science environment

New Rules For Commercial Composting In Portland: Food Only

By Cassandra Profita (OPB)
April 8, 2014 1:25 a.m.
Within a year, commercial composting in Portland will be limited to food only.

Within a year, commercial composting in Portland will be limited to food only.


A big change is on the way for businesses that compost commercial food waste in Portland.


Metro, the regional government that oversees the city's commercial food waste collection, is changing the rules for what kind of material it accepts at its Portland transfer station.

Within a year, the program will restrict commercial compost collection in Portland to food scraps only. That means businesses will not be able to compost food-related materials such as soiled cardboard, napkins, plates or compostable plastic utensils. The change does not affect residential curbside food scrap collections.

Paul Ehinger, director of solid waste operations at Metro, says a large volume of non-food items have been causing problems for the methane digester that receives the material. Commercial food waste used to go to the Nature's Needs composting facility in North Plains, but that facility was recently restricted from accepting the material because of the stench it created in the surrounding community.


JC Biomethane in Junction City now receives the commercial compost material and uses it to generate electricity in its methane digester. But its digester isn't designed to handle the material it's been receiving.

"Some of this material essentially doesn't digest," Ehinger said.

On Nov. 1, Metro will no longer accept regular or waxed cardboard as part of the commercial composting program. On March 1, 2015, the transfer station will only accept food scraps. Ehinger said businesses that put too much non-food waste in their composting bins will be charged the higher rate for garbage disposal, and the load will be sent to the landfill instead.

"Our expectation is that we'll get probably relative quick compliance from some not so quick from others," said Ehinger. "But it will improve the situation at JC Biomethane, and they've agreed they can live with it for that long."

Ehinger says until the new rules kick in, Metro will be working to sort food scraps from other material at its transfer station in Northwest Portland.

Here's the letter Metro sent to businesses on March 28 announcing the change.

Metro letter on new compost rules