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US EPA Update. ASARCO HAYDEN PLANT SITE July 21 and 22, 2009 AGENDA 1. Welcome and Introductions 2. Residential Yard Cleanup 3. Upcoming Investigation Asarco property soil Air Quality 4. Risk Update . Background- EPA Involvement.
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US EPA Update ASARCO HAYDEN PLANT SITE July 21 and 22, 2009 AGENDA 1. Welcome and Introductions 2. Residential Yard Cleanup 3. Upcoming Investigation Asarco property soil Air Quality 4. Risk Update
Background- EPA Involvement • 2006. Phase I investigation begins and site qualifies for the Superfund National Priorities List (NPL). • March - June, 2008. Replacement of soil in 15 yards. • May 2008. Settlement agreement finalized. • December 2008 –August 2009 cleanup of remaining yards
Residential Yard CleanupProcess • Access Agreement • Sampling at 9 points across property (0-2”) • Cleanup initiated if avg. concentration above: • Arsenic - 24.3 mg/kg • Lead - 400 mg/kg • Copper - 9300 mg/kg • And potential exposure
Residential Yard Cleanup • Stages of cleanup on contaminated property • Assess owners needs • Excavate 1 foot down, reassess • Excavate an additional foot, if needed • If still contaminated, lay orange mesh • Backfill with clean soil
Residential Yard Cleanup • Why are some homes clean: • Prior removal and replacement of contaminated soil for landscaping • Addition of clean fill for grading • Erosion of contaminated soil • Distance from source of contamination
Residential Yard Cleanup • Can Residential Soil Get Recontaminated? • Two short stacks until early 1970’s • Mid 1950’s, 13,000 lbs copper per day from stacks • Mid-2000’s 16 lbs copper per day from stack • Kennecott no longer operating • Replaced soil stays clean Clarkdale, 1917 Asarco, 2009
Residential Yard Cleanup Parcels on both towns • Total number: 658 • Total Sampled: 649 • Total contaminated: 260 • Cleaned to date: 220
Residential YardCleanup • EPA/ADEQ oversight • Split samples • EPA analyzed lab data results separately • Each parcel tracked
Residential YardCleanup • EPA/ADEQ oversight • Split samples • EPA analyzed lab data results separately • Each parcel tracked
Hayden Soil • Each yard color coded • Various types of excavation
Winkelman Soil
Soil Concentrations Copper Naturally Occurring Soil Concentration Highest Concentration Arizona Soil zero Remediation Level (Screening Level)
Soil Concentrations Copper Naturally Occurring Soil Concentration Highest Concentration 20,000 39,700 ppm 1,270 3,100 Arizona Soil zero Remediation Level (Screening Level) 15 Yard Removal Typically No Concern Concentrations of Concern
Soil Concentrations Copper Naturally Occurring Soil Concentration Highest Concentration 20,000 39,700 ppm 1,270 3,100 9,300 Arizona Soil zero Remediation Level (Screening Level) Current Removal 230 yards 15 Yard Removal Typically No Concern Concentrations of Concern
Next Steps • Remedial Investigation by Asarco • On-site soil • Air Quality • Groundwater and drinking water • Overseen by EPA with ADEQ
Remedial InvestigationOn-Site Soil • EPA has found high concentrations of metals • Asarco will continue on-site soil sampling on Asarco owned property • Tailings material in Hayden • Former Kennecott Smelter • Concentrator • Asarco Smelter
Remedial Investigation Air • EPA has found elevated concentrations of metals • Over two years of sampling • Air Monitor near Hayden city hall and on high school in Winkelman
Past Air Sampling Results Hayden air sampler * EPA Region 9 Preliminary Remediation Goals From Table 4-35, RI Report
Past Air Sampling Results • Patterns • Particulates are highest when wind is blowing from the large tailings pile and track hopper areas • Highest levels of Arsenic, Lead and Cadmium occur when wind is blowing from smelter
Future investigation will focus on smelter and other areas Determine sources of poor air quality More air samplers Residential areas Smelter areas Other sources Remedial Investigation - Air
Risk Assessment • Toxicity Assessment • Non Cancer • Lead, copper, arsenic • Hazard Index = Daily exposure without adverse effect • Harm may occur above a certain dose • Cancer • Risk based • Probability of getting cancer over a lifetime • Can be managed • Arsenic, cadmium and chromium
Risk AnalysisNon-Cancer Hazard Index 30 1/30 1/15 1 15
Risk AnalysisNon-Cancer Hazard Index 30 1/30 1/15 1 15 Background Soil - unaffected by contamination
Risk AnalysisNon-Cancer Hazard Index 30 1/30 1/15 1 15 Highest soil level in Hayden
Risk AnalysisNon-Cancer Hazard Index 30 1/30 1/15 1 15 15 yard soil replacement
Risk AnalysisNon-Cancer Hazard Index 30 1/30 1/15 1 15 15 yard soil replacement and current action
Risk Assessment • Toxicity Assessment • Non Cancer • Lead, copper, arsenic • Hazard Index = Daily exposure without adverse effect • Harm may occur above a certain dose • Cancer • Arsenic, cadmium and chromium • Risk based • Probability of getting cancer over a lifetime • Risk can be managed
Risk AnalysisCancer 1x10-7 1x10-6 1x10-5 1x10-4 1x10-3
Risk AnalysisCancer One in ten thousand One in a million 1x10-7 1x10-6 1x10-5 1x10-4 1x10-3
Risk AnalysisCancer One in ten thousand High Risk Low Risk One in a million 1x10-7 1x10-6 1x10-5 1x10-4 1x10-3 Risk Management Range
Risk AnalysisCancer One in ten thousand High Risk Low Risk One in a million 1x10-7 1x10-6 1x10-5 1x10-4 1x10-3 Soil Air Background - Unaffected by Hayden Operations
Risk AnalysisCancer One in ten thousand High Risk Low Risk One in a million 1x10-7 1x10-6 1x10-5 1x10-4 1x10-3 Soil Air Hayden
Risk AnalysisCancer One in ten thousand High Risk Low Risk One in a million 1x10-7 1x10-6 1x10-5 1x10-4 1x10-3 Soil l Air Hayden and Winkelman 15 yard soil replacement
Risk AnalysisCancer One in ten thousand High Risk Low Risk One in a million 1x10-7 1x10-6 1x10-5 1x10-4 1x10-3 Soil Air Hayden and Winkelman 15 yard soil replacement
Community Advisory Group • Self-forming Stakeholder Group • Receive funds for a technical advisor • EPA can provide: • Advertising of meetings • Meeting logistics • Copies of cleanup documents • Attendance/presentations by EPA representatives
John Hillenbrand Remedial Project Manager USEPA (SFD-6-2) 75 Hawthorne St. San Francisco, CA 94105 415-972-3494 David CooperCommunity Involvement Coordinator USEPA (SFD-6-3) 75 Hawthorne St. San Francisco, CA 94105 415-972-3245 800-231-3075 (mssg line)