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BETX and TPHg and TPHd (see Soil Sample Recap Attached) 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 MW#7D,were installed north and south of the pump islands in September of 2000 (see attached Site Map) Monitoring wells MW#8S and MWBD were installed in a single bore hole inside the existing building, west of the pump islands on October 3, 2000 INSTALLATION OF EIGHT MONITORING WELLS REPORT PROCEDURE FOR BORE HOLE SOIL SAMPLING AND ANALYSIS The four bore holes drilled for installation of the 100 feet deep monitoring well were drilled with an eight-inch hollow stem auger Soil samples were extracted at five intervals starting at twenty feet below the surface with a two-inch BX split spoon sampler with brass or stainless steel liners Each soil sample liner was capped with a teflon sheet and plastic cap and stored under ice The bore hole for MW#8D was located inside the existing building to the west of the pump island This building now houses a large truck and automobile tire distribution warehouse The building ceiling height was too low to allow a conventional drilling rig to drill the borehole A limited access rig was imported from Southern California to drill this borehole Drilling was very slow in this confined space All soil samples were transported under chain of custody to Sherwood Labs for analysis by EPA Method 8020 for BTEX and EPA Method 8015 for TPHg and TPHd (see recap of soil analysis attached) Soil samples were transferred by chain of custody to Entech Analytical Labs for analysis by EPA Method 8260B for oxygenates FINDINGS FROM SOIL ANALYSIS The main impact of the gasoline spill is present in the MW#513 soil boring With concentrations of up to 27,000 mg/Kg for TPHg at a depth of forty-five feet, this location must be the near the center of the spill location This soil bore has gasoline above detection levels from a depth of twenty-five feet to seventy feet and is located near the over excavation area The soil bore for MW#413, located on the east side of Wilson Way,produced no samples above the detection level for any of the compounds in gasoline or diesel All of the other bore holes yielded one or more samples above detection levels(see recap of soil analysis attached) Only the bore holes for MW#1 (samples at 20'and 25'of depth),and MW#5 (Sample at 20'of depth)have TPHd over detection levels (see recap of soil analysis attached) CONCLUSIONS Under the canopy area the gasoline contamination plume extends in the soil from a depth of twenty-five feet to seventy feet The highest concentrations of gasoline compounds outside of the canopy area lie within a sandy silt or silty sand aquifer that is about fifteen to twenty feet thick, starting at fifty-five feet below the surface The higher concentrations of Zylene and the low concentrations of Benzene indicate that these gasoline compounds are old and weathered 2