Have you ever let a few eggs or a handful of raspberries spoil in your fridge, only to toss them into the garbage? If so, you’re in good company. In the United States, up to 40 percent of all food that is produced gets thrown away, creating tens of millions of pounds of waste each year that ends up in landfills and incinerators, producing powerful climate-warming emissions.
Taking aim at what some say is a critical piece of the climate fight, Boston Mayor Michelle Wu on Thursday said the city is launching a citywide composting program.
All Boston residents who live in residential buildings with six units or fewer are eligible for the program, and can sign up on the city’s website now. In July, officials will drop off compost bins, manuals, and other necessary materials to all participants. Residents can collect compostable materials — including fruits and vegetables, coffee grounds, meat and seafood scraps, houseplant trimmings, egg shells, and other organic materials — in their bins, and then, starting on Aug. 1, place them on the curb to be collected on their regular trash and recycling days by two compost firms, Portland, Maine-based Garbage to Garden and Boston-based Save That Stuff.
“Curbside food waste collection is an important example of how we can each have an impact in moving our city toward sustainability with how we dispose of our food scraps,” Wu said in a statement.
Other Massachusetts municipalities including Cambridge and Natick have rolled out composting initiatives in recent years. Last year, Hamilton became the first town in the state to make composting mandatory.
Wu said the project is part of her vision for a Green New Deal. Though it’s not discussed as much as other environmental issues like energy and transit, food waste is a big problem for the climate, because when it rots in landfills or gets burned in garbage incinerators, it produces planet-heating greenhouse gas pollution.
“Reducing food waste must be a part of our strategy to fight climate change,” said Emily Broad Leib, director of Harvard Law School’s Food Law and Policy Clinic. According to one environmental nonprofit’s estimates, she noted, scaling up home composting programs nationally could divert tens of thousands of tons of greenhouse gas emissions every year.
Instead of being thrown into the trash stream, the material collected will be turned into compost at Save that Stuff’s site in West Bridgewater, which will be made available to Boston parks, gardens, and schools.
Some compost will also be sent to Waste Management’s Centralized Organic Recycling Facility in Charlestown, where it will be processed into a thick slurry and driven to the Greater Lawrence Sanitary District in North Andover to be processed in anaerobic digesters and turned into biogas which can be used for energy or heat. In a press release, the city said that this means some compost will be turned into “clean energy.”
Kirstie Pecci, a senior attorney and director of the Zero Waste Project for the environmental nonprofit Conservation Law Foundation, said it’s not so simple because the process can create another form of waste. Before the water treatment plant processes compost slurry into biogas, she said, the material is mixed with sludge from the sewer system, which can contain heavy metals, microplastics, and PFAS, a carcinogenic forever chemical.
After it’s processed, it leaves behind a byproduct that can be toxic, she said. That material is sometimes turned into fertilizer, which she said is problematic because it can contaminate farmland. Last year, a Sierra Club report found that a fertilizer produced at Greater Lawrence Sanitary District contained PFAS.
Even if it’s not turned into fertilizer, Pecci said, the byproduct can cause problems. If the material is incinerated, it can release the toxins within it — and greenhouse gases — into the air. And if it is put in a landfill, it can leach those pollutants into groundwater.
“The city is trying to do the right thing, but this is not the right thing,” she said. This can’t be a part of the strategy we’re adopting long term.”
According to Boston city officials, the majority of food waste sent to the Greater Lawrence Sanitary District gets converted into biogas, while only a minimal portion ends up in dried fertilizer product — and all processes at the facility are in full comportment with federal and state regulations.
“The new curbside food waste collection program will reduce the City’s reliance on landfills and incinerators, and make it more convenient for Boston residents to recycle their household food scraps,” said a spokeswoman for Wu.
Land that can be used for composting, the city said, is rare in Boston. But officials are working to “expand partnerships with neighborhood farms for turning food waste into compost,” the spokesperson said.
This story has been updated to include additional comments from the City of Boston.