DENVER — The Denver Department of Public Health & Environment (DDPHE) and Waste Management (WM) are partnering to build what officials said will be Colorado’s largest renewable natural gas facility at the Denver Arapahoe Disposal Site landfill. It will mark the state’s first landfill gas-to-RNG plant.

The project, approved by the Denver City Council on Monday, is billed as a major step toward the city’s climate and air-quality goals. Under the agreement, WM will finance, construct and operate the facility, while Denver will receive royalty payments from the revenue generated. 

“Denver is confronting the climate crisis head-on,” Mayor Mike Johnston said in a statement. “This is a bold example of how we can move aggressively toward clean, renewable energy, while also supporting innovation and economic growth for a cleaner, more vibrant Denver.”

Landfill gas currently produced at the city-owned site is partly captured and converted to electricity, with the remainder burned off to comply with air permit requirements. The new facility is expected to capture and refine nearly all of the gas, upgrading it into pipeline-quality fuel that officials say is almost chemically identical to natural gas but with a smaller carbon footprint.

WM leaders said the project will contribute to local sustainability efforts and expand the region’s renewable energy supply.

“This project can help provide a local, sustainable energy source for our local communities,” said David Brannon, WM’s area vice president for the Four Corners region. “We are grateful to state and local officials for their collaboration and commitment in making this project a success.”

City officials said the reduction in flaring will decrease emissions of ozone-forming compounds and other pollutants, improving air quality. They also cited the plan as a key piece of Denver’s larger climate strategy.

Construction is expected to begin in late 2026, with the facility slated to start operations in 2027.