January 25, 2011 | General

Improving Economics Of Food Waste Recycling

removing contaminantsBioCycle January 2011, Vol. 52, No. 1, p. 20
An airport hotel and a chain of convenience stores utilize new option for on-site collection and storage of source separated food waste.
Dan Sullivan

THE 419-room Philadelphia (Pennsylvania) Airport Marriott recently achieved a 75 percent recycling rate, reduced its waste stream by 18 tons/ month and its waste management costs by 27 percent, according to Stephen Storer, the hotel’s engineering supervisor. His inspiration to initiate the ambitious waste reduction program came from findings of a waste audit of the hotel conducted by Advanced Enviro Systems (AES) in nearby Chester, Pennsylvania. The investigation included temporarily collecting all food scraps in an open-top Dumpster on an experimental basis to gauge their volume. It soon became apparent that the largest percentage of the Philadelphia Airport Marriott’s waste stream was food waste.
Once it was decided to separate and divert food waste, a permanent solution to on-site collection and storage was needed. In addition to the open top Dumpster used during the audit, other strategies considered were a toter-swap system or adding a second, self-contained compactor dedicated to food waste. Both were rejected, as they failed to address the issues of odors, pests and spillage.
biofilter To counter those challenges, AES recommended installation of a 20-cubic yard (cy) BiobiN, an organic residuals collection container with a patented biofilter that circulates air through the contents. This creates an aerobic environment that minimizes odors and vector attraction. The system also utilizes carbon – such as paper, wood chips and cardboard – to jumpstart the process. The BiobiN organics collection technology was developed in Australia by Peter Wadewitz. It was recently licensed for development and distribution in the U.S. by environmental entrepreneur Richard Chambers, now president of BiobiN North America, who tweaked the system to meet OSHA standards and other requirements for the new market, including the ability to be hauled as a standard roll-off container.
Storer’s drive to implement food waste diversion from the landfill came at an opportune time as the Wilmington Organics Recycling Center (WORC), a commercial composting facility about 15 miles down the road in Delaware, had recently opened its doors (see “Urban Facility Delivers Food Waste Composting Capacity,” June 2010). Tip fees at the Wilmington facility meant a per-ton savings of nearly $30 over hauling to the local landfill, but Storer still had to factor in the infrastructure investment, including the BiobiN and a catwalk to both protect the biofilter and accommodate loading from the dock. Still the cost savings were significant. One reason is that food waste is now hauled once every 24 days instead of every 10 days.
“For this to work, you have to have the absolute cooperation of employees,” says Storer. Marriott employees have bought into the food waste recycling and other sustainability initiatives as a matter of pride. “We’re a Green Seal certified hotel,” he explains. “It’s on our website and in our brochures at the front desk. In Pennsylvania, only three hotels are Green Seal certified, and two of them are Marriotts.”
Since most of the organic material diverted at the hotel is nitrogen-rich food waste, AES arranged to have a carbon source, such as wood chips or finished compost, put into the bin at WORC each time after it’s emptied. The Marriott also includes newspapers and other scrap paper. Hotel kitchen staff load the container twice a day with pre and postconsumer food waste from the restaurant, room service and banquet facilities. Compostable bags are also utilized.

