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1 <br /> GROUNDWATER SAMPLING <br /> The wells were purged to dryness. The groundwater samples were <br />' collected via a clean bailer, placed in 40 ml VOAs, labeled, placed <br /> in a cooled ice chest and transported to a state certified <br /> laboratory (MCCAMPBELL ANALYTICAL INC. ) under Chain of Custody <br />' (COC) documentation for analysis. The groundwater samples from MW- <br /> 1 and MW-2 wells had a hydrocarbon odor. <br />' ANALYTICAL RESULTS <br /> The analytical methods are those required in the 'tri-Regional <br /> GAd " whish are directives of the Regional Water Quality <br /> Control Board and requested by the SJCEHD. <br />' The analyses completed were for Total Petroleum Hydrocarbons, as <br /> gasoline (TPHG) ; Benzene, Toluene, Ethylbenzene and Xylene (BTEX) <br /> and Methyl-tent-butyl ether (MTBE) via EPA Modified Method <br />' 8020/8015. <br /> The results of the groundwater samples in ug/L (parts per billion <br /> {ppb}) for TPHG, MTBE and BTEX are shown in Table 1. <br /> Laboratory Data Sheets with detection limits and a copy of the <br /> Chain of Custody (COC) are contained in Appendix B. <br /> SUMMARY, CONCLUSIONS AND RECOMMENDATIONS <br /> The calculated gradient is S 72 W or 2880 at 0. 02 ft/ft. This is <br /> a generally westerly gradient. The direction and slope have <br /> changed from southerly found in the prior calculated gradients. <br /> The gradient direction and slope changes are most likely due to <br /> changes in recharge from surface waters. <br /> Based on the analytical data from prior quarterly reports, it <br /> appears that no detectable concentrations of MTBE are impacting the <br /> groundwater at this site. <br /> The groundwater beneath the site has been impacted and heavy <br /> I gasoline and BTEX contamination were detected in the groundwater <br /> samples from MW-1 and MW-2. The concentrations of TPHG and BTEX in <br /> MW-1 have increased significantly. Lesser concentrations of <br /> . gasoline and BTEX were detected in the sample from MW-3 . <br /> JPCA recommends continued monitoring of the wells to further <br /> evaluate the amount of contamination and consistency of the <br /> i3 <br /> I ;t <br /> I <br />