ARCHIVED REPORTS XR0012867 - Laserfiche WebLink

Home Browse Search

1501 WEST CHARTER WAY WKANo. 3964.01 December 21, 1998 Page 2 approximately 5.5, 10.5 and 16 feet. The sample obtained from boring B2 was obtained at approximately 3 feet below site grade.- Subsurface soils consisted primarily of silty/clayey sands. Once samples were collected;the borings were backfilled with soil cuttings under the direction of Michael Infurna with San Joaquin County Public Health Services Department (SJCPHSD). Once, backfilled, eachboring was capped with concrete to match the existing surface as best _ --possible. Our field observations indicated that petroleum hydrocarbons were likely,present in soil obtained from each of thehand.augured borings.- To confirm this observation, three of the four soil samples were submitted with chain-of-custody documentation to a California-certified laboratory for analysis. The samples were collected, preserved, and transported in accordance with our September 29, 1998 Workplan. The samples were analyzed for Total Petroleum Hydrocarbons (TPH) as diesel using EPA Method 8015 Modified and TPH as gasoline and Benzene, Toluene, Ethylbenzene and Xylene-(BTEX) and the fuel oxygenate MTBE using 8260B. Laboratory analysis revealed relatively low concentrations of diesel, gasoline, Xylene and MTBE in boring B l (between the USTs) to a depth of approximately 16.5 feet. The analytical results for the sample obtained from boring B2, revealed significant concentrations of diesel and gasoline at a depth of approximately 2.5 feet beside the dispenser island. The complete - laboratory reports and chain=of-custody documentation-are attached. Based on the above laboratory data, petroleum hydrocarbons are present in soils in the vicinity of the.USTs and the dispenser island. Because the purpose of our work was simply to evaluate the site for the presence of petroleum hydrocarbons,-no effortwas made delineate the extent of the l contamination. With this in mind, we recommend that a larger scale soil boring investigation be completed at the site i6-adequately evaluate the extent of contamination. To that end, we believe that this work can be completed under the existing workplan on file with SJCPHSD. This should be confirmed with Mr.4nfuma prior to the start of any work. Additionally, SJCPHSD will likely .require that groundwater be evaluated beneath this site. The addition of a groundwater investigation may require that a workplan addendum be filed with the SJCPHSD. _ INK WALLACE•KUHL Heydedpupe "'� Er ASSOCIATES INC.