_Final Permit_20210728 (2)Permit NC0004979 STATE OF NORTH CAROLINA DEPARTMENT OF ENVIRONMENTAL QUALITY DIVISION OF WATER RESOURCES PERMIT TO DISCHARGE WASTEWATER UNDER THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM In compliance with the provision of North Carolina General Statute 143-215.1, other lawful standards and regulations promulgated and adopted by the North Carolina Environmental Management Commission, and the Federal Water Pollution Control Act, as amended, Duke Energy Carolinas, LLC is hereby authorized to discharge wastewater from a facility located at the Allen Steam Station 253 Plant Allen Road (NCSR 2525) Belmont Gaston County to receiving waters designated as the Catawba River (Lake Wylie), unnamed tributary to the Catawba River, and South Fork Catawba River in the Catawba River Basin in accordance with effluent limitations, monitoring requirements, and other applicable conditions set forth in Parts I, II, and III. This permit modification shall become effective August 1, 2021. This permit and authorization to discharge shall expire at midnight on July 31, 2023. Signed this day July 26, 2021. for DocuSigned by: Polot 8FB19B649DD2478... S. Daniel Smith, Director Division of Water Resources By Authority of the Environmental Management Commission Page 1 of 26 Permit NC0004979 SUPPLEMENT TO PERMIT COVER SHEET All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby revoked. As of this permit issuance, any previously issued permit bearing this number is no longer effective. Therefore, the exclusive authority to operate and discharge from this facility arises under the permit conditions, requirements, terms, and provisions included herein. Duke Energy Carolinas, LLC is hereby authorized to: 1. Continue to discharge: • Outfall 001: once through cooling water. • Outfall 002: Ash Basin discharge. This outfall includes domestic wastewater, stormwater from the coal pile area, miscellaneous stormwater flows, ash sluice, wastewater from turbine non-destructive testing, landfill leachate, FGD blowdown, yard drain sump, water treatment filter backwash, extracted groundwater, laboratory wastes, and the power house sump at Unit 5. The domestic waste is pre-treated by a septic tank. Outfall 002 wastewater is treated using chemical coagulation, settling, and pH neutralization. Outfall 002 and Outfall 006 might be operational at the same time during the transition period. • Outfall 002A: coal yard sump overflow (discharge from coal handling and storage areas). • Outfall 002B: power house sump overflow (floor wash water, boiler blowdown, water treatment waste, condensates, equipment cooling water, sealing water and miscellaneous leakage). • Outfall 003: miscellaneous equipment non -contact cooling and sealing water. • Outfall 004: miscellaneous non -contact cooling water, vehicle washwater, and intake screen backwash. • Outfall 006: Upon completion of construction of the Retention Basin, discharge domestic wastewater, wastewater from ash pond dewatering process, stormwater from the coal pile area, miscellaneous stormwater flows, ash sluice, wastewater from turbine non-destructive testing, CCR landfill leachate, FGD blowdown, yard drain sump, water treatment filter backwash, bottom ash purge from the submerged flight conveyers (purge volume not to exceed 10% of the water systems volume), extracted groundwater, laboratory wastes, and the power house sump at Unit 5. The domestic waste is pre-treated by a septic tank. Outfall 006 wastewater is treated using chemical coagulation, settling, and pH neutralization. Outfall 002 and Outfall 006 might be operational at the same time during the transition period. • Outfall 007: the emergency spillway of the new Retention Basin. The spillway is designed for a flood greater than 100-year event. Sampling of this spillway is waived due to unsafe conditions associated with sampling during an overflow event. • Outfall 008: the emergency spillway of the retired Ash Pond. The spillway is designed for a flood greater than 100-year event. Sampling of this spillway is waived due to unsafe conditions associated with sampling during an overflow event. • Toe Drain Outfalls 103 (lat. - 35°10.512'; long.-8100.360'), 104 (lat. - 35°10.541'; long. - 8100.364'), 108 (lat. - 35°10.710'; long - 81°0.384'), and 108B (lat. - 35°10.689'; long - 81°0.391'): 4 potentially contaminated toe drains. From a facility located at the Plant Allen Steam Station on Plant Allen Road (NCSR 2525), south of Belmont in Gaston County, and 2. Without adding detergents or chemicals of any kind, discharge Asiatic clam/debris filter backwash from the intake filter screen, in accordance with condition A. (10.), and 3. Continue to operate a Flue Gas Desulfurization (FGD) wet scrubber wastewater treatment system discharging to the Ash Basin/Line Retention Basin through Internal Outfall 005; consisting of: • A flow equalization tank and a maintenance tank • Feed systems for lime, sulfide, iron addition, polymer, hydrochloric acid, and nutrient addition • Two clarifiers Page 2 of 26 Permit NC0004979 • Dual heat exchangers • Selenium reduction bioreactors • A sludge treatment system including three filter presses; and 4. Discharge from said treatment works at the location specified on the attached map into the Catawba River classified as WS-IV B (outfalls 002, 002A, 002B, 004, 006, 008, 103, 108, and 108B), the unnamed tributary to Catawba River classified as WS-IV B (Outfall 104), and the South Fork Catawba River classified as WS-V (outfalls 001 and 003), in the Catawba River Basin. Page 3 of 26 Permit NC0004979 Part I A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 001) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is authorized to discharge from outfall 001- Condenser Cooling Water (CCW). Such discharges shall be limited and monitored2 by the Permittee as specified below: EFFLUENT CHARACTERISTICS LIMITS MONITORING REQUIREMENTS Monthly Average Daily Max. Measurement Frequency Sample Type Sample Location Flow, MGD Daily Pump Logs Effluent Temperature (June 1 — September 30)1 38.9 °C (102 °F) DailyGrab or Instantaneous Effluent Temperature (October 1 — May 31)1 35 °C (95 °F) DailyGrab or Instantaneous Effluent Notes: 1. Based upon studies conducted by the permittee and submitted to the Division, it has been determined pursuant to Section 316(a) of the Clean Water Act that the thermal component of the discharge assures the protection and propagation of a balanced, indigenous population of shellfish, fish and wildlife in the receiving water body. 2. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR application system. Please See Special Condition A. (26.). Chlorination of the once through condenser cooling water, discharged through outfall 001, is not allowed under this permit. Should Duke Energy Carolinas, LLC wish to chlorinate its condenser cooling water, a permit modification must be obtained beforehand. Page 4 of 26 Permit NC0004979 A. (2.