COMPOSTING: Compost Facilities Demonstrate Spirit Of Recycling

Steve Crawford and George Johnson

While materials recovery facilities and composting plants nationwide have elected to purchase and install new, often expensive equipment, two small operations, located in Portage and Pardeeville, Wis., chose to design and construct their facilities around used equipment.

Bill and Dick Casey, brothers and operators at the Pardeeville and Portage plants respectively, report a savings of 60 to 70 percent on the drums alone. The design for the Portage plant was a cooperative effort between the brothers and Mike Horkan of Portage. They collaborated with Columbia County and RMT Engineering, Madison, WIs., on the facilities.

Both are located in Columbia County, approximately 50 miles northwest of Madison. The smaller Portage facility, which began operation in 1986, receives mixed waste and sludge for composting after each resident removes recyclables. Portage served as a prototype for the larger Pardeeville plant, which began operations in 1991, and re-ceives comingled and source-separated recyclables and composts municipal solid wastes (MSW).

Both operations employ a modified Eweson/Dano composting technology which uses rotating in-vessel composting with double concentric trommel screen assemblies. The drums at both plants are ap-proximately 160 feet long and 12 feet in diameter. Portage has one drum with capacity of about 40 tons per day (tpd). Columbia Coun-ty has two drums, a capacity of 80 tpd of mixed waste and sewage sludge and a five-day retention. Both import and retrofit vintage cement kilns for drums. The Co-lumbia County drums, motors, gears and drives were originally constructed in the early 1950s by Missouri-Portland Cement. Portage used newer drums, motors, gears and drives from a cement company in Davenport, Iowa.

Using the recycle-reliant concept to design and construct the facilities resulted from a visit to an in-vessel facility in the mid-1980s. Portage officials decided they could build their own plant with used equipment, a little ingenuity and a great deal of perseverance. The Portage plant was built around a used 400-foot-long cement kiln purchased from the Davenport Cement Co. A local contractor trimmed a 160-foot-long section for use as an in-vessel composting drum and kept the remainder as reimbursement for labor.

The only new part of the plant is the building, according to Tom Pinion of the Portage Public Works Department. The total capital cost for the facility was $1.1 million, with the drum costing $150,000. A similarly sized new drum would cost approximately $900,000.

The Pardeeville facility, with a total cost of $2.5 million, serves the rest of the county. With two drums offering a capacity of 80 tpd of MSW organics and sludge, the plant includes a separate building for collection and sorting of commingled and source-separated recyclables.

Like the Portage facility, the operator chose used conveyor as-semblies. While the conveyor frames were designed and built by plant operators, all original rollers and belts were used. The materials recovery division started operations with used John Deere hay balers and government surplus fork lifts.

The facility is applying its compost at nearby agricultural sites and Portage is temporarily using compost at its landfill. It will begin applying its compost after the landfill closes in April.