Deschutes Recycling expanded its yard trimmings composting operation to include commercial food waste. Produce from garden at the facility is donated to local food bank.
BioCycle November 2014
Deschutes Recycling in Bend, Oregon, in partnership with Deschutes County, operates a food and green waste composting facility at the county’s Knott Landfill. Brad Bailey, president of Deschutes Recycling, says his firm began composting yard trimmings and wood waste on the site in 2000. Previously, those materials were ground into mulch at the facility, which is on about 5 acres. Deschutes Recycling also operates the Recycling Center at the landfill.
In 2010, Deschutes Recycling became the second facility in Oregon to receive a permit from the Oregon Department of Environmental Quality to compost food waste. (Pacific Region Compost in Monmouth, Oregon was the first.) That fall, Deschutes Recycling helped start a commercial food waste collection pilot in partnership with St. Charles Health Systems and Bend Garbage & Recycling. Today, the company composts about 600 tons of food waste, 13,000 tons of green waste and takes in 2,400 tons of wood waste annually. Food waste from about 40 accounts in Bend is brought to the site by two local haulers, Bend Garbage & Recycling and Cascade Disposal. Landscapers and local residents bring in green and wood waste.
A Peterson 4710B horizontal grinder is used to process incoming yard trimmings and wood waste. Ground green waste is blended with food waste, including meat and dairy products and loaded into one of several 30-cubic yard (cy) modified drop boxes (see photo). “Aeration piping is laid in the bottom of the box before loading with the ground food and green waste mix. The mix is then topped with compost to help eliminate vectors and act as a biofilter to reduce odor,” explains Bailey. “It is run under positive air flow for about 30 days. The material, which goes through pathogen reduction in the vessel, enables us to keep the food waste blend contained and controlled in order to achieve PFRP. After the 30 days, the box is unloaded and material is moved into the windrow composting process. The windrows are about 400 feet long, 25 feet wide and 10 feet high. Early in the process, material is turned weekly, then biweekly and then less often as decomposition progresses. Front-end loaders, equipped with Tink Rollout buckets, are used to turn the piles. It takes about five to six months to make finished compost.
Oregon’s dry climate necessitates frequent watering of the windrows, Bailey notes. “We’ve experimented with ways to add water. Initially we used a water truck; now we use fire hoses to water the windrows while turning.” He’s also experimenting with a radial irrigation system normally used for watering agricultural fields. Controlling odor at the composting site has only recently become an issue with increases in volume, he adds. “To remedy this we are working to increase aeration with more frequent turning.”
Building Markets, Growing A Garden
About 13,500 cubic yards/year of finished compost are produced. Deschutes Recycling uses a Screen-It ball deck screen manufactured by CEC, which efficiently screens outthe overs from the finished products. The company sells SoilBuilder, its compost screened to five-eighth-inch, and BioFine, a potting mix and topdressing product that is screened to three-eighth-inch. The ReGrow blend, which contains food-based compost (also screened to three-eighth-inch), is comparable in texture and appearance to BioFine. Most of the compost is sold in bulk, but some is sold in 1-cubic foot bags at Deschutes Recycling and a few area retailers. “Our bagging system is totally manual at this point except for the bag sealer machine,” says Bailey. “Although our bagged products are not a huge percentage of our sales, the bags help market our compost and are useful to customers who only need small quantities.”
He adds that demand for compost has been growing steadily, especially in Central Oregon. The finished compost has a moisture content in the high 30s-low 40s percentile. “We’re working to raise that, since customers like it a little moister,” notes Bailey. “We produce a very mature and useable product that is certified through the US Composting Council’s Seal of Testing Assurance program. The compost has been well-received in the area; that’s the key to developing a consistent market.” Deschutes Recycling rents walk-behind spreaders to customers using compost for topdressing.
About four years ago, Deschutes Recycling planted a vegetable garden at the site to demonstrate the benefits of using compost. The garden yields about 1,200 pounds of produce annually, which is donated to NeighborImpact, an agency that distributes to food banks throughout Central Oregon. “Our soil on this site isn’t great, so we amended it with a blend of our compost and topsoil that we get from recycling sod,” explains Bailey. “When sod comes in, we stockpile it and eventually screen out the topsoil.” In addition to its own garden, Deschutes Recycling donates compost to other community gardens in the region.
Dan Emerson is a Contributing Editor to BioCycle.