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f iJl Table 1 Current Quarter Groundwater Chemical Data(August 25,2003) Sample TPHG Ben Tol Ethyl Xyl MTBE TBA D1PE ETBE TAME u l UO u u8A UO u UgA UO u u MW-1 ND ND ND ND ND ND ND ND ND ND MW-2 970 16 14 11 53 ND ND 11 ND ND MW-3 780000* 230 270 2600 17000 ND ND ND ND ND MW-4 ND ND ND ND ND ND ND ND ND ND MW-5 ND ND ND ND ND ND ND ND ND ND N W-6 NA NA NA NA NA NA NA NA NA NA MW-7 ND ND 077 ND ND ND ND ND ND ND MW-8 ND ND ND 36 12 ND ND ND ND ND MW-9 3800004 320 100 3100 11000 ND ND ND ND ND Equip ND ND 10 ND ND ND ND ND ND ND Blank Lab ND ND ND ND ND ND ND ND ND ND Blank ND-None detected ug/I-micrograms per liter Ben-Benzene Tol-Toluene Xyl-Xylene NA—No analysis Fuel Ox -Fuel Oxygenates by Method 8260 from Dec 1997 forward Ethyl-Ethylbenzene 12 Dichloroethane and Ethylene Dibromide ND in all wells these analyses discontinued in 2000 *-0 22 feet of degraded product present on water in well at time of sampling,sampler removed 500 milliliters • 4-0 31 feet of degraded product present on water in well at time of sampling sampler removed 60 milliliters See historic data table for previous monrtonng well sampling results Discussion Groundwater flow direction is northerly at a flow gradient that is consistent with historically observed northerly flow trends (see Figure 1) Groundwater levels have declined about 0 75 feet in wells since the last quarter Floating product was present in MW-3 (apparent thickness of 0 22 feet) and in MW-9 (apparent thickness of 0 31 feet) and a total of about 560 milliliters was bailed and removed Since samples were collected and analyzed from those wells, the TPHG levels increased in wells MW-3 and MW-9 Benzene concentrations declined in Well MW-3 and only increased slightly in MW-9 MTBE was not detected in any well however one very low detection of D1PE was present in MW-2 A quality control equipment blank analysis of the contract sampler equipment showed one very low detection of Toluene Contaminant TPHG concentrations increased in MW-3 and MW-9 and a decline in groundwater levels suggesting a residual TPHG source in those wells vicinity Wells MW-3 and MW-9 have historically shown elevated TPHG concentrations on the site and observed fluctuations have been interpreted as local contaminant drainage and desorption from sediment near the casing Separate phase product was observed in MW-3 and MW-9 during this sampling event and is interpreted to arise from drainage within the capillary fringe and aquifer sediment Previous site study, including geophysical study for additional potential product sources did not reveal any subsurface structures as possible tanks for product sources Previous observations indicate that product presence tends to diminish when groundwater levels rise during the rainy months (aquifer recharge), and reappear during dry months (aquifer discharge) • Page 2