Here’s the release from the Environmental Protection Agency (Christie St. Clair):
Today, the U.S. Environmental Protection Agency (EPA) posted the final fate and transport report for the Gold King Mine (GKM) release. The report focuses on understanding pre-existing river conditions, the movement of metals related to the GKM release through the river system, and the effects of the GKM release on water quality. The research supports EPA’s earlier statements that water quality in the affected river system returned to the levels that existed prior to the GKM release and contamination of metals from the release have moved through the river system to Lake Powell.
“This report is a comprehensive analysis of the effects on water quality from the Gold King Mine release,” said Dr. Thomas A. Burke, EPA’s Science Advisor and Deputy Assistant Administrator of EPA’s Office of Research and Development. “While data indicate that water quality has returned to pre-event conditions, EPA is committed to continue our work with States and Tribes in the river system affected by the Gold King Mine release to ensure the protection of public health and the environment.”
The area affected by the Gold King Mine release consists of complex river systems influenced by decades of historic acid mine drainage. The report shows the total amount of metals, dominated by iron and aluminum, entering the Animas River following the release — which lasted about nine hours on August 5, 2015 –was comparable to four to seven days of ongoing GKM acid mine drainage or the average amount of metals carried by the river in one to two days of high spring runoff. However, the concentrations of some metals in the GKM plume were higher than historical mine drainage. As the yellow plume of metal-laden water traveled downstream after the release, the metal concentrations within the plume decreased as they were diluted by river water and as some of the metals settled to the river bed.
There were no reported fish kills in the affected rivers, and post-release surveys by multiple organizations have found that other aquatic life does not appear to have suffered harmful short-term effects from the GKM plume. The concentrations of metals in well-water samples collected after the plume passed did not exceed federal drinking water standards. No public water system using Lake Powell as a source of drinking water has reported an exceedance of metals standards since the release.
Some metals from the GKM release contributed to exceedances of state and tribal water quality criteria at various times for nine months after the release in some locations. Metals from the GKM release may have contributed to some water quality criteria exceedances during the spring 2016 snow melt. Other exceedances may reflect longstanding contributions of metals from historic mining activities in the region and natural levels of metals in soils and rocks in the area. EPA will continue to work with states and tribes to interpret and respond to these findings.
Results from this analysis will inform future federal, state and tribal decisions on water and sediment monitoring. EPA will continue to work with states and tribes to ensure the protection of public health and the environment in the river system affected by the Gold King Mine release.
Read the final report, “Analysis of the Transport and Fate of Metals Released From the Gold King Mine in the Animas and San Juan Rivers”: https://cfpub.epa.gov/si/si_public_file_download.cfm?p_download_id=530074
Read the report’s executive summary: https://cfpub.epa.gov/si/si_public_file_download.cfm?p_download_id=530075
More information on the Fate and Transport analysis: https://www.epa.gov/goldkingmine/fate-transport-analysis
More information on the 2015 Gold King Mine incident: https://www.epa.gov/goldkingmine
From The Durango Herald (Luke Perkins):
The 2015 Gold King Mine spill deposited nearly 540 tons of metals over a 9-hour period into Cement Creek, which feeds into the Animas River, the Environmental Protection Agency said Friday in it final report on the scope and ongoing effects of the spill.
The EPA estimated that roughly one percent of the metals, mostly iron and aluminum, contained in the spill came from the mine, with the rest coming from the waste piles on the hillside below the mine adit and the stream bed of Cement Creek.
The study states “the volume of the GKM release was equivalent to four to seven days of ongoing GKM acid mine drainage,” or “one to two days of high spring runoff.”
But, as indicated in previous tests, the river returned to pre-spill levels.
There have been no reported fish kills or significant impacts on other aquatic life, but the EPA will continue to monitor the waterways impacted by the spill, the agency said Friday in a release.
The study also looked at water quality in the Animas to see if it had returned to pre-event conditions and if the impacts of the spill itself had long-term detrimental ramifications on the river given the history of mining in the region…
“The research supports EPA’s earlier statements that water quality in the affected river system returned to the levels that existed prior to the GKM release and contamination of metals from the release have moved through the river system to Lake Powell,” the release said.
Following Aug. 5, 2015 spill, the concentration of contaminants exceeded water quality standards in multiple locations impacted.
