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3.0 CONCLUSIONS, RECOMMENDATIONS AND PROJECT STATUS Between March 28, and June 29, 2006, the groundwater surface beneath the site dropped an average of 0 60 feet, the groundwater gradient decreased from 0 0033 to 0 0002 foot/foot, and the groundwater flow direction remained toward the west-northwest These groundwater surface characteristics are consistent with seasonal and historical trends Between March 28, and June 29, 2006, the concentrations of petroleum hydrocarbons detected in groundwater, including TPH-as-d,esel, TPH-as-gasoline and BTEX compounds, generally increased in all three wells The oxygenate compounds continued to be below laboratory detection limits Since the three monitoring wells were installed in December 2000, the concentrations of petroleum hydrocarbons in groundwater have generally declined, probably in response to source removal and natural attenuation processes As shown on Figures 4, 5, and 6, the lateral extent of impacted groundwater at the groundwater table is undefined for TPH-as-diesel and TPH-as-gasoline, and mostly defined for benzene Impacted groundwater appears to be concentrated beneath the former USTs, and to the west and north of the former USTs On May 8, 2003, Ramage Environmental published Work Plan, Additional Site Investigation EHD approved the work plan on June 3, 2003 On November 1, 2005, EHD met with representatives of the San Joaquin County Facilities Management Department Ina letter summarizing the meeting dated November 17, 2005, EHD stated that 1 This site is currently performing routine quarterly groundwater monitoring and sampling The work plan to continue the investigation of the vertical and lateral extent of the contamination approved by EHD in June 2003 should be implemented A site conceptual model and/or cross section should be prepared by your consultant to identify contaminant migration pathways EDB should be added to the suite of analytes being tested for in the groundwater samples Ramage Environmental recommends that the approved work plan should be implemented, once funding is available within the county budget, and that a site conceptual model and/or cross- section should be completed upon completion of the approved scope of work In the meantime, the plume of impacted groundwater should continue to be monitored on a quarterly basis 9