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1 ' Boyett Petroleum 419 Main Street, Manteca, California - Quarterly Groundwater Sampling Report ' September, 2001 Narrative ' - On December 17, 2001, GeoAnalytical Laboratories, Inc., conducted field measurements, well pumping and groundwater sampling on nine (9) groundwater monitoring wells ' located at this site(Figures 1 and 2). Groundwater elevations were taken from nine (9) wells prior to pumping (Table I & Appendix B). Monitoring wells MW-1 through MW-9 were evacuated by means of a steam-cleaned, stainless steel bladder type pump. During the three (3) volume pump down of each well, samples were collected to measure field pH, electrical conductivity. ' and tempbrature (Table 3 & Appendix B). Once stability was achieved, a minimum of three (3) well volumes were removed and samples were collected with a disposable . bailer. The samples were then labeled and placed in an ice chest cooled with Ice®. The were samples p e e then logged on a Cham of Custody (Appendix A) and transported to , ' the State-certified laboratory, GeoAnalytical Laboratory Inc., in Modesto, California. The analysis requested for the nine (9) water samples was EPA method 8260B for BTX&E (Benzene, Toluene, Xylene, and Ethyl-Benzene), oxygenates, Ethylene Dibromide (EDB), and 1,2-Dichloroethane (1,2-DCA), and EPA method GCFID (5030/Luft) for gasoline.'The analytes and concentrations detected are listed in Table 2 of this report. ' Groundwater Gradient The water level measurements from eight (8) monitoring wells (MW-1 — MW-8) were used to construct a groundwater gradient map (Figure 3). MW-9 is a deep well, therefore it is not used in the gradient calculation. This quarter, the groundwater gradient trend is ' North 5° West with a downward slope of 0.002 ft/ft. Historical groundwater gradient maps are provided for reference in Appendix C.