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Based on landfill development with the currently approved base liner system and the allowance for a 5 -foot -thick final soil cover, the proposed excavation plan provides sufficient soil for development at refuse -to -daily soil ratios of 5:1 for waste disposal. 2.5.4 Erosion Control Based on the U.S. Department of Agriculture's Revised Universal Soil Loss Equation, the potential for soil loss from well -vegetated final slopes can control soil loss to below the 2 -tons - per -acre criterion established in the U.S. Environmental Protection Agency (EPA) Guideline Manual for Landfill Design Liner Systems and Final Cover (EPA, 1982) (Appendix B). When final soil cover is placed over completed landfill areas, the proposed soil cover will include organic materials, track -walked straw mulch, and hydroseeding. After vegetation is established, these measures will control soil loss to within the 2 -tons -per -acre criterion established for landfills (EPA, 1982). 2.5.5 Stability Analysis The static global slope stability analyses were performed in a December 2007 report for existing and future modules for the proposed increases in fill heights (Appendix Q. Existing Modules 1 and 3 were analyzed assuming conservative shear strength parameters based on recent testing on liner materials. The results indicate acceptable factors of safety (greater than 1.5). The results of isthe most critical global slope stability cross-sections for Modules 4 through 11 of the proposed vertical expansion also showed adequate static factors of safety. The results for the static slope stability of the most critical interim waste slope within Modules 5 through 11 yielded an acceptable static factor of safety if each future liner system design and construction satisfies specified shear strength values (Appendix Q. The seismic analyses showed that the potential for permanent displacement does not exist during the maximum probable earthquake event along any of the critical cross-sections analyzed for the landfill (Appendix Q. 11 The results of the slope stability analysis indicate the existing and planned slopes meet the acceptance criteria of CCR Title 27. 2.5.6 LFG Monitoring and Control Title 27 CCR (20921) requires that owners or operators of all municipal solid waste landfill units implement routine LFG migration monitoring programs to ensure that concentrations of methane do not exceed 25 percent of the lower explosive limit (LEL) in facility structures, or the LEL at the facility property boundary. To comply with this regulation, the County has installed 18 monitoring probes at 1,000 -foot centers along the perimeter of the landfill (Figure 3). These probes will be monitored in the postclosure period. (JTD Appendix I). PCMP for NCRCSL 2-6 Department of Public Works/Solid Waste O:ISan Joaquin CountylNCRCSL11180401PCPMPIFinal ReporAPCPMP_Rev_Jan_20 laDoc County of San Joaquin —January 7, 2010