Laserfiche WebLink
l <br /> WEISS ASSOCIATES <br /> Three shallow background soil samples were analyzed for copper, sodium, sulfate, calcium, <br /> soluble chromium,and chlorides to characterize the natural background concentrations of these <br /> compounds in the site soil <br /> Table 1 presents the results of the Phase I ethylene and propylene glycol analyses The <br /> highest propylene glycol concentrations, up to 28,000 ppm, were detected beneath Vault 1 <br /> Propylene glycol was also detected at 2,600 ppm in the soil beneath Vault 6 The highest <br /> ethylene glycol concentration, at 1,200 ppm, was detected beneath Vault 1 Neither propylene <br /> glycol nor ethylene glycol was detected above the detection limit in any of the soil samples <br /> from beneath Vault 5 <br /> The results of the Phase I metals and other inorganic analyses are presented in Table 2 <br /> The California Department of Health Services(DHS)has established a Soluble Threshold Limit <br /> Concentration (STLC) and a Total Threshold Limit Concentration (TTLC) for total chromium, <br /> total hexavalent chromium,soluble total chromium,soluble hexavalent chromium,and copper <br /> Only the soluble hexavalent chromium concentrations detected in samples from Vault 8 <br /> exceeded these limits Soluble total chromium concentrations in all samples at Vault 7 were <br /> below the STLCs for soluble total chromium No STLC or TTLC has been established for <br /> sodium, calcium, sulfates, or chloride However, calcium and chloride concentrations in the <br /> samples from Vault 8 exceeded the background concentrations of these compounds The <br /> background concentrations of sodium and sulfate were not significantly exceeded in any of the <br /> samples <br /> The Phase I investigation results suggested a release from or adjacent to Vaults 1,6, and <br /> 8 Therefore, the objective of the Phase II investigation was to assess the vertical extent and <br /> concentrations of the released chemicals in soil beneath Vaults 1, 6 and 8 and to characterize <br /> the ground water quality beneath these vaults <br /> 15 CURRENT VAULT STATUS <br /> Between January 1 and June 1, 1990, DWG transferred refrigeration fluids to new <br /> above-ground chemical storage tanks at the site and discontinued using the underground vaults <br /> To decommission the vaults, DWG removed all residual fluids and solids and decontaminated <br /> each vault with three separate, high pressure rinses of water and industrial cleaner Since the <br /> D 1ALL1331DWGX331R1MA1 WP Page 4 <br />