1 / 29

TVA Kingston Ash Recovery Project Roane County, TN

TVA Kingston Ash Recovery Project Roane County, TN. Project Update September, 2012 Neil Carriker. 3 ½ Years of Recovery. June 28, 2012. December 23, 2008. Overview. Project accomplishments Phases 1 & 2 Phase 3 — What to do about the residual ash?. CERCLA Removal Action Strategy.

sun
Télécharger la présentation

TVA Kingston Ash Recovery Project Roane County, TN

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


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

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

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

  4. CERCLA Removal Action Strategy • 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)

  5. Phase 2 Operations • Ash Excavation • North Embayment (complete) • 865,000 CY removed by December2011 • Middle Embayment: • 65% complete--finish mid-2013) • 800,000 CY removed/330,000 CY left • Relic: 308,000 CYs relocated • Ash Stacking • Central Dredge Cell 1,006,000 CY • Lateral Expansion 337,000 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

  6. 3 ½ Years of Recovery June 28, 2012 December 23, 2008

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

  8. Phase 3 – River SystemSampling & Analysis Plan

  9. 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

  10. 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

  11. 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

  12. SummaryHuman 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

  13. Ecological Risk AssessmentSummary • 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 Mayfly Nymph Killdeer

  14. Fish Community

  15. Fish Community

  16. 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

  17. 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)

  18. 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

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

More Related