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Geological Teckjeics Inc. <br /> Page 3 <br /> Groundwater Monitoring Report <br /> Project No.989.2 <br /> I <br /> November 20,2001 <br />� r <br /> 2.2 Laboratory Analyses <br /> The groundwater samples collected on September 27, 2001 were delivered to Sherwood <br /> Labs (Department of Health Services Certification No. 1400), of Hilmar, California, for the <br /> following analysis: <br /> • Benzene, toluene, ethylbenzene and xylene (BTEX by EPA method 8020) <br /> • Gasoline range petroleum hydrocarbons (TPH-Gasoline by EPA method 8015(m)) <br /> ' • Fuel oxygenate suite ((MTBE, DIPE, ETBE,TAME, and TBA)by EPA method 8260) <br /> • 1,2-Dibromoethane and 1,2-Dichloroethane (1,2 DCA and EDB by EPA method 8260) <br /> The fuel oxygenates, 1,2 DCA and EDB samples were submitted to Entech Analytical Labs <br /> of Santa Clara, CA (DHS # 2346). <br /> ' A Chain of Custody was completed for all samples collected and tracked to ensure sample <br /> integrity. Laboratory data sheets with detection limits are included in Appendix C. <br /> 3.0 FINDINGS AND DISCUSSION <br /> 3.1 Hydrology of Site <br /> ' On September 27, 2001, the depth to groundwater was measured in all of the wells prior to <br /> purging. Depths to groundwater ranged from a high of 7.39-feet below the top of casing to <br /> a low of 8.73-feet below the top of casing. The wells are screened at 5-feet bgs and <br /> ' groundwater surface continues to be below the tops of the screens in the 6 monitoring wells. <br /> Groundwater elevations were calculated and are summarized in Table 2 of Appendix A. <br /> Site-specific groundwater gradient was calculated using MW-1, MW-3 and MW-6, and <br /> found to be N35°W at 0.005 ft/ft. This is consistent with previous monitoring events this <br /> ' year. The calculated groundwater gradient is displayed on the groundwater gradient map, <br /> Figure 3. <br /> 3.2 Groundwater Analytical Results <br /> • Low concentrations of BTEX and TPH-gasoline were present in MW-1 & 4. The levels <br /> have decreased from previous monitoring events. <br /> • A very low concentration of Xylene is present in MW-3. All other constituents were <br /> non-detect. <br /> • No BTEX or TPH-gasoline were found in MW-2, 5, & 6. <br />