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2.0 Groundwater Conditions <br /> Groundwater occurred in wells at a depth of about 7.8 to 8.4 feet below the surface (see <br /> Table 1). A groundwater contour map was prepared; the historic groundwater flow <br /> direction is north northwesterly (see Figure 1). Water levels in the monitoring wells <br /> declined since the previous measurements and the calculated flow gradient this quarter is <br /> 0.006. The gradient appears to have steepened slightly. <br /> 3.0 Chemical Analysis <br /> One groundwater samples were analyzed at STUChromalab,Inc., a State certified analytical <br /> laboratory from the monitoring and domestic wells. The sample was tested for the <br /> following; Total Petroleum Hydrocarbons as Gasoline (TPHG) and Diesel (TPHD), <br /> Benzene (B), Toluene (T), Ethylbenzene (E) and Xylene (X), Methyl-tert-butyl-ether <br /> (MTBE) and fuel oxygenates, 1,2 Dichloroethane and Ethylene Dibromide using EPA <br /> Methods 3510/8015, 8020, 8240 and 8260. The analyses were run on a "normal" <br /> turnaround(five-to ten working days). The results are presented in Figure 2 and Table 2 <br /> and historic data in Tables 3 and 4 below. <br /> Table 2. Groundwater Monitoring Well Chemical Data, September 2004 <br /> Sample TPHD TPHG Ben Tot Ethyl Xyl TBA MTBE DIPE ETBE TAME 12 EDB <br /> DCA <br /> v ug/l ug/l ug/l ug/l ug/l ug/l ug/I ug/l ug/l ugll ug/l ug/l ug/l <br /> MW-1 NS NS NS NS NS NS NS NS NS NS NS NS NS <br /> MW-2 NS NS NS NS NS NS NS NS NS NS NS NS NS <br /> MW-3 810# ND ND ND ND ND ND ND ND ND ND ND ND <br /> N <br /> ND ND ND ND ND ND ND ND ND ND ND ND ND <br /> ND ND ND ND ND ND ND ND ND ND ND ND ND <br /> NID—None detected. NS—Not sampled. See laboratory reports. #-Laboratory reports the diesel results do not match the diesel <br /> standard. <br /> 4.0 Discussion <br /> TPHD ,contaminants were observed at MW-3 at 810 micrograms per liter(ugll) during this <br /> sampling event. This is an increase from the previous sampling. Highly degraded TPHD <br /> has been observed at MW-3 previously and the laboratory reports that this result did not <br /> match the laboratory standard for Diesel. The increased TPHD may be due to drainage <br /> from the former tank pit in the area around the well given the water level decline. <br /> S.IC EHD has requested that Wright provide an estimate the quantity of residual dissolved <br /> contaminant for the next sample event when all three wells are scheduled for sampling and <br /> chemical analysis(fourth quarter 2004). <br /> Page 2 of 5 <br />