Composting is the process of transforming organic waste into humus, a critical component of healthy, fertile soil. In rural areas, this can be accomplished by periodically turning large piles, or windrows, of organic waste over themselves using specialized equipment. In more urban areas, Aerated Static Pile (ASP) composting is generally preferred, where piles can be covered and mechanically aerated in order to minimize the site’s footprint and odors.
There are 5,000 composting facilities nationwide, yet it is a highly fragmented market, with only 500 facilities accepting food scraps. according to BioCycle magazine.
A relatively large facility — processing up to 40,000 tons per year — is expected to cost $5 to $9 million in upfront capital and $17 to $28 per incoming ton to operate. Most existing compost facilities are much smaller, lacking economies of scale — the national average is closer to 5,000 tons per year, according to BioCycle. For example, a 50,000 ton-per-year facility incurs nearly half the capital cost of a 10,000 ton-per-year facility on a per-ton basis. Since contamination is a critical issue in large-scale composting, the Roadmap modeling assumes state-of-the-art depackaging and screening equipment is used despite the higher capital costs incurred. From a system perspective, higher costs of screening feedstocks will most likely be offset by higher market value of cleaner compost.
In the near term, adding new compost facilities is expected to be most successful in the Northeast and the Northwest due to high market values for compost and high costs of disposal. Given the mandate to divert commercial food waste in California, the Roadmap also assumes an increase in composting facilities, despite slimmer profit margins.