BOULDER — Boulder has changed its composting rules for businesses because of what it described as a high level of contamination in the compost stream.

A1 Organics, which processes compost materials from community businesses, is more frequently rejecting loads of materials because of contamination, the city said in a press release. When rejected, those loads go to the landfill.

Main contaminants, the city said, include plastics, disposable gloves, diapers, glass and non-compostable to-go containers. 

The new rules:

• Allow businesses to remove front-of-house, customer-facing compost receptacles. (Customer-facing recycling and back-of-house composting are still required).
• Allow businesses with public restrooms to remove bathroom compost receptacles.

“We believe these changes are necessary to course correct and improve the quality of our compost stream,” said Jamie Harkins, policy adviser, in a written statement. “This is an important lesson learned through leading zero-waste practices nationwide.”

According to the city’s zero-waste business advisers, front-of-house composting does not typically have much food in it. Instead, bins fill with compostable foodware, napkins and contaminants such as plastic and glass.

“We value the partnership of our community and local businesses as we work together to create high-quality compost that restores our soils and absorbs carbon instead of polluting our landscapes,” said Harkins. “This starts with thoughtful sorting while working on larger system changes that make it easy for consumers to do the right thing.”

The city also is “redoubling efforts to educate the community about proper sorting,” the press statement said.

“While waste diversion remains important, we cannot recycle and compost our way out of the climate crisis,” said Harkins. “Recognizing this, we are exploring innovative ways to prevent creating waste in the first place, like reusable foodware options for takeout and delivery. We’re also beginning to explore what regulations to reduce single-use plastics that contaminate our compost and soils might look like.”