Summary & Conclusions

The SWMU 6 Soil Sampling Results Report (URS, 2001) presented a detailed comparison of site data to USEPA Region III RBCs for the residential and industrial scenarios. Based on MDC comparisons, the
inorganic constituent arsenic was reported as present in exceedance of the Residential and Industrial RBCs. Other MDCs were reported as below Industrial RBCs. Subsequently, the data was compared to background
Point Estimates as established in the Facility-Wide Background Study (IT Corp., 2002).

The MDC for arsenic is below background Point Estimates and therefore arsenic is not considered a risk at the site. One detection of aluminum, while above the background Point Estimate, is below the Industrial RBC
(Table 2). This detection of aluminum is well below the Industrial RBC value of 200,000 mg/kg. Given the industrial nature of the site, the depth bgs, the lack of viable pathways, and the toxicity of the constituent, this
exceedance is not considered a risk at SWMU 6.

Based on the information presented in the SWMU 6 Soil Sampling Results Report and herein, concentrations of chemicals detected in soil samples at the site do not present a residual risk.