ARCHIVED REPORTS_XR0007337 - Laserfiche WebLink

Home Browse Search

' the pump islands were demolished and removed, and on January 7, 1993 the hydrocarbon-affected soil was excavated from the area The limits of the excavation and the confirmation soil sample locations are illustrated in Figure 3 The pump island excavation reached a maximum depth of approximately 6 feet bgs adjacent to the ' west pump island The majority of the hydrocarbon-affected soil consisted of sand backfill which was up to 3 feet thick near the pump islands 1 Below the sand was a dark grey to black clay which effectively attenuated the vertical ' migration of the hydrocarbons The depth to the sand/clay contact was greatest in the vicinity of the pump islands and decreased towards the edges of the excavated ' area which limited the horizontal migration of the hydrocarbons Based on the visual inspection and field screening of the excavation with the PID and the laboratory rresults of the confirmation sampling, all the hydrocarbon-affected soil in the vicinity of the former pump islands was removed 44 REMOVAL OF THE SEPTIC TANK A septic tank was discovered on the site and removed At the request of the SJCDPHS, a soil sample (SEP 1 ) was obtained from the bottom of the septic tank excavation and analyzed for total oil and grease, TPH-G, and BTEX (see Table 2) No petroleum hydrocarbon constituents were detected in the sample 45 REMOVAL OF THE SERVICE BAY HOISTS ' The service bay hoists that were inside the former service station building were removed and a soil sample (HST-1 ) was obtained from the bottom of the excavation (see Table 2). The samples were analyzed for total oil and grease No petroleum ' hydrocarbon constituents were detected in the samples Sample ST, obtained in the area of the hoists contained 33 ppm total oil and grease r / Welhauser C O A P O R A T 1 0 N P21 Woo wp(03184) 6 r