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w <br /> ,y <br /> t <br /> Vertical and Horizontal Delineation of Plume History <br /> Monitoring Wells MW#1,MW#2, and MW93 were installed in September of 1999 to a depth of sixty <br /> feet Soil samples from the soil bores were extracted at five foot intervals from a depth often feet to sixty <br /> feet(see site map for location attached) All three soil bores produced samples above detection levels <br /> for BTEX and TPHg and TPHd (see Soil Sample Recap Attached) <br /> Monitonng Wells MW#4S and MW#4D were installed on the east side of Wilson Way in September of <br /> 2000 Also,monitoring wells MW#5D,MW#6S and MW#6D,MW47S and MW97D were installed north <br /> and south of the pump islands in September of 2000 (see attached Site Map) <br /> Monitoring wells MW98S andMW#8D were installed in a single bore hole inside the existing building, <br /> west of the pump islands on October 3,2000 Monitoring wells MW#9S and MW#9D were constructed <br /> in a single soil bore on August 14, 2002 The installation of five CPT's was completed on March 19, <br /> 2003 Monitoring well MW#1D was installed on May 28, 2003 to a depth of 150' <br /> SECOND QUARTER 2003 MONITORING WELL SAMPLE ANALYSIS REPORT <br /> Sampled 06/26/03 <br /> WATER ANALYSIS OF SAMPLES FROM MONITORING WELLS <br /> On June 26, 2003 Del-Tech Geotechnical Support Services extracted water samples from each <br /> monitoring well using standard industry practices under the supervision of Foothill Engineering A report <br /> of this work by Del-Tech Geotechnical Support Services is attached and is a part of this report The water <br /> . samples were transported on ice by chain of custody to Sherwood Labs for analysis by Method SW802OF <br /> for BTEX, and TPHg Samples of each set of groundwater extractions were forwarded to Entech <br /> Analytical Labs of Santa Clara, California for analysis by EPA Methods 8260FA <br /> FINDINGS FROM GROUNDWATER SURFACE DETERMINATION <br /> The groundwater elevation on this site has lowered about three and half feet from the last sample event <br /> and is about three feet lower than in the second quarter of last year The slope of the groundwater <br /> gradient for this event is down slope to the north ten degrees east at S=0 002 The last monitoring event <br /> had a hydraulic gradient with the down slope was in the same direction and gradient <br /> FINDINGS FROM MONITORING WELL SAMPLE ANALYSIS FOR BTEX AND TPHg <br /> Samples from monitoring wells MW44S,MW#4D,MW#5D,MW#6D,MW#6S,MW#7S,and MW#7D <br /> were analyzed at below detection limits for TPHg Monitoring wells MW#2 ,MW#8D,and MW#9S are <br /> the only monitoring wells that analyzed higher than the last event for TPHg Maximum concentrations <br /> of TPHg were found in MW#1 at 80,$00 ppb and MW#2 at 18,700 ppb(See groundwater analysis recap <br /> attached) <br /> FINDINGS FROM MONITORING WELL SAMPLE ANALYSIS FOR OXYGENATES <br /> The presence of 1,2-DCA was detected in samples extracted from MW#1,MW#1D,1\4W#5D,MW#7D, <br /> MW#8S&8D,and MW#9S&9D The highest concentration of 1,2-DCA was found in monitoring well <br /> MW#1 which is located in the dispenser island area, and in MW#8D which is directly west of MW#1 <br /> EDB was detected in MW#1 for this event TBA was detected in MW#1,MW#lD,MW#6S, MW#8S, <br /> iand MW#9S & 9D (See groundwater analysis recap attached) <br /> 2 <br />