Green industry companies are generators of yard and tree trimming residuals and users of high quality soil amendments. It's no wonder composting fits this sector like glove.
THE DUAL hats worn by nurseries and landscapers make them perfect candidates for establishing a composting operation. These companies are large volume users of high quality soil amendments. At the same time, they generate significant quantities of compost feedstocks such as grass clippings, tree trimmings, land clearing debris and other organic residuals. Furthermore, these operations often own grinders and front-end loaders. As a result, many green industry companies have been composting on the side for years. Others have gotten into the business more recently as a result of increasing disposal costs - or outright bans of putting yard trimmings in the landfill. Whatever the motivation, companies featured in this article have weaved composting into their day to day operations.
BAGGING THE PRODUCT
"Some people get into composting in order to get rid of waste products and turn them into a profit," says Chris Smith, the owner of Seasons DownEast, a landscaping business in Rockport, Maine. "That's a very good reason, but my intention was to come up with a really good, weed-free planting media." Smith began making compost eight years ago to grow perennials and annuals in greenhouses, and it has proven to be a worthwhile venture.
In fact, Smith formed a separate company - Land and Sea Composting - to manage and market the combination of fish residuals, yard trimmings, manure and peat moss that go into the soil blend products. Leaves and grass clippings collected from residents in the towns of Camden and Rockport are trucked to his facility each fall. Smith and five employees also collect chicken, horse and cow manures from area farms, as well as ground mussel shells and fish from seafood processing plants. The company gets the materials for free, but pays a trucking fee for the fish and mussel residuals. Smith has applied for a permit to add food scraps to his compost mixture, and expects to begin collecting them from local supermarkets this spring. The materials are windrowed outdoors on five of the company's 20 acres, turned with a Wildcat turner as needed, and composted for four to 12 months.
An on-site bagging operation was started four years ago and currently produces up to 100,000 bags of compost annually. Brightly colored, 40-pound bags retail for approximately $7 each at local landscape companies, garden centers and hardware stores. The remaining compost not used by Seasons DownEast is sold in bulk to long standing local customers.
DIVERSION AND TOPSOIL
Garden Gate Landscaping in Silver Spring, Maryland began composting almost 10 years ago, and presently composts or recycles 95 percent of the materials it collects from landscaping jobs, according to company representative Charles Bowers. "Landfill restrictions have been getting tighter, and we saw that eventually there would be problems with them accepting organic materials," says Bowers. "We don't landfill anything anymore except trash."
Many materials are composted on site, including sod, grass clippings, leaves, and soil dug up when the company installs patios and walkways. Larger pieces of brush and heavier wood are separated out, ground in a tub grinder and taken to a wood recycler. Composting is done outdoors in passively aerated windrows, as well as turned windrows. When finished, compost is tested at the University of Maryland for acidity, trace elements and other factors. The material is mixed with other ingredients to make approximately 500 cubic yards a year of topsoil. Garden Gate also purchases municipal leaf compost for landscaping jobs from the City of Silver Spring.
COMPOST BENEFITS
In Kennedyville, Maryland, the 2,000 acre wholesale Angelica Nursery has taken composting to heart. "We compost everything, including tree trunks, root systems and culled junk trees," says Jim Kohl, the nursery's vice-president. The company began making and using compost five years ago to increase the amount of organic matter in the soil. This spring, they expect to produce enough to spread a one-inch layer of compost on 15 acres.
After size reducing larger land clearing debris in a commercial tub grinder, materials are composted outdoors in open windrows for two and a half to three months. The windrows are turned with a front-end loader every other day the first month, and then every three to four days for the second and third months. The compost is left to cure for varying periods of time, and then tested at Brookside Laboratories in Delaware. "This is a nursery operation, not a composting operation, so we fit it in when we can," Kohl notes.
The nursery chooses to compost the materials rather than burn them under a permit or take them to the landfill. "The composting process is not that labor intensive and we get the payoff of having compost to put back in the soil," says Kohl.
Each season, Angelica Nursery also uses four or five tractor trailer loads of composted biosolids from the City of Baltimore in a potting mix for containerized ornamental landscape plants. Vic Priapi, chief propagator, is pleased with the results. "The 10 percent compost we put in the potting mix provides all the micro elements needed, such as manganese, zinc and iron," he says.
DESERT COMPOSTING
Desert Compost in Tucson, Arizona is a division of The Groundskeeper, a landscape maintenance company with operations in Tucson, Phoenix and Las Vegas. Three years ago, The Groundskeeper began composting yard trimmings generated by its own operations as well as other contractors and a power company. Desert Compost now has three composting sites two in Tucson and one in Phoenix. A fourth is expected to open in Las Vegas in 1997. About 15,000 tons/ year of green waste are processed in total. "The only problem with composting in the Southwest is water," says Robert Traub, who oversees the composting division. "We are using 6,000 to 7,000 gallons/site/day. Recycled water is used at two of our sites - from the power company's cooling tower at one place, and reclaimed greywater from an adjacent sewage treatment plant at the other."
Desert Compost has two grinders, one turner and one loader, which are transported between the three facilities. "We send the grinder, loader and turner ahead, and then send the screen later," says Traub. Finished compost is distributed in bags and bulk to The Groundskeepr's production divisions, other landscapers and area nurseries.
With permission from the Arizona Department of Environmental Quality (ADEQ), Desert Compost initiated a pilot project this spring to test the composting of two tons of produce residuals from a Safeway supermarket. Produce residuals were ground with green waste and then put into a windrow. "We are allowed to compost for a 16 week period," explains Traub. "We have in process about one ton of produce and four tons of green waste." He adds that ADEQ is drafting composting regulations, and expects that results of the pilot will be used to help shape permitting requirements for food residual composting.
The one challenge he's found to date was a pile going anaerobic. "We solved it by turning more frequently," Traub notes. "I estimate that the maximum amount of food waste we could take in and not have piles go anaerobic would be 10 to 12 percent on a volume basis, or about 1,000 tons/year of food waste."
Desert Compost is starting a program to receive yard trimmings from the City of Tucson. It also processes bedding material from a race track and bark. The tipping fee at its composting sites is $22/ton. -M.F.
