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Grinding and trommel screening of the material prior to composting has significantly im- proved the quality of the final compost product. More mechanized processing has included magnetic and eddy current separation for improved removal of iron and aluminum com- ponents of the waste stream. The decision on the amount of preprocessing will be deter- mined by economics and the final use of the compost product. Semi-solid materials such as grit, sewage sludge, and food processing residue and liquid wastes such as grease, holding tank pumpings, and septic tank pumpings will be placed on other materials such as ground green material or wood waste or recycled compost and mixed as soon as possible to minimize the potential for leachate formation and odors. The amount of these materials accepted will be limited by the availability of other feed stocks. Design Alternatives Alternative 1. Exhibit 4 shows the layout for Windrow composting using a front end loader to turn the compost piles. Feedstock requiring preprocessing or grinding would be unloaded and processed in the RRF area. Ground and processed feedstock would be moved to the composting area using front-end loaders or dump trucks and placed into rough Windrows. Mixtures will be determined using volumetric proportions. Semi-solid and liquid feedstocks would be transported to the Windrow area and deposited directly on the rough Windrows. The quantity added would not exceed the quantity necessary to raise the moisture content to desirable limits. If semi-solid and liquid feedstocks are not avail- able, water will be added using a water truck. The rough Windrows would then be mixed using front- end loaders. After mixing the Windrows would be formed in final configura- tion approximately 8 feet high and 16 feet wide at the base. Windrows would be turned as necessary to maintain aerobic conditions and for pathogen reduction in accordance with CFR 503. Turning of Windrows would be using front end loaders. A 30-foot-wide aisle is provided between pairs of Windrows to allow access for the front end loader for efficient turning. Initial turning frequency would depend on the specific mixture being composted, but would be every 2 to 3 days for mixtures containing MSW, sludge, septic tank pump- ings, and other highly putresible materials. The turning frequency would be much less for green material and wood waste; once every 1 to 2 weeks. Later in the process depending on the composting period, the Windrows would be turned every 2 to 4 weeks. Water would be added prior to turning as necessary using a water truck to maintain moisture at the desired levels. The composting period would be 4 to 8 weeks depending on the quality of the product desired and the initial feedstock composition. Initially, Forward is planning to proceed with this option. Alternative 2. Exhibit 5 shows the layout for Windrow composting using a Windrow turner. The process is the same as described above except a Windrow turner would be used to mix the feedstocks, create the Windrows, and turn the Windrows. The Windrow dimensions proposed are 8 feet high and 18 feet wide at the base. The space between Windrows is 8 feet to provide access for a water truck for water addition and for fire con- trol. This is Forward's next option if the need for additional composting capacity or the economics of using a Windrow machine justify the initial cost of the Windrow machine. wa1OM9N4.wp5/27 9/28/94 27 i