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 002-normal operation/decanting) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is authorized to discharge from outfall 002 — ash pond effluent (decanting the free water above the settled ash layer that does not involve mechanical disturbance of the ash). Such discharges shall be limited and monitored4 by the Permittee as specified below: EFFLUENT CHARACTERISTICS LIMITS MONITORING REQUIREMENTS Monthly Average Daily Maximum Measurement Frequency Sample Type Sample Location Flow, MGD Weekly Instantaneous or Estimate Influent or Effluent Oil and Grease 15.0 mg/L 20.0 mg/L Monthly Grab Effluent Total Suspended Solids8 30.0 mg/L 50.0 mg/L Monthly Grab Effluent Total Copper 1 1.0 mg/L 1.0 mg/L Monthly Grab Effluent Total Iron 1 1.0 mg/L 1.0 mg/L Monthly Grab Effluent BOD, 5-day, 20° C6 30.0 mg/L 45.0 mg/L Monthly Grab Effluent Fecal Coliform (geo. mean) 6 200/100 mL 400/100 mL Monthly Grab Effluent Total Selenium , µg/L Weekly Grab Effluent Total Arsenic, µg/L Weekly Grab Effluent Total Silver 0.255 µg/L 1.081 µg/L Weekly Grab Effluent Total Nickel, µg/L Monthly Grab Effluent Total Lead, µg/L Monthly Grab Effluent Total Mercury 2, ng/L Weekly Grab Effluent Total Nitrogen (NO2 + NO3 + TKN), mg/L Quarterly Grab Effluent Total Phosphorus, mg/L Quarterly Grab Effluent Chronic Toxicity 3 Quarterly Grab Effluent Total Hardness, mg/L Monthly Grab Effluent Turbiditys, NTU Monthly Grab Effluent Bromide, mg/L Monthly Grab Effluent pH7 Between 6.0 andu�9.0 standard u Monthly Grab Effluent Footnotes: 1. The limits for total copper and total iron only apply when chemical metal cleaning wastewaters are being discharged. 2. Mercury shall be measured using EPA Method 1631E. 3. Whole Effluent Toxicity shall be monitored by chronic toxicity (Ceriodaphnia) P/F at 23.6%, see Special Condition A. (17.). 4. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR application system. Please See Special Condition A. (26.). Page 5 of 26 Permit NC0004979 5. The discharge from this facility shall not cause turbidity in the receiving stream to exceed 50 NTU. If the instream turbidity exceeds 50 NTU due to natural background conditions, the discharge cannot cause turbidity to increase in the receiving stream. Therefore, if the effluent measurement exceeds 50 NTU, the Permittee shall sample upstream and downstream turbidity in the receiving waterbody, within 24 hours, to demonstrate the existing turbidity level in the receiving waterbody was not increased. All data shall be reported on the DMRs. (See 15A NCAC 2B .0211 (21)). NTU - Nephelometric Turbidity Unit. 6. The limit and monitoring apply only when the domestic wastewater is being discharged to the basin. 7. The facility shall continuously monitor pH when the decanting process commences (and the pump is operating) and the decanting pump shall be shutoff automatically when the 15 minutes running average pH falls below 6.1 standard units or rises above 8.9 standard units. Pumping will be allowed to continue if interruption might result in a dam failure or damage. The continuous pH monitoring is only required when the pumps are employed for decanting. 8. The facility shall continuously monitor TSS concentration when the decanting process commences (and the pump is operating) and the decanting pump shall be shutoff automatically when one half of the Daily Maximum limit (15 minutes average) is exceeded. Pumping will be allowed to continue if interruption might result in a dam failure or damage. The continuous TSS monitoring is only required when the pumps are employed for decanting. There shall be no discharge of floating solids or visible foam in other than trace amounts. If any one of the pollutants (As, Se, Hg, Ni, and Pb) reaches 85% of the allowable level during the decanting/dewatering, the facility shall immediately discontinue discharge of the wastewater and report it to the Regional Office and Complex NPDES Permitting Branch via telephone and e-mail. The facility is allowed to drawdown the wastewater in the ash pond to no less than three feet above the ash. The rate for lowering the liquid level in a coal ash pond shall not exceed one (1) foot per day unless a higher rate is supported to the satisfaction of DEMLR and in accordance with NCAC, Title 15A, Subchapter 2K. The facility shall use a floating pump suction pipe with free water skimmed from the basin surface using an adjustable weir. Lowering the level below the three feet mark triggers the limits and conditions in Section A. (3.) of the permit. By November 1, 2018 there shall be no discharge of pollutants in fly ash transport water. This requirement only applies to fly ash transport water generated after November 1, 2018. In accordance with the N.C.G.S. § 130A-309.210, by December 31, 2019, the facility shall convert to the disposal of dry bottom ash, as defined in the Coal Ash Management Act ("CAMA"). The facility shall notify via e-mail DWR Complex NPDES Permitting Unit and DWR Mooresville Regional Office, in writing, seven calendar days prior to the commencement of the decanting. When the facility commences the ash pond/ponds decanting, the facility shall treat the wastewater discharged from the ash pond/ponds using physical -chemical treatment, if necessary, to assure state Water Quality Standards are not contravened in the receiving stream. Duke Energy shall notify DWR NPDES Permitting and DWR Mooresville Regional Office, in writing, within seven calendar days of installing additional physical -chemical treatment at this Outfall. Page 6 of 26 Permit NC0004979 A. (3.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 002-dewatering) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the commencement of dewatering and lasting until expiration, the Permittee is authorized to discharge from outfall 002 — ash pond effluent (dewatering-removing the interstitial water). Such discharees shall be limited and monitored4 by the Permittee as specified below: EFFLUENT CHARACTERISTICS LIMITS MONITORING REQUIREMENTS Monthly Average Daily Maximum Measurement Frequency Sample Type Sample Location Flow, MGD 3.09 Daily Instantaneous or Estimate Influent or Effluent Oil and Grease 15.0 mg/L 20.0 mg/L Weekly Grab Effluent Total Suspended Solids° 30.0 mg/L 50.0 mg/L Weekly Grab Effluent Total Copper 1 1.0 mg/L 1.0 mg/L Weekly Grab Effluent Total Iron 1 1.0 mg/L 1.0 mg/L Weekly Grab Effluent BOD, 5-day, 20° C 7 30.0 mg/L 45.0 mg/L Weekly Grab Effluent Fecal Coliform (geo. mean) 7 200/100 mL 400/100 mL Weekly Grab Effluent Total Selenium, µg/L Weekly Grab Effluent Total Arsenic, µg/L Weekly Grab Effluent Total Silver 3.74 µg/L 15.13 µg/L Weekly Grab Effluent Total Mercury 2, ng/L Weekly Grab Effluent Total Nitrogen (NO2 + NO3 + TKN), mg/L Weekly Grab Effluent Total Phosphorus, mg/L Weekly Grab Effluent Chronic Toxicity 3 Monthly Grab Effluent Total Hardness, mg/L Weekly Grab Effluent Turbidity5, NTU Weekly Grab Effluent Bromide, mg/L Weekly Grab Effluent Total Chromium, µg/L Weekly Grab Effluent Total Lead, µg/L Weekly Grab Effluent Total Nickel, µg/L Weekly Grab Effluent Total Cadmium, µg/L Weekly Grab Effluent Total Zinc, µg/L Weekly Grab Effluent TDS, mg/L Weekly Grab Effluent pHs Between 6.0 and 9.0 standard units Weekly Grab Effluent Footnotes: 1. The limits for total copper and total iron only apply when chemical metal cleaning wastewaters are being discharged. 2. Mercury shall be measured using EPA Method 1631E. 3. Whole Effluent Toxicity shall be monitored by chronic toxicity (Ceriodaphnia) P/F at 4.7%, see Special Condition A. (17.). Page 7 of 26 Permit NC0004979 4. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR application system. Please See Special Condition A. (26.). 5. The discharge from this facility shall not cause turbidity in the receiving stream to exceed 50 NTU. If the instream turbidity exceeds 50 NTU due to natural background conditions, the discharge cannot cause turbidity to increase in the receiving stream. Therefore, if the effluent measurement exceeds 50 NTU, the Permittee shall sample upstream and downstream turbidity in the receiving waterbody, within 24 hours, to demonstrate the existing turbidity level in the receiving waterbody was not increased. All data shall be reported on the DMRs. (See 15A NCAC 2B .0211 (21)). NTU - Nephelometric Turbidity Unit. 6. The facility shall continuously monitor TSS concentration when the dewatering process commences (and the pump is operating) and the dewatering pump shall be shutoff automatically when one half of the Daily Maximum limit (15 minutes average) is exceeded. Pumping will be allowed to continue if interruption might result in a dam failure or damage. The continuous TSS monitoring is only required when the pumps are employed for dewatering. 