BioCycle June 2015
In October 2010, the Assistant Secretary of the U.S. Army announced a new Net Zero Initiative, intended to achieve permanent reductions in energy and water consumption, and convert waste into resources. At the Fort Drum Army base in Jefferson County, New York, the Fort Drum Net Zero solid waste working group began looking into composting as part of its compliance with the initiative.
Installation Forester Rodger H. Voss organized a “weigh and sort” at one of the base’s four dining facilities to assess how much food waste is produced. The assessment showed that 92 percent of the waste produced (by weight) was either compostable or recyclable. The amount of food waste produced per meal was estimated at slightly over a half-pound/person, including food prep and postconsumer waste, notes Voss.
He then began gathering information on composting from the Cornell University Waste Management Institute, the Development Authority of the North Country (which operates a local landfill), and the Onondaga County Resource Recovery Agency (OCRRA), which runs a nearby food waste composting operation. It was decided to use the results of a pilot study done by OCRRA to guide the set up of Fort Drum’s composting operation. Voss also took a US Composting Council operators training course that was offered in New York State in 2014. The composting program got underway in November 2014, and is diverting six to seven tons/week of organics — an amount expected to grow steadily in the coming months and years.
Collection And Composting
The base serves meals to about 17,000 soldiers and employees. Picking up the food waste at Fort Drum’s four dining facilities and one commissary (grocery store) has been “fairly simple, since our Public Works team does all the trash pick up,” Voss says. One of the two garbage dumpsters at each facility has been retrofitted for compostables. “We fitted the dumpsters dedicated to composting with locks to prevent unauthorized dumping, painted them and added stickers listing “the ‘do’s and don’t’s’ of what can be put in there,” he explains.
Cans in food prep areas designated for compostable waste are fitted with biodegradable bags sold at the base supply store. One of the base’s compactor trucks was repurposed to collect the food waste; no modifications were made to the vehicle. “We initially had concerns about liquid spilling out of the truck, but haven’t had a problem,” Voss notes. “We plan to preload the trucks with a bed of wood chips if liquid spillage becomes an issue over the summer months.”
He adds that when food waste collection began last fall, “it started a little slow as people were learning (the rules). We had a lot of contamination with the wrong bags placed in the wrong dumpsters. But that has definitely been getting better and we’ve seen a good increase in the amount collected.”
At this point, Fort Drum is only able to divert preconsumer food waste because postconsumer waste is collected by a private firm under a contract with the government. A contract modification to enable diverting postconsumer waste diversion “is in the works,” adds Voss. Once that is accomplished, he expects the weekly tonnage to “at least double.”
Along with food waste, the preconsumer material also includes waxed fruit boxes and wooden crates. Fort Drum uses a Roto Chopper MP2 wood chipper, equipped with an inline magnet, to break up the wooden boxes. Chipped material is used as a carbon source for composting. Discarded pallets, ammo boxes, dimensional lumber and other waste wood also is being chipped and used as amendment. The base produces 350 to 400 tons/year of wood waste. (Recently, Fort Drum began selling some of the chipped wood to a 60 MW biomass plant located on the base’s property. The power plant pays Fort Drum $5/ton for the chipped wood waste.)
Originally, Voss was mixing carbon and food waste in a 3:1 ratio. However, because most of the wood waste used is kiln-dried lumber, the moisture content of the mix was too low. Voss is now using a 2-to-1 ratio and, at times, the ratio has been as low as 1:1. Fort Drum also composts soiled paper and cardboard that can’t be recycled, along with fine, shredded paper produced by the base’s document-shredders.
Material is composted on a five-acre site with a gravel surface. It is placed in five bays, each 50 feet deep by 14 feet wide. A concrete surface will soon be added, and Voss expects to have the aeration system, designed by O2 Compost (the same supplier that OCRRA used) up and running soon. For now, the piles are turned weekly using a front-end loader, for the first two to three weeks. The first batch, comprised of 20 tons of food waste, was started in November and was expected to take six months to yield cured compost, Voss says. It will be screened to a half-inch, using a trommel screen. Once the aeration system is operating, he expects composting to take only 30 to 60 days, with another one to two months of curing.
Performance of the first round of food waste composting allayed some concerns about the effect of area’s cold winter climate. “Even in subzero winter weather, within a week the temperature was up to 140°F,” he says.
Voss notes that the facility has not had any odor issues, due to the location of the composting facility, prevailing winds and cold weather. “The food scraps are processed quickly upon pick-up so we haven’t had any issues to date,” he explains. “This summer will be telling as to what issues we may have. The site is already used for waste transfer, accepting trash from on base. There aren’t any new odors.”
Because Fort Drum composts only its own food waste on-site, it is exempt from New York State Department of Environmental Conservation permitting requirements. Once the initial batch of compost is ready this summer, Voss plans to make it available to residents of the base for gardening, and also use it to return nutrients to the soil, after trees are removed by the base’s forest management crew.
At current levels, wood waste diversion alone is saving the post about $92,000 a year in tipping and hauling fees, Voss says. Being able to divert 350 tons/year of food waste should add at least another $20,000 in savings. The composting and wood waste recycling also has given Fort Drum a good start in complying with the Secretary of the Army’s Net Zero initiative. When fully implemented, Fort Drum’s diversion rate should increase by 8 to 10 percent from food waste, and more than that for wood waste, Voss adds. Eventually, Fort Drum plans to expand food waste collection to include a number of privately operated restaurants on the base, including a McDonald’s, Burger King, food court and more. “Once we have the infrastructure in place, we plan to bring them on-line,” he says.
Dan Emerson is a Contributing Editor to BioCycle.