By Alison Uralli
FARMINGTON, N.M. (Reuters) - The head of the U.S. Environmental Protection agency told the Navajo Nation president on Thursday that her agency would work closely with the Native American tribe in handling a toxic waste spill into river waters from a defunct Colorado gold mine.
Navajo Nation President Russell Begaye has pledged to take legal action against the EPA, which has taken responsibility for inadvertently causing the spill last week that sent toxic waste flowing into rivers in the Four Corners region where part of the 250,000-member tribe's reservation is located.
"(The) EPA is not unfamiliar with litigation, but frankly none of that tone and tenor was in the discussion this morning," EPA Administrator Gina McCarthy said at a news conference in Farmington, New Mexico, after meeting with Begaye.
The encounter came a day after McCarthy announced the water quality of the Animas River in Colorado, which was rendered bright orange by the toxic waste spill from the abandoned Gold King Mine near Silverton, Colorado, had returned to pre-spill levels.
An EPA operation on Aug. 5 accidentally spilled more than 3 million gallons (11.3 million liters) of acid mine sludge containing heavy metals such as arsenic, mercury and lead. The torrent of waste gushed first into a stream just below the site before washing into the Animas.
The contamination also reached New Mexico where it flowed into the San Juan River, a Colorado River tributary that winds through the Navajo reservation into Utah. Navajo communities rely on the San Juan for fishing and agriculture.
The spill led two Colorado municipalities, including Durango, and the New Mexico towns of Aztec and Farmington, to shut off their river intakes.
The governors of Colorado, New Mexico and Utah declared a state of emergency over the spill, and New Mexico's governor also suggested her administration could take legal action against the EPA.
Colorado Governor John Hickenlooper said on Wednesday the Animas appeared to have returned to normal, with no sign of lasting environmental harm.
Dilution has gradually diminished concentrations of contaminants, EPA officials have said, even as they warned that deposits of heavy metals have settled into river sediments, where they can be churned up and unleash a new wave of pollution when storms hit or rivers run at flood stage.
"Frankly, the sediment is where the longer-term responsibility is for this agency, and we will meet that responsibility," McCarthy said.
(Additional reporting by Keith Coffman in Denver; Writing by Alex Dobuzinskis; Editing by Daniel Wallis and Peter Cooney)