Build it and they will compost.

That’s the premise behind an October report from the Rhode Island Food Policy Council, which proposes public/private investment in at least four composting facilities in Rhode Island that could process the nearly 90,000 tons of food waste currently finding its way into the Central Landfill in Johnston annually, where it generates greenhouse gases as it decomposes.

“This accounts for approximately 32% of the total municipal solid waste,” according to the report. “From a financial perspective, landfilling this organic waste is costing the state $5.6 million every year in tipping fees alone, a number that will only increase as the landfill gets closer to closing.”

The landfill is projected to be filled by 2046, according to the report.

To reassure those who would be investing in the composting facilities being called for, the report identifies seven end markets for compost in the state, ranging from residential to stormwater management. It concludes there is the potential to produce 13.2 million cubic yards annually of compost in Rhode Island, with revenues of between $1.5 billion and $6.2 billion.

“Based on the potential of the seven end markets identified in the report, we’re confident the state would be able to utilize all finished product [compost] generated by these facilities,” said Isaac Bearg, the Food Policy Council’s climate and environment program director.

Bearg researched and wrote the 40-page report, together with compost markets research intern Eliana Hornbuckle.

The report doesn’t include an estimate of how much compost is currently being produced in Rhode Island, or how much revenue it’s currently generating.

“Unfortunately, that is not really a number that exists at the moment,” Bearg said. “There’s nobody really tracking how much compost is being produced.”

Hornbuckle will be putting out a survey to local composters to “address that particular issue and question.”

“The current capacity is pretty low when it comes to composting of food waste scraps here in Rhode Island, with Earth Care Farm being the one major facility accepting food scraps for composting, and I believe they’re only at around 7,500 tons per year,” Bearg said.

Jayne Merner, who with her father, Michael, has been making compost on their Earth Care Farm in Charlestown for nearly 50 years, confirmed the farm composts 7,500 tons of food scrap annually. Merner said her estimation of the amount of compost currently being produced overall in Rhode Island is a “very small fraction” of the 13.2 million cubic yards projected by the Food Policy Council report.

“We make about 6,000 cubic yards a year of finished product and we sell 6,000 cubic yards,” Merner said. “That’s why we’re starting a second site.”

Earth Care Farm’s second site will be in Sterling, Conn., and is expected to produce 30,000 cubic yards of compost annually — five times the Rhode Island site’s capacity — when it opens this year after a lengthy permitting process.

“I’m on the seventh of seven permits,” Merner said.

Rhode Island passed a food waste ban in 2016, but it only applies to certain businesses, colleges, universities, and K-12 schools, and bypasses households entirely.

“This shortcoming of the wasted food ban, coupled with a lack of enforcement and food scrap composting infrastructure, has resulted in a lack of wasted food diversion and compost production within the state,” according to the Food Policy Council report.

Vermont also has a food waste ban, but unlike Rhode Island, Vermont’s ban applies to everyone, including individual households, which are expected to segregate out organic waste to keep it out of the landfill. Even though it’s impossible to police whether households are complying with the ban, Josh Kelly, solid waste program manager for Vermont’s Department of Environmental Conservation, said the ban is working relatively well.

“Our food waste estimate in 2023 was that we’re recovering close to 57% of what we could [recover] in the food stream,” Kelly said. “That’s pretty good when you think about all the challenges we have, like the ick factor. It’s really messy for people who live in apartments. That’s why kids are told to empty the trash. No one else wants to do it.”

Merner, of Earth Care Farm, believes that while it’s important to encourage more production of compost, it’s even more important to make good compost.

“What’s the point of making crappy compost? I don’t see the point of it,” Merner said. “Sure, on roadsides you could have a little lesser quality, but none of it should be filled with trash. Let’s get down on contamination control, then expand and amplify.”

Earth Care Farm sells all the compost it can make for $85 per cubic yard, double the going rate, because of its quality, according to Merner, but others, particularly municipalities, have a hard time selling their compost for $2 per yard, she said, because it’s contaminated with glass, plastics, and weed seeds.

John O’Malley, a 75-year-old gardener in Wakefield, has been using Earth Care Farm compost for nearly as long as the farm has been making it. O’Malley said he grew up in the housing projects in Providence, and never saw a tomato plant until he was 21 years old.

“I didn’t know potatoes grew in the ground,” he said.

O’Malley has been making up for his lack of exposure to gardening early on for more than 50 years, planting a large garden at home where he raises 30 kinds of tomatoes and seven kinds of potatoes, not to mention garlic, onions, and lots of Asian greens, including bok choy and mustard plants from China.

A former history teacher at South Kingston High School, O’Malley began traveling around Rhode Island after he retired, planting gardens at both public and private schools. He was planting a garden at a private Catholic school in Providence eight or nine years ago, he said, when he decided to use compost made locally, rather than relying on his usual source of supply, Earth Care Farm.

“I had a (cubic) yard of compost delivered and it was loaded with weed seeds,” O’Malley said. “I got it in Providence from a private business. As soon as we planted with the students a bunch of weeds came up, endless weeds. I’ve never seen anything like that.”

O’Malley declined to identify the business where he bought the compost, but said he didn’t go back for more. Like Merner, he pointed to compost made by municipalities as sometimes falling short on quality.

“Municipalities are doing the right thing in composting yard waste and weeds but the quality is not so much there,” O’Malley said.

Mark Dennen, supervising environmental scientist in the Rhode Island Department of Environmental Management’s Office of Land Revitalization and Sustainable Materials Management, said the quality of compost varies from community to community.

“Some make really nice compost,” he said. “Some you got plastic bags. They try to strain it out as best as they can. At the end they put it through a sieve, which also catches some of the compost and it ends up being disposed of as waste. It’s just like the issue with recycling. Some communities have high rates of contamination, and some have lower rates.”

For his part, Bearg said he doesn’t disagree with anything Merner has to say about the importance of producing quality compost.

“I guess I’m coming at it from a slightly different angle,” Bearg said. “Yes, we need more quality compost, but what we also need is infrastructure that’s going to produce that quality compost. We’re never going to get probably even close to that total market, but we don’t need to. If we can reach a fraction of that market we’re still going to be able to sell all the compost we produce in this state.”