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Utah Attorney General Sean Reyes announced on Friday that Utah plans to sue the federal government for last year's Gold King Mine spill in light of previously unreported EPA data that demonstrate the state may face continuous water contamination.

Erica Gaddis, assistant director of water monitoring in the Utah Department of Environmental Quality, said scientists in her department were analyzing raw data from the Environmental Protection Agency's website when they discovered two sets of high metals readings from the San Juan River that the EPA had not reported to the department. Some of these samples found that levels of lead, cadmium, copper, zinc and other heavy metals were as much as 10 times above the state's water quality standards.

And because the EPA estimates that the majority of the contamination from the mine spill is lodged in sediment upstream from Utah, it might only get worse as rising water during the spring runoff pulls sediment from the riverbanks and sends it flowing into Utah.

"According to the experts, there's no reason now for undue concern, but we want to be cautious and ensure that we have the best information to share with the residents of Utah," said Alan Matheson, executive director of the DEQ. "As a matter of public trust, we are committed to sharing the best information with people when we get it. We are concerned that the EPA needs to do the same. When they found samples that were elevated, it would have been appropriate that they contact us."

In a news release, Reyes said Utah waited to take legal action against the EPA because the state hoped for a cooperative effort that would result in faster reimbursement and remediation.

"Perhaps there is still a chance for that to happen," he said, "but Utah needs to be in a position to file a lawsuit if the federal government is not more responsive and transparent. The discovery that the EPA did not share relevant information is a cause for serious concern and could lead to additional claims after we have fully investigated that omission."

Matheson said the state will be re-initiating its water monitoring on the San Juan River next week. The state independently monitored the San Juan and Lake Powell for signs of contamination for three weeks after the initial Gold King Mine incident in August, but stopped after the EPA put a mutually agreeable monitoring plan into effect.

The EPA ceased its monitoring sometime in the late fall, Matheson said.

EPA spokeswoman Nancy Grantham issued a statement saying only that the agency is looking into Utah's concerns.

The EPA has been posting the raw data from its monitoring to its public website, but did not mention the high metals concentration in any of its communications with Utah officials, said the DEQ's Gaddis. And the data is posted in a format that's difficult to read and interpret, she said.

"We want them to continue to put out the raw data," though analyzing it takes "a lot of our staff resources," she said.

"But we will continue to do that and report out to the public."

The highest levels, Gaddis said, were detected on Sept. 24 and 28, events that both appear to be related to stormy weather in Colorado and New Mexico. That could mean that routine increases in the rivers' flow gradually will push more metals downstream into Utah waters and, eventually, Lake Powell — which has been tapped as the source for a planned pipeline to send 28 billion gallons of water a year to southwestern Utah.

Utah didn't see the dramatic orange-tinged pulse of contamination that turned heads in Colorado, but will be feeling its effects for a long time to come, as the state will be the final resting place for all that sediment, she said.

The EPA, Gaddis said, "estimates that the majority of what came out of the Gold King spill is still in the sediment upstream of Utah. Our concern is that as the spring runoff begins … those metals are going to come up again when the river rises."

What Utah has seen so far, she said, may be "the tip of the iceberg."

Utahns should also realize, she said, that this contaminated sediment has been building upstream for decades due to mine discharges that haven't made the news. There has been some effort to estimate just how many tons of metals may be buried in the rivers' sediment, but Gaddis said she didn't believe those numbers were accurate.

"That is one of our long-term questions: What is the total volume and tonnage of metals released into the Animas River?" she said. "All of that will at some point make its way to Lake Powell."

The state has also filed a request for additional information on the samples the EPA collected in October.

Gaddis said it's unlikely the EPA will come up with a mass-scale plan for removing the sediment before it travels downriver.

"The concentrations are not high enough to require that level of cleanup," she said. "That's why it's really important to us that these mines get cleaned up, so that this stops. Once it gets into the river, it's really difficult to remove."

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