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C"'Iogual reckfws I= Page 4 <br /> V Quarter 2002 Groundwater Monitoring Report <br /> Project No 507 2 <br /> June 17,2002 <br /> 1.3 Laboratory Analyses <br />' The groundwater samples collected on February 26, 2002, were delivered to Sherwood Labs <br /> Corporation, Department of Health Services Certification No 1400, of Hilmar, California, <br /> for analysis <br />' Sherwood Labs analyzed the groundwater samples for <br />' • Benzene, Toluene, Ethyl Benzene, and Xylene (BTEX) by EPA method 8020 <br /> • Total Petroleum Hydrocarbons as Gasoline (TPH-G) by EPA method 5030/8015 <br /> • MTBE by EPA Method 8020 <br />' Sherwood forwarded samples from well MW-4, MW-5 and MW-9 to Entech Analytical <br /> Labs Inc , Department of Health Services Certification No 2346, of Santa Clara, California, <br />' for analyses of <br /> • MTBE, DIPE, ETBE, TAME, TBA, EDB and 1,2 DCA by EPA method 8260 <br />' • Methanol and Ethanol by EPA method 8015 <br /> The results and detection limits for the above analyses are listed in Table 3 of Appendix A <br /> while the lab analytical results are presented in Appendix B <br /> As required under AB2886, the laboratory data was submitted electronically to GeoTracker <br />' on April 26, 2002 - confirmation number 3241559624 <br />' 2.0 FINDINGS AND DISCUSSION <br /> The results of the groundwater sample analyses indicate the following <br /> • Wells MW-1, MW-2 and MW-3 remain free of detectable contamination <br /> • MW-4, MW-5 and MW-9 have significant BTEX and TPH-G contamination <br /> i • MW-6 and MW-8 have minor TPH-G or BTEX contamination <br /> • Water table well MW-7 contained 7 3 µg/l MTBE This was non-detect for the <br /> ' December 2001 event but has previously contained 13 - 15 pg/1 MTBE for the first two <br /> events completed when the well was installed in May 2001 <br /> • Water table well MW-10 contained 0 7 gg/l xylene This is the second event in which <br /> ' xylene was detected in the well at a level dust above the laboratory reporting limit of 0 3 <br /> µg/l <br /> ' • Deep well MW-109 contained minor BTEX contamination for the fourth consecutive <br /> event A reduction in contaminant concentrations from the first sampling event was <br /> noted, however sufficient monitoring has been performed to conclude that it is probably <br /> not the result of a drilling artifact <br />