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a� Chemical Analytical Methods and Results Eight groundwater samples were analyzed using EPA Methods 5030/8015, 602 and 8260 for Total Petroleum Hydrocarbons as Gasoline (TPHG), Benzene, Toluene, Ethylbenzene and Xylene (BTEX) and fuel oxygenates including Methyl-tert-butyl-ether (MTBE), Tert-Butyl Alcohol (TBA), Di-Isopropyl Ether(RIPE), Ethyl tert-butyl ether (ETBE), Tert-Amyl Methyl Ether TAME) The analytical results of the groundwater samples for this sampling event are attached and listed below in Table 1 (and Figures 2, 3 and 4, and historic data is presented in attached historic sampling data spreadsheet Table 2) Table 1. Current Quarter Groundwater Chemical Data(January 12,2004) Sample TPHG Sen Toi Ethyl X l MTBE TBA DIPS ETBE TAME u u u u u u I u8A u u 119/1 MW-1 ND ND ND ND ND ND ND ND ND ND MW-2 2800 25 31 1 43 14 ND ND ND ND ND MW-3 14000 40 43 530 1800 ND ND ND ND ND MW-4 450 ND 47 39 41 ND ND ND ND ND MW-5 No Data No Data No Data No Data No Data No Data No Data No Data No Data No Data MW-6 420 ND ND ND ND ND ND ND ND ND MW-7 ND ND ND ND ND ND ND ND ND ND MW-8 ND ND ND 36 12 ND ND ND ND ND MW-9 88000 800 110 4400 11000 ND ND ND ND ND Equip ND ND ND ND ND ND ND ND ND ND Blank Lab ND ND ND ND ND ND Nn ND ND ND Blank ND-None deter ted ug/l-micrograms per liter Ben-Benzene Tot-Toluene Xyl-Xylene NA--No analysis Fuel Ox.-Fuel Oxygenates by Method 8260 from Dec,1997 forward Ethyl-Ethylbenzene 1,2 Diehloroethane and Ethylene Dibromide ND in all wells,these analyses discontinued in 2000 See historic data table for previous momtormg well samphng results No Data—Car parked over Well MW-5 on January 12,2004 Discussion Groundwater flow direction is northerly at a flow gradient that 1s consistent with historically observed northerly flow trends (see Figure 1) Groundwater levels have risen about 0 5 feet in wells since the last quarter A sample was not collected from MW-5 since a car was parked on the well TPHG concentrations declined in MW-3 and in MW-9 Benzene concentrations declined in Well MW-3 and only increased slightly in MW-9 Well MW-4 showed TPHG detection MTBE and related oxygenates were not detected in any well Separate phase product was not observed in MW-3 and MW-9 during this sampling event TPHG concentrations on the site and historically observed fluctuations have been interpreted as local contaminant drainage and desorption from aquifer sediment near the casing, and influenced by aquifer recharge and discharge Previous observations indicate that product presence and contaminant concentrations generally tend to dimimsh when groundwater levels rise during the rainy months (aquifer recharge), and reappear during dry months(aquifer discharge) The interpreted plume snapped location remains generally narrow and largely remains in the same area Wells MW-1, MW-4 and MW-5 have historically not shown contaminant detection Whsle MW-4 did show Page 2