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5-11 The existing flare station is located in the northeastern portion of the landfill (Drawing 11). The flare station consists of two enclosed ground flares that have a combined capacity of approximately 5,400 cubic feet per minute (cfm). The landfill gas is routed to the existing flare station. Landfill gas will be routed to the new LFGTE when it becomes operational and the remainder will be flared. As landfill gas cools within the gas extraction system piping, condensate is formed. Condensate generation is dependent upon gas flow and variations in ambient temperatures. Along with the gas extraction system, a condensate management system handles condensate that collects in the low points of the landfill gas extraction system piping. Condensate from these low points is gravity -fed to the leachate ponds. 5.3 Design Calculations 5.3.1 Soil Balance Soil excavated from each phase (Table 9) will be stockpiled in areas of future phases or on the borrow area north of the landfill. This stockpiled soil can be utilized for daily cover operations, if needed, or will be saved for final cover soil needs (approximately 564,974 cy). The existing Forward Landfill currently accepts construction debris and contaminated soil in sufficient quantities to generally provide for daily cover operations. Table 10 presents phase fill and soil volumes required for each phase as well as soil available onsite and import or borrow required. Any soil surplus or deficit will be stockpiled/borrowed from the existing borrow area located north of the landfill. Landfill capacity/soil calculations are included in Appendix F. 5.3.2 Static and Seismic Stability The stability of the Forward Landfill was evaluated by based on the development plans and available information regarding likely refuse, soils, and liner materials. As required in 27 CCR, the analyses addressed both the surficial stability of final cover soils and the gross stability of the final landfill contours. The analyses considered static and pseudo -static loading conditions, and included evaluation of the seismic displacement that could occur under earthquake loads. A copy of GLA's analysis (2001) is included in Appendix K. 5.3.2.1 Seismicity An assessment of the seismic exposure for the Forward Landfill site was completed by Geosyntec Consultants (2001) and is included in Appendix K. Based on that assessment, two potential earthquake events were considered for design: a MCE of Mw 7.9 associated with the San Andreas Fault at a distance of about 70 miles; and a Mw 6.7 earthquake associated with the Great Valley (Segment 7) Fault at a distance of about 21 miles. The to following parameters were used in the seismic slope stability evaluations: Forward Landfill SWT Engineering Joint Technical Document - April 2014 z:\projects\allied waste\forward\five year permit rvw 2013\itd-5 yr pr 2013\text\sec 5 final.doc