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Ms Margaret Lagono Project 880-040 IA August 24, 2001 Page 2 A total of five GeoprobeTM borings (GP-I through GP-5) were completed on August 15 and 16, 2000 using a direct push ng 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 GeoprobeTM investigation GROUNDWATER MONITORING RESULTS Groundwater samples and depth to water data were collected on July 27, 2001 from monitoring wells MW-1 through MW-3 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 (methyl tert-butyl ether [MtBE], di-isopropy ether [D1PE], ethyl tert-butyl ether [ETBE], tert-amyl methyl ether [TAME] and tert-butyl alcohol [TBA]) using U S Environmental Protection Agency (USEPA) Methods 8015 Modified, 8020 and 8260, respectively Field and laboratory procedures are presented as Attachment A Certified analytical reports, sham-of-custody documentation, and field data sheets are presented as Attachment B Second Quarter Groundwater Monitoring Results Groundwater levels at the site have decreased 1 17 feet since the previous sampling event on April 23, 2001 Groundwater flow dunng the third quarter was generally to the northeast at an average gradient of 0 002 ft/ft, which is consistent with the previous sampling event Ground- water elevation data are presented in Table 1 A groundwater elevation contour map based on the July 27, 2001 data is shown on Figure 1 TPH-g was detected 1n wells MW-1, MW-2 and MW-3 at concentrations of 13,000 micrograms per liter(pg/l), 190 µg/1 and 870 µg/1, respectively Benzene was detected in wells MW-1 and MW-3 at concentrations of 1,700 pg/l and 2 1 µg/1, respectively MtBE was detected in wells MW-1, MW-2 and MW-3 at concentrations of 40,000 µg/l, 4,800 µg/1, and 360 µg/l, respectively TAME was reported in wells MW-1 at a concentration of 290 µg/1 No TBA above raised reporting limits was reported in groundwater samples this quarter Groundwater analytical data are presented in Table 1 A TPH-g, benzene, and MtBE concentration map based on the July 27, 2001 data is shown on Figure 2 CONCLUSIONS Groundwater levels have decreased 1 17 feet since the second quarter 2001 sampling event Groundwater samples indicate a decrease in TPH-g and BTEX constituents since the previous N 1sacDP120011PRAP1818800401A laa doc