On Monday, I was able to visit Veteran's Compost in Aberdeen where our cafeteria food waste will be hauled so that it can be processed and turned into compost rather than add to landfills. It was fascinating!
Upon arrival, our 64-gallon green canister (like those pictured) will be offloaded onto a mixing pad. Once there, workers will have to inspect the waste and remove any plastic contaminants by hand -- we'll have to be very careful in the cafeteria this year! We're up for it. It is on the mixing pad where carbon and nitrogen layers are added to accelerate initial bacteria growth.
The material is then moved to piles where it cooks for 2-3 months. The piles are capped with a carbon layer (used woodchips) to contain the smell and deter pests. The company uses a positive aeration system to push oxygen into the piles on 15-20 minute timers. This helps regulate the temperature (have to get hot enough[>131F] to kill off pathogens, but not too hot) and the pushed air also means the piles don't have to be physically turned (which would also release a righteous odor).
Once ready, the material enters the screener (large cylindrical machine pictured), which uses a grating to separate materials that has broken down enough (and is small enough to pass through) from the "overs" which get pushed back into the composting process. The compost that goes through then sit to rest/cool/cure for months before its ready for bagging!
It was a ton of interesting learning, which I hope I've relayed accurately. The company that produces our compostable trays had representatives at the tour as well -- they came all the way from Maine to see the composting of their trays in action. MPT was there filming for an episode of Farm & Harvest that follows crabbing from the bay to the table and on to composting. The crew was not certain of an air date, but once known we'll pass it along.