About 40 miles away, Two Particular Acres, a farm and composting facility in Royersford, Pennsylvania, is servicing a Wawa convenience store that recently installed a 10-cy BiobiN. Ned Foley, owner of Two Particular Acres, picks up the bin at the store, also in Royersford, once every four to six weeks. Wawa partnered with AES to import this bin through Wadewitz’s Australian company as a trial. The successful pilot program led to the founding of BiobiN North America and subsequent U.S. production of the bins. Foley, no stranger to food waste composting, is currently working on another pilot program with Weis Markets grocery store chain (see “Grocer, Composter And Quarry Operator Divide And Conquer,” November 2010). The 10-cy bin in Royersford is the first to be imported to the United States, while the 20-cy unit at the Philadelphia Airport Marriott is the first to roll off the assembly line at BiobiN North America.
Generators of food residuals and composters face two major issues when trying to create an effective diversion program – odors/vectors and the cost of trucking, says Foley. “Traditionally, the solution to the first issue is to have the hauler pick up the material daily or every few days. The odor/vector problem is alleviated, although not eliminated, but the trucking problem is exacerbated exponentially. The generator who only produces a few hundred pounds of food waste every few days has a substantial cost hurdle to overcome if they want to divert organics to composting. And generally the cost of the trucking is borne, at least in part, by the composter who must substantially reduce the tip fees to remain competitive.”
Foley describes the BiobiN as a simple and elegant solution to both issues. The food waste is stored in an aerobic condition, coupled to a biofilter, which eliminates odors and vectors. With that issue under control, he says, trucking returns to a more economical volume equation. “Instead of two or three times a week pickup, trucking is reduced to once every four to six weeks. Reduced truck traffic and cost is the net effect, and food waste diversion becomes a recyclable to be handled like all other recycling materials.” Foley adds 6 inches to 8 inches of wood chips to the BiobiN before returning it to Wawa.
While the Marriott is generating about three to four tons of food waste a week that goes to Wilmington, the pilot Wawa store has been averaging about 1 ton a week for Two Particular Acres. WORC utilizes a GORE Cover system, processing up to 550-tons a day in 63, 1,000-cy windrows, while Foley uses aerated static pile technology developed by O2 Compost Systems of Snohomish, Washington.
BiobiN North America is working with Wawa to develop receptacles of varying sizes – down to 1.5 cy – that can work in areas such as congested cities, where real estate is at a premium and the available footprint for food waste containment may be small. “One thing we’re trying do with our waste program is reduce the number of pick ups,” explains Fred Wood, Business Performance Manager at Wawa, whose father started the convenience retail chain named after the family dairy and Delaware County, Pennsylvania, town where the dairy and corporate headquarters reside. “The problem with recycling is it’s good in name and theory, but it increases the amount of truck traffic to a site.”
Wawa recently installed 10-cy bins at stores in New Castle, Delaware, near WORC, and in West Chester, Pennsylvania. Wawa also will be testing a 3-cy prototype at its corporate headquarters in Wawa, Pennsylvania. “The big containers are too big for most small stores, so we are going to test the smaller units at our corporate center cafeteria and give exposure to our management,” says Wood.
According to Judy Ward, president and CEO of AES, the Wawa in Royersford has cut out an average of 8 to 9 trash trips per month. “There are both economic and environmental advantages to this,” she says. “They used to collect trash four times a week; now they collect trash twice a week and the food waste bin every six weeks.” Her company started out as an equipment service provider and waste consultant to Wawa, and that evolving relationship is now partially driving development of the North American version of the BiobiN. With 580 Wawa stores operating across Pennsylvania, New Jersey, Delaware, Maryland and Virginia, a multitude of situations must be accommodated. Wood explains he likes the flexibility of the smaller 1.5- to 3-cy units. “If we need more capacity, then we will just add another one,” he says. “The biofilter is designed to take on a multitude of smaller units.”
Ward adds that Wawa’s infrastructure cost also is less. “They don’t have to install gates and concrete pads as with the roll-off units,” she explains. “The smaller unit still offers more capacity than standard toters, but with a little more flexibility than the larger roll-off version.” She points out that contaminants are easy to spot in the top-loading containers. Clients are given a long wooden-handled trash picker to remove items that shouldn’t be in the bin.
Wawa is no stranger to adaptation. Fred Wood’s father, dairyman Grahame Wood, opened the first Wawa Food Market in 1964 when home delivery of milk was falling out of fashion. It helped usher in the 24-hour convenience store in the 1970s, introduced no-surcharge ATMs and gasoline/convenience retail operations in the mid-1990s and touch-screen-order delis at the turn of the millennium. “It morphs along and keeps changing every generation,” Wood adds. “Our new store prototypes always include gasoline — and now we’ve started to pilot diesel in some locations. One of our core values is to embrace change; so we are constantly watching and responding to customer’s changing needs and preferences. And if the market changed, we would change with the market. Once again, it’s a supply and demand issue. As more biofuels are available and more cars run on them, maybe this would be more attractive.”
Both Wawa’s and the Marriott’s high-level involvement and willingness to experiment have driven the creation of BiobiN North America as well as the evolution of the product. And while her two clients are both realizing the economic benefits of diverting organics from the landfill – and would be way out front should any future legislative mandate require such diversion – Ward says the venture is also about taking an environmental leadership position. “That is exactly what Mr. Marriott tells all his employees,” confirms Storer.

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