DENVER -- The Environmental Protection Agency said Friday it will not repay claims totaling more than $1.2 billion for economic damages from a mine waste spill the agency accidentally triggered in Colorado, saying the law prohibits it.

The EPA said the claims could be refiled in federal court, or Congress could authorize payments.

But attorneys for the EPA and the Justice Department concluded the EPA is barred from paying the claims because of sovereign immunity, which prohibits most lawsuits against the government.

A view of the contaminated Animas River near Durango, Colorado. CBS Denver

“The agency worked hard to find a way in which it could pay individuals for damages due to the incident, but unfortunately, our hands are tied,” EPA spokeswoman Nancy Grantham said.

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A total of 73 claims were filed, some by farmers who lost crops or had to haul water because rivers polluted by the spill were temporarily unusable for irrigation and livestock. Rafting companies and their employees sought lost income and wages because they couldn’t take visitors on river trips. Some homeowners sought damages because they said their wells were affected.

The August 2015 spill at the Gold King Mine in southwestern Colorado released 3 million gallons of wastewater tainted with iron, aluminum, manganese, lead, copper and other metals. Rivers in Colorado, New Mexico and Utah were polluted, with stretches of waterway turning an eerie orange-yellow.

Some of the affected rivers pass through Indian reservations.

Rep. Scott Tipton, R-Colo., expressed disbelief at the EPA’s decision, saying the agency had promised to compensate the people who suffered.

“The news today is a complete departure from that commitment, and our states, local governments, and tribes can rest assured that we will continue to work to make the EPA accountable for the mess they have made,” he said.

New Mexico Sens. Tom Udall and Martin Heinrich and Rep. Ben Ray Lujan, all Democrats, also accused the agency of reneging on a pledge.

“We are outraged at this last-ditch move by the federal government’s lawyers to go back on the EPA’s promise to the people of the state of New Mexico - and especially the Navajo Nation - that it would fully address this environmental disaster that still plagues the people of the Four Corners region,” they said.

An EPA-led contractor crew triggered the spill while doing exploratory excavation work at the mine entrance in advance of a possible cleanup. The Gold King is one of hundreds of inactive mines in the Colorado mountains that continuously spew polluted water into rivers or have the potential to do so.

The EPA has designated the area a Superfund site to pay for a broad cleanup. Initial research is underway.

State, federal and tribal officials have been harshly critical of the EPA for causing the spill and for its handling of the aftermath, including the costs. The Navajo Nation and the state of New Mexico have already sued the agency in federal court, and other lawsuits are likely after Friday’s announcement.

Last month, the EPA said it would pay $4.5 million to state, local and tribal governments to cover the cost of their emergency response to the spill, but the agency rejected $20.4 million in other requests for past and future expenses, again citing federal law.

Two members of Colorado’s congressional delegation criticized that decision, saying Congress passed a law in December that removed some of the legal obstacles the EPA cited in turning down the $20.4 million.