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EXISTING CONDITIONS MSubsurface Stratigra�hv The subsurface materials in the Northern San Joaquin Valley generally consist of continental deposits which are highly stratified, interbedded, coarse-grained sedunents and fine-grained cohesive to luthtfied sediments Subsurface sediments in the Lodi area are comprised mainly of sands with discontinuous lenses of clay and silt to depths of approxiniately 100 feet The alluvial deposits encountered beneath the site generally consist of interbedded sand, silt, and clay, with a predominance of sand Figure 2 is a subsurface cross section that illustrates the stratigraphy beneath the site De th to Ground Water Since 1992, when mcasurements began, the depth to the top of the zone of saturation (water table) at and near the site has vaned from about 51 feet below ground surface(bgs)to about 57 feet bgs Ground-Water Gradient According to GEOCON, the ground-water gradient of first encountered ground water is generally to the south in the Lodi area The overall areal ground-water hydraulic gradient at the site is also to the south with a value of approximately 0 0025 Figure 3 is a ground-water elevation (water table)map of the site Nearby Production Wells 1 Well records at the California Department of Water Resources office in Sacramento were searched to identify and locate ground-water production wells within 2000 feet of the 305 South Hutchins Street site Two existing ground-water production wells were identified Both wells belong to the City of Lodi and were installed as city water supply wells Mr Frank Beeler of the City of Lodi Municipal Service Center provided information about the current status of the wells The oldest of the two wells, commonly known as "old well No 3", was constructed in 1948 to a total depth of 230 feet Casing in the well was perforated at 102-144 foot depth and 180-230 foot depth The well is located approximately 1600 feet east-northeast of 305 South Hutchins Street, in the alley between Church and School Streets, south of Walnut Street Tlus places the well cross- and upgradient from the 305 South Hutchins Street site "Old well No 3" has not been in use since 1989 when tetrachloroethene was found dissolved in water from it According to Mr Beeler, no dissolved fuel hydrocarbons were found in water from"old well No 3"at the time it was taken out of service The second city water supply well, designated Well 3R, is located approximately 1100 feet northwest of 305 South Hutchins Street, at 144 South Rose Street Thus places the well upgradient of the 305 South Hutchins Street site Well 3R was constructed in 1992 to a total depth of 360 feet The casing is slotted from 210 to 340 foot depth According to Mr Beeler, Well 3R produces as much as 800 gallons per minute (gpm) and is currently in use He also indicated that there have been no problems with the quality of water produced from Well 3R 5