ARCHIVED REPORTS XR0001498 - Laserfiche WebLink

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TABLE 3 ' ANALYTICAL RESULTS FOR BORING B-1 IN FORMER TANK CAVITY October 9, 1990 1 Sample TPH as I (mg/kg) Ethyl- Total ID Gas Benzene Toluene benzene Xylene Lead ' B1-20 93 05 15 35 14 11 BI-30 6100 31 520 170 520 NA 1 B1-40 13 021 26 037 13 NA B1-50 ND 001 0 025 ND 0 007 NA ' B1-60 ND ND ND ND ND 9 3 ' ND =Not detected NA=Not Anatyzed ' TPH as gasoline and BTE&X.The borings were completed as groundwater monitoring wells (MW-1 through MW-3) A benzene concentration of 0 0079 mg/kg was detected at a depth of 45 feet in MW-2, just south of the tank pit Analytical results for soil borings B-1 through B-3 (MW-1 through MW-3) are presented in Table 4 Based on these and prior results, GeoAudit recommended further excavation to remove the contaminated soil At the request of Mr Gotelli, GeoAudit submitted an Interim Remediation Plan for overexcavation Excavation activities and results are presented in section 3 5 On March 17, 1993, the water level in each well was measured, the wells were purged, and water samples were collected The initial gradient direction was determined to be 0 0073 ft/ft directed S 7° W Benzene and xylene were detected in MW-2 at 3 7 tLg/L and 1 1 µg/L, respectively A summary of all analytical results for groundwater samples is presented as fTable 5 3.4 Quarterly Groundwater Monitoring Between June 1993 and April 1994, monitoring wells at the site were sampled a total of four I times Prior to each sampling, the depth to groundwater was measured in each well using a Sohnst water level meter The wells were purged of standing water to stabilize pH, temperature and conductivity using submersible pumps or PVC bailers Purge water was stored on-site in 55-gallon DOT drums All samples were collected using disposable bailers and were analyzed by a state-certified laboratory for TPH as gasoline and BTE&X Historical groundwater depths are included in Table 5 i i 0-1.p-1 A.du S.—I.. 6 Q