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It may be of significance that MW-3 is not directly down-gradient from MW-1. It is possible that normal cross-gradient variations in groundwater contribute to the differences between these two wells. PROPOSED WATER STANDARD The Water Standards for detection monitoring would apply to all wells (see"Return to Detection Monitoring",below). No new water standards are proposed at this time. CORRECTIVE ACTION MEASURES The following discussion of Corrective Action Measures is based on the results of this Evaluation Monitoring, in which VOC contamination was not detected. In general,no new corrective action is proposed due to the current compliance by Foothill Landfill with the applicable sections of CCR Title 27. PROPOSED T THIS TIME Removal of Ponding (Completed) The ponding of water adjacent to MW-3 and near the edge of waste was corrected in 1998, preventing further intrusion of water into the refuse. Once corrected,the LFG production in the wetted refuse apparently subsided and the impact gradually dissipated to the"non-detect'levels indicated today. The dissipation of the impact indicates that the present drainage features and management practices are successful in preventing groundwater degradation. Return to Detection Monitoring Because the groundwater at the Foothill Landfill is found to be free of VOC contamination,the wells would return to detection monitoring per Title 27 Section 20420. Installation of an Additional Background Well Although not strictly a corrective action,review of the revised groundwater gradients and the location of the groundwater monitoring wells has brought to our attention the need for an additional groundwater monitoring well. Therefore,we propose a new well installed directly UP- gradient from MW-2R(see"Monitoring Plan",below). Engineering Feasibility Report 5 Foothill Sanitary Landfill October 30,2003 San Joaquin County Solid Waste