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1 <br /> Mr George Takemori Project OF90-002 05 <br />• August 15, 1996 <br /> Page 3 <br /> MW-9 through MW-14 In addition, on May 17, 1996, groundwater samples were <br /> collected from monitoring wells MW-9 through MW-11 and MW-14 for laboratory <br /> analyses Well MW-9 was partially obstructed and well purging could not be performed, <br /> therefore, a groundwater grab sample was collected Wells MW-3 through MW-5 were <br /> dry during the site visit Floating product was not observed in any of the monitoring wells <br /> Well locations are shown on Figure 2. EMCON's sampling and analysis procedures are <br /> presented in Appendix A <br /> The surveyed elevations and the depth to groundwater measurements, summarized in <br /> Table 2, were used to evaluate the flow direction beneath the site The flow direction on <br /> April 16 and May 17, 1996, was toward the northeast with a hydraulic gradient of <br /> 0 001 (see Figures 3 and 4) Groundwater elevations increased approximately 3 80 feet <br /> from the previous sampling event (February 1996) in wells MW-9 through MW-14 <br /> Analytical Methods and Results <br /> Groundwater samples collected from wells MW-9 through MW-11 and MW-14 were <br />• analyzed for TPHG using modified U S Environmental Protection Agency (USEPA) <br /> Method 5030/DHS LUFT and for BTF-X using USEPA Method 5030/8020 The samples <br /> were analyzed at Columbia Analytical Services, Inc , in San Jose, California (Cahfomia <br /> Department of Health Services Hazardous Waste Testing Laboratory Certification <br /> No. 1426) Copies of the chain-of-custody records and laboratory analysis reports are <br /> presented in Appendix B <br /> The results of laboratory analyses indicate that TPHG and BTEX were not detected in <br /> groundwater samples collected from wells MW-9 and MW-10 Dissolved hydrocarbons <br /> were detected in wells MW-11 and MW-14 TPHG concentrations ranged from 270 parts <br /> per billion (ppb) in well MW-11 to 2,500 ppb in well MW-14 Benzene concentrations <br /> ranged from below laboratory detection luruts in well MW-11 to 45 ppb in well MW-14 <br /> Analytical results are summarized in Table 2 Concentrations of TPHG and benzene are <br /> shown on Figure 2 <br /> DISTRIBUTION OF PETROLEUM HYDROCARBONS <br /> The following sections discuss the distribution of petroleum hydrocarbons in the soil and <br /> groundwater <br /> • <br /> SACW\PJ"F9MF900020 5AS-95Spw 1 <br />