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— Side slopes: geocomposite drain layer with nonwoven geotextile separator/filter • 60 -mil high-density polyethylene (HDPE) geomembrane • Geosynthetic clay liner (GCL) on prepared surface • 1 -foot thick prepared subgrade (base only). Area 1 was constructed in two (2) phases. The first phase of approximately 36 acres was completed in 2003. The second phase of approximately six (6) acres was completed in 2006. A portion of the liner installed in the second phase was placed over refuse of Module "I" at the request of CVRWQCB. The extension of the Resource Conservation and Recovery Act (RCRA)- and California Code of Regulations (CCR) Title 27 -compliant liner into Area 2, which is south of Area 1, is scheduled for early 2015. Groundwater impacts were not observed at the FSL prior to first quarter 2000. Volatile organic compounds (VOCs) were first detected at groundwater monitoring well MW -3 during the first quarter 2000 monitoring event. Based on our review of the monitoring record of MW -3 and landfilling practices conducted at FSL, the following release scenario has been developed: • Ponding occurred near MW -3 from 1995 to 1998. • In the spring of 1998, the ponding was corrected by filling the depressions and re -grading the area to drain away from refuse. • In March 2000, groundwater impact was first detected at MW -3, approximately 4.5 years after ponding first occurred. No other wells were impacted. • In February 2002, groundwater impact was no longer detected at MW -3, approximately four (4) years after the ponding was corrected. • On November 6, 2002, nine (9) months after the last detection of VOCs at MW -3, the County submitted an Evaluation Monitoring Plan (EMP) at the request of CVRWQCB. This EMP proposed methods to delineate the nature and extent of groundwater impact previously seen at MW -3. The EMP included drilling and sampling from temporary borings, and a step -out step-down approach if groundwater contamination was detected at those borings. There were no detections. • On January 30, 2003, Waste Discharge Requirements (WDR) R5-2003-0020 was issued. The WDR required the closure of unlined Module "I" and required the monitoring of soil gas for VOCs as corrective action measures. To comply with the soil gas monitoring requirements of the WDRs, the County commenced the analysis of VOCs from gas samples collected from the site's soil gas wells that had previously been installed to comply with the LFG migration monitoring requirements set by CalRecycle. • In June 2003, an EMP was completed. The EMP consisted of the collection of groundwater samples from several temporary soil borings in the vicinity of MW -3, which resulted in no VOC detections in the water samples from the soil borings. Additionally, Foothill Sanitary Landfill 2 Department of Public Works, Solid Waste Division Revised Engineering Feasibility Study County of San Joaquin — December 19, 2014