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E, y Monitoring Wells MW#4S and MW#4D were installed on the east side of Wilson Way in September of 2000 Also, monitoring wells MW#5D, MW#6S and MW#6D, MW#7S and MW47D were installed north and south of the pump islands in September of 2000 (see attached Site Map) Monitoring wells MW#8S and MW SD were installed in a single bore hole inside the existing building, � west of the pump islands on October 3, 2000 FIRST QUARTER 2001 MONITORING WELL SAMPLE ANALYSIS REPORT Sampled 3/16/01 WATER ANALYSIS OF SAMPLES FROM MONITORING WELLS On March 16, 2001, Del-Tech Geotechnical Support Services extracted water samples from each monitoring well using standard industry practices under the supervision of Foothill Engineering A report of this work by Del-Tech Geotechnical Support Services is attached and is apart of this report The water samples were transported on ice by chain of custody to Sherwood Labs for analysis by EPA Methods 602 and 5030/8015(M) for BTEX, and TPHg TPHd was analyzed by EPA Method 3510/8015(M) FINDINGS FROM GROUNDWATER SURFACE DETERMINATION The groundwater elevation on this site has raised about +/- 0 9' from the last sampling in December of 2000 The direction of flow is to the northeast at the time of this event The slope of the gradient is S = 0 001 (see attached site drawing) The groundwater elevation is three feet below last years measurement at the same time of the year The slope of the groundwater gradient for this event is to the . Northeast The slope last year was to the Southeast, a change of 90 degrees FINDINGS FROM MONITORING WELL SAMPLE ANALYSIS The concentration of TPHg in monitoring wells MW#1, MW#2, MW#3 has reduced to less than a third of the concentrations reported at the same time last year Monitoring well MW#8S has reduced concentrations of TPHg by 50% from the third quarter of 2000 sampling event All of the deep monitoring wells (MW46D, MW#7D, MW#5D, and MW#8D) show reduced concentrations of TPHg over the last three events (See attached sample data recap sheets) The samples from the monitoring wells on the east side of Wilson Way continue to be non-detect For past events, analysis by EPA Method 8260 was reported as non-detect To conserve funds, water samples for this event and in the future will not be analyzed for EPA Method 8260, unless requested by the PHS-EHD CONCLUSIONS The significant lower concentrations of TPHg in the monitoring wells that represent first water, may be a result of lower elevation of the groundwater There continues to be a general downward trend in the levels of contamination in the groundwater of all monitoring wells from the first sampling event on 9/22/99 For the first time,monitoring well MW#7D has been analyzed as non-detect for all parameters RECOMMENDATIONS A review of groundwater receptors in the area of the site should be conducted to help determine the cause of the change in groundwater elevation and flow gradient direction 2