Colorado School of Mines Research Institute Site DRAFT REMEDIAL INVESTIGATION/FEASIBILITY STUDY AND PROPOSED PLAN

Meeting Agenda Introductions (6:30-6:35) Site Background (6:35-6:40) Review of Site Remedial Investigation and Feasibility Study (6:40-6:50) Remedial Alternatives and Preferred Alternative (6:50-7:05) Public Comment (7:05-7:55) Meeting Closure (7:55-8:00)

Presentation and Comments Meeting Transcript/Record Formal Comment Follow Presentation Written Comment – Forms Available Oral Comment – Please Note on Sign-In Sheet

Site Background Research Complex On Site Mining and Minerals Industry Investigations Settling Pond Between Buildings and Creek for Wastewater 17 Research Buildings CSMRI Ceased Operations at Site in 1987

Environmental Impacts Drums Tailings Ponds Industrial Sewer System Buildings/Building Components Soils Sample Storage Areas

Environmental Activities 1992 Water Main Break EPA Response Pond Excavation Soil Stockpile Building Drain Decontamination Selected Building Demolition Drums and Gas Cylinder Disposal

Environmental Activities Soil Stockpile Evaluation and Disposal Additional Drum Removal Building Evaluation and Demolition Additional Subsurface Investigation Concrete and Asphalt Evaluation and Disposal

Remedial Investigation Work Plans Characterization Survey Work Plan Site Safety and Health Plan Sampling and Analysis Plan Quality Assurance Plan Background Evaluation National Oil and Hazardous Substances Pollution Contingency Plan (NCP) Multi-Agency Radiation Surveys and Site Investigation Manual (MARSSIM)

Remedial Investigation Surface Soils Gamma Survey Surface Features Survey Topographic Survey Sampling and Laboratory Analysis Sub-Surface Soils Test Pits Soil Borings

Investigation Results Areas with Elevated Metals Concentrations (Cadmium, Lead, Mercury, Arsenic) Some Areas With Elevated Gamma Activity (Radium, Thorium, Uranium)

Investigation Results Upper Foot of Soils Most Affected Limited Deeper Areas Near Former Buildings Also Affected Groundwater Sampling (Four Quarters – Six Wells) Two Wells – Uranium Temporarily Above Drinking Water Limit One Well – TCE Temporarily Above Drinking Water Limit

Site Risks/Hazards Site As-Is Lifetime Risk for Onsite Full-Time Resident Between Four per 1000 and Eight per 10,000 Minimal Risks to Neighbors Some Long-Term Risk to Environment Metals and Radionuclides to Groundwater

Remedial Action Objectives Eliminate Human Exposure Pathways Develop Soil Cleanup Levels to Limit Exposures Minimize Radon Gas Risk Minimize Possible Lead Exposures to Children Prevent Off-Site Migration of Materials

Remedial Action Objectives Limit Ground Water and Surface Water Concentrations to Safe Drinking Water Act Standards Reduce Radiation Exposures to Levels As Low As Reasonably Achievable (ALARA) Comply With Applicable or Relevant and Appropriate Requirements (ARARs)

Remedial Alternatives – One NO FURTHER ACTION Institutional Controls Relocate Water Main Maintain Security Fencing/Signage Erosion Control Prohibition of Construction/Use Monitoring

Remedial Alternatives - Two Engineered Cap – Entire Site Clay Cap Prevents Surface Release/Exposure Prevents Surface Water Infiltration Alternative Slurry Wall Prevents Ground Water Infiltration Long-Term Institutional Controls Monitoring

Remedial Alternatives - Three Engineered Cap w Partial Removal Soils Over Elevated Radium, Thorium, Uranium Removed From Site Alternatives Remove to 15 pCi/g or 5 pCi/g Remaining Materials Consolidated and Capped Long-Term Institutional Controls Long-Term Monitoring

Remedial Alternatives - Four On-Site Solidification With Cap/Cell Consolidation of Affected Soils Solidification With Concrete and Fly Ash Alternative Includes Engineered Disposal Cell 0.9 Acre Cap/Cell Long-Term Institutional Controls Long-Term Monitoring

Remedial Alternatives - Five Off-Site Disposal Excavation and Removal of All Affected Material Local Solid Waste Landfill Specialized Landfill Alternate for Radium/Thorium/Uranium Affected Soils Unrestricted Future Use

Evaluation of Alternatives Protection of Human Health and Environment Compliance With Applicable or Relevant and Appropriate Requirements (ARARs) Long-Term Effectiveness and Permanence Reduction of Toxicity, Mobility, or Volume Through Treatment

Evaluation of Alternatives Short-Term Effectiveness Implementability Cost State Acceptance Community Acceptance

Preferred Alternative Excavation and Off-Site Disposal (Alternative Five) Substantial Long-Term Risk Reduction Removal of Source Material Returns Ground Water to Background Values Reasonable Timeframe Cost Advantages Complies With ARARs

Community Involvement Web Site Document Repositories CSM Arthur Lakes Library Golden Public Library CSM Environmental Health & Safety Department

COMMENTS ON DRAFT RI/FS Comments Due February 20, 2004 Comment Form US Mail – Attn: Linn Havelick, CSM, 1500 Illinois Street, Golden, CO Oral Comments Recorded