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r Ms Margaret Lagorio Project No 880-040 IA November 8, 2002 Page 8 1 Groundwater Results Groundwater analytical data collected during the DPE test are summarized in Table 3 Laboratory reports with chain-of-custody (COC) documentation are included in Attachment F Prior to the DPE test, TPHg, benzene, and MtBE concentrations in well MW-1 were 4,900, 1,000, and 17,000 pg/L, respectively, as reported in the Second Quarter 2002 ' sampling event on April 23, 2002 Effluent concentrations of TPHg, benzene, and MtBE ✓ at the start of the DPE test were 460, 49 and 3,800 pg/L, respectively At the end of the test, effluent concentrations of TPHg, benzene and MtBE were 420, 4 5, and 1,600 µg/L, respectively, and the concentrations in well MW-1 were 1,300, 260, and 9,900 µg/L, respectively During the test a total of 19,700 gallons of groundwater were pumped from well MW-1, or an average rate of 2 74 gallons/minute Depth to water was monitored in wells MW-2 through MW-5 throughout the test rChange in groundwater elevation was recorded almost immediately following the start of the test The average drawdown in wells MW-4 and MW-5 was approximately ' 0 22 feet, in well MW-3 it was approximately 0 16 feet, and in well MW-2 it was approximately 0 13 feet I Vapor Results ' Vapor analytical data are summarized in Table 4 and laboratory reports with chain-of-custody (COC) documentation are included in Attachment F rAt the start of the DPE test, TPHg, benzene, and MtBE were not detected in vapor extracted from well MW-1 After 3 hours, TPHg, benzene, and MtBE concentrations ' were 2,300, 6 5, and 93 mg/m3, respectively Hydrocarbon concentrations fluctuated throughout the test, but generally declined by the end of the 5-day test In the final hour i ' N VancfpilProjectslProjects18801040%lakOI IO%ssessment and Intenm Remedial ReporLdoc