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F ' fluctuating with the rise and fall of the groundwater elevation High groundwater elevations yield the • highest concentrations The groundwater gradient was to the west for this event, which is a complete reversal of the historic trends Before this current event all other events have produced a hydraulic gradient to the east or north If the present condition continues, this may explain the plume movement to the west under the building It also could be concluded that when the groundwater elevation drops, the gradient changes from the east to the west RECOMMENDATIONS It is recommended by the author that a deep monitoring well be installed in the dispenser area near monitoring well MW#1 This monitoring well should be installed to a depth of 100 to125 feet The author also recommends that two monitoring wells be installed west of the newly established MW#9S & 9D to determine the extent of both TPHg and 1,2-DCA contamination under the building One well would monitor first water to a depth of 60 feet The other well would monitor groundwater at the depth of 100 feet or more WORK IN PROGRESS The only work in progress is quarterly monitoring of the existing monitoring wells The soil stockpile on the westside of the site has been classified as non-detect for all analytes Authorization for removal has been requested of EHD REPORT ON SOIL BORE SAMPLE ANALYSIS AND CONSTRUCTION OF MW#9S&MW9D Sampled 08/15/2002 PROCEDURE The soil bore was drilled with a track mounted low profile drill with an 8" hollow stem auger The low profile drill was required due to the 16'clearance in the budding Soil samples were extracted with a split spoon sampler at five foot intervals from a depth of 20' to100' Soil was retained in a brass tube with Teflon sheet cover and a plastic cap Soil samples were transported under chain of custody to Sherwood Labs for analysis Sherwood analyzed the samples for BTEX and TPHg by EPA Method SW8020F Sherwood transported,under chain of custody,a portion of these soil samples to Entech Labs for analysis by EPA Method 8260FA for oxygenates and lead(see attached Soil Sample Analysis Recap sheet) Groundwater samples were not extracted during this soil bore FINDINGS FROM SOIL BORE SAMPLE ANALYSIS Samples from a depth of 60', 65', and 70' were the only samples that contained BTEX or TPHg above detection levels from this soil bore None of the soil samples analyzed contain Benzene above the detection levels and none of the soil samples contained 1,2-DCA above detection levels The soil bore was terminated at 100' of depth with some soil caving experienced at that depth MONITORING WELL CONSTRUCTION FOR MW#9S AND MW#9D Monitoring well MW#9D was constructed with a 1" PVC casing to a depth of 95', with the bottom 5' screened MW#9S was constructed with a 2" PVC casing to a depth of 60', with a 20' screened section 3