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4-12 4.7 Site Life Projection 4.7.1 Site Life Calculations In order to calculate the site life for the Forward Landfill, the following criteria was utilized. ♦ Remaining Site Capacity as of 3/31/14 20.0 mcy ♦ Refuse to Cover Ratio 4:1 ♦ In -Place Density 1,588 lbs/cy Based on the above criteria and utilizing an inflow rate of 5,520 tpd with a 2 percent annual growth rate and taking into account a maximum weekly permitted refuse inflow rate of 46,080 tons/week, the Forward Landfill will have a projected site life of approximately 7 years (as of December 31, 2013). Based on these calculations (see Table 8), operations at the Forward Landfill could extend to approximately 2021 (current permitted closure year). However, based on updated tonnage projections and remaining capacity, the site could reach capacity in approximately 20+ years (from the end of 2013) as shown in Appendix E. At this time, the closure year is not being updated as the EIR does not currently support an extended closure year. 4.7.2 Factors Affecting Site Capacity is Many factors can affect the ultimate site capacity of a given landfill including variations in waste type, compaction rates, the use of ADCs and the annual tonnage delivered to the landfill. The actual daily tonnage at the Forward Landfill depends on economic and population growth factors. The tonnage can also vary as the contracts with clients fluctuate and specialty markets change. Therefore, there may be times when the Forward Landfill will accept at or near the maximum permitted tonnage or times where it may fall way below. Table 8 provides an estimate of the inflow to the Forward Landfill for permitting purposes. In addition, long-term landfill settlement can also have a great impact on site capacity and may average 25 percent of the total refuse thickness. The total effects of settlement will depend on various factors or processes such as the types of refuse placed and their corresponding moisture content, the refuse placement density, consolidation of the refuse under loads imposed by overlying fill, and biological and chemical decomposition. It is estimated that much of this total settlement will occur during the operating life of the landfill and will be accounted for in periodic topographic surveys. Remaining site capacity will be evaluated periodically and any significant changes will be addressed during future operating permit revisions. Forward Landfill SWT Engineering Joint Technical Document - April 2014; Amended June 2014 z:\projects\allied wasteWorward\five year permit rvw 2013\jtd-5 yr pr 2013\text\sec 4jinal.docx