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Mr. Brian Cobb August 29, 1995 ' Page 2 SVE Pilot Tests ' Two separate SVE pilot tests were performed on Site on May 1, 1995 Wells MW-5 and MW-2 were used as test wells for the SVE pilot tests (Figure 1) For each test, the unlet to ' the Rotron brand blower was connected to the test well via a 2-inch-diameter flexible hose The outlet of the blower was connected to two 55-gallon granular activated carbon (GAC) canisters, arranged in series, also using flexible hose. The blower was powered using a portable 240-volt, 3-phase generator. The flow rate for the blower was measured using a pitot-type magnehelic flow meter Vacuum measurements at the observation well heads were measured using an oil manometer capable of reading both vacuum and pressure Field 11' records collected during the pilot tests are attached The following describes the procedures followed during each of the tests. ' Well MW-5 SVE Pilot Test. This SVE pilot test was conducted over a 2-112-hour period. The flow rate at the well was started at 20 cubic feet per minute (cfm) and incrementally increased to 40 cfm, then to 50 cfm, at approximately 75-minute intervals However, at ' three different periods during the test, the blower shut down due to overheating The blower was off for approximately 30 minutes each time. The blower was allowed to operate at a maximum rate of approximately 50 cfm for approximately 75 minutes The maximum vacuum sustained at Well MW-1 during this test was 52 inches of water at a flow rate of 50 cfm A portable photo-ionization detector (PID) was used to monitor concentrations of volatile organic compounds (VOC) in the vapor effluent and monitor the GAC units for breakthrough during the test. Vacuum, flow rate, and VOC concentrations for the test well and resulting vacuum measurements recorded at the monitoring well heads are presented in Table 1. Well MW-2 SVE Pilot Test The second SVEilot test was run for approximately Y 45 minutes The flow rate at the well was held constant at 20 cfm throughout the duration of the test The maximum vacuum sustained at Well MW-2 during this test was 98 inches of water Vacuum and flow rate measurements and VOC concentrations (as measured with the PID) measured in the test well, and resulting vacuum measurements,recorded at the monitoring well heads are presented in Table 1 r , In addition to the measurements collected during the two SVE pilot tests, one vapor sample was collected from Well MW-5 at the end of the fust pilot test The sample was collected using a vacuum pump connected to a sample tap located near the well head, downstream of �I the flow meter and upstream of the first GAC The sample was stored in a dry cooler until being submitted to Air Toxics LTD , a State of California Department of Toxic Substances'I i Control certified analytical-laboratory. The sample was analyzed for the presence of total petroleum hydrocarbons as gasoline(TPHg) and benzene, toluene, ethylbenzene, and xylene I 08!17/9516 VJLn156RI565-6T1.TR-01 WP51 r HpLmwr1Ap II I t , ' Brown andValdwell 'Cons'ultants r I