Presenters in the WasteExpo session "Food Scrap Composting: The Wave of the Future?" were united in their belief that an increased corporate, governmental and public push toward sustainability means the diversion of food waste will only become more commonplace going forward. The session focused largely on commercial food scrap diversion as opposed to residential collection.
John Connolly of JFConnolly & Associates laid out the motivations for implementing food waste collection programs and the ways food scrap diversion helps contribute to sustainability. He emphasized that for commercial organics diversion to succeed it must meet the operational goals of all stakeholders (waste generators, waste service vendors, government and non-governmental organizations), be relatively easy to manage, benefit the environment and remain profitable. In many cases, said Connolly, the government impetus is there to grow food waste management, but industry infrastructure is lacking. As examples, he cited the U.S.'s (EPA) stated goal of doubling the current national organics diversion rate of 3 percent and listed states eager to ban food waste from landfills but unable to due to lack of facilities ready to receive that diverted material.
Tim Lesko of Greenco Environmental, Georgia's only permitted composting facility, got more into the nitty gritty of turning food waste into compost. (View a Waste Age profile of Greenco's operation). Organic waste comprises 27 percent of Georgia's waste stream, according to Lesko, and 44 percent of that is food waste. He noted that pre-consumer food waste is generally easier to compost than post-consumer due to lower contamination from non-compostable materials, but that there is a far greater volume of post-consumer material available and greater demand for that service.
Lesko detailed on-the-ground food waste collection, noting that the material requires little-to-no compaction since it is so dense, but that weight and density means his collection vehicles often meet or exceed DOT weight limits. He emphasized the importance of source checking for contaminants (as totes/bins are dumped into the hopper) "because it is impossible to find three or four wine bottles in 100 tons of combined food waste." He concluded by detailing how food waste is composted once it reaches Greenco's facility. Some landfill managers were visibly envious to hear that, volumetrically, there is 75% shrinkage from the time waste enters Lesko's facility to the time it leaves as compost.
Andrew Shakman of LeanPath Inc. provided a food waste generator's perspective, describing things he'd learned working closely with restaurant operators to implement food waste diversion. Shakman said foodservice operators have recently been compelled to become much more knowledgeable about where their food comes from and how it is processed. Becoming cognizant of where that food goes after it leaves the restaurant is the next logical step. This is complicated by the fact that many restaurateurs have been trained to abhor waste and see it as an indicator of negligence, and thus are reluctant to even consider the waste their kitchen is producing. Moreover, they have fears that diverting food waste will create inefficiencies, generate unpleasant smells and increase costs.
Shakman showed how these fears can be allayed through training and education, articulating the upstream and downstream costs of food waste that can be offset through diversion. He also emphasized the critical importance of EPA's food waste recovery hierarchy, which in many cases can prevent the need to send material to composting in the first place. Like Connolly, Shakman noted the importance of getting buy-in from all stakeholders, from dishwashers up through restaurant ownership.
A lively Q&A followed the presentations. Asked about odors, Lesko noted that they are a fact of life at a composting facility, but that pests are controllable, with his chief pests being turkey vultures and some insects (but no rodents). Having previously stated that a proper ratio of "woody" green waste must be mixed with the food waste to achieve composting, Lesko admitted that availability of this woody waste was a limiting factor for his operation, since most of that material in Georgia goes to biomass energy generation.
Frequency of collection was a hot topic, with consensus being that twice a week is optimal, especially for restaurants. But some operations (Lesko noted that one of his clients was a seafood restaurant) may require more frequent pickups. The amount of "juice" produced by food waste was addressed, with Lesko detailing the way his trucks are sealed and Connolly noting one truck he had seen with a custom false floor perforated to collect fluids. That led to a discussion of liquid food waste (soups, beverages, etc.). Lesko noted a great deal of demand in this sector, but Shakman felt that there were more reuse opportunities for liquid organics and that it was more difficult to collect and process.
The session concluded with a discussion of dining ware and packaging made from polylactic acid (PLA) and other biodegradable compostables. Given that the material is expensive, energy-intensive to produce, hard to distinguish from plastic, and adds little nutrient value to compost, there was some consensus that it may be more trouble than it's worth.