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Forward Landfill Gas Probe Monitoring Report COMPLIANCE WITH TITLE 27 Based on an internal determination that the former perimeter landfill gas monitoring probe network at the Forward Landfill did not meet the current requirements of Title 27, RSI initiated efforts to bring the network into compliance. As part of this effort, in 2008 RSI implemented a drilling and perimeter landfill gas monitoring probe installation program. Upon completion, the existing perimeter landfill gas monitoring network consisted of 27 multi-completion perimeter landfill gas monitoring probes surrounding Forward. Following completion of installation of these probes, it was discovered through survey that the spacing between probe locations in two instances were greater than 1,000 feet (GP-16 to GP-17 = 1,008 feet; and GP-24 to GP-25 = 1,010 feet), and therefore not in compliance with Title 27. As a result, EHD requested additional perimeter probes be installed, and SCS Engineers, working on behalf of RSI, prepared and submitted the Response to San Joaquin County Letter Regarding Revised Title 27, Perimeter Probe Monitoring Network Workplan, Forward Island Landfill(SWIS No. 39- 14A-0015), dated May 28, 2009. The Workplan addressed comments made by the EHD regarding the noncompliance of the existing network and called for installation of two new probes, one between GP-16 and GP-17, and the other between GP-24 and GP-25. After the workplan was approved by EHD, RSI contracted with BAS to implement the workplan. The following key elements were the focus of the SCS workplan: • Install perimeter landfill gas monitoring probes on the landfill property, outside the trash prism in native soils, at locations designed to reduce the maximum lateral spacing between adjacent probes within the existing network to less than 1,000 feet. • Install each probe to the lowest elevation of trash or seasonal low water table, whichever is deepest. Since, the lowest elevation of the trash prism is approximately 25 amsl, and SCS determined the seasonal low water table to be below the trash prism, the seasonal low water table was used as the target elevation for installation of the probes. • Construct probes with multiple screen intervals as necessary, depending on the target depth. To prevent short-circuiting of air flow, a minimum 5 feet of seal was required between screen intervals. 2 BRYAN A.STIRRAT&ASSOCIATES (J:\Republic Services\Forward\2009.0087 Probe CQA\Report\Probe Installation Report.docm:01/19/10)