How on-site digesters are helping divert food waste from landfill

Food waste has long been a disproportionate part of the waste stream. Gold Medal Environmental, based in Sewell, New Jersey, is working to change that through its innovative organic waste solutions. Michael Schmidt, a 15-year environmental services specialist and the executive vice president of strategic growth and development at Gold Medal Environmental, believes technology-backed solutions are the way of the future to help manage this material.

Since the New York-based green technology company BioHiTech Global Inc. acquired Gold Medal Environmental, which provides commercial and residential waste and recycling collection in New Jersey and Philadelphia, in early 2018, the hauler has been growing its Philadelphia footprint with BioHiTech’s on-site aerobic digesters that divert food waste from landfills.

“BioHiTech said to us, ‘Here’s an opportunity.’ We can expand our global reach in the rather tight geographic footprint of Philadelphia [by leveraging this technology],” Schmidt says.

BioHiTech’s aerobic digesters break down food into liquid, which can then be simply discharged into the sewer system. As more research is conducted on aerobic systems, specifically the positive and negative effects of the digester outflow on wastewater treatment plants, Schmidt says the industry is becoming more receptive to this new technology thanks to its potential to help solve the global food waste problem.

“Food waste makes up [20 percent] of the waste stream,” Schmidt says. “If we can find a way to keep that food waste out of the waste stream and out of landfills, we dramatically reduce the reliance on landfills.”

Technology rising

Following the acquisition, BioHiTech moved to target Gold Medal’s existing commercial municipal solid waste (MSW) customers with its food waste solution and reached out to new customers who would benefit from incorporating the digester.

“We focus most on universities, hotels and grocery stores,” Schmidt says. “Given food is mostly water, they’re essentially throwing out liquid and it’s really heavy, so stores can not only reduce their carbon footprint and impact on environment by using these systems, but they can reduce their waste disposal bill as well.”

Aerobic digesters can process anywhere from 250 to 2,000 pounds of food waste per day using oxygen, microorganisms and warm water to break down food. Compared with anerobic digestion and composting, aerobic digestion is an accelerated process, Schmidt says.

While thinking of the pros and cons of each, Schmidt says aerobic digestion has less environmental impact because it eliminates the need for hauling.

“Composting is a great idea, but it requires another truck on the road emitting carbon,” he says. “It’s going to a compost facility, where food breaks down and emits gas. Is this really something that’s going to solve the global issue of carbon emissions?”

A 2015 University of Delaware study assessed BioHiTech’s digester for food waste management. The study examined four food waste management pathways: transporting aerobically digested waste through the sewer to a wastewater treatment plant for further treatment; trucking aerobically digested waste to an anaerobic digester for further treatment and conversion into energy; trucking the waste to a landfill for disposal; and trucking the waste to a compost facility for further treatment.

The study concluded that releasing wastewater into the sewer is an environmentally favorable pathway and “takes advantage of the existing wastewater treatment infrastructure.” However, continued research needs to be done to fully vet the effects of the digester outflow, “which may help future stakeholders feel more confident in the product.”

“With new technology, there are always questions and hesitations,” Schmidt says. “One of the biggest questions we hear is centered on exactly what is being sent down the drain when you use an aerobic digester. The University of Delaware study found as microorganisms go down the drain with the food, they help clean the pipes of grease buildup as they make their way to the wastewater treatment facility. It’s not wrecking the ecosystem. It’s helping the process.”

Cloud-based technology that comes with the digesters allows Gold Medal customers to share live data to engage the community and inspire behavioral change.

“Customers go online [and] pull information that tells them how many pounds of food waste they diverted from the landfill that day, week or year. Then they pass along that information because people want to know their university or hotel is doing something that is working to reduce carbon emissions and working to reduce the need for landfill,” Schmidt says.

Temple University in Philadelphia has installed three digesters on campus, which has helped the college cut its food waste costs by 40 percent over traditional composting. Schmidt says that while Gold Medal’s clients include notable commercial customers, like the Four Seasons, perhaps their most high-profile client is Lincoln Financial Field, home of the Philadelphia Eagles.

Eagles Go Green

Lincoln Financial Field has always had a strong partnership with its waste hauler, New Castle, Delaware-based Waste Masters Solutions, says Norman Vossschulte, director of fan experience and Eagles Go Green spokesperson. So when the composting facility near the stadium closed, the hauler suggested digesters as a possible solution.

“We thought that could be something really interesting. We just didn’t know much about the technology— it was just starting to be used out in the industry,” Vossschulte says. “We heard that some large overseas sports facilities and big hotels and casinos had installed them.”

The stadium tested BioHiTech’s digester out on a smaller scale at its training facility. Eight tons of pre-consumer food waste were diverted from landfill as a result. It worked so well that a larger digester was installed at the stadium, which diverted 28 tons of food waste from landfill in 2018.

Vossschulte says billboards and signs around the stadium informing fans of sustainability efforts double as educational tools to create awareness and drive change.

Before Lincoln Financial Field became one of the “greenest” stadiums in the world, according to the U.S. Department of Energy, Vossschulte says its sustainability crusade began in 2005 when “we ripped open a trash bag and asked, ‘What’s recyclable and what’s not?’ And then we asked, ‘How can we recycle everything?”’ He credits Eagles owner Jeffrey Lurie for his dedication and leadership in making the stadium sustainable.

Commenting on the partnership, Schmidt says, “They’re ranked one of the greenest sports stadiums in the country, so in terms of analysis and the degree of research on the Eagles’ side, they did their due diligence. I think it brings credibility that our food waste solution works.”

Zero landfill

Food digesters are a part of BioHiTech’s and Gold Medal’s vision to virtually eliminate landfill usage for organics and create a valuable renewable fuel from waste. BioHiTech began operations at its first fully automated HEBioT renewable resource recovery facility in Martinsburg, West Virginia, which will allow Gold Medal to divert 100,000 tons of MSW per year from area landfills, Schmidt says. Waste will be produced into solid recovered fuel (SRF), which will be used by Alpharetta, Georgia-based Argos USA, one the largest producers of Portland cement in the U.S.

“You look at this growing population and you start to realize the number of landfills that are going to be closing in the next five years, and there aren’t a whole lot of people who are welcoming the development and expansion of landfills,” Schmidt says. “There needs to be a solution. Not a five-year or 10-year solution. A solution needs to be here now.”

Between aerobic digesters and the HEBioT process, Schmidt believes the time is now to implement new waste management technology.

“As the population continues to grow, we continue to battle for the use of land,” Schmidt says. “I really feel like using raw land for landfills is irresponsible. We have solutions to bring food waste out of the waste stream. Using these solutions is a step in the right direction for the future to help reduce our reliance on landfills.”

This article originally ran in the April issue of Waste Today. The author is a digital editor for the Recycling Today Media Group and can be reached at kmaile@gie.net.