This necessitated the building of an interim water treatment plant at Gladstone that was mandated to operate through November 2016, said Cynthia Peterson, community involvement coordinator for the Bonita Peak Mining District. The EPA concluded a public comment session on Dec. 14 regarding the future of the treatment plant, and will release a final decision by the end of January, Peterson said. But the EPA has a preferred course of action.
“EPA’s preferred plan for the water treatment plant is for its continued operations and to look at additional options in the future as we understand more about the nature and spread of the contamination,” she said.
The agency also is conducting remedial investigation to understand the impact of the 48 sites in the mining district, which was named a Superfund site in September, on river contamination, Peterson said. This represents the first step before clean-up operations can begin.
From the Associated Press (Matthew Daly) via The Farmington Daily Times:
Agency says only 1 percent of the metals came from inside the mine and the rest were “scoured” from waste piles on nearby hills and stream beds
Nearly 540 tons of metals — mostly iron and aluminum — contaminated the Animas River over nine hours during a massive wastewater spill from an abandoned Colorado gold mine, the Environmental Protection Agency said today in a new report on the 2015 blowout that turned rivers in three states a sickly yellow.
The total amount of metals entering the river system was comparable to levels during one or two days of high spring runoff, although the concentration of metals was significantly higher at the spill’s peak, the report said.
In February, the EPA estimated the amount of metals in the release at 440 tons. The agency said additional data and improved analysis resulted in the higher final estimate.
The EPA said its research supports earlier statements that water quality in the affected river system has returned to pre-spill levels…
The EPA said in its report that only 1 percent of the metals came from inside the mine, while 99 percent were “scoured” from waste piles on nearby hills and stream beds. The iron and aluminum reacted with the river water to cause the eye-catching mustard color that was visible for days as the plume traveled down the river system into Lake Powell, the EPA said.
Besides iron and aluminum, the spill released manganese, lead, copper, arsenic, zinc, cadmium and a small amount of mercury into the river, the EPA said…
New Mexico Environment Secretary Butch Tongate accused the EPA of using the taxpayer-funded report to try to defend its actions. The state has sued the agency over the spill.
Colorado officials said they had no comment on the report. Utah officials didn’t immediately respond to a request for comment.
From The Denver Post (Jesse Paul):
“While data indicate that water quality has returned to pre-event conditions, EPA is committed to continue our work with States and Tribes in the river system affected by the Gold King Mine release to ensure the protection of public health and the environment,” Dr. Thomas A. Burke, EPA’s science adviser and deputy assistant administrator in its office of research and development, said in a statement…
The disaster, which turned the Animas River a toxic-looking yellow-orange, prompted concern and anger downstream, particularly in the Navajo Nation and New Mexico, where officials have been continually complaining about the spill’s water-quality impacts and have filed lawsuits against the EPA. The concentrations of some metals in the Gold King mine plume were higher than historical mine drainage, the EPA said in a news release announcing the report’s findings, but the impacts on water quality were not long lasting as some had worried…
There were no reported fish kills in the Animas or San Juan rivers, and the EPA says surveys have round that other aquatic life does not appear to have suffered any short-term impacts…
Also, the agency says the concentrations of metals in well-water samples collected after the 3 million-gallon spill’s plume passed through areas did not exceed federal drinking water standards. No public water system using Lake Powell as a source of drinking water has reported an exceedance of metals standards since the release, according to the EPA.
“Some metals from the GKM release contributed to exceedances of state and tribal water quality criteria at various times for nine months after the release in some locations,” the release said. “Metals from the GKM release may have contributed to some water quality criteria exceedances during the spring 2016 snow melt.”
However the EPA says other metal-level exceedances may reflect the longstanding mine drainage from the region’s historic sites as well as natural levels of metals in southwest Colorado’s soils and rocks. Silverton and its surroundings are now slated to get a federal cleanup of their leaching, historic mines under the EPA’s Superfund program.
The mines and mining sites in Silverton’s surroundings — including the Gold King — pour an estimated 5.4 million gallons of metal-laden waste into the Animas’ headwaters each day.
“Results from this analysis will inform future federal, state and tribal decisions on water and sediment monitoring,” the EPA release said, though it did not immediately elaborate.