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I E ` 15 September'2045 '. AGE-NC Project No 98-0465 ' Page 5 of 8 ' ,J f 3 3 HYDROCARBON-IMPACTED GROUND WATER Grab ground water samples collected from soil borings B 1 through B5 on 23, 25 and 27 May 2005 were and analyzed for the petroleum hydrocarbon products listed in`Section 2 2 MTBE was ' detected in sample B1-W-42-46' at a concentration of 6 4 micrograms per liter (µg/1) No other target analytes were detected at or above laboratory detection limits in the samples ' analyzed Analytical results of ground water samples are summarized in Table 2 The laboratory report (CTEL Project Numbers CT214-0505228, CT214-0505250 and CT214-0505272), QA/QC ' reports, and chain of custody forms are included in Appendix D a ' 3 4 GROUND WATER GRADIENT AND FLOW DIRECTION The elevation of ground water in each of the monitoring wells was calculated by subtracting the ' depth to ground water from the surveyed casing elevations (Table 1) Depths to ground water averaged 8 96 feet below surface grade (bsg) Ground water elevations at the site ranged from 5 66 feet(MW-4)to 5 87 feet(MW-2)below mean sea level(MSL) Ground water elevations at the ' • adjacent site(Sanchez Property)ranged from 6 24 feet(MW-5)to 7 02 feet(MW-6A and MW-6B) below MSL (Table 3) During this monitoring event, the ground water elevations were within the screened intervals of the wells Wells MW-1 through MW-4, and wells MW-2 through MW-7 on the adjacent site were used to ' model ground water flow direction and calculate the gradient The ground water flow direction was inferred towards the northwest at the former UST location The hydraulic gradient was determined to be 0 006 feet/feet (ft/ft) at the northwestern property boundary (1856 Country Club Boulevard) ' and 0 005 ft/ft or less at the UST location Figure 4 illustrates the contoured ground water elevations as measured on 14 April 2005' ' 35 ANALYTICAL RESULTS OF QUARTERLY GROUND WATER SAMPLES , I BTEX compounds were not detected at concentrations at or above the laboratory reporting limits'm any of the ground water samples TPH-g was detected in the ground water sample collected from _ MW-1 at a concentration of 570 pg/l ' ' r MTBE was detected in samples collected from MW-1 and MW-3 at concentrations of 27 µg/1 and 16 gg/l, respectively No other fuel oxygenated compounds were detected in the ground water Ianalysis at or above laboratory detection limits ' r , Advanced GeoEnvironmental,Inc ,