June 15, 2004 | General


BioCycle June 2004, Vol. 45, No. 6, p. 30
Sumter County solid waste facility incorporates front-end recovery of recyclables as part of integrated management system.
Miriam Zimms

IN MARCH 2004, a new rotary digester began operating at the Sumter County, Florida Solid Waste, Recycling and Composting Facility (SWRCF) at Lake Panasoffkee. The original digester is currently undergoing repairs. At full capacity, the two digesters are designed to process about 200 tons of municipal solid waste (MSW) and biosolids.
The new digester, 14 feet in diameter by 185 feet long, is able to process 120 tons/day of MSW and biosolids utilizing a three-day retention time under its current Florida Department of Environmental Protection permit. The system will also provide an opportunity for varied organics projects and farm demonstrations to be done by researchers through the Florida Organics Recycling Center for Excellence (FORCE) located at the facility.
Sumter County has been composting organic residuals since 1988 and began using its first digester in 1997. The facility was one of the first in the United States to incorporate upfront processing of recyclables. The new digester – constructed and installed by A-C Equipment Services to accelerate the conversion of organic residuals into compost – will allow the County to manage the waste from its rapidly growing population. Sumter County has grown from 30,000 in 1988 to 76,000 in 2004.
According to the Board of County Commissioners (BOCC), the expectation is that the County’s population will continue to double in the next decade. The BOCC has asked Kessler Consulting, Inc. to review the various disposal, recycling, composting and transfer options needed to meet that expected development.
State funds were allocated in 2000 to Sumter County to establish the Florida Organics Recycling Center for Excellence (FORCE) – a cooperative project between the Florida Department of Environmental Protection, Sumter County and public-private researchers. The Center’s goal is to develop practical solutions for using Florida’s organic wastes through a centralized, statewide effort. It is headquartered at the Sumter County SWRCF where research and demonstrations will include: Composting of various feedstocks and blends; Monitoring programs for process control, market needs and environmental concerns; Testing various organics technology applications; A 40-acre demonstration farm site using various types of compost on specific crops; and Reviewing and improving regulatory barriers to foster organics utilization in Florida.
To fulfill the above goals, an office/laboratory structure has been completed; seven organics recycling projects have received grants of $200,000; the in-vessel digester as described above is composting MSW and biosolids; and Dr. Joan Bradshaw – formerly Conservation Coordinator for St. Petersburg – has been named FORCE superintendent. For more details, visit the web site at:
Miriam Zimms is with Kessler Consulting, Inc., based in Tampa, Florida.
INCOMING municipal solid waste is conveyed to a totally enclosed materials recovery area, where sorters pull out corrugated cardboard, newspaper, bottles, cans and plastics. “These are commercial and residential materials, so we pull off a lot of corrugated,” says Mitch Kessler, who oversees plant operations for the county. “If the paper market is really good, sorters also will pull that; if not, that material goes to composting. About 20 percent of what goes through the sorting line is recovered for recycling.”
Materials remaining on the line are conveyed to the digesters. Air from the digesters is treated through a biofilter. Next, materials pass through a two-inch screen; unders from that screen go into windrows, and overs go back into the digester. Feedstocks are composted in windrows for 21 days, and then moved to a curing area for a minimum of six weeks. In total, about 65 percent of incoming MSW are recovered via composting and recycling.

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