7. The limit and monitoring apply only when the domestic wastewater is being discharged to the basin. 8. The facility shall continuously monitor pH when the dewatering process commences (and the pump is operating) and the dewatering pump shall be shutoff automatically when the 15 minutes running average pH falls below 6.1 standard units or rises above 8.9 standard units. Pumping will be allowed to continue if interruption might result in a dam failure or damage. The continuous pH monitoring is only required when the pumps are employed for dewatering. 9. The limit applies only when pumping is used for dewatering. There shall be no discharge of floating solids or visible foam in other than trace amounts. If any one of the pollutants (As, Se, Hg, Ni, and Pb) reaches 85% of the allowable level during the decanting/dewatering, the facility shall immediately discontinue discharge of the wastewater and report it to the Regional Office and Complex NPDES Permitting Branch via telephone and e-mail. The rate for lowering the liquid level in a coal ash pond shall not exceed one (1) foot per day unless a higher rate is supported to the satisfaction of DEMLR and in accordance with NCAC, Title 15A, Subchapter 2K. The facility shall use a floating pump suction pipe with free water skimmed from the basin surface using an adjustable weir. By November 1, 2018 there shall be no discharge of pollutants in fly ash transport water. This requirement only applies to fly ash transport water generated after November 1, 2018. In accordance with the N.C.G.S. § 130A-309.210, by December 31, 2019, the facility shall convert to the disposal of dry bottom ash, as defined in the Coal Ash Management Act ("CAMA"). The facility shall notify DWR Complex NPDES Permitting Unit and DWR Mooresville Regional Office seven calendar days, in writing, prior to the commencement of the dewatering. When the facility commences the ash pond/ponds dewatering, the facility shall treat the wastewater discharged from the ash pond/ponds using physical -chemical treatment, if necessary, to assure state Water Quality Standards are not contravened in the receiving stream. Duke Energy shall notify DWR NPDES Permitting and DWR Mooresville Regional Office, in writing, within seven calendar days of installing additional physical -chemical treatment at this Outfall. Page 8 of 26 Permit NC0004979 A. (4.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 002A) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is authorized to discharge from outfall 002A — Coal Yard Sump Overflows. Such discharges shall be limited and monitored2 by the Permittee as specified below: EFFLUENT CHARACTERISTICS LIMITS MONITORING REQUIREMENTS Monthly Average Daily Maximum Measurement Frequency Sample Type Sample Location1 Flow, MGD Per discharge event Estimate Effluent pH Between 6.0 and 9.0 standard units Per discharge event Grab Effluent Oil and Grease 15.0 mg/L 20.0 mg/L Per discharge event Grab Effluent Total Suspended Solids 30.0 mg/L 50.0 mg/L Per discharge event Grab Effluent BOD, 5-day, 20° C4 30.0 mg/L 45.0 mg/L Per discharge event Grab Effluent Fecal Coliform (geo. mean)4 200/100 mL 400/100 mL Per discharge event Grab Effluent Total Copper3 1.0 mg/L 1.0 mg/L Per discharge event Grab Effluent Total Iron3 1.0 mg/L 1.0 mg/L Per discharge event Grab Effluent Footnotes: 1. Effluent sampling shall be conducted at a point upstream of discharge to the receiving stream. 2. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR application system. Please See Special Condition A. (26.). 3. The limits for total copper and total iron only apply when chemical metal cleaning wastewaters are being discharged. 4. The limit and monitoring apply only when the domestic wastewater is being discharged to the basin. There shall be no discharge of floating solids or visible foam in other than trace amounts. All flows shall be reported on monthly DMRs. If no flow occurs during a given month, the words "no flow" should be clearly written on the front of the DMR. All samples shall be of a representative discharge. Page 9 of 26 Permit NC0004979 A. (5.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 002B) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is authorized to discharge from outfall 002B — Power House Sump Overflows. Such discharges shall be limited and monitored3 by the Permittee as specified below: EFFLUENT CHARACTERISTICS LIMITS MONITORING REQUIREMENTS Monthly Average Daily Maximum Measurement Frequency Sample Type Sample Locations Flow, MGD Per discharge event Estimate Effluent pH Between 6.0 and 9.0 standard units Per discharge event Grab Effluent Oil and Grease 15.0 mg/L 20.0 mg/L Per discharge event Grab Effluent Total Suspended Solids 30.0 mg/L 100.0 mg/L Per discharge event Grab Effluent Total Copper2 1.0 mg/L 1.0 mg/L Per discharge event Grab Effluent Total Iron 1.0 mg/L 1.0mg/L Per discharge event Grab Effluent Footnotes: 1. Effluent sampling shall be conducted at a point upstream of discharge to the receiving stream. 2. The limits for total copper and total iron only apply when chemical metal cleaning wastewaters are being discharged. 3. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR application system. Please See Special Condition A. (26.). There shall be no discharge of floating solids or visible foam in other than trace amounts. All flows shall be reported on monthly DMRs. If no flow occurs during a given month, the words "no flow" should be clearly written on the front of the DMR. All samples shall be of a representative discharge. Page 10 of 26 Permit NC0004979 A. (6.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 003) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is authorized to discharge from outfall 003 — miscellaneous equipment non -contact water and sealing water. Such discharges shall be limited and monitored1 by the Permittee as specified below: EFFLUENT CHARACTERISTICS LIMITS MONITORING REQUIREMENTS Monthly Average Daily Maximum Measurement Frequency Sample Type Sample Location Flow, MGD Weekly Estimate Effluent Footnotes: 1. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR application system. Please See Special Condition A. (26.). Chlorination of the once through cooling water, discharged through outfall 003, is not allowed under this permit. If Duke Energy Carolinas, LLC wishes to chlorinate this once through cooling water, a permit modification must be obtained beforehand. A. (7.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 004) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is authorized to discharge from outfall 004- miscellaneous non -contact cooling water, vehicle washwater, and intake screen backwash. Such discharges shall be limited and monitored) by the Permittee as specified below: EFFLUENT CHARACTERISTICS LIMITS MONITORING REQUIREMENTS Monthly Average Daily Maximum Measurement Frequency Sample Type Sample Location Flow, MGD Weekly Estimate Effluent Oil and Grease 15.0 mg/L 20.0 mg/L Quarterly Grab Effluent Footnotes: 1. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR application system. Please See Special Condition A. (26.). Chlorination of the once through cooling water, discharged through outfall 004, is not allowed under this permit. If Duke Energy Carolinas, LLC wishes to chlorinate this once through cooling water, a permit modification must be obtained beforehand. Page 11 of 26 Permit NC0004979 A. (8.