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GENESIS ENGINEERING&REDEVELOPMENT Drill mud cuttings overlay the native soils. The drill mud can be distinguished from the underlying native sediments by the lighter color,highly plastic and sticky character when wet, and the lack of mica. Often the contact between native soils and drill mud contains a thin layer of decomposing vegetative matter,apparently vegetation that was growing on the original ground surface that was buried by the drill mud disposal. 2.2 Hydrogeology Depth to groundwater in the shallowest water-bearing zone beneath the Site currently ranges from approximately 9 to 20 feet below the top of the well casing, or approximately 6.5 to 17.5 feet below ground surface ("bgs"). Groundwater elevations range from approximately sea level to 11 feet below mean sea level. Shallow groundwater beneath the Site appears to be unconfined. The groundwater table is shallowest adjacent to the slough on the west side of the Site, and slopes to the east. Groundwater flow beneath the Site is consistently to the east, and away from Whiskey Slough, at a relatively steep gradient ranging from approximately 0.028 to 0.033 ft/ft. Groundwater flow direction does not change between high and low tide. A downward vertical gradient has consistently been observed between piezometers P-1 and P-2 and well MW-5. Water levels in the slough show a cyclic fluctuation that indicates that the slough is directly affected by tidal fluctuations. The water level pattern observed in the slough is semi-diurnal, with two high tides and two low tides each day. Well MW-2, located adjacent to the slough, shows diurnal tidal fluctuations. Downgradient wells MW-4, MW-5, MW-6, and the piezometers show no cyclic daily fluctuations, suggesting that tidal influence from the slough does not extend to the eastern side of the Site. 2.3 Surface and Groundwater Use in the Site Vicinity Seven water-supply wells were identified in the vicinity of the Site, and an eighth well (domestic) is proposed for installation. All of the identified wells are located at least 1,000 feet from the Site. Where well use was specified on the driller's logs,the wells were listed as domestic. However, field reconnaissance indicates that some of the wells in the vicinity of the Site may be used for agricultural purposes. According to Mr. Greg Olivero of San Joaquin County Environmental Health Department("SJCEHD"), water demand in the vicinity of the Site is met by private wells and surface water. There is no public water purveyor in the vicinity. The nearest surface water body is Whiskey Slough, located adjacent to the Site on the west. However,Whiskey Slough is upgradient of the Site, and is a losing stream in the Site William DePaoli Property 2 of 7 Additional Groundwater Investigation Work Plan June 2009