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1 <br /> ' Boyett Petroleum <br /> 429 Main Street, Manteca, California <br /> Quarterly Groundwater Sampling Report <br /> December, 2000 <br />' Narrative <br /> On December 29, 2000, and January 16, 2001, GeoAnalytical Laboratories, Inc., <br /> conducted field measurements, well pumping and groundwater sampling on eight (8) <br />' groundwater monitoring wells located at this site (Figures 1 and 2). <br /> Groundwater elevations were taken from four (8) wells prior to pumping (Table 1 & <br />' Appendix B). Monitoring wells MW-1 through MW-8 were evacuated by means of a <br /> steam-cleaned, stainless steel bladder type pump. During the three (3) volume pump <br /> down of each well, samples were collected to measure field pH, electrical conductivity and <br />' temperature (Table 3 & Appendix B). Once stability was achieved, a minimum of three <br /> (3) well volumes were removed and samples were collected with a disposable bailer. The <br /> samples were then labeled and placed in an ice chest cooled with Ice®. <br />' • The samples were then logged on a Chain of Custody (Appendix A) and transported to the <br /> State-certified laboratory, GeoAnalytical Laboratory Inc., in Modesto, California. The <br /> analysis requested for the eight (8) water samples was EPA method 8260B for BTX&E <br /> (Benzene, Toluene, Xylene, and Ethyl-Benzene), oxygenates, Ethylene Dibromide (EDB), <br /> and 1,2-Dichloroethane (1,2-DCA), and EPA method GCFID (5030/Luft) for gasoline. <br /> The analytes and concentrations detected are listed in Table 2 of this report. <br />' Groundwater Gradient <br />' The water level measurements from eight (8) monitoring wells were used to construct a <br /> groundwater gradient map (Figure 3). This quarter, the groundwater gradient trend is <br /> South 45° West with a downward slope of 0.0013 ft/ft. Since the sampling event in <br /> September, 2000, the groundwater has fallen an average of 1.5 feet. Historical <br /> groundwater gradient maps are provided for reference in Appendix C. <br /> Summary of Analytical Findings <br /> 1 <br /> This quarter, detectable contamination levels were identified in the monitoring wells listed <br />' below: <br />