Laserfiche WebLink
AWALAF <br /> A <br /> Working To Restore Nature <br />' Report on Vapor Extraction Test January 29, 1993 <br /> Coca-Cola Former Distribution Facility, Stockton, California 5400601 <br /> CONCLUSIONS <br /> Based on the results of this and previous investigations, the conclusions are as follows <br /> o The majority of petroleum hydrocarbons in soil at the site appear to be located within <br /> a radius of about 20 feet from the former tank pit, and down to a depth of about 25 <br /> feet <br />' o The lateral and vertical extent of petroleum hydrocarbons in soil appear to be <br /> delineated at the site <br /> o Soil vapor extraction is a feasible method of soil remediation at this site for gasoline <br /> hydrocarbons in the soil <br /> o The average effective radius cit influence of each vapor extraction well is estimated to <br /> range from a low of 10 feet for well VEW-I to a high of about 30 feet for most of the <br /> other vapor wells <br /> o The proposed vapor extraction system (VES) will bring three existing vapor extraction <br /> wells on line (VEW-2, VEW-3, and VEW-7) The estimated effective radius of <br /> influence for each of these three wells is shown in Plate 6, and extends over the <br /> impacted area shown in the TPHg soil concentration contour snap, Plate 4 It is <br /> recommended that two of these wells (VEW-3 and VEW-7) which are screened <br /> substantially deeper than the vertical area of concern, be grouted with a <br /> cement/bentonite slurry from the bottom of the well up to 30 feet below grade This <br /> will focus the vacuum in the vertical area of concern <br />' o The proposed average design flow for each well is 75 cubic feet per minute (cfm) with <br /> a total projected well flow of 225 cfm The wellhead design vacuum is 60 inches of <br /> water column The proposed off-gas abatement device is a thermal oxidizer <br /> 1 o Based on laboratory analyses of vapor samples collected during the vapor test, the TPHg <br /> concentration at vapor system startup is estimated at 5,287 mg/m3, which is a relatively <br /> 1 moderate concentration <br /> o During the first month of operation, it is proposed to operate only the well in the <br /> former tank pit VEW-3, in order to contain petroleum hydrocarbons beneath the tank <br /> pit, and reduce lateral and vertical migration of the vapors During the second month <br /> 17 <br />