New Mexico announced last week that it is suing Colorado in the U.S. Supreme Court to place responsibility for the contamination from a massive mine waste spill last year as well as decades of toxic drainage from mines near the headwaters of a shared river, the Associated Press reported.
The spill from the Gold King Mine sent millions of gallons of wastewater containing arsenic, lead and other heavy metals into the Animas River. The plume coursed downstream into the San Juan River and eventually Lake Powell.
New Mexico’s lawsuit seeks damages and demands that Colorado address problems at the mines.
New Mexico is also suing the U.S. Environmental Protection Agency in the wake of the August 2015 spill, which fouled rivers in three states.
In response, Gov. John Hickenlooper’s office expressed disappointment that New Mexico has chosen “costly and time-consuming litigation.”
The statement said the litigation doesn’t affect Colorado’s commitment to addressing challenges posed by historic drainage from mines into the Animas River and other watersheds in the state.