Department of Ecology News Release - October 30, 2023

Washington proposes new rule to decrease methane emissions from landfills

Rule would require more capture and control of planet-warming gas

Closed and open Washington landfills will need to comply with stricter methane rules.


Reducing methane gas emissions is one of the best strategies for cutting greenhouse gas emissions in the near term. The Washington Department of Ecology is proposing a rule to reduce emissions of methane by requiring municipal solid waste landfills to meet more stringent requirements to prevent the gas from escaping into the atmosphere. 

When organic material such as food and yard waste decomposes in a landfill, it emits methane and carbon dioxide (CO2) – two gases that contribute to climate change. Methane has approximately 83 times the global warming potential of CO2 over a 20-year period and is responsible for more than 25% of the global warming experienced today.

“Methane gas emissions from landfills are a significant contributor to the climate crisis, and this new program will help us take measures to reduce them,” said Laura Watson, Ecology’s director. “Cutting landfill methane emissions is an important step toward meeting our statewide commitment to reduce greenhouse gas emissions by 95% by 2050.” 

Ecology’s proposed rule would apply to most municipal solid waste landfills that have received solid waste after Jan. 1, 1992.

To comply with the new regulation, landfill owners and operators will have to meet additional requirements for collecting and controlling methane, as well as new state monitoring and reporting requirements. The state will make $15 million in grants available to help landfill owners and operators cover costs associated with meeting these requirements. The grants are funded from revenue generated under the Climate Commitment Act.

With this rulemaking, Washington will join California, Oregon, and Maryland in implementing more protective standards for decreasing methane emissions from landfills. 

Provide input

We are accepting public comments on this rule beginning Monday, Oct. 30, 2023. 
Submit comments online, by mail, or at a public hearing:

  • Comment online
  • Mail to:
    Bill Flagg
    Department of Ecology
    Air Quality Program
    P.O. Box 47600
    Olympia, WA  98504-7600
  • Public hearing: We will hold a public hearing on Wednesday, Dec. 6, 2023. We will provide an overview of the proposed rule and hold a question-and-answer period, followed by public comment. Register here.

Contact information

Susan Woodward