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the eastern edge of the landfill. Refuse in this area could have an effect on water quality if rainwater in the drainage ditch were to percolate through the refuse and reach the shallow aquifer below. The results of the investigation indicated that refuse is present below the ditch, but does not extend below the road. The investigation revealed that the final closure cover did not extend over the refuse in the ditch area. Preliminary results of this investigation were transmitted to the LEA as requested. In early 2006, improving trends in water quality at MW-4 were noted, apparently beginning in late 2004 as a result of removing ponding from the drainage ditch along the east side of the landfill. In February 2006, the CIWMB required additional investigation of the closure cap and refuse on the eastern edge of the landfill footprint. In March 2006, the County formally submitted the results of the investigation and a proposed plan to upgrade and extend the closure cap adjacent to the access road to the LEA and CIWMB. The closure cap would be extended using geocomposite clay liner(GCL) In August 2006, CVRWQCB staff issued a violation for the insufficient groundwater monitoring of the shallow aquifer on the western side of the landfill; however, that aquifer does not exist. In October of 2006, the County proposed a Phase 2 investigation of the extent of closure cap, incorporating comments from the LEA and CIWMB staff received since February 2006. Amok In December 2006, CVRWQCB staff issued a violation for the presence of VOCs in groundwater at monitoring well MW-5, and directed the County to perform evaluation monitoring. In mid-January 2007, the County submitted a revised Phase 2 plan to further define the edge of closure cap and refuse along the eastern footprint edge, incorporating further comments from CIWMB and CVRWQCB staff. In late January 2007, the County submitted a proposal to increase corrective action along the eastern edge of the landfill footprint in response to the violation received in December 2006. This proposal included increase in LFG collection with a horizontal LFG collector beneath a HDPE liner along the affected footprint edge. On March 9, 2007, CVRWQCB staff issued a second violation for the presence of VOCs in groundwater at monitoring well MW-5. In March 2007 the County submitted an Evaluation Monitoring Program(EMP) work plan to the CVRWQCB further assess the nature and extent of potential off site migration of landfill gas in the vadose zone and VOCs and chloride in groundwater. The EMP includes the installation of two permanent groundwater monitoring wells, and groundwater and vadose zone soil gas sampling at nine temporary borings. Corral Hollow Landfill 3 Department of Public Works/Solid Waste 2n°Quarter 2007 Groundwater Monitoring County of San Joaquin—July 31,2007