TransAlta Centralia Mine has 8 groundwater monitoring wells, 7 of which have been polluted above federal advisory levels based on samples collected between December 13, 2010 and October 24, 2018. Groundwater at this site contains unsafe levels of sulfate, manganese, cobalt, lithium and arsenic.
Site descriptionTransAlta Centralia Mine was an open-pit coal mine owned by the Canadian-based TransAlta Corporation. The coal mine is located approximately 5 miles northeast of Centralia, Washington. On November 27, 2006, TransAlta stopped operations at the mine, citing increasing operation costs. The company now receives coal from the Powder River Basin in Wyoming to supply its coal burning power plant, which currently has a capacity of 670 MW. First commissioned in 1972, Unit 1 of the Centralia plant was retired in 2020, and Unit 2 will be retired in 2025. The residual ash waste is disposed of in the Limited Purpose Landfill, which has an area of 18 acres and is regulated under the CCR rule. There is also a surface impound directly south of the disposal area to manage leachate from the landfill. You can find the industry-reported data here. For more information on the TransAlta Centralia Mine, see EIP’s 2019 National Coal Ash Report.