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Internal Outfall 005) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the effective date of this permit and lasting until permit expiration, the Permittee is authorized to discharge from internal outfall 005- treated FGD wet scrubber wastewater to ash settling basin/Line Retention Basin. Such discharges shall be limited and monitored2 by the Permittee as specified below: EFFLUENT CHARACTERISTICS LIMITS MONITORING REQUIREMENTS ' Monthly Average Daily Maximum Measurement Frequency Sample Type Sample Location Flow, MGD Monitor & Report Monthly Pump logs or similar readings Effluent Total Arsenic 8.0 µg/L 18.0 µg/L Quarterly Grab Effluent Total Mercury3 34.0 ng/L 103.0 ng/L Quarterly Grab Effluent Total Selenium 29.0 µg/L 70.0 µg/L Quarterly Grab Effluent Nitrate/nitrite as N 3.0 mg/L 4.0 mg/L Quarterly Grab Effluent Oil and Grease Quarterly Grab Effluent Total Suspended Solids 30.0 mg/L 100.0 mg/L Monthly Grab Effluent pH Monthly Grab Effluent Footnotes: 1. "Effluent" shall be defined as the discharge from the FGD wastewater treatment system prior to commingling with other waste streams. 2. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR application system. Please See Special Condition A. (26.). 3. The facility shall use method 1631E. All flows shall be reported on monthly DMRs. If no flow occurs during a given month, the words "no flow" shall be clearly written on the front of the DMR. All samples shall be of a representative discharge. The permittee will operate the FGD wastewater system until all coal-fired generation units at the site are retired. Performance of the FGD wastewater treatment system shall be optimized to maximize pollutant reduction and minimize variability. This permit may be reopened and modified if changes are made to 40 C.F.R. 423. Page 12 of 26 Permit NC0004979 A. (9.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 006) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning upon commencement of operations and lasting until expiration, the Permittee is authorized to discharge from outfall 006 — Retention Basin discharge. Such discharges shall be limited and monitored) by the Permittee as specified below: EFFLUENT CHARACTERISTICS DISCHARGE LIMITATIONS MONITORING REQUIREMENTS Monthly Average Daily Maximum Measurement Frequency Sample Type Sample Location Flow, MGD Weekly Instantaneous or Estimate Effluent pH Between 6.0 and 9.0 standard units Monthly Grab Effluent TSS 30.0 mg/L 100.0 mg/L Monthly Grab Effluent Oil and Grease 15.0 mg/L 20.0 mg/L Monthly Grab Effluent BOD, 5-day, 20° C5 30.0 mg/L 45.0 mg/L Monthly Grab Effluent Fecal Coliform (geo. mean)5 200/100 mL 400/100 mL Monthly Grab Effluent Fluoride, mg/L Monthly Grab Effluent Total Mercury2, ng/L Monthly Grab Effluent Total Silver 1.17 µg/L 4.79 µg/L Monthly Grab Effluent Total Iron3 1.0 mg/L 1.0 mg/L Monthly Grab Effluent Total Zinc, µg/L Monthly Grab Effluent Total Arsenic 2,776 µg/L 5,201 µg/L Monthly Grab Effluent Total Cadmium, µg/L Monthly Grab Effluent Total Chromium, µg/L Monthly Grab Effluent Total Copper3 1.0 mg/L 1.0 mg/L Monthly Grab Effluent Total Lead, µg/L Monthly Grab Effluent Total Nickel, µg/L Monthly Grab Effluent Total Selenium, µg/L Monthly Grab Effluent Total Nitrogen (NO2 + NO3 + TKN), mg/L Quarterly Grab Effluent Total Phosphorus, mg/L Quarterly Grab Effluent Sulfates, mg/L Monthly Grab Effluent Chlorides, mg/L Monthly Grab Effluent Bromide, mg/L Monthly Grab Effluent TDS, mg/L Monthly Grab Effluent Total Hardness, mg/L Monthly Grab Effluent Temperature, °C Monthly Grab Effluent Conductivity, µmho/cm Monthly Grab Effluent Chronic Toxicity4 Monthly Grab Effluent Footnotes: 1. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR application system. Please See Special Condition A. (26.). 2. The facility shall use EPA method 1631E. 9. The limits for total copper and total iron only apply when chemical metal cleaning wastewaters are being discharged. The facility shall achieve these limits for Copper and Iron prior to the discharge to the Lined Retention Basin. 3. Whole Effluent Toxicity shall be monitored by chronic toxicity (Ceriodaphnia) P/F at 5.4%, see Special Condition A. (17.). 4. The limit and monitoring apply only when the domestic wastewater is being discharged to the basin. Page 13 of 26 Permit NC0004979 Except for those discharges authorized below, or when the bottom ash transport water is used in the FGD scrubber, there shall be no discharge of pollutants in bottom ash transport water. Bottom ash transport water shall be discharged to the FGD scrubber during normal operations. If the FGD Scrubber is unavailable to receive bottom ash transport water, the discharge of pollutants in bottom ash transport water (bottom ash purge water) from a properly installed, operated, and maintained bottom ash system to the Lined Retention Basin is authorized under the following conditions: A. To maintain system water balance when precipitation -related inflows are generated from a 10-year storm event of 24-hour or longer duration (e.g., 30-day storm event) and cannot be managed by installed spares, redundancies, maintenance tanks, and other secondary bottom ash system equipment; or B. To maintain system water balance when regular inflows from waste streams other than bottom ash transport water exceed the ability of the bottom ash system to accept recycled water and segregating these other waste streams is feasible; or C. To maintain system water chemistry where current operations at the facility are unable to currently manage pH, corrosive substances, substances or conditions causing scaling, or fine particulates to below levels which impact system operation or maintenance; or D. To conduct maintenance not otherwise described above and not exempted from the definition of transport water in 40 C.F.R. § 423.11(p), and when water volumes cannot be managed by installed spares, redundancies, maintenance tanks, and other secondary bottom ash system equipment. In no event shall the total volume of the discharge to the Lined Retention Basin exceed a 30-day rolling average of ten percent of the primary active wetted bottom ash system volume. The volume of daily discharges used to calculate the 30-day rolling average shall be calculated using measurements from flow monitors or pump logs. Based on a calculated bottom ash transport system volume of 640,800 gallons, the 30 day rolling average discharge shall not exceed 0.064 MGD. There shall be no discharge of floating solids or visible foam in other than trace amounts. A. (10.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 007) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is authorized to discharge from outfall 007 — Emergency spillway of the new Retention Basin. Such discharges shall be limited and monitored) by the Permittee as specified below: EFFLUENT CHARACTERISTICS DISCHARGE LIMITATIONS MONITORING REQUIREMENTS Monthly Average Daily Maximum Measurement Frequency Sample Type Sample Location Flow, MGD Waived Estimate Effluent pH Waived Grab Effluent TSS Waived Grab Effluent Oil and Grease Waived Grab Effluent The emergency spillway is designed for a flood greater than 100-year event in Gaston County. Sampling of this spillway is waived due to unsafe conditions associated with sampling during an overflow event. Monitoring is required for any other rain event that might trigger a discharge. Page 14 of 26 Permit NC0004979 A. (11.