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1ZIN <<fSecond Qusrler 1997 Status Report-Former Uicovery Chevrolet July 7, 1997 Quarterly monitoring and sampling of the monitoring wells begin in March 1995. Historically, depth to groundwater has fluctuated between 9.86 and 11.53 feet bgs. Groundwater appears to flow toward the north-northwest at a gradient of approximately 0.003 to 0.005. Floating product has not been observed in the monitoring wells. TPHg, BTEX, or Oil and Grease have not been detected in well MW-3. TPHg concentrations in wells MW-1 and MW-2 have ranged from 60 to 17,000 ppb, and benzene concentrations have ranged from 10 to 3,100 ppb. Historical quarterly groundwater monitoring and chemical analytical data are summarized in Table 1. Two additional groundwater monitoring wells (MW-4 and MW-5) were installed by Horizon Environmental Inc., on April 3, 1997. These wells were installed to a total depth of 20 feet bgs. Soil and groundwater chemical analytical results and installation details were presented in Horizon Environmental's well installation report. PRESENT QUARTER FIELD ACTIVITIES Quarterly monitoring and sampling of the groundwater monitoring wells for the second quarter 1997 was performed by G-R on June 12, 1997. Field monitoring and chemical analytical data from the current quarter are summarized in Table 1. The G-R groundwater sampling procedures are summarized in Appendix A. Copies of the G-R field data sheets J are presented in Appendix B. Copies of the laboratory analytical report and completed chain-of-custody form are presented in Appendix C. Groundwater Monitorin and Gradient Evaluation Depth-to-water (DTW) measurements were obtained by G-R from groundwater monitoring wells MW-1 through MW-5 prior to well purging and sample collection. Static groundwater levels were measured from the north edge of the top of each well casing and recorded to the nearest ±0.01 foot. Groundwater was measured between 9.97 and 10.89 feet bgs. These water-level data were used to construct a Potentiometric Map (Figure 3). Based on these data, the shallow groundwater beneath the subject site appears to flow toward the north- northeast at a gradient of approximately 0.004. Each well was inspected for the presence of floating product. Floating product or a product sheen was not observed in any of the groundwater monitoring wells this quarter. Laboratory Analytical Data The groundwater samples were collected in sample containers supplied by the laboratory. The samples from wells MW-1 through MW-5 were analyzed for TPHg by Environmental Protection Agency (EPA) Method 50301GC-FID, and for benzene, toluene, ethylbenzene, and total xylenes (BTEX) and Methyl Tertiary Butyl Ether (MTBE) by EPA Method 8020. 9146.04-2 3 i I