Laserfiche WebLink
1 <br /> I <br /> Groundwater samples were collected from the five wells using a disposable Teflon sampling <br /> bailer, packed in an iced cooler, and transported under Chain-of-Custody manifest to Sparger <br /> ' Technology, Inc , a California-certified analytical laboratory located in Sacramento, California <br /> The laboratory analyzed each field sample for benzene, toluene, ethylbenzene, xylenes (BTEX) <br /> and Total Petroleum Hydrocarbons as gasoline (TPH-gasoline) using EPA Method 8015/8020 <br /> I <br /> The laboratory reports and chain-of-custody documents are included as Appendix B <br /> Analytical results of the third quarter 1996 sampling event indicate that petroleum hydrocarbons <br /> ' are present in the groundwater beneath the site Total Petroleum Hydrocarbons as gasoline was <br /> detected in groundwater samples collected from VW-I at 260 micrograms per liter (ug/L) and in <br /> ' VW-2 at 11,000µg/L Benzene was detected in the groundwater sampled collected from VW-1 <br /> at 0 86 µg/L and in VW-2 at 1,300µg/L Toluene, ethylbenzene, and/or xylenes were also <br /> ' present in groundwater samples collect from VW-I and VW-2 The current and historical <br /> laboratory results and their detection limits are summarized in Table 2 <br /> ' 4.0 Conclusion and Recommendations <br /> Since May 1992, the groundwater surface has risen an average of 19 06 feet This extreme rise <br /> in the groundwater table has resulted in groundwater elevations above the screened interval of <br /> ' the groundwater monitoring wells This condition has probably resulted in inconsistent <br /> groundwater flow direction and gradient interpretations and unrepresentative groundwater <br /> sample collection and analytical results To obtain data that better represents groundwater <br /> ' conditions, groundwater samples were collected from two vapor extraction wells, which are <br /> screened across the current groundwater table <br /> The groundwater sample collected this quarter from vapor extraction well (VW-2) contained the <br /> ' highest concentrations of gasoline hydrocarbons detected to date Total Petroleum Hydrocarbons <br /> as gasoline was detected in VW-2 at 11,000µg/L Benzene was detected at 1,300µg/L <br /> ' Based on the groundwater sampling results from the vapor extraction wells IT recommends that <br /> additional environmental corrective action be performed at the site Specific recommendations <br /> relative to the continued monitoring and potential remediation at the site are as follows <br /> 2 <br />