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Rev.0,4/22/11 Project 110219 investigation groundwater levels were measured in three domestic wells located within a 1-mile radius of the landfill. Groundwater elevations ranged from 64 to 110 feet MSL. Groundwater flows generally north-to south at the site at a depth of between 60 and 40 ft MSL with gradient from north to south (JTD Figure 12 in Appendix C). Groundwater elevations fluctuate seasonally less than one foot. A seasonal creek is present at the east side of the site. In the winter months, this creek flows into a stormwater pond. There are no springs on the property and United States Geological Survey (USGS)topographic maps do not indicate springs located within 1-mile of site. The landfill site is located within the San Joaquin Hydrologic Region, Eastern San Joaquin Sub basin, which encompasses 707,000 acres (The California Department of Water Resources, 2003). According to California's Bulletin 118 for the San Joaquin River Hydrologic Region, 2003, groundwater measurements over the past 40 years have shown a continuous decline in groundwater levels in the Eastern San Joaquin County. As a result of declining water levels, poor quality water has been moving eastward along a 16-mile front on the east side of the San Joaquin River Delta. The degradation was particularly evident in Stockton where a saline front is moving eastward. Large areas of elevated nitrate in groundwater exist within the sub basin located southeast of Lodi and south of Stockton. For the entire basin, 689 public supply water wells were sampled from 1994 through 2000. Samples analyzed indicated that 523 wells (76%) met the state primary MCLs for drinking water. The others (24%) had constituents that exceeded one or more MCLs. These included: inorganics (aluminum, arsenic, manganese, iron, and total dissolved solids), radiological particles, nitrates, pesticides, and VOCs. Calcium-magnesium bicarbonate or calcium-sodium bicarbonate types characterize the majority of the basin. Bicarbonate is the predominant anion in the eastern part of the basin. Groundwater quality throughout the region is suitable for most urban and agricultural uses (The California Department of Water Resources, 1994). Groundwater use on and surrounding the property is agricultural, domestic supply, and groundwater monitoring. Eight wells were identified within 1 mile of the landfill site. The screened sections of these wells vary between bottom depths of 255 feet to as deep as 467 feet. One off-site well appears to be down gradient, west-southwest of the site (review of California Department of Water Resources files reported in "Report of Waste Discharge Related to the Permitting and Installation of Composite Landfill Liner System for Module 1 and Future Modules", Emcon, 2002; and by Kleinfelder Inc, August 2004). There are five wells on the landfill property. These include a domestic well (LW-1) and four groundwater monitoring wells. 3.4 Geology/Soils The landfill is located near the transition between the foothills of the Sierra Nevada province to the east and the flat Great Valley province to the west. In the area surrounding the landfill, X?PROJECISIAMERESCOA 10219-FOOTHILL LFGTE FACILJTYt_ENGJNEERINGSan Joaquin Canty Site Approval ApplicatiomTootltill LFGTE-Project Description(final4-22-11).doc CORNERSTONE 3-2 LEWIS ENGINEERING Environmental Gronp,LLC i