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Utah scientists await mine wastewater results from another spill

By Amy Joi O'Donoghue, KSL | Posted - Mar. 18, 2019 at 7:56 p.m.

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SALT LAKE CITY — A treatment plant malfunctioned over the weekend and sent toxic mine wastewater into a creek that will likely reach the San Juan River in New Mexico on Tuesday.

From there, it will meander into Utah over the next several days.

The plant in Colorado was handling the aftermath of 3 million gallons of metals-laden sludge from the 2015 breach of the Gold King Mine in Colorado, which prompted multiple lawsuits from impacted states, including Utah.


So once again, environmental scientists from the Utah Department of Environmental Quality were scrambling to see what the impacts are from another high profile contamination event.

Those scientists, joined by experts from the U.S. Geological Survey, are waiting on water samples collected from four Utah locations that include Mexican Hat, Montezuma Creek and Sand Island near Bluff.

Those will be compared to water samples taken in the days to come to determine the extent of contamination from 800,000 gallons of acidic mine wastewater that escaped from a treatment plant into Cement Creek sometime Friday. The U.S. Environmental Protection Agency is now reporting that teams cleared the road on Saturday and the agency was able to access the plant and stop the release into Cement Creek.

According to the federal agency, an extreme snowstorm Thursday knocked out power at the Interim Water Treatment Plant at the Bonita Peak Superfund site in Gladstone, Colorado.

After the power outage, a backup generator kicked on and powered a pump to divert the water from the Gold King Mine into treatment ponds. The pump ran for 20 hours before it ran out of fuel and shut down. At that point, the diverted water began to flow into Cement Creek and into the Animas River. It will eventually reach the San Juan River and flow into Lake Powell.

The mine was discharging approximately 300 gallons per minute of acid mine waste into Cement Creek before power was restored on Saturday.


An EPA-contracted work crew breached the Gold King Mine, sending a release of 3 million gallons of metals laden mustard-colored sludge into the Animus River near Silverton, Colorado in 2015. From there, the sludge — filled with lead and arsenic — spread out into a plume that sparked an intense response by states. The spill contaminated the San Juan River after it entered Utah and ended at Lake Powell, where the full impact of the sediment deposited is being evaluated.

In response to the lawsuits, Justice Department attorneys argued that the EPA had immunity from the spill, which New Mexico and other critics insist has been minimized by the federal agency in terms of the environmental impact and duration of the remediation.

The spill required Utah water quality scientists to return to the San Juan River in 2016 to monitor how much metals-laden sediment might be churned up with spring runoff.

Congress passed legislation that directs up to $4 million to be paid to states and tribes and other entities for longtime monitoring of impacted waterways. The law went into effect in 2016.

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