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Monday, November 9, 2026Nov 9

New Mexico sues Colorado over huge 2015 mine waste spill

FILE - In this Aug. 14, 2015, file photo, water flows through a series of sediment retention ponds built to reduce heavy metal and chemical contaminants from the Gold King Mine wastewater accident, in the spillway downstream from the mine, outside Silverton, Colo. New Mexico is suing the state of Colorado, saying its neighbor to the north should be held responsible for the contamination caused by the 2015 Gold King Mine spill as well as decades of toxic drainage from mines near the headwaters of the Animas River. (AP Photo/Brennan Linsley, File)
FILE - In this Aug. 14, 2015, file photo, water flows through a series of sediment retention ponds built to reduce heavy metal and chemical contaminants from the Gold King Mine wastewater accident, in the spillway downstream from the mine, outside Silverton, Colo. New Mexico is suing the state of Colorado, saying its neighbor to the north should be held responsible for the contamination caused by the 2015 Gold King Mine spill as well as decades of toxic drainage from mines near the headwaters of the Animas River. (AP Photo/Brennan Linsley, File) FILE - In this Aug. 14, 2015, file photo, water flows through a series of sediment retention ponds built to reduce heavy metal and chemical contaminants from the Gold King Mine wastewater accident, in the spillway downstream from the mine, outside Silverton, Colo. New Mexico is suing the state of Colorado, saying its neighbor to the north should be held responsible for the contamination caused by the 2015 Gold King Mine spill as well as decades of toxic drainage from mines near the headwaters of the Animas River. (AP Photo/Brennan Linsley, File)

ALBUQUERQUE, N.M. (AP) – New Mexico is suing the state of Colorado, saying its northern neighbor should be held responsible 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 New Mexico Attorney General’s Office and the state Environment Department announced late Wednesday that they filed a complaint against Colorado with the U.S. Supreme Court. It seeks damages and demands that Colorado address problems at the mines.

It marks the second major legal salvo fired by New Mexico in the wake of the August 2015 spill, which fouled rivers in three Western states with a bright-yellow plume of arsenic, lead and other heavy metals. The state also is suing the U.S. Environmental Protection Agency and the owners of two mines.

“We had hoped EPA and Colorado would try to work with us and come up with solutions,” New Mexico Environment Secretary Ryan Flynn told The Associated Press. “But the state of Colorado, its leadership, seems intent on defending EPA at every turn and is unwilling to work with us to move forward in a meaningful manner.”

The Colorado governor’s office and attorney general didn’t immediately respond to requests for comment Thursday. The EPA has declined to comment on the lawsuit, but it has said repeatedly that it takes responsibility for the cleanup at the Gold King Mine.