Protecting Oregon's Environment
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Oregon Department of Environmental Quality

Land Quality 

Solid Waste

Prevention and Reuse
Recovery and Compost
Oregon's Recycling Laws
Conferences, Training & Workshops

DEQ's Composting Program

Composting facilities are operations that use biological processes (microorganisms) to decompose organic feedstocks such as yard debris, animal manures and food scraps. Aerobic composting uses microorganisms that prefer oxygen, while anaerobic digesters use microorganisms that thrive in low oxygen environments. Aerobic composters produce compost, while anaerobic digesters create and capture methane gas to create electricity or other fuel products. Digesters also create liquid and solid products that can be used for soil fertilizing and conditioning.

The products of composting facilities provide numerous environmental benefits. The use of compost, when incorporated into soil, can improve soil tilth and fertility; it can provide a more stable form of nitrogen less susceptible to leaching into water supplies. Compost also helps reduce compaction and increases infiltration. Incorporation of compost into soil stores carbon, helping to reduce atmospheric carbon. By capturing methane gas, anaerobic digesters avoid the release of methane to the atmosphere, a significant component of greenhouse gas.

DEQ supports and encourages composting. At the same time, DEQ is aware that, if not conducted in the proper manner, or if conducted at an improper location, composting presents potential environmental problems, most notably to surface water and groundwater.

Regulating Composting Facilities and Anaerobic Digesters - Rules and Permits

Oregon’s composting rules require permits for composting facilities and also provide exemptions from permitting requirements for certain small, low-risk composting facilities. The composting rules include permitting requirements for anaerobic digestion facilities in addition to aerobic composting facilities. Under the rules, anaerobic digesters are considered composting facilities but are issued separate anaerobic digester permits addressing issues specific to anaerobic digesters. For more information on composting facility permits and the permitting process, please view Regulating Composting Facilities and Anaerobic Digesters.

Residential Composting

Reports and Issues

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For more information about DEQ's Land Quality programs, visit the DEQ contact page.

Oregon Department of Environmental Quality
Headquarters: 700 NE Multnomah Street, Suite 600, Portland, OR 97232
Phone: 503-229-5696 or toll free in Oregon 1-800-452-4011
Oregon Telecommunications Relay Service: 1-800-735-2900  FAX: 503-229-6124

The Oregon Department of Environmental Quality is a regulatory agency authorized to protect Oregon's environment by
the State of Oregon and the Environmental Protection Agency.

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