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The City of Portland, Oregon

Sustainability at Work

Providing free tools and expertise to achieve your goals

Phone: 503-823-7037

Email: sustainabilityatwork@portlandoregon.gov

What happens to your food waste?

Food scraps from Portland businesses are taken to an anaerobic digestion facility, where they are blended into a liquid and then broken down by bacteria. The bacteria create methane, which is captured and burned to make electricity.

anaerobic digestion process

Portland’s residential and business compost are different

The compost collected in Portland’s residential curbside program goes to a different type of processing facility than the compost collected by businesses, which is one reason there are different guidelines for what is allowed in residential compost and business compost.

Residential compost

The food scraps and yard debris collected in Portland’s residential curbside compost program goes to a commercial compost facility.

Recology North Plains compost facility

How does it work?
At commercial compost facilities, compost is laid out in big rows that are regularly mixed, or “turned.” These rows function like a bigger, hotter version of a backyard compost bin. 

What can go into it?
Food is the key ingredient. It’s what provides the nutrients that farmers and gardeners need for healthy crops. Some non-food items are also allowed: yard debris, paper towels and napkins, and pizza boxes. These non-food items help provide a balanced mix of fiber, and wet and dry materials. 

What’s the end product?
Nutrient-rich compost that farmers, gardeners and vineyards add to their soil to help grow food and other plants.

Business compost

The food scraps collected in Portland’s commercial compost program go to an anaerobic digestion facility.

JC Biomethane digester facility

How does it work?
Food waste is blended into a liquid and is broken down by bacteria. The bacteria create methane, which is captured and burned to make electricity.

What can go into it?
Food is the key ingredient, and is the only thing allowed in business compost. Food is what the bacteria want to eat, and other materials gum up the system and have to be filtered out.

What’s the end product?
Energy for homes and businesses, as well as fertilizer to enrich soils.


How do food scraps turn into energy?

Watch how an Anaerobic Digestion Facility turns food waste into energy:

JC Biomethane for Kids from Kelly Lyon Photography on Vimeo.


Learn more