ARCHIVED REPORTS_XR0001974 - Laserfiche WebLink

Home Browse Search

smAAM.lune 15, 1992 ARCO Service Station No 548, Stockton, California collected. The effluent vapor sample was collected to estimate the destruction efficiencv of the I C engine The VET monitoring data are recorded in Table I Laboratory Anaivses and Results RESNA initiates a Chain of Custodv Record that accompanied the vapor samples to a State-certified laboratory The vapor samples were anaivzed at Sequoia Analytical in Sacramento. California (Hazardous Waste Testing Laboratory Certificate No 1624), for total petroleum nvdrocarbons as gasoline (TPHg) and benzene, toluene, ethvlbenzene, and total xvlene isomers using modified Environmental Protection Agency Methods 8015 and 8020, respectiveiv The results of the laboratory analvses are recorded in Table 1 Copies of the Chain of Custodv Records and laboratory reports are attached During the VET the highest observed vacuum was 0 31 inches of water from observation well VW-1 while extraction well VW-3 was undergoing an air flowrate of 74 cfm and a vacuum of 63 inches of water Wells VW-1 and VW-3 are approximately 28 feet apart.. Results of laboratory analvses of vapor samples collected from wells VW-1 VW-2, and '%'-W- 3 indicated that influent TPHg concentrations ranged from 21,000 to 87,000 milligrams per cubic meter The analvtical results of the I C engine effluent vapor sample indicates that the I C engine nas a destruction efficiencv of approximately 95 percent CONCLUSIONS Utilizing the vacuum and distance measurements obtained during the VET, an effective radius of influence can be estimated for the site The effective radius of influence is defined as the radial distance from a vapor-extraction well within which recorded vacuum levels indicate that suosuriace air flowrates are sufficient for remediation RESNA estimates that a wellhead flow rate of 80 cfm will result in an effective radius of influence of approximately 30 feet for one \apor-extraction well (Plate 2) Based on previous investigations (RESNA, Report No 30004-5 report in preparation), the limits of soil containing nvdrocarbons extend vertically from approximately 30 to 45 feet below surface trade and extends lateraiiv to the north east and slightly south of the existing tanks, as shown on Plate 2 RESNA estimates that extraction from the three existing vapor- extraction wells will allow for the removal of hvdrocarbons from the described zone RESNA proposes using a thermal or catalvtic oxidizer to extract and treat the gasoline hydrocarbons from beneath the site 041 kcar 30004-s 2