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S ti 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,MW47S and MW#71)were installed north and south of the pump islands in September of 2000 (see attached Site Map) Monitoring wells MW#8S and MW8D were installed in a single bore hole inside the existing building,west of the pump islands on October 3, 2000 SECOND QUARTER 2001 MONITORING WELL SAMPLE ANALYSIS REPORT Sampled 6/19/2001 WATER ANALYSIS OF SAMPLES FROM MONITORING WELLS On June 19,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 a part 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 iThe groundwater elevation on this site has dropped about 4 5' from the last sampling done on March 16, 2001 The groundwater elevation is about five feet below the second quarter measurement of last year The slope of the groundwater gradient for this event is to the East at S=0 001 The slope last year at his date was to the Southeast, a change of 45 degrees FINDINGS FROM MONITORING WELL SAMPLE ANALYSIS The concentration of TPHg in monitoring wells MW#2,M W#3 returned to typical concentrations,from the extreme lows oflast quarter Monitoring well MW#8S produced lower TPHg is quarter MW47D,MW#7S, MW#6D, and MW#6S are non-detect for all analyzed compounds this quarter The monitoring wells (MW#4S&MW#4D)onthe eastside of Wilson Way indicated low concentrations ofanalyzed compounds for the first time this quarter (See attached sample data recap sheets) CONCLUSIONS The significant lower concentrations ofTPHg in the monitoring wells MW#7S and MW#6S maybe a result of lower elevation of the groundwater The plume has moved to the east and has reached both the shallow and deep wells on the eastside of Wilson Way The four monitoring wells near the center of the spill area continue to decline in concentration Monitoring wells MW#8S and MW#8D,directly west of the spill area, have declined to less than 20 percent of the original samples extracted in10/09/2001 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 The groundwater sample results gathered by the last four groundwater sample events indicate that both the vertical depth and horizontal limits ofthe contamination have been reached and further investigation below 2