The Navajo Nation is suing the U.S. Environmental Protection Agency (EPA) for what it sees as negligence in cleaning up the mine tailings spill at the Gold King Mine that spilled into the Animas River spilling into three states and the Navajo Nation.

The EPA has taken responsibility for the accidental release of toxic acid mine waste last August. But in the lawsuit filed Aug. 16, the Navajo Nation alleges that the EPA has failed to properly remediate the disaster and compensate the thousands of farmers who rely on the San Juan River, which flows from the Animas through New Mexico and Utah, to irrigate their crops and sustain their cattle and sheep, CNN reported.

“EPA, we’re holding your feet to the fire,” Navajo Nation President Russell Begaye said, promising that generations of Navajos are willing to fight. “We will not let you get away with this because you have caused great damage to our people, our river, our lifeblood.”

In the lawsuit filed Tuesday morning, which is not seeking a specific dollar amount in damages, the Navajos allege that the EPA has failed to adequately remediate the disaster a year after the dispersal of 880,000 pounds of heavy metals into the Animus river watershed near Silverton, CO. The chemicals flowed from the Animas, along some 200 miles of the San Juan River in New Mexico, which runs through the Navajo Nation and continues into Utah.

“After one of the most significant environmental catastrophes in history, the Nation and the Navajo people have yet to have their waterways cleaned, their losses compensated, their health protected or their way of life restored,” the complaint filed by the Navajo Nation in US District Court for the district of New Mexico alleges.

“Despite repeatedly conceding responsibility for the action that caused millions of dollars of harm to the Nation and the Navajo people, the U.S. EPA has yet to provide any meaningful recovery. Efforts to be made whole over the past year have been met with resistance, delays, and second-guessing. Unfortunately this is consistent with a long history of neglect and disregard for the well-being of the Navajo,” the lawsuit said.

The Navajo Nation joins New Mexico in pursuing legal action over the spill. The state sued the EPA and Colorado this year, citing environmental and economic damage.

Tribal officials at the news conference and in the lawsuit pointed to delays and resistance by the EPA, saying the agency has failed to compensate Navajos for their losses or provide any meaningful recovery efforts over the past year.

The EPA has dedicated more than $29 million to respond to the spill and for monitoring, but much of that is going toward stabilization and ongoing drainage at the mine. Reimbursement of state, local and tribal costs is underway, but the tribe has received only a fraction of the nearly $1.6 million doled out to all the parties.

The lawsuit alleges that the EPA, its contractors and the mining companies, who are also named in the lawsuit, ignored the buildup of contaminants over many years, failed to follow "reasonable and necessary precautions" to avoid the spill when they began the mine cleanup operation in August 2015.