SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

3.0 FINDINGS Versar's findings are based on the results of observations and data collected during field investigations, and laboratory analyses of soil and groundwater samples. Analyses were performed by a California Department of Health Services-certified laboratory, using State, Federal, and industry standard methods. Copies of the laboratory analytical results are included as Appendix C. 3.1 AASF A total of four soil samples and one grab-groundwater sample were collected from boring B28. Extractable petroleum hydrocarbons in the diesel/jet fuel range were detected in the two and five foot samples at a maximum concentration of 420 mg/kg. Extractable petroleum hydrocarbons were not detected in the remaining samples collected from 10 feet and 20 feet bgs. The laboratory analytical results are summarized in Table 1. Groundwater samples were collected from three groundwater monitoring wells on March 8, 2004. Laboratory analysis of groundwater samples collected from monitoring wells MW-1, MW-2 and MW-3 did not detect concentrations of extractable petroleum hydrocarbons in the diesel or jet fuel range, or volatile hydrocarbons (including fuel oxygenates). One groundwater sample, collected from monitoring well MW-2 contained 0.110 mg/L of TPH-g. Table 2 summarizes the results of groundwater monitoring. 3.2 CSMS Four soil samples and one grab-groundwater sample were collected from boring B29, located north of the vehicle wash rack in the CSMS building (Figure 4). Laboratory analysis did not detect concentrations of extractable hydrocarbons or PCBs in any of the samples. Table 3 summarizes the laboratory analytical results from CSMS sampling. Thirty soil samples were collected from 10 borings along the north boundary drainage ditch. Laboratory analysis detected 20 mg/kg of oil-range hydrocarbons in one near-surface sample (Boring DD6 at 0.5 foot bgs). Laboratory analysis did not detect concentrations of extractable hydrocarbons in any of the other 29 samples. Metals concentrations detected in the samples were all below applicable regulatory guidelines (Table 3). Two soil samples were collected from boring B10b, located near the waste storage area. Laboratory analysis did not detect concentrations of extractable hydrocarbons in either of the samples. Metals concentrations detected in the samples were all below regulatory thresholds for residential soils. One soil sample was collected from boring B11, located near the sandblasting area. Laboratory analysis did not detect concentrations of extractable hydrocarbons, purgeable hydrocarbons, or VOCs, or concentrations of heavy metals that exceeded the USEPA Region 9 Preliminary Remediation Goals(PRGs) for direct contact exposure pathway for industrial soil. I04700.4766.230/OSSEPT2004 8