One of the nation's largest American Indian tribes is the latest entity to pursue legal action against the federal government over a massive mine waste spill that tainted rivers in three Western states.
Navajo Nation officials say they have directed their attorneys to file a lawsuit over what they call an "unprecedented environmental disaster."
Navajo President Russell Begaye, Navajo Attorney General Ethel Branch and other tribal officials planned to discuss details of the legal action during a news conference Tuesday in Shiprock, New Mexico.
A federal contractor triggered the spill in August 2015 during preliminary cleanup work. Three million gallons of wastewater carrying arsenic, lead and other heavy metals tainted rivers in Colorado, New Mexico and Utah.
The U.S. Environmental Protection Agency has said it takes responsibility for the spill.