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silty clayey sand A zone aquifer from the B zone aquifer that is found at approximately 21 feet bgs and is approximately 6 to 7 feet thick The aquitard separating the A and B zone aquifers is considered leaky, see section on pump test results and Appendix D - Pump Test The B zone aquifer consists of cleaner moderately sorted fine to coarse sand that shows graded bedding(fine to coarse with depth) Beneath the B zone aquifer is stir' clay that extends from approximately 27 feet bgs to 40 feet bgs The original five monitor wells did not encounter groundwater in the A zone aquifer when initially drilled and sampled Depth to water measurements taken between 1993 and February 1996 indicate that the A zone aquifer was dry (depth to water greater than 17 feet bgs) MW 1 through MW5 are screened across both the A and B zone aquifers Sometime after February 1996 depth to groundwater measurements indicated that groundwater was in contact with the A zone aquifer, see Table 1 and Figures 8 and 9 The groundwater in the vicinity of the site is semiconfined Groundwater elevation at the site varies from a wet year high of 7 feet bgs (silty clay formation above the A zone) to about 22 - 23 feet bgs (B zone) during the previous drought period Groundwater flow direction in the A zone at the site has generally been to the west since December 1997 The B zone shows a similar flow direction, which would be expected due to the connection between zones at wells MW through MW5 DEPTH TO WATER MEASUREMENTS Depth to water was measured at the dewatering well R1B and closes monitoring well MW3 during the dewatering/excavating process, see Table 4 The measurements were made from the surveyed elevation at the top of casing at each well using an electrical air/water interface probe Free product sheen was observed entering the excavation from the exposed sidewalls during the over-excavation into the A zone Table 1 presents groundwater chemical and depth to water measurements obtained from wells associated with the Sanchez property and also depth to water measurements obtained from the adjacent property to the southeast, Country Club Food and Fuel Western Geo-Engineers surveyed the top of casings for temporary piezometers on February 5, 2003 using level and rod COLLECTION AND CERTIFIED ANALYSIS OF GROUNDWATER SAMPLES WEGE and Pittman Well Purging (PIAT) personnel collected quarterly groundwater samples from the eleven monitor wells at the site on January 31, 2003, see Table 1 for analytical results tabulation Of particular interests are the high concentrations of hydrocarbons in the newly installed piezometers PZ1A, PZ1B and PZ2A Thus area was over-excavated to the 30 foot depth and dewatering during excavation removed 84,097 gallons of gasoline contaminated groundwater that contained an estimated 0 9 gallons of gasoline, see Tables 3 and 4 6 Update Status March 2003