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 008) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is authorized to discharge from outfall 008 — Emergency spillway of the retired ash basin. Such discharges shall be limited and monitored) by the Permittee as specified below: EFFLUENT CHARACTERISTICS DISCHARGE LIMITATIONS MONITORING REQUIREMENTS Monthly Average Daily Maximum Measurement Frequency Sample Type Sample Location Flow, MGD Waived Estimate Effluent pH Waived Grab Effluent TSS Waived Grab Effluent Oil and Grease Waived Grab Effluent The emergency spillway is designed for a flood greater than 100-year event in Gaston County. Sampling of this spillway is waived due to unsafe conditions associated with sampling during an overflow event. Monitoring is required for any other rain event that might trigger a discharge. Page 15 of 26 Permit NC0004979 A. (12.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 103) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is authorized to discharge from outfall 103 — Toe Drain Discharge. Such discharges shall be limited and monitored1 by the Permittee as specified below: EFFLUENT CHARACTERISTICS DISCHARGE LIMITATIONS MONITORING REQUIREMENTS Monthly Average Daily Maximum Measurement Frequency2 Sample Type Sample Location Flow, MGD Monthly/Quarterly Estimate Effluent pH3 Monthly/Quarterly Grab Effluent TSS 30.0 mg/L 100.0 mg/L Monthly/Quarterly Grab Effluent Oil and Grease 15.0 mg/L 20.0 mg/L Monthly/Quarterly Grab Effluent Fluoride, mg/L Monthly/Quarterly Grab Effluent Total Mercury4, ng/L Monthly/Quarterly Grab Effluent Total Barium, mg/L Monthly/Quarterly Grab Effluent Total Iron, mg/L Monthly/Quarterly Grab Effluent Total Manganese, µg/L Monthly/Quarterly Grab Effluent Total Zinc, µg/L Monthly/Quarterly Grab Effluent Total Arsenic, µg/L Monthly/Quarterly Grab Effluent Total Cadmium, µg/L Monthly/Quarterly Grab Effluent Total Chromium, µg/L Monthly/Quarterly Grab Effluent Total Copper, µg/L Monthly/Quarterly Grab Effluent Total Lead, µg/L Monthly/Quarterly Grab Effluent Total Nickel, µg/L Monthly/Quarterly Grab Effluent Total Selenium, µg/L Monthly/Quarterly Grab Effluent Nitrate as N, mg/L Monthly/Quarterly Grab Effluent Sulfates, mg/L Monthly/Quarterly Grab Effluent Chlorides, mg/L Monthly/Quarterly Grab Effluent TDS, mg/L Monthly/Quarterly Grab Effluent Total Hardness, mg/L Monthly/Quarterly Grab Effluent Temperature, 0C Monthly/Quarterly Grab Effluent Conductivity, µmho/cm Monthly/Quarterly Grab Effluent Footnotes: 1. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR application system. Please See Special Condition A. (26.). 2. The facility shall conduct monthly sampling from the effective date of the permit. After one year from the effective date of the permit the monitoring will be reduced to quarterly 3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units. 4. The facility shall use EPA method 1631E. If no discharge occurs during the reporting period or the Permittee is unable to obtain a representative sample due to low -flow conditions at the toe drain, the Permittee shall submit its DMR, as required, and indicate "No Flow" for the toe drain (15A NCAC 02B .0506(a)(1)(E)). There shall be no discharge of floating solids or visible foam in other than trace amounts. Page 16 of 26 Permit NC0004979 A. (13.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 104) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is authorized to discharge from outfall 104 — Toe Drain Discharge. Such discharges shall be limited and monitored1 by the Permittee as specified below: EFFLUENT CHARACTERISTICS DISCHARGE LIMITATIONS MONITORING REQUIREMENTS Monthly Average Daily Maximum Measurement Frequency2 Sample Type Sample Location Flow, MGD Monthly/Quarterly Estimate Effluent pH3 Monthly/Quarterly Grab Effluent TSS 30.0 mg/L 100.0 mg/L Monthly/Quarterly Grab Effluent Oil and Grease 15.0 mg/L 20.0 mg/L Monthly/Quarterly Grab Effluent Fluoride, mg/L Monthly/Quarterly Grab Effluent Total Mercury4, ng/L Monthly/Quarterly Grab Effluent Total Barium, mg/L Monthly/Quarterly Grab Effluent Total Iron, mg/L Monthly/Quarterly Grab Effluent Total Manganese, µg/L Monthly/Quarterly Grab Effluent Total Zinc, µg/L Monthly/Quarterly Grab Effluent Total Arsenic, µg/L Monthly/Quarterly Grab Effluent Total Cadmium, µg/L Monthly/Quarterly Grab Effluent Total Chromium, µg/L Monthly/Quarterly Grab Effluent Total Copper, µg/L Monthly/Quarterly Grab Effluent Total Lead, µg/L Monthly/Quarterly Grab Effluent Total Nickel, µg/L Monthly/Quarterly Grab Effluent Total Selenium, µg/L Monthly/Quarterly Grab Effluent Nitrate as N, mg/L Monthly/Quarterly Grab Effluent Sulfates, mg/L Monthly/Quarterly Grab Effluent Chlorides, mg/L Monthly/Quarterly Grab Effluent TDS, mg/L Monthly/Quarterly Grab Effluent Total Hardness, mg/L Monthly/Quarterly Grab Effluent Temperature, 0C Monthly/Quarterly Grab Effluent Conductivity, µmho/cm Monthly/Quarterly Grab Effluent Footnotes: 1. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR application system. Please See Special Condition A. (26.). 2. The facility shall conduct monthly sampling from the effective date of the permit. After one year from the effective date of the permit the monitoring will be reduced to quarterly 3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units. 4. The facility shall use EPA method 1631E. If no discharge occurs during the reporting period or the Permittee is unable to obtain a representative sample due to low -flow conditions at the toe drain, the Permittee shall submit its DMR, as required, and indicate "No Flow" for the toe drain (15A NCAC 02B .0506(a)(1)(E)). There shall be no discharge of floating solids or visible foam in other than trace amounts. Page 17 of 26 Permit NC0004979 A. (14.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 108) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is authorized to discharge from outfall 108 — Toe Drain Discharge. Such discharges shall be limited and monitored1 by the Permittee as specified below: EFFLUENT CHARACTERISTICS DISCHARGE LIMITATIONS MONITORING REQUIREMENTS Monthly Average Daily Maximum Measurement Frequency2 Sample Type Sample Location Flow, MGD Monthly/Quarterly Estimate Effluent pH3 Monthly/Quarterly Grab Effluent TSS 30.0 mg/L 100.0 mg/L Monthly/Quarterly Grab Effluent Oil and Grease 15.0 mg/L 20.0 mg/L Monthly/Quarterly Grab Effluent Fluoride, mg/L Monthly/Quarterly Grab Effluent Total Mercury4, ng/L Monthly/Quarterly Grab Effluent Total Barium, mg/L Monthly/Quarterly Grab Effluent Total Iron, mg/L Monthly/Quarterly Grab Effluent Total Manganese, µg/L Monthly/Quarterly Grab Effluent Total Zinc, µg/L Monthly/Quarterly Grab Effluent Total Arsenic, µg/L Monthly/Quarterly Grab Effluent Total Cadmium, µg/L Monthly/Quarterly Grab Effluent Total Chromium, µg/L Monthly/Quarterly Grab Effluent Total Copper, µg/L Monthly/Quarterly Grab Effluent Total Lead, µg/L Monthly/Quarterly Grab Effluent Total Nickel, µg/L Monthly/Quarterly Grab Effluent Total Selenium, µg/L Monthly/Quarterly Grab Effluent Nitrate as N, mg/L Monthly/Quarterly Grab Effluent Sulfates, mg/L Monthly/Quarterly Grab Effluent Chlorides, mg/L Monthly/Quarterly Grab Effluent TDS, mg/L Monthly/Quarterly Grab Effluent Total Hardness, mg/L Monthly/Quarterly Grab Effluent Temperature, 0C Monthly/Quarterly Grab Effluent Conductivity, µmho/cm Monthly/Quarterly Grab Effluent Footnotes: 1. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR application system. Please See Special Condition A. (26.). 2. The facility shall conduct monthly sampling from the effective date of the permit. After one year from the effective date of the permit the monitoring will be reduced to quarterly 3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units. 