Colorado School of Mines Research Institute Site

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

2. 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)

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

5. Site Background • Research Complex On Site 1912-1987 • Mining and Minerals Industry Investigations • Settling Pond Between Buildings and Creek for Wastewater • 17 Research Buildings • CSMRI Ceased Operations at Site in 1987

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

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

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

9. 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)

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

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

12. 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

13. 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

14. 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

15. 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)

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

18. 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

19. 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

20. 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

21. 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

22. 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

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

24. 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

25. Community Involvement • Web Site • http://www.is.mines.edu/ehs/csmri/csmri.htm • Document Repositories • CSM Arthur Lakes Library • Golden Public Library • CSM Environmental Health & Safety Department

26. COMMENTS ON DRAFT RI/FS • Comments Due February 20, 2004 • lhavelic@mines.edu • Comment Form • US Mail – Attn: Linn Havelick, CSM, 1500 Illinois Street, Golden, CO 80401 • Oral Comments • Recorded