Laserfiche WebLink
r <br />11 <br />n <br />0 <br />preventive maintenance to maintain the final cover's integrity. The <br />effectiveness of these containment and maintenance features will be <br />verified through a monitoring program. <br />The refuse limit along the site's southern boundary was investigated <br />and confirmed by backhoe excavation. The limit of refuse fill was <br />determined to exist beyond the site boundary. The City of Tracy will <br />therefore coordinate with any adjacent landowners to determine the <br />disposition of the existing fill and proposed drainage structures <br />('Y' -ditch) in that area. <br />GAS GENERATION <br />The gas produced by decomposing refuse within a landfill consists pri- <br />marily of methane and carbon dioxide and escapes by vertical or lat- <br />eral movement. Because the methane component is lighter than air, <br />landfill gas tends to rise and exit through the landfill cover if the <br />cover is sufficiently permeable. At the Corral Hollow site, the in- <br />place solid waste volume is expected to generate a significant amount <br />of landfill gas. Appropriate closure procedures have been developed <br />to provide for landfill gas production. <br />A methane generation model (MGM) analysis was conducted to estimate <br />the quantity of landfill gas to be produced in future years. The MGM <br />was performed using the following parameters: <br />• Based on limited information, landfilling operations were <br />estimated to have begun in 1965. <br />• Based on comparisons between USGS topographic quadrangles <br />and the proposed final grade, overall refuse capacity was <br />calculated to be approximately 2,060,000 cubic yards. <br />• Refuse generation was assumed to have increased linearly <br />over time. This was modeled using data received from San <br />Joaquin County for 1983 through 1986. <br />• National averages for refuse composition and moisture <br />content were utilized. <br />PJ9 9390310.00D <br />0 <br />