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3 0 CONCLUSIONS, RECOMMENDATIONS AND PROJECT STATUS <br /> ' Between April 25, and September 12, 2005, the groundwater surface dropped an average of 1 96 <br /> feet, the groundwater gradient decreased from 0 0071 to 0 0064 foot/foot, and the groundwater <br /> flow direction remained toward the north-northeast These groundwater flow and gradient <br /> characteristics are relatively consistent with seasonal and historical trends <br /> Between April 25, and September 12, 2005, the concentrations of gasoline compounds in <br /> groundwater generally declined In MW-2, the concentration of MTBE decreased from 1 4 to 1 2 <br /> }tgll Gasoline compounds in the subsurface remain defined to the vicinity of well MW-2 and the <br /> former UST system Previous investigations have shown that the former on-site water supply well <br /> and nearby domestic wells have not been impacted by gasoline compounds released from the <br /> former UST system <br /> In general, the concentrations of gasoline compounds in groundwater beneath the site have <br /> declined, most likely in response to prior source removal efforts and natural attenuation <br /> processes Given the low and rapidly declining concentrations of gasoline compounds in <br /> groundwater, active soil and groundwater remediation has not been necessary to reduce <br /> concentrations to below water quality goals MTBE has not been detected above 5 µg11 (the <br /> secondary California Maximum Contaminant Level [MCL]) since March, 2003 (in well MW-2), and <br /> lie no other gasoline compound has exceeded its respective MCL, in any well, over the last four <br /> quarters <br /> Based on these conclusions, Ramage Environmental recommends that the nine monitoring wells <br /> ' be monitored and sampled during the fourth quarter of 2005, after which, should gasoline <br /> compounds remain below their respective MCLS and/or below reporting limits, the site should be <br /> considered for regulatory closure <br /> ' 10 <br />