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Findings The groundwater elevation in the wells varies from the same as the last event to a drop of+/- 04 feet. MW-I continues to have the highest concentration of gasoline contamination for TPHg at 132,000 ppb. which is higher than 127,000 ppb. of the last sampling event. In general, all of the monitoring wells to east of the UST excavation have shown continued improvement in lower values for both TPHg and Benzene over last two sampling events The groundwater hydraulic gradient was calculated at 5=0.005 with the down slope in the northeast direction, which is very similar to the direction of flow for the second quarter sampling event last year. This gradient applies to the shallow well data of MW-1,MW-2, and MW-3 only(see a site map attached), Conclusions The hydraulic gradient for this monitoring event is in the more traditional hydraulic gradient direction of northeast. The slope of the hydraulic gradient is steeper for this event,than for the last event. In general, all of the monitoring well groundwater samples, with the exception of MW-1, yielded lower concentrations of TPHg than last quarter. The MW-1 groundwater sample results were in the same range of concentration as last years second quarter monitoring event. Recommendations The author recommends that monitoring well sampling be continued on a quarterly basis. Work in Progress The preapproval for the pump test has been received from the Cleanup Fund and that work is scheduled to start on August 20,2002,with the extraction well installation.After the extraction well is installed, the work plan calls for mobilization of the 21,000 gallon tank and pump installation. Please contact Ervin Rifenburg of this office at (209)368-9381 if you have any questions on this report. Respectfully submitted, QRoFEssta4 Foothi n nee g ,��, �N RIFEkeG�r� � m No. 187 rvin R en g,PErFpFcAt `A. cc: Michael D. & Sharon Olivarez, 436 W. Scotts Av. Stockton, Ca. 3