Agenda - Council - 11/25/1980 - Laserfiche WebLink

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- 23- and increase methane yield. After 10 years of methane recov- ery, the material in the cell could be aerated and then dis- tributed as a humus, with such a management practice, cells could be reused and would provide an alternative to landfill expansions. e. Landfill Methane Recovery This technology is slmilar to the clay digester except that shredding and landfill design are not as important. Seven landfills in the United States are currently recovering meth- ane. Landfill methane recovery is not an alternative to land- fill expansion unless shredding is employed or if humus is recovered from the landfill. Composting of mixed waste is also feasible as an alternative to land disposal. Altoona, Pennsylvania, and about 10 other cities in the United States currently compost mixed waste. Mixed waste includes not only food wastes and yard wastes, but also undesir- able materials such as glass, metal and plastic. Mixed waste and source-separated organics are both suitable for composting wsth sewage sludge. Solid waste is a good bulking agent for sludge and the sludge enhances the overall nutrient value of compost. 3. OTHER SYSTEMS There are several other, more experimental processes that may prove to be viable alternatives, including alcohol production from cellulose materials, cement-like #guup'' processes that use demoli- tion debris as part of an aggregate and large-scale brush chlpping machinery. As research data becomes available for these systems, further assessments of their disposal abatement potentials should be completed. .The disposal of diseased shade tree waste in the Region has his- torically been an additional burden on the landfills. In the past two to three years, however,, landfill operators have purposely raised the drop charge for tree waste to the point that it is now prohibitively expensive. Also, the recovery rate of this valuable wood resource has increased through the use of tree chippers, sawmills and firewood production. Still, small amounts of wood waste are being landfilled that could be potentially utilized. 4. CONCLUSIONS Resource recovery technologies, in conjunction with waste separa- tzon and waste processing methods, are capable of reducing the solid waste stream by a total of 75 percent. Several existing high-technology facilities already recover 70 to 75 percent of the solid waste stream, including Madison's RDF facility (Boley, Madi- son Public works) and the Dano composting process (Dano Resource Recovery, Inc., 1978). Both Of tnese high-technology processes rely on materials recycling to attain these high recovery rates.