4. The facility shall use EPA method 1631E. If no discharge occurs during the reporting period or the Permittee is unable to obtain a representative sample due to low -flow conditions at the toe drain, the Permittee shall submit its DMR, as required, and indicate "No Flow" for the toe drain (15A NCAC 02B .0506(a)(1)(E)). There shall be no discharge of floating solids or visible foam in other than trace amounts. Page 18 of 26 Permit NC0004979 A. (15.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS (Outfall 108B) [15A NCAC 02B .0400 et seq., 02B .0500 et seq.] During the period beginning on the effective date of this permit and lasting until expiration, the Permittee is authorized to discharge from outfall 108B — Toe Drain Discharge. Such discharges shall be limited and monitored' by the Permittee as specified below: EFFLUENT CHARACTERISTICS DISCHARGE LIMITATIONS MONITORING REQUIREMENTS Monthly Average Daily Maximum Measurement Frequency2 Sample Type Sample Location Flow, MGD Monthly/Quarterly Estimate Effluent pH3 Monthly/Quarterly Grab Effluent TSS 30.0 mg/L 100.0 mg/L Monthly/Quarterly Grab Effluent Oil and Grease 15.0 mg/L 20.0 mg/L Monthly/Quarterly Grab Effluent Fluoride, mg/L Monthly/Quarterly Grab Effluent Total Mercury4, ng/L Monthly/Quarterly Grab Effluent Total Barium, mg/L Monthly/Quarterly Grab Effluent Total Iron, mg/L Monthly/Quarterly Grab Effluent Total Manganese, µg/L Monthly/Quarterly Grab Effluent Total Zinc, µg/L Monthly/Quarterly Grab Effluent Total Arsenic, µg/L Monthly/Quarterly Grab Effluent Total Cadmium, µg/L Monthly/Quarterly Grab Effluent Total Chromium, µg/L Monthly/Quarterly Grab Effluent Total Copper, µg/L Monthly/Quarterly Grab Effluent Total Lead, µg/L Monthly/Quarterly Grab Effluent Total Nickel, µg/L Monthly/Quarterly Grab Effluent Total Selenium, µg/L Monthly/Quarterly Grab Effluent Nitrate as N, mg/L Monthly/Quarterly Grab Effluent Sulfates, mg/L Monthly/Quarterly Grab Effluent Chlorides, mg/L Monthly/Quarterly Grab Effluent TDS, mg/L Monthly/Quarterly Grab Effluent Total Hardness, mg/L Monthly/Quarterly Grab Effluent Temperature, 0C Monthly/Quarterly Grab Effluent Conductivity, µmho/cm Monthly/Quarterly Grab Effluent Footnotes: 1. The permittee shall submit Discharge Monitoring Reports electronically using NC DWR's eDMR application system. Please See Special Condition A. (26.). 2. The facility shall conduct monthly sampling from the effective date of the permit. After one year from the effective date of the permit the monitoring will be reduced to quarterly 3. The pH shall not be less than 6.0 standard units nor greater than 9.0 standard units. 4. The facility shall use EPA method 1631E. If no discharge occurs during the reporting period or the Permittee is unable to obtain a representative sample due to low -flow conditions at the toe drain, the Permittee shall submit its DMR, as required, and indicate "No Flow" for the toe drain (15A NCAC 02B .0506(a)(1)(E)). There shall be no discharge of floating solids or visible foam in other than trace amounts. Page 19 of 26 Permit NC0004979 A. (16.) SPECIAL CONDITION FOR THE DISCHARGE OF ASIATIC CLAM/DEBRIS FILTER BACKWASH [NCGS 143-215.3 (a) (2) and NCGS 143-215.66] The permittee may backwash the intake filter for Unit 5 condenser cooling water on an as -needed basis. It is understood that this wash water will contain materials indigenous to the Catawba River such as Asiatic clams and light debris. As these are naturally occurring in the river environment, they may be discharged with no adverse affects to the receiving stream. The Permittee may not add any detergent, chemicals or other non -indigenous material to the wash water without explicit permission from the Division of Water Resources. A. (17.) CHRONIC TOXICITY PASS/FAIL PERMIT LIMIT (QUARTERLY/MONTHLY) (Outfall 002 and Outfall 006) [15A NCAC 02B .0200 et seq.] The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant mortality to Ceriodaphnia dubia at an effluent concentration of 23.6% for decanting/normal operations (Outfall 002), 5.4% for retention basin discharge (Outfall 006), and 4.7% for dewatering (Outfall 002). The permit holder shall perform at a minimum, quarterly (for normal operation/decanting at Outfall 002 and Outfall 006), and monthly (for dewatering at Outfall 002) monitoring using test procedures outlined in the "North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised December 2010, or subsequent versions or "North Carolina Phase II Chronic Whole Effluent Toxicity Test Procedure" (Revised- December 2010) or subsequent versions. Effluent sampling for this testing must be obtained during representative effluent discharge and shall be performed at the NPDES permitted final effluent discharge below all treatment processes. If the test procedure performed as the first test of any single month results in a failure or ChV below the permit limit, then multiple -concentration testing shall be performed at a minimum, in each of the two following months as described in "North Carolina Phase II Chronic Whole Effluent Toxicity Test Procedure" (Revised -December 2010) or subsequent versions. All toxicity testing results required as part of this permit condition will be entered on the Effluent Discharge Monitoring Form (MR-1) for the months in which tests were performed, using the parameter code TGP3B for the pass/fail results and THP3B for the Chronic Value. Additionally, DWR Form AT-3 (original) is to be sent to the following address: Attention: North Carolina Division of Water Resources Water Sciences Section/Aquatic Toxicology Branch 1621 Mail Service Center Raleigh, North Carolina 27699-1621 Or, results can be sent to the email, ATForms.ATB@ncdenr.gov. Completed Aquatic Toxicity Test Forms shall be filed with the Water Sciences Section no later than 30 days after the end of the reporting period for which the report is made. Test data shall be complete, accurate, include all supporting chemical/physical measurements and all concentration/response data, and be certified by laboratory supervisor and ORC or approved designate signature. Total residual chlorine of the effluent toxicity sample must be measured and reported if chlorine is employed for disinfection of the waste stream. Should there be no discharge of flow from the facility during a month in which toxicity monitoring is required, the permittee will complete the information located at the top of the aquatic toxicity (AT) test form indicating the facility name, permit number, pipe number, county, and the month/year of the report with the notation of "No Page 20 of 26 Permit NC0004979 Flow" in the comment area of the form. The report shall be submitted to the Water Sciences Section at the address cited above. Should the permittee fail to monitor during a month in which toxicity monitoring is required, monitoring will be required during the following month. Assessment of toxicity compliance is based on the toxicity testing quarter, which is the three month time interval that begins on the first day of the month in which toxicity testing is required by this permit and continues until the final day of the third month. Should any test data from this monitoring requirement or tests performed by the North Carolina Division of Water Resources indicate potential impacts to the receiving stream, this permit may be re -opened and modified to include alternate monitoring requirements or limits. NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum control organism survival, minimum control organism reproduction, and appropriate environmental controls, shall constitute an invalid test and will require immediate