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i February 21, 2001 Ms. Margaret Lagorio Page 2 A total of five Geoprobe®borings (GP-1 through GP-5)were completed on August 15 and 16, 2000 using a direct push rig. The borings were advanced to groundwater at which time a discrete water sample was collected. Following groundwater sample collection the borings were continued to a maximum depth of 30 feet bgs Three groundwater monitoring wells (MW-1 through MW-3) were installed on September 6, 2000 at the locations shown on Figure 2. The well locations were selected based upon results of the Geoprobe®investigation. GROUNDWATER MONITORING RESULTS Groundwater samples and depth to water data were collected on January 15, 2001 from monitoring wells MW-1 through MW-7. The groundwater monitoring event was coordinated with the Blaine Tech Environmental who monitors the 76 Station east of the subject site. Groundwater samples were analyzed for the presence of total petroleum hydrocarbons as gasoline (TPH-g), benzene, toluene, ethylbenzene, xylenes (BTEX compounds), and for five gasoline oxygenates (MtBE, DIPE, ETBE, TAME and TBA) using EPA Methods 8015 Modified, 8020 and 8260, respectively. Field and laboratory procedures are presented as Attachment A. Certified analytical reports, chain-of-custody documentation, and field data sheets are presented as Attachment B. First Quarter Groundwater Monitoring Results Groundwater levels at the site have remained stable since the previous sampling event on September 21, 2000. Groundwater flow during the first quarter was generally to the northeast with an average gradient of 0.0008 ft/ft,which is consistent with the previous sampling event. Groundwater elevation data are presented in Table 1. A groundwater elevation contour map based on the January 19, 2001 data is shown on Figure 1. TPH-g was detected in wells MW-1 and MW-3 at concentrations of 2,250 pg/L and 1,870 µg/L, respectively. Benzene was detected in wells MW-1 and MW-3 at concentrations of 178 pg/L and 18.2 pg/L, respectively. MtBE was detected in wells MW-1, MW-2 and MW-3 at concentrations of 34,200 µg/L, 21,600 µg/L and 682 µg/L, respectively. ETBE was reported in well MW-1 at 2.60 pg/L,. TAME was reported in wells MW-1, MW-2 and MW-3 at concentrations of 215 µg/L, 168 p,g/L and 4.43 µg/L, respectively. TBA was reported in wells MW-1 and MW-2 at concentrations of 3,910 pg/L and 2,520 pg/L, respectively. Groundwater analytical data is presented in Table 1. A TPH-g,benzene, and MtBE concentration map based on the January 19, 2001 data is shown on Figure 2. CONCLUSIONS Groundwater samples collected indicate a decrease in TPH-g and BTEX constituents since the previous sampling event. However, oxygenate concentrations have increased in all three wells. Wran cfp 11 ProjectsTrojects1880104011 a1010718800401 qOl.doe