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Y 20 March 2002 AGE-NC Project No 95-0144 ' Page 3 of 7 An aquifer pumping test was performed at the UST No 8 location utilizing EW-1 m May 2001 ' Results of the test Indicated that ground water extraction would be a feasible remediation alternative Procedures and results were summarized in Aquifer Pumping Test Report - May 2001, dated 09 October 2001, prepared by AGE Based on previous Investigations, AGE has Identified two potential hydrogeologic units Informally 1 Identified as the upper and lower water zones These two zones are separated by approximately 5 to m 10 feet of clay and silty clay It is not known how effectively the Intervening fine grained Interval hydrologically separates the informal hydrogeologic units though some contamination has migrated through or around it During the previous 6 years of ground water monitoring data, ground water flow direction in the upper water zone at the site has been consistently toward the north to northeast Therefore,it is Inferred that the migration of dissolved hydrocarbons in ground water would also be toward the north to northeast Ground water flow direction In the lower zone has been toward the west-northwest, southwest and southeast As can be seen in Table 4 and Figure 4,petroleum hydrocarbon-impacted ground water at the site is limited to the area surrounding the former UST No 8 location Only minor,intermittent detections of analytes have been obtained in samples from MW-13 and MW-20B,defining the northern extent lie of impacted ground water in the upper and lower zones South of the former UST No 8 location, ground water samples collected from MW-19A and MW-19B have contained only minor concentrations of benzene,toluene,ethyl benzene and total xylenes(BTEX) constituents(less than ' 5 µg/1),TPH-g has been non-detect and concentrations of TPH-d have declined steadily or have been non-detect since monitoring began in August 1998 It appears that MW-19A and MW-19B are located at the southern margin of Impacted-ground water at the site The east, west and vertical ' extent of impacted-ground water is not well defined 3.0. PROCEDURES On 13 February 2002, depth to water was measured in ground water monitoring wells MW-1, MW-2, MW-4, MW-5, MW-8, MW-11, MW-12, MW-13, MW-19A, MW-19B, MW-20A, MW-20B, MW-21A and MW-21B A vehicle parked over MW-18 prevented measuring depth to 1' water Additionally, ground water samples were collected from wells MW-1, MW-2, MW-4, , MW-13,MW-19A,MW-19B,MW-20A,MW-20B,MW-21 A and MW-21B in accordance with the revised monitoring schedule established at a 03 April 1998 meeting with the EHD ' Field activities were performed in accordance with guidelines issued by the Regional Water Quality Control Board-Central Valley Region(RWQCB)and by the EHD for investigation of underground storage tank (UST) sites and sampling of ground water monitoring wells, respectively Advanced GeoEnvironmental,Inc 1