Conclusions - Contaminated Soil Remedial Alternatives
Based on the detailed analysis of contaminated soil remedial alternatives in the Feasibility Study, Alternative 4, “Excavation and Off-site Disposal,” is the most favorable remedial alternative to achieve the Remedial Action Objectives (RAOs), but final selection of a preferred alternative will be proposed and documented in the forthcoming Proposed Plan.
While Alternative 3, “Phytoremediation,” is initially less costly than Alternative 4, the unknowns associated with it render the costing criterion only slightly more favorable than Alternative 4. Alternative 4 will meet the RAOs in the shortest time, with the fewest unknowns. It will address all chemicals of concern under all site-specific conditions and it has been successfully conducted many times throughout Spring Valley site.
Conclusions - Explosive Hazards Remedial Alternatives
Based on the detailed analysis of remaining explosive hazards remedial alternatives for the areas of focus, Alternative 6, “Digital Geophysical Mapping of Accessible Areas, Remove Selected Anomalies,” is the most favorable remedial alternative to achieve the RAOs, but final selection of a preferred alternative will be proposed and documented in the forthcoming Proposed Plan. On an individual property basis, Alternative 6 is the least costly of the four alternatives. Alternative 6 is protective of human health and the environment, is compliant with applicable or relevant and appropriate requirements, and will meet the RAOs in the shortest time period.
For further information regarding the various alternatives evaluated and the analysis and comparison of those alternatives, the Feasibility Study can be downloaded by clicking here.
The next step in the CERCLA process now that the Feasibility Study has been finalized will be for USACE to compose a Draft Final Proposed Plan. The Proposed Plan formally presents the Army's preferred alternatives as a result of the Feasibility Study analysis. A formal public comment period will be held to allow the community an opportunity to review and comment on the Proposed Plan before it is finalized.