TVA Kingston Ash Recovery Project Roane County, TN
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Transcript of TVA Kingston Ash Recovery Project Roane County, TN
TVA Kingston Ash Recovery Project Roane County, TN
Project UpdateSeptember, 2012
Neil Carriker
3 ½ Years of Recovery
December 23, 2008 June 28, 2012
Overview
• Project accomplishments – Phases 1 & 2
• Phase 3 — What to do about the residual ash?
• 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
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 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
3 ½ Years of Recovery
December 23, 2008 June 28, 2012
Phase 3
• Residual ash summary• Human health risk assessment• Ecological risk assessment• River System EE/CA Alternatives
Phase 3 – River SystemSampling & Analysis Plan
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
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
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
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 ashAgrees with 2010 TN DOH Public Health AssessmentAgrees with ORAU/Vanderbilt Medical Screenings
• 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 AssessmentSummary
Mayfly Nymph
Killdeer
Fish Community
Fish Community
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
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)
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
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