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SECTION 3 Sloe Stability In accordance with Title 27 regulations, both static and seismic stability analyses were performed for WMU FU-08. The seismic stability analysis is based on a seismic hazard analysis performed in 2001 (GeoSyntec,2001). WMU FU-08 will be filled with designated wastes (Class II) in the southern portion and municipal solid wastes (Class III) in the northern portion. Refuse placed in portions of WMU FU-08 will overlie existing municipal solid waste fill (Class III). Interface liners will be placed in these areas to separate the designated and municipal solid wastes. Refuse placed on the northern side of the northern portion of WMU FU-08 will eventually form the final landfill slope and will be constructed at a 3:1 (horizontal:vertical)slope with 20-ft wide benches every 50 vertical feet. The eastern and southern refuse fill slopes in the southern portion of WMU FU-08 are temporary and will be constructed at a 3:1 grade. Refuse will be placed against the 3:1 eastern slope once future WMUs to the east of WMU FU-08 are constructed. The southern boundary of WMU FU-08 will eventually be connected to WMU D-02 and the refuse in WMU FU-08 and WMU D-02 will form a contiguous mass. In the interim,the southern slope of WMU FU-08 will be graded at a 3:1 slope. The western slopes will be filled against existing refuse slopes. The following slope stability conditions were considered for the WMU FU-08 design: • WMU FU-08 Southern Portion. This condition represents the planned fill configuration of the southern portion of WMU FU-08. Based on the geometry, construction against adjacent WMUs, and site development plans, the planned fill elevation in the southern portion of WMU FU-08 is approximately 150-feet. The critical section is through the eastern slope. • WMU FU-08 Northern Portion. This condition represents the maximum fill configuration of WMU FU-08 in the northern portion. Based on the geometry and construction against adjacent WMUs, the maximum fill elevation in northern portion of WMU FU-08 is approximately 150- feet. The critical section is through the southern slope. • Forward Landfill Final Grades. This condition represents the maximum fill configuration for the landfill once adjacent WMUs have been constructed and the entire landfill is at its maximum fill configuration. The maximum elevation in WMU FU-08 at the final grade condition is at an approximately 195-foot elevation. However, in this condition the southern portion of WMU FU- 08 will be buttressed on all sides with adjacent WMUs,with the exception of a cross section that extends through the southwest corner of the cell in the southwest to northeast direction. The effective slope of this cross section is approximately 5:1. The critical stability configurations were selected based on the Construction Drawings and WMU FU- 08 refuse grading plans in Appendix A and B,respectively. The internal stability of the interface and side slope lining system was also considered. A protective operations soil layer will be placed against the slopes as WMU FU-08 filling operations progress(i.e., the operations layer will not be "hung" on the side slope). To minimize slope liner loads, it was assumed that the operations layer would be placed up to a maximum height of 10 feet above the WMU FU-08 REPORT 3-1