follow-up testing to be completed no later than the last day of the month following the month of the initial monitoring. A. (18.) BIOCIDE CONDITION [NCGS 143-215.1] The permittee shall not use any biocides except those approved in conjunction with the permit application. The permittee shall notify the Director in writing not later than ninety (90) days prior to instituting use of any additional biocide used in cooling systems which may be toxic to aquatic life other than those previously reported to the Division of Water Resources. Such notification shall include completion of Biocide Worksheet Form 101 and a map locating the discharge point and receiving stream. Completion of Biocide Worksheet Form 101 is not necessary for those outfalls containing toxicity testing. Division approval is not necessary for the introduction of new biocides into outfalls currently tested for whole effluent toxicity. A. (19.) ADDITIONAL CONDITIONS AND DEFINITIONS [NCGS 143-215.3 (a) (2) and NCGS 143-215.66] 1. The facility shall provide an Annual Report (in pdf format) on the Closure Activities to demonstrate the progress towards closing the power generating units by the end of 2028. 2. EPA methods 200.7 or 200.8 (or the most current versions) shall be used for analyses of all metals except for total mercury (EPA Method 1631E). 3. All effluent samples for all external outfalls shall be taken at the most accessible location after the final treatment but prior to discharge to waters of the U.S. (40 CFR 122.41(j)). 4. The term low volume waste sources means wastewater from all sources except those for which specific limitations are otherwise established in this part (40 CFR 423.11 (b)). 5. The term chemical metal cleaning waste means any wastewater resulting from cleaning any metal process equipment with chemical compounds, including, but not limited to, boiler tube cleaning (40 CFR 423.11 (c)). 6. The term metal cleaning waste means any wastewater resulting from cleaning [with or without chemical cleaning compounds] any metal process equipment including, but not limited to, boiler tube cleaning, boiler fireside cleaning, and air preheater cleaning (40 CFR 423.11 (d)). 7. For all outfalls where the flow measurement is to be "estimated" the estimate can be done by using calibrated V-notch weir, stop -watch and graduated cylinder, or other method approved by the Division. 8. The term "FGD wet scrubber wastewater" means wastewater resulting from the use of the flue -gas desulfurization wet scrubber. 9. There shall be no discharge of polychlorinated biphenyl compounds. 10. The permittee shall report the presence of cenospheres observed in any samples on the DMRs. 11. The applicant is permitted to discharge chemical metal cleaning wastes to the ash basin. Page 21 of 26 Permit NC0004979 12. Nothing contained in this permit shall be construed as a waiver by the permittee of any right to a hearing it may have pursuant to State or Federal laws and regulations. A. (20.) STRUCTURAL INTEGRITY INSPECTIONS OF ASH DAMS [15A NCAC 02K.0208] The facility shall meet the dam design and dam safety requirements per 15A NCAC 2K. A. (21.) CLEAN WATER ACT SECTION 316 (a) THERMAL VARIANCE [40 CFR 125, Subpart H] The thermal variance granted under Section 316(a) terminates on expiration of this NPDES permit. Should the permittee wish a continuation of its 316(a) thermal variance beyond the term of this permit, reapplication for such continuation shall be submitted in accordance with 40 CFR Part 125, Subpart H and Section 122.21(m)(6) not later than 3.5 years from the effective date of the permit. Reapplication shall include a basis for continuation such as a) plant operating conditions and load factors are unchanged and are expected to remain so for the term of the reissued permit; b) there are no changes to plant discharges or other discharges in the plant site area which could interact with the thermal discharges; and c) there are no changes to the biotic community of the receiving water body which would impact the previous variance determination. The next 316(a) studies shall be performed in accordance with the Division of Water Resources approved plan. The temperature analysis and the balanced and indigenous study plan shall conform to the specifications outlined in 40 CFR 125 Subpart H, the EPA's Draft 316(a) Guidance Manual, dated 1977, and the Region 4 letter to NCDENR, dated June 3, 2010. EPA shall be provided an opportunity to review the plan prior to the commencement of the study. The facility shall select a new cold water reference area approved by the Division of Water Resources during the next 316(a) study. Copies of all the study plans, study results, and any other applicable materials should be submitted to: 1) Electronic Version Only (pdf) Division of Water Resources WQ Permitting Section - NPDES 1617 Mail Service Center Raleigh, NC 27699-1617 2) Electronic Version (pdf) and Hard Copy Division of Water Resources Water Sciences Section 1623 Mail Service Center Raleigh, NC 27699-1623 A. (22.) CLEAN WATER ACT SECTION 316 (b) [40 CFR 125.95] The permittee shall comply with the Cooling Water Intake Structure Rule per 40 CFR 125.95. The permittee shall submit all the materials required by the Rule 3.5 years from the effective date of the permit. Copies of all the study plans, study results, and any other applicable materials should be submitted to: 1) Electronic Version Only (pdf) Division of Water Resources WQ Permitting Section - NPDES Page 22 of 26 Permit NC0004979 1617 Mail Service Center Raleigh, NC 27699-1617 2) Electronic Version (pdf) and Hard Copy Division of Water Resources Water Sciences Section 1623 Mail Service Center Raleigh, NC 27699-1623 Pursuit to 40 CFR 125.98 the Director has determined that operating and maintaining the existing traveling screen system which includes a fish handling return system meets the requirements for the interim BTA. Nothing in this permit authorizes take for the purposes of a facility's compliance with the Endangered Species Act. A. (23.) FISH TISSUE MONITORING NEAR ASH POND DISCHARGE [NCGS 143-215.3 (a) (2)] The facility shall conduct fish tissue monitoring annually and submit the results with the NPDES permit renewal application. The objective of this monitoring is to evaluate potential uptake of pollutants by fish tissue near the ash pond discharge. The parameters analyzed in fish tissue shall be arsenic, selenium, and mercury. The monitoring shall be conducted in accordance with the sampling plan approved by the Division. The plan should be submitted to the Division within 180 days from the effective date of the permit. Upon approval, the plan becomes an enforceable part of the permit. Copies of all the study plans, study results, and any other applicable materials should be submitted to: 1) Electronic Version Only (pdf) Division of Water Resources WQ Permitting Section - NPDES 1617 Mail Service Center Raleigh, NC 27699-1617 2) Electronic Version (pdf) and Hard Copy Division of Water Resources Water Sciences Section 1623 Mail Service Center Raleigh, NC 27699-1623 A. (24.) INSTREAM MONITORING [15A NCAC 02B.0500 ET SEQ.] The facility shall conduct monthly in -stream monitoring for total arsenic, total selenium, total mercury, total chromium, dissolved lead, dissolved cadmium, dissolved copper, dissolved zinc, total bromide, total hardness (as CaCO3), turbidity, temperature, and total dissolved solids (TDS). The monitoring results shall be reported on the facility's Discharge Monitoring Reports and included with the NPDES permit renewal application. The upstream site is approximately 250 meters upstream of Outfall 006 and the downstream location is approximately 250 meters downstream of Outfall 002. A. (25.) PRIORITY POLLUTANT ANALYSIS [NCGS 143-215.1 (b)] The permittee shall conduct a priority pollutant analysis (in accordance with 40 CFR Part 136) once per permit cycle at all external outfalls and submit the results with the application for permit renewal. Page 23 of 26 Permit NC0004979 A. (26.