The Sierra Club is suing Burlington Northern Santa Fe in federal court in Seattle over coal dust that blows off trains into Washington rivers and Puget Sound.
The suit filed Wednesday says the railway sends an average of four trains or 480 open-top rail cars through the state each day carrying coal from mines in Wyoming and Montana to Canada or the only remaining coal-fired power plant in Washington at Centralia.
The number could increase significantly under pending proposals for three coal export terminals in Washington and Oregon.
The suit follows a notice of violations sent to the railroad in April from the Sierra Club, Puget SoundKeeper, Columbia Riverkeeper, RE Sources for Sustainable Communities and Friends of the Columbia Gorge.
A spokesman for BNSF has been asked to comment.