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Module I is an inactive unlined module covering approximately 80 acres. A Site Improvement Project (SIP) is currently underway. The SIP includes a final cover on top of Module I, a side slope barrier on Module 1, a landfill gas collection system, and partial cover of the surfaces of Module I that are not covered by the side slope barrier or final closure cap. Module 1 covers approximately 34 acres and was completed in December 2003. It is fitted with a geomembrane base liner and a leachate collection and recovery system (LCRS). Leachate from the module drains by gravity to a sump and is pumped into a 10,000 gallon storage tank. The leachate is applied to the waste surfaces and travel surfaces within Module 1. Leachate is never applied to Module I. The site is bordered by agricultural land. There are eight domestic or agricultural wells within a mile of the facility. There is one domestic well within the permitted boundary of the facility and is used for landfill operation and domestic use for the on-site caretaker. 1.2.1 Hydrogeology To a depth of about 200 feet soil layers consist of moderately to well -cemented layers of sandstone and siltstone with claystone and conglomerates. The soil is mostly moderately slow in permeability with sporadic sandy layers that are well drained. The measured hydraulic conductivity of the native soils underlying the Unit ranges between 5 x 10-3 and 1.4 x 10"7 centimeters/second. Groundwater is first encountered approximately 120 to 150 feet below the native ground surface. Groundwater is unconfined or partially confined and fluctuates less than one foot seasonally. Groundwater flow is toward the southwest with an average gradient of approximately 0.002 foot per foot. Monitoring data indicates background groundwater quality has an electrical conductivity ranging between 153 and 710 micromhos/cm, and concentrations of total dissolved solids (TDS) ranging between 151 and 250 mg/1. The groundwater in the San Joaquin River Basin is considered suitable or potentially suitable for municipal and domestic water supply, agricultural supply, industrial service supply, and industrial process supply. The current groundwater monitoring system is comprised of three monitoring wells, one upgradient well (MW -1) and two down gradient wells (MW -2R and MW -3). Two additional groundwater monitoring wells will be constructed in 2006. 1.2.2 Environmental Monitoring Foothill Sanitary Landfill prior to March 2000, had not impacted groundwater. From March 2000 to October 2001 VOCs were detected at MW -3. Contamination was ascribed to ponding along a road on refuses adjacent to MW -3 from three previous winters. Covering with refuse and grading corrected this problem and the landfill gases have since dissipated. In June 2003, the Evaluation Monitoring Program was completed and found temporary borings to be free of contaminants. A landfill gas monitoring probe was installed near MW -3 and four VOCs were detected, however, these constituents were 73467 2 August 9, 2006 LA 31109 Corrective Action Financial Assurance Cost Estimate Foothill Sanitary Landfill