Previous Investigations (Updated): As described previously, potential UXO items at the site were investigated and removed in 1997. Previous analytical results indicate that soils at the site exceed background criteria for lead and other metals.

Data Needs: Previously-sifted soils will be assessed to determine a viable method for disposition.

Interim Measures Activities:

1. Sifted soils at SWMU B-20 will be sampled and analyzed to provide information for the assessment of treatment/disposal options. Samples will be analyzed for metals, physical parameters (density, porosity, etc.), and TCLP metals. Approximately one sample per 200 cubic yards of sifted soils will be collected.

2. An assessment for the proper disposition of the previously sifted soil piles will be conducted within budgeting constraints. The assessment will include a review of the bench-scale treatability study results for SWMU B-20, a review of the analytical data for SWMU B-20, an evaluation of treatment and disposal options with regard to effectiveness; implementability; cost; reduction of mobility, toxicity, or volume; compliance with ARARs; and overall protection of human health and the environment. The assessment will also evaluate if a CAMU would be appropriate for treating CSSA soils.

3. A Soil Pile Disposition Assessment Report will be prepared documenting the evaluation of treatment and disposal options. The Report will recommend a treatment option for the B-20 soils and if CSSA should apply to establish a CAMU.

4. If the Disposition Assessment Report indicates that a CAMU is appropriate for treating CSSA soils, a CAMU application will be prepared. The CAMU application will be prepared as a separate document from the Disposition Assessment Report.

5. After the Disposition Assessment Report has been prepared, a treatability study of the recommended treatment option will be conducted. One cubic yard of soil (three 55-gallon drums) from SWMU B-20 will be treated during the treatability study.

6. After the treatability study has been completed, a treatability study report will be prepared documenting results of the study.