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L Following purging and recharge, groundwater samples were collected from the wells using dedicated and disposable sampling bailers. Irrigation Well #2 was allowed to flow at the two wellhead until the downhole pump was automatically activated. A groundwater sample was collected directly at the wellhead through a sample port. The groundwater samples were contained in laboratory-supplied containers, and transported in an iced cooler with chain-of-custody documentation to Excelchem Environmental Labs (Excelchem), a state of California certified analytical laboratory (#2119). Excelchem analyzed the groundwater samples for TPH-as-gasoline, benzene, toluene, ethylbenzene, and xylenes (BTEX) by EPA Method 8021 B18015M, and for MTBE, di-isopropyl ether (DIPE), ethyl-t-butyl ether (ETRE), tert-amyl methyl ether (TAME), tert-butanol (TBA) and 1,2-DCA by EPA is Method 82608. Analytical results of the groundwater samples indicate that dissolved concentrations of gasoline hydrocarbons continue to exist in groundwater beneath the site. Consistent with previous quarterly groundwater sample analytical results TPH-as-gasoline and BTEX compounds were not detected in any of the groundwater samples. MTBE was detected in five of the wells, at a maximum concentration of 52.1 µg11 at MW-5. 1,2-DCA was detected in four wells, at a maximum concentration of 12.2 µg/l at MW-5. Groundwater from Irrigation %W Well #2 did not contain detectable concentrations of any of the gasoline compounds. The %.0 cumulative analytical results are summarized in Table 3, and the laboratory reports are t.e included in Appendix A. k.e v Between August 25, and December 15, 2005, the concentrations of gasoline compounds in the groundwater monitoring wells remained relatively consistent. As shown on Figure 8, MTBE in groundwater appears to be limited to the groundwater table to the northeast (downgradient) of the former UST. Groundwater collected from Irrigation Well #2 has been free of gasoline compounds for 23 consecutive quarters. 2.3 Wastewater Disposal t.. On December 21, 2005, Doulos Environmental, Inc. transported approximately 220 gallons of �-' groundwater, accumulated from sampling activities as non-hazardous waste, to InStrat, Inc. in v Rio Vista, California. 1nStrat treated the wastewater with granular activated carbon and ,., disposed of it according to their waste discharge permit. A copy of the non-hazardous water transport form is included in Appendix B. 10