ARCHIVED REPORTS_1994 - Laserfiche WebLink

Home Browse Search

Alternative 3. Exhibit 6 shows the layout for aerated static pile composting using the extended pile technique. Mixing of materials would occur adjacent to the RRF. Processed material would be placed prior to dumping semi-solid or liquid feedstock. Mixing would be accomplished using a front end loader, compost mixer or Windrow machine depending on the quantity of maternal to be mixed. At the composting area a 1-foot-thick layer of ground wood waste would be placed over the aeration pipes. The compost mixture would be placed over the ground wood waste to a depth of 7 feet. The compost mixture would be covered with a 1-foot-thick layer of insulating material. The extended process is con- structed without a space between adjacent piles or cells. The piles would be 75 feet long. Aeration would be provided using one 400-cfm blower per pile and two 4-inch aeration pipes per pile. The aeration system would be designed to either pull air from the piles (negative) or blow air into the piles (positive). Initially, the aeration system would be operated in the negative mode and the exhausted air would be piped to a biofilter for reduc- tion in odorous compounds and VOC reduction. The basic composting process criteria are similar to Windrow composting except the piles are not turned. Forward will consider this option if necessary for odor or VOC control for the feedstocks they desire to compost. Alternative 4. Exhibit 7 shows the layout for a combination of aerated static pile and Windrow composting. The criteria are the same as for options 2 and 3 with the exception that 4 weeks composting time is assumed for the aerated static pile method. The alterna- tive provides some capacity for the higher cost aerated static pile process with the remain- der of the space used for Windrow composting. This provides some capacity for more difficult wastes that might require aerated static pile composting for odor and VOC control, but provides Windrow composting for aerated curing of the aerated static pile compost and other less sensitive feedstocks. Forward would consider this option for limited capacity if odor or VOC control is necessary for some feedstocks, but not all feedstocks. Alternative 5. Exhibit 8 shows the layout for a combination of enclosed agitated bed and Windrow composting. The criteria are the same as option 4. The enclosed agitated bed process replaces the aerated static pile process. Enclosing the composting process provides a higher level of odor and VOC control and eliminates the effect of precipitation and poten- tial for leachate generation. This may allow Forward to compost feedstocks not otherwise permissible. The agitated bed process consists of concrete bins 10 feet wide 230 feet long and 5.5 feet high. A track mounted mixer mixes the compost daily and at the same time moves the compost from the inlet to the outlet. Aeration is provided by blowing air up through the pile. All air is contained in the building and is exhausted through a biofilter for odor and VOC reduction. iCuring and Screening. Following composting, the mixture may be screened or placed in piles 10 feet high and 20 feet wide at the base for curing. In curing a slower rate of decomposition occurs. Curing of 1 to 6 months will be provided. A longer curing period is desirable for high quality compost. The curing period will depend on the quality desired and this in turn will depend on the market or final use of the product. The capacity of the composting site is significantly less to produce a higher quality compost product. After curing the material may be screened. Screening produces a higher quality material, but wa10029B64.wp5/28 9/28/94 '28