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1 <br /> Eckertld Stora a Com an <br /> Co g p y <br /> 757 Moffat Blvd, Manteca, California <br /> ' Quarterly Groundwater Sampling Report <br /> December, 1999 <br /> ' Narrative <br /> On December 10, 1999, GeoAnalytical Laboratories, Inc., conducted field measurements, <br /> well pumping and groundwater sampling on six (6) groundwater monitoring wells <br /> located at this site (Figure 1 & 2). The new well, MW-8 was accidentally omitted during <br /> ' this site visit. WHF, Inc., became aware of the omission on December 20, 1999 and <br /> contacted GeoAnalytical Laboratories, Inc. to notify them of the omission. <br /> GeoAnalytical Laboratories revisited the site on January 5, 2000 and collected a <br /> groundwater sample from MW-8. <br /> Groundwater elevations were taken from eight wells prior to pumping (Table 1 & <br /> Appendix B). All monitoring wells were evacuated by means of a steam-cleaned, <br /> stainless steel bladder-type pump, except MW-2. During the three (3) volume pump <br /> down of each well, samples were collected to measure field pH, electrical conductivity <br /> and temperature (Table 3 & Appendix B). Once stability was achieved, a minimum of <br /> three (3)well volumes were removed and samples were collected with disposable bailers. <br /> The samples were then labeled and placed in an ice chest cooled with Blue Ice®. <br /> ' The samples and trip blank were then logged on a Chain of Custody and transported to <br /> the State-certified laboratory, GeoAnalytical Laboratories, Inc., in Modesto, California. <br /> ' The analyses requested for the water samples was EPA method 602 for BTX&E <br /> (Benzene, Toluene, Xylene, and Ethylbenzene) and MTBE (Methyl t-butyl ether), EPA <br /> method 5030/Luft (GCFID) for Gasoline, and EPA method 3510/Luft for Diesel. MTBE <br /> contamination was confirmed by EPA method 8260. The laboratory analytical data, <br /> chain of custody report, and QA/QC documents can be found in Appendix A of this <br /> ' report <br /> Groundwater Gradient <br /> ' The water level measurements from monitoringwells MW-4 MW-6 and MW-7 were <br /> , <br /> used to calculate the gradient and construct a groundwater gradient map (Figure 3). The <br /> ' gradient for this quarter is N61°E at 0.0027 ft/ft. Historical gradient maps are included in <br /> . Appendix C. The groundwater elevation at the site has risen since last quarter,by an <br /> ' average of 0.39 feet across the site. <br />