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' From June 1999 through June 2000, ENSR operated a sod vapor extraction (SVE) system at the <br /> . site Initially, ENSR extracted from VW-1D, VW-1S, VW-2S, VW-3, and VW-4 After several <br /> months of operation, air sparging was initiated in MW-1 According to ENSR, the remediation <br /> system removed over 7,000 pounds of gasoline hydrocarbons from the subsurface In July <br /> ' 2000, ENSR decommissioned the system and removed the equipment from the site <br /> On November 28, 2000, Ramage Environmental published Environmental Site Investigation <br /> Report documenting the results of a sensitive receptor survey and the drilling of confirmation soil <br /> borings <br /> ' According to available records, three property parcels within 2,000-feet of the site have <br /> operating water wells These properties include the San Joaquin Catholic Cemetery (site), St <br /> Joseph's Hospital, and a residential dwelling at 1821 North Hunter Street <br /> To confirm the effectiveness of remediation efforts, soil samples were collected every 10 feet to <br /> a total depth of 100 feet directly beneath the former USTs The soil sample results indicated <br /> that except for 560 milligrams per kilogram (mg/kg) of TPH-as-gasoline in soil at a depth of <br /> ' approximately 10 feet below ground surface (bgs), the vadose zone was almost completely <br /> remediated by the SVE system <br /> To delineate the vertical extent of impacted groundwater, discrete groundwater samples were <br /> collected at 75, 90, and 125 feet bgs from sod borings located approximately 20 feet northeast <br /> (downgradient) of the former USTs The discrete groundwater sample results indicated that the <br /> vertical extent of impacted groundwater was mostly delineated Concentrations of methyl tertiary <br /> ' butyl ether(MTBE) decline significantly with depth and are not present in the 125-foot <br /> groundwater-bearing interval Only 1,2-dichloroethane (1,2-DCA) was detected in the 125-foot <br /> groundwater sample, at a low concentration of 0 5 micrograms per liter (µg/1) <br /> 4 <br />