ALBUQUERQUE – One of the nation’s largest American Indian tribes is planning to sue over damages caused by the Gold King Mine spill that occurred in August 2015 above Silverton.

Navajo Nation President Russell Begaye, Navajo Attorney General Ethel Branch and other tribal officials plan to announce Tuesday that they have directed their attorneys to file a lawsuit over what they describe as an “unprecedented environmental disaster.”

Begaye recently renewed the call for the federal government to reimburse Navajo farmers, saying the U.S. Environmental Protection Agency’s actions in the wake of the 2015 spill have created a culture of distrust.

An EPA-led crew accidentally triggered the spill 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 EPA has said it takes responsibility for the spill.

Earlier this month, federal investigators have confirmed that a criminal investigation is going in connection to the Gold King Mine spill.

The Environmental Protection Agency Office of Inspector General has said it launched the criminal probe – which has been underway since last year – in response to “high public interest.”

“Based on requests from several members of the House and Senate, the OIG is conducting both a program evaluation and a criminal investigation of the Gold King Mine spill,” the release stated.

The Office of Inspector General is an independent office within the EPA that performs audits, program evaluations and investigations of the EPA.