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3.0 CONCLUSIONS, RECOMMENDATIONS AND PROJECT STATUS Between June 29, and September 21, 2005, the groundwater surface dropped an average of 1 09 feet, the groundwater gradient increased from 0 0104 to 0 0114 foot/foot, and the groundwater flow direction remained toward the northeast These groundwater surface characteristics are consistent with historical and seasonal trends Between June 29, and September 21, 2005, gasoline compounds in groundwater generally decreased at MW-1, and remained relatively consistent at MW-2 and MW-3 Concentrations of gasoline compounds in groundwater at MW-1 have generally declined, since the monitoring wells were installed in July 2002, probably due to source removal efforts and natural attenuation processes Since March 2004, concentrations of MTBE have been detected in the perimeter wells (MW-2 and MW-3) During the third quarter of 2005, the MTBE concentrations detected in MW-2 and MW-3 were both below the state of California Secondary Maximum Contaminant Level (MCL) of 5 µg11 ' On November 1, 2005, EHD met with representatives of the San Joaquin County Facilities Management Department In a letter summarizing the meeting dated November 17, 2005, EHD �• states that There is a sand lens at 35 feet bgs at this site that may be a migratory pathway for the ' MTBE contamination It was discussed that placement of soil borings up-gradient (southwest) and cross-gradient(southeast) of MW-9 and obtaining soil samples and grab water samples from 35 feet bgs may provide definition for the site If those samples are non detect then the site should be evaluated to see If further investigation is needed ' Ramage Environmental recommends that a work plan be prepared that outlines the scope of work requested by EHD in addition, the plume of impacted groundwater should continue to be ' monitored on a quarterly basis to further evaluate natural attenuation of the plume of impacted groundwater r I I I 7