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TransAlta power plant agreement

TransAlta is a coal-fired power plant in Centralia that was required by the Legislature to shut down its coal-fired boilers in two phases. We regulate air pollution from industrial facilities, including power plants, and are monitoring TransAlta's emissions.

TransAlta agreed to reduce mercury, greenhouse gas, and nitrogen oxide pollution

Aerial view of TransAlta in Centralia with steam coming out of smokestacks

Aerial view of TransAlta

In 2010, the Governor's office and Ecology negotiated agreements with TransAlta, Washington's only coal-fired power plant and largest emitter of greenhouse gases. TransAlta accounts for 10 percent of all greenhouse gas emissions statewide. The agreements reduced emissions of mercury, greenhouse gases, and nitrogen oxides.

Legislation requires one coal-fired boiler to meet the greenhouse gas emission performance standard by 2020 and the second boiler to meet the standard by 2025.

2010 settlement agreement details

The settlement negotiated an agreement with TransAlta that reduced:

  • Mercury emissions by 50 percent by installing new technology.
  • Nitrogen oxide emissions by 20 percent by using low sulfur and low nitrogen coal.

The agreement required TransAlta to burn low sulfur coal to protect and improve visibility in national parks and wilderness areas. We issued this Best Available Retrofit Technology (BART) decision in 2010.

2011 legislation to reduce mercury, greenhouse gas, and nitrogen oxide pollution

In 2011, the governor signed the TransAlta Energy Transition Bill. The Governor's office, TransAlta, environmental groups, and the local community collaborated to transition from coal to natural gas. The bill reduces emissions from energy production while allowing TransAlta to move to cleaner fuels. The plant's two coal-fired boilers must meet the state's greenhouse gas emission performance standard for power plants by:

  • December 31, 2020 for the first boiler.
  • December 31, 2025 for the second boiler.

As part of the negotiation, TransAlta agreed to install selective non-catalytic reduction technology to further reduce nitrogen oxide emissions. Nitrogen oxides help form regional haze by creating fine particles in the atmosphere.

In December 2011, the Governor and TransAlta signed a Memorandum of Agreement required by the legislation.

The revised Best Available Retrofit Technology order implements the requirements in the law to stop burning coal by 2025.