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i <br /> to the presence of elevated levels of hydrocarbons beneath the three tanks, the San Joaquin <br /> County Public Health Services, Environmental Health Division (PHS/EHD) requested <br /> additional work be performed at the site <br /> 23 Monitoring Well Installation and Sampling <br /> Five soil borings (B1 through B5) were drilled at the site between February 11 to 14, 1994. <br /> I Borings B1 through B4 were completed as groundwater monitoring wells MW-1 through <br /> MW-4, respectively. A total of twenty-two soil samples were analyzed by Sparger <br /> Technology, Inc. (STI) for total petroleum hydrocarbons (TPH) as gasoline and diesel, and <br /> I volatile aromatics (BTE&X) The analytical results of the soil samples are summarized in <br /> Table 1. <br />' Groundwater samples were collected from each well on February 22, 1994. No free product <br /> was encountered. The samples were analyzed for TPH as gasoline and diesel and BTE&X <br /> I by STI TPH as gasoline and BTE&X were detected in each well, TPH as diesel was <br /> detected in MW-4 The analytical results of all groundwater samples are summarized in <br /> Table 4. <br /> 3.0 PROCEDURES <br />' 3.1 Monitoring Well Purge Procedures <br /> On September 23, 1994, the depth to water in each momtonng well was measured relative <br /> to the top of the casing using a Solinst water level meter (Table 3) However, free <br /> hydrocarbon product was encountered in MW-4 Therefore, an interface probe was used to <br />' measure free product thickness (Table 2) <br /> PVC bailers were used to remove between nine and ten gallons of water from MW-1, MW-2 <br />' and MW-3 to stabilize temperature, pH, and the conductivity Well parameters were <br /> measured at one-gallon intervals using an ICM Water Analyzer (Appendix A) The purge <br />' water was stored in 55-gallon DOT-approved drums at the site <br /> 3.2 Sample Collection and Laboratory Analysis <br />' After stabilization, water samples were collected using disposable plastic bailers The <br /> samples were placed in 40-m1 vials and transported in a chilled container to Pan-Agricultural <br /> I Environmental Labs, Inc in Madera, California Each sample was analyzed for TPH as <br /> gasoline and BTE&X in accordance with EPA methods 5030/8015m and 602, respectively <br />' 33 Free Product Removal <br /> Because free product was encountered in MW-4, a free product removal plan was proposed <br />