1. TVA Kingston Ash Recovery Project Roane County, TN Project Update September, 2012 Neil Carriker

2. 3 ½ Years of Recovery December 23, 2008 June 28, 2012

3. Overview Project accomplishments – Phases 1 & 2 Phase 3 — What to do about the residual ash?

4. Phase 1: Time-Critical (Complete) –3.5 million cu yd removed from Emory River –4.0 million tons disposed at Perry County, AL (completed 12/01/10) –Emory River reopened May 29, 2010 Phase 2: Non-Time Critical (On-going) –2.8 million cu yd –Reinforced, on-site disposal area –Perimeter containment wall Phase 3: Residual Ash –Addressing residual ash in river system –River ecosystem and human health risk assessments –Long-term monitoring (5-year reviews) CERCLA Removal Action Strategy

5. Phase 2 Operations Ash Excavation – North Embayment (complete) 865,000 CY removed by December 2011 – Middle Embayment: 65% complete--finish mid-2013) 800,000 CY removed/330,000 CY left – Relic: 308,000 CYs relocated Ash Stacking – Central Dredge Cell1,006,000 CY – Lateral Expansion337,000 CY – Ash Pond 213,000 CY – Complete by late 2013 Perimeter Wall Construction – 38% Complete – Finish by mid-2014 Cell Cap & Closure – Liner/Drainage Layer/2 feet of clay + soil – Finish End of 2014

8. 3 ½ Years of Recovery December 23, 2008 June 28, 2012

17. Phase 3 Residual ash summary Human health risk assessment Ecological risk assessment River System EE/CA Alternatives

18. Phase 3 – River System Sampling & Analysis Plan

19. TVA’s River System Investigation Framework for Human Health and Ecological Risk Assessments Multiple approaches to evaluate effects Overall Scope: More than:  16,000 samples collected  400,000 analyses on those samples Rigorous Data Quality Assurance Several Environmental Consultants & Labs State/Federal Orgs (TDEC, TWRA, USGS, USACE, ORNL, USFWS) 12 Universities

20. River System SAP Investigations Water – Groundwater – Surface water – Water within sediments (pore water) Ash nature & extent – How much? – Where is it? Sediment – Mixing with ash? – Transport by storm flows? – Toxicity testing Living Organisms – Bioaccumulation – Fish and Benthic Community Surveys

21. Residual Ash ● Approximately 510,000 CY, total 3 % in Emory Reach C (ERM 3.5—6) –82 % in Emory Reaches A & B (ERM 0—3.5) –1% in Clinch Reach A (CRM 0—3) –14% in Clinch Reach B (CRM 3-4.5) ● Maximum ash depth is ~4-6 ft

22. Summary Human Health Risk Assessment Examined multiple exposure scenarios Used data from Kingston, not somewhere else Followed EPA risk assessment guidance Results:  Confirmed risks from legacy PCBs and Hg in fish tissues  TDEC fish consumption advisory pre-dating the spill  No unacceptable risks associated with residual ash  Agrees with 2010 TN DOH Public Health Assessment  Agrees with ORAU/Vanderbilt Medical Screenings

23. Seventeen receptors Risk indicators: –Arsenic –Selenium Findings: –Moderate/Low risk to organisms that: Live in sediment Eat organisms that live in sediment - Benthic Invertebrate (bugs) - Tree Swallow - Killdeer Ecological Risk Assessment Summary Mayfly Nymph Killdeer

24. Fish Community

26. Removal Action Objectives Protect invertebrate populations in Watts Bar Reservoir – Arsenic and selenium in ash-contaminated sediment Protect shoreline-feeding and aerial-feeding bird populations – Uptake of arsenic and selenium through diet (benthic invertebrates) Restore ecological function and recreational use of the river system to pre-release conditions Dispose of wastes from the removal action in accordance with applicable regulations

27. Alternatives Evaluated Alternative 1:Monitored Natural Recovery – Natural mixing/burial; 30 year monitoring program with 5 Year Reviews (NPV=$10M) – Sediment fate/transport modeling Alternative 2:In-situ capping – Alt 2a: cap 200 acres of ash deposits >0.5’ thick (NPV=$44.8M) – Alt 2b: cap 160 acres of ash deposits subject to scouring (NPV=$38.7M) Alternative 3:Dredging – Alt 3a: dredge 440,000 cys of ash deposits (NPV=$179.1M) – Alt 3b: dredge 160,000 cys in areas of greater ecological significance (NPV=$83.4M)

28. Community Involvement Phase 3 EE/CA Process Conducted 6 educational workshops – March-June 2012 at Roane State Community College River System EE/CA Report (and HHRA & BERA) – Made available for public comment Friday, August 10 – Public comment period - 08/11/12 – 10/10/12 Public Meeting on August 21 Press Releases/Fact Sheets Phase 3 Action Memo & Responsiveness Summary - Fall 2012

29. River System EE/CA available for review: – www.tva.gov/kingston www.tva.gov/kingston – www.epakingstontva.com www.epakingstontva.com – Kingston & Harriman, TN Public Libraries (on DVD) – On DVD upon request