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Landfill gas–to–energy facility at Cedar Hills Regional Landfill
Privately owned facility converts landfill gas to pipeline quality natural gas and reduces greenhouse gas emissions

• Project description
• Major benefits
• Project schedule – major milestones
• Contacts

Project description

In 2008, the King County Solid Waste Division contracted with renewable energy company INGENCO (external) – doing business as Bio Energy (Washington) LLC, (BEW) (external) to generate usable energy from methane gas produced by decomposing garbage at Cedar Hills Regional Landfill.

In early 2009, BEW completed major construction of the landfill gas processing facility on about two acres of land leased from King County at the 920-acre Cedar Hills Regional Landfill in Maple Valley. BEW owns and operates the facility, which includes a quarter-mile pipeline for transporting the processed landfill gas to Williams Northwest Pipeline and on to Puget Sound Energy's natural gas-fired power plants. The facility operates 24 hours a day, seven days a week and also generates supplementary electricity for use on site.

In September 2010, the BEW facility continues to operate in the commissioning stage, which involves testing equipment and operating systems. The current gas processing efficiency varies between 80-92 percent based on the volume of gas collected.

Once the commissioning stage is completed and the facility is operating at full capacity, BEW expects to deliver about 5.5 million cubic feet of gas per day, which is enough to power about 24,000 homes.

Major benefits

• Waste reduction - Prior to this facility, landfill gas was burned off through the landfill gas flare system. Now, instead of being wasted, landfill gas is converted into pipeline quality gas and is being used to generate power.
• Reduction in greenhouse gas emissions - Because the converted landfill gas replaces an equal amount of nonrenewable natural gas, this project will result in a 63 percent overall reduction of greenhouse gas emissions at the landfill.
• Revenue - proceeds from the sale of the gas will help keep solid waste disposal rates low and will provide approximately $1 million annually to the Solid Waste Division.

Project schedule – major milestones

Contacts

Bio Energy Washington
If you have any questions or comments about BEW’s landfill gas processing facility or would like to schedule a facility tour, call the BEW comment line at 425-392-3918 or visit BEW (external).

King County Solid Waste Division
If you have questions or comments about the operation of the Cedar Hills Regional Landfill, or would like a tour of the landfill, call 206-296-4490, TTY Relay: 711. This phone line is answered 24 hours a day, seven days a week. You can also use our online comment form.

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