Facility could turn food scraps into energy

Published Aug 11, 2017 at 4:00pm

By late next year, commercial trash haulers could be starting new routes that collect only food scraps from large institutions like nursing homes and hospitals.

Instead of going to the landfill mixed in with trash like it does now, the food waste would be ground into a slurry at a new processing facility to be built at the Oneida-Herkimer Solid Waste Authority in north Utica. That liquid would then be sent via pipe to the adjacent Oneida County wastewater treatment plant, where it would be processed in an anaerobic digester. 

The end result? Biogas that can be burned to create energy. Anaerobic digestion is a series of biological processes in which microorganisms break down biodegradable material in the absence of oxygen. One of the end products is the biogas that can be combusted to generate electricity and heat.

The sewage treatment plant would hardly be the first one to accept liquified food waste, and it certainly won’t be the last. Efforts to keep food products out of landfills are growing nationwide, and many are doing it by collecting and composting food scraps. But there is increasing interest in sending food waste, particularly from large commercial sources, to facilities that use anaerobic digesters to convert the waste into biogas. 

The Solid Waste Authority is well aware of the trend to legislatively ban food scraps from landfills.

“We see it happening across the globe, quite honestly,” said William A. Rabbia, executive director.

With that in mind, a feasibility study of handling food waste separately from trash was initiated. Part of the evaluation included visits by Rabbia and authority staff to three source-separated organics facilities. The conclusion was that such a process could work. A factor in the determination was the fact that the sewage treatment plant next door to the authority’s facility is undergoing a substantial upgrade, including the installation of anaerobic digesters. The latter development makes processing food waste more manageable at the authority’s Leland Avenue facility because there will be a convenient place to send the slurry.

The authority’s motivation to pursue source separation for food waste is wanting to be ready to respond should New York enact restrictions on landfilling food scraps. Though the details are complicated and any implementation is far off, such a possibility is a real one.

After much discussion and previous attempts to pass legislation, Gov. Andrew M. Cuomo included food waste diversion in his proposed executive budget for 2017-18. He wanted New York to join California, Massachusetts, Vermont, Connecticut and Rhode Island as states with some form of legislated organic waste diversion. The ban would have applied to any commercial operation that produced two tons or more of food waste a week. 

While the proposal did not, in the end, make it out of the legislature, there’s no reason it can’t surface again, especially in light of Cuomo’s past support for keeping food scraps out of landfills.

Furthermore, New York City is already on board. As of July 1, 2015, the mayor’s office updated a local law to set requirements and enforcement dates for certain large, commercial food generators to divert their biodegradable food waste from the landfill-bound municipal solid waste stream. If fully implemented, it would eventually ban residentially generated organic waste from landfills as well.

“It’s coming,” said County Legislator James M. D’Onofrio, R-15, New Hartford, of required food waste separation during a recent Public Works Committee meeting when the authority’s plan was discussed. He’s also a member of the authority’s board of directors.

While a state requirement about source separation of food waste may be in the offing, Rabbia doesn’t foresee a local law.

“We’re not looking to do a local mandate on that,” he said. His approach is to implement a voluntary system locally involving large food waste generators and trash haulers. Conversations have already started with haulers. 

Such a system would be paid for through tipping fees. The authority executive is hopeful that the charge would be less than the regular tipping fee, thereby providing an incentive for generators to separate food scraps from the trash stream.

Rabbia said there is no intent to discourage food scrap generators from donating leftover food for human consumption, composting, like Hamilton College does, or feeding it to animals.

The project cost is an estimated $2.6 million. Half of the money would come from a $1.3 million grant awarded to the county through the state’s 2016 Consolidated Funding Application program. The authority would pay the remainder. A request for proposals to build the facility has been issued. Responses are due later this month.

The plan calls for the food waste processing facility to be up and running by the last quarter of 2018, a timeframe that coincides with the expected completion of the anaerobic digesters at the sewage treatment plant.

A side benefit of diverting food waste is that it will take longer for the landfill in Ava to be filled to capacity because there’s going to be less trash going into the facility. The most recent projection is that its useful life is another 70 years, a number that’s expected to increase if the food scraps go elsewhere, according to Rabbia.