1. NPDES Permitting for Coal Ash Ponds in North Carolina EMC Meeting January 12, 2012 Sergei Chernikov, Ph.D. 1

2. EMC meeting n Information Item n Regulatory Framework n Power Plant Components n Water Quality Concerns and Waste Streams n Permitting and Monitoring n DWQ Oversight 2

3. 13 coal fired plants: 7 Duke Energy 6 Progress Energy 3

4. Future Trends n Conversion to Natural Gas, Closure n Water Quality Benefits: thermal and chemical pollution will be reduced. n Weatherspoon Power Plant – retired on 10/1/2011 n During the next 4 years: 6 coal fired plants will be converted to natural gas or closed: n 1) Lee Power Plant – converted by the end of 2012 n 2) Sutton Power Plant – converted by the end of 2013 n 3) Buck Steam Station – converted by the end of 2014 n 4) Dan River Steam Station – converted by 2014 n 5) Cape Fear Power Plant – retired by 2014 n 6)Riverbend Steam Station – retired by 2015 4

5. Regulatory Framework – DWQ/NPDES n Wastewater discharges, technology based limits - 40 CFR 423. Update is scheduled for 2014. n Thermal discharges. Section 316 (a) of Clean Water Act. n Cooling Water Intake Structures (CWIS). Section 316 (b) of Clean Water Act. n State water quality standards and EPA criteria. 5

6. Waste Streams n Once through cooling system discharge (up to 1,450 MGD), cooling tower and boiler blowdown. n Domestic wastewater, boiler chemical cleaning, water treatment plant discharge, laboratory waste, coal pile runoff, stormwater. Flue Gas Desulfurization. NC Clean Smokestacks Bill of 2002 - reduce air emissions of NOx and SO 2. n Heavy metals, As, Se, organics, TSS, BOD, chlorides, TDS, heat, high or low pH. n Whole Effluent Toxicity. n Volume of Ash Pond Discharge ~ 3-10 MGD. 6

7. Receiving Stream Boiler & Turbines WTP Coal pile Scrubber Domestic WWTP Landfill FGD Treatment System Ash Pond Old Ash Pond CWIS Cooling Towers Typical Plant Components Stormwater 7

8. Ash Disposal n Bottom ash, fly ash, and ash transport water. n Ash may include trace amounts of heavy metals, chlorides, As, and Se. n Ash is usually managed in ash settling pond. n Dry handling - environmentally friendly, easier to recycle, 40 CFR NSPS limitations. 8

9. Dan River Ash Basin (21 acres) Photo provided by Duke Energy 9

10. Allen Ash Basin (169 acres) Photo provided by Duke Energy 10

11. Permit Limits – Ash pond Discharge n Permit limits are based on the statistical evaluation of the effluent data for the last 4-5 years – Reasonable Potential Analysis. n Limits are implemented only if Reasonable Potential to exceed water quality standards or criteria exists. n Facilities conduct effluent monitoring, surface water monitoring, fish tissue monitoring. n New Permit Conditions: Ash Pond Closure, Dam Safety, and Fish Tissue Monitoring in some permits that did not monitor in the past. 11

12. DWQ Oversight n Annual inspections n DMR submitted monthly. n Extensive biological monitoring. n Historically – very good compliance with NPDES permits. 12

13. Duke Energy Stations StationFGD SystemAsh PondLandfills (only coal ash and FGD waste) 1) Riverbend Gaston County No2 activeNo 2) Marshall Catawba County Yes Dry fly ash handling 1 active1 inactive (coal ash) 1 active (FGD waste) 1 active (coal ash) 3) Allen Gaston County Yes1 active 1 retired 1 active (coal ash, off-spec gypsum, sludge) 4) Cliffside Rutherford County Yes Dry fly ash handling – Unit 5 1 active 2 retired 1 active (coal ash, FGD waste) 5) Buck Rowan County No3 activeNo 6) Dan River Rockingham County No2 activeNo 7) Belews Creek Stokes County Yes Dry fly ash handling 1 active1 inactive (coal ash) 2 active (1 - coal ash and sludge, 1 - gypsum ) 13

14. Progress Energy Plants StationFGD SystemAsh PondLandfills (only coal ash and FGD waste) 1) Asheville Buncombe County Yes1 active 1 retired No 2) Roxboro Person County Yes1 active 1 retired 1 inactive (coal ash) 1 active (coal ash, FGD waste) 3) Mayo Person County Yes1 activeNo 4) Sutton New Hanover County No2 active 1 retired No 5) Cape Fear Chatham County No2 active 3 retired No 6) Weatherspoon Robeson County No1 activeNo Facility retired in 2011 7) Lee Wayne County No1 active 3 retired No 14

15. Questions? 15