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS [G.S. 143-215.1(b)] Federal regulations require electronic submittal of all discharge monitoring reports (DMRs) and program reports. The final NPDES Electronic Reporting Rule was adopted and became effective on December 21, 2015. NOTE: This special condition supplements or supersedes the following sections within Part II of this permit (Standard Conditions forNPDES Permits): • Section B. (11.) Signatory Requirements • Section D. (2.) Reporting • Section D. (6.) Records Retention • Section E. (5.) Monitoring Reports 1. Reporting Requirements [Supersedes Section D. (2.) and Section E. (5.) (a)] The permittee shall report discharge monitoring data electronically using the NC DWR's Electronic Discharge Monitoring Report (eDMR) internet application. Monitoring results obtained during the previous month(s) shall be summarized for each month and submitted electronically using eDMR. The eDMR system allows permitted facilities to enter monitoring data and submit DMRs electronically using the internet. The eDMR system may be accessed at: https: / /deq.nc.gov/about/divisions /water -resources /edmr. If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the facility being physically located in an area where less than 10 percent of the households have broadband access, then a temporary waiver from the NPDES electronic reporting requirements may be granted and discharge monitoring data may be submitted on paper DMR forms (MR 1, 1.1, 2, 3) or alternative forms approved by the Director. Duplicate signed copies shall be submitted to the following address: NC DEQ / Division of Water Resources / Water Quality Permitting Section ATTENTION: Central Files 1617 Mail Service Center Raleigh, North Carolina 27699-1617 See "How to Request a Waiver from Electronic Reporting" section below. Regardless of the submission method, the first DMR is due on the last day of the month following the issuance of the permit or in the case of a new facility, on the last day of the month following the commencement of discharge. Starting on December 21, 2025, the permittee must electronically report the following compliance monitoring data and reports, when applicable: • Sewer Overflow/Bypass Event Reports; • Pretreatment Program Annual Reports; and • Clean Water Act (CWA) Section 316(b) Annual Reports. The permittee may seek an electronic reporting waiver from the Division (see "How to Request a Waiver from Electronic Reporting" section below). Page 24 of 26 Permit NC0004979 2. Electronic Submissions In accordance with 40 CFR 122.41(1) (9), the permittee must identify the initial recipient at the time of each electronic submission. The permittee should use the EPA's website resources to identify the initial recipient for the electronic submission. Initial recipient of electronic NPDES information from NPDES-regulated facilities means the entity (EPA or the state authorized by EPA to implement the NPDES program) that is the designated entity for receiving electronic NPDES data [see 40 CFR 127.2(b)]. EPA plans to establish a website that will also link to the appropriate electronic reporting tool for each type of electronic submission and for each state. Instructions on how to access and use the appropriate electronic reporting tool will be available as well. Information on EPA's NPDES Electronic Reporting Rule is found at: https: / /www.federalregister.gov /documents /2015 / 10/22 /2015-24954/national-pollutant-discharge- elimination-system-npdes-electronic-reporting-rule Electronic submissions must start by the dates listed in the "Reporting Requirements" section above. 3. How to Request a Waiver from Electronic Reporting The permittee may seek a temporary electronic reporting waiver from the Division. To obtain an electronic reporting waiver, a permittee must first submit an electronic reporting waiver request to the Division. Requests for temporary electronic reporting waivers must be submitted in writing to the Division for written approval at least sixty (60) days prior to the date the facility would be required under this permit to begin submitting monitoring data and reports. The duration of a temporary waiver shall not exceed 5 years and shall thereupon expire. At such time, monitoring data and reports shall be submitted electronically to the Division unless the permittee re -applies for and is granted a new temporary electronic reporting waiver by the Division. Approved electronic reporting waivers are not transferrable. Only permittees with an approved reporting waiver request may submit monitoring data and reports on paper to the Division for the period that the approved reporting waiver request is effective. Information on eDMR and the application for a temporary electronic reporting waiver are found on the following web page: http://deq.nc.gov/about/divisions/water-resources/edmr 4. Signatory Requirements [Supplements Section B. (11.) (b) and Supersedes Section B. (11.) (d)] All eDMRs submitted to the permit issuing authority shall be signed by a person described in Part II, Section B. (11.)(a) or by a duly authorized representative of that person as described in Part II, Section B. (11.)(b). A person, and not a position, must be delegated signatory authority for eDMR reporting purposes. For eDMR submissions, the person signing and submitting the DMR must obtain an eDMR user account and login credentials to access the eDMR system. For more information on North Carolina's eDMR system, registering for eDMR and obtaining an eDMR user account, please visit the following web page: http: / /deq.nc.gov/about/divisions /water -resources /edmr Certification. Any person submitting an electronic DMR using the state's eDMR system shall make the following certification [40 CFR 122.22]. NO OTHER STATEMENTS OF CERTIFICATION WILL BE ACCEPTED: "I 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 Page 25 of 26 Permit NC0004979 on my inquiry of the person or persons who manage the.rystem, or those persons directly responsible forgathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fines and imprisonment for knowing violations." 5. Records Retention [Supplements Section D. (6.)] The permittee shall retain records of all Discharge Monitoring Reports, including eDMR submissions. These records or copies shall be maintained for a period of at least 3 years from the date of the report. This period may be extended by request of the Director at any time [40 CFR 122.41]. A. (27.) APPLICABLE STATE LAW (State Enforceable Only) [NCGS 143-215.1(b)] This facility shall meet the General Statute requirements under NCGS 5 130A-309.200 et seq. This permit may be reopened to include new requirements imposed under these Statutes. A. (28.) COMPLIANCE BOUNDARY [15A NCAC 02L.0107] The compliance boundary for the disposal system shall be specified in accordance with 15A NCAC 02L .0107(a) or (b) dependent upon the date permitted. An exceedance of groundwater standards at or beyond the compliance boundary is subject to remediation action according to 15A NCAC 02L .0106(c), (d), or (e) as well as enforcement actions in accordance with North Carolina General Statute 143-215.6A through 143-215.6C. The compliance boundary map for this facility is incorporated herein and attached hereto as Attachment A. Page 26 of 26