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Since 1993, a contractor to the site owner has sampled the onsite monitoring wells every quarter. <br />Groundwater samples have been analyzed for TPH using EPA Method 8015, BTEX using EPA <br />Method 8020, and HVOCs using EPA Method 601. Analytical results indicate the following <br />maximum concentrations: TPH at 430 parts per billion (ppb), benzene at 42.5 ppb, 1,1-DCA at <br />5.4 ppb, 1,2-DCA at 2.7 ppb, and 1,1-DCE at 2.9 ppb (4). In April 1993, a contractor to the EHD <br />collected groundwater samples from the onsite domestic well. The samples were analyzed for <br />HVOCs using EPA Method 601. Analytical results of the groundwater samples indicated the <br />following concentrations of HVOCs: 1,1,-DCA at 63 ppb, 1,1,-DCE at 230 ppb, and TCE at 12 <br />ppb (5). <br /> <br />2.4 Regulatory Involvement <br />2.4.1 U.S. Environmental Protection Agency. The Marlowe site is not listed in the Resource <br />Conservation and Recovery Information System (RCRIS) database as of November 22, 1994 (8). <br />2.4.2 California Environmental Protection Agency. <br />Regional Water Quality Control Board, Central Valley Region, (RWQCB). In 1993, the EHD <br />notified the RWQCB about the presence of HVOCs in groundwater beneath the site. In response <br />to this, the RWQCB requested that the EHD take responsibility for oversight of onsite activties <br />related to groundwater contamination. (9) <br />2.4.3 San Joaquin County, Environmental Health Division. Since 1988, the EHD has been <br />actively involved with activities related to removal of the onsite USTs containing gasoline. Post- <br />removal sampling and analyses have indicated the presence of petroleum hydrocarbons in soil and <br />groundwater beneath the site. The EHD has been working with the site owner to remediate the <br />petroleum hydrocarbon groundwater contamination beneath the site. To determine whether the <br />USTs had impacted groundwater beneath the site, four monitoring wells were installed on site by <br />the site owner between 1988 and 1994. Since 1993, three of the monitoring wells have been <br />sampled every quarter. In 1993, the EHD sampled the onsite domestic drinking-water well and <br />two offsite domestic drinking-water wells for TPH, BTEX, and HVOCs. Based on analytical <br />results of the sampling event, the onsite domestic well was taken out of service in 1993 because of <br />HVOC contamination. The EHD is working with the site owner to implement soil and <br />groundwater remedial activities on site pertaining to the petroleum hydrocarbon contamination. As <br />part of this process, the site owner has installed a vapor extraction well on site and is in the process <br />of submitting a soil remediation plan to the EHD. (3,4,10) <br />3.0 HAZARD RANKING SYSTEM FACTORS <br /> <br />3.1 Sources of Contamination <br />Potential sources of hazardous substances stored at the site include: <br />two 55-gallon drums containing solvent wastes at the MPI Label Systems, Inc. <br />facility. <br />fifteen gallons of solvent wastes stored at the Sweets Tinware facility. <br />PA Marlowe Property-SS • 6/95 <br /> 5 Printed on 50% recycled paper.