WASHINGTON (AP) — U.S. officials knew of the potential for a catastrophic “blowout” of toxic wastewater from an inactive gold mine, yet appeared to have only a cursory plan to deal with such an event when government contractors triggered a 3-million-gallon (11.4-million-liter) spill, according to internal documents released by the Environmental Protection Agency.
The EPA released the documents late Friday following prodding from The Associated Press and other media organizations.
The Aug. 5 spill came as workers excavated the entrance to the idled Gold King Mine near Silverton, Colorado, accidentally unleashing a torrent of pent-up, toxic water that fouled rivers in three states.
Among the documents is a June 2014 work order for a planned cleanup that noted that the old mine had not been accessible since 1995, when the entrance partially collapsed.
“This condition has likely caused impounding of water behind the collapse,” the report says. “Conditions may exist that could result in a blowout of the blockages and cause a release of large volumes of contaminated mine waters and sediment from inside the mine, which contain concentrated heavy metals.”
A May 2015 action plan for the mine also noted the potential for a blowout. The plan was produced by Environmental Restoration LLC, a private contractor working for the EPA.
It was not clear what, if any, additional precautions were taken to prepare for such a release. EPA spokeswoman Melissa Harrison said Saturday she could not immediately answer questions about the matter.
A 71-page safety plan for the site produced by Environmental Restoration included only a few lines describing steps to be taken in the event of a spill: Locate the source and stop the flow if it could be done safely, begin containment and recovery of the spilled materials, and alert downstream sanitary districts and drinking water systems as needed.
There are at least three ongoing investigations into exactly how EPA triggered the disaster, which tainted rivers in Colorado, New Mexico and Utah with lead, arsenic and other contaminants. The toxic plume travelled roughly 300 miles (480 kilometers) to Lake Powell on the Arizona-Utah border.
EPA says its water testing has shown contamination levels have since been returning to pre-spill levels, though experts warn the heavy metals have likely sunk and mixed with bottom sediments that could someday be stirred back up.
The documents released by the agency do not include any account of what happened immediately before or after the spill. The wastewater flowed into a tributary of the Animas and San Juan rivers, turning them a sickly yellow-orange color.
Elected officials in affected states and elsewhere have been highly critical of the EPA’s initial response. Among the unanswered questions is why it took the agency nearly a day to inform local officials in downstream communities that rely on the rivers for drinking water.
Communication problems have persisted in the spill’s aftermath, according to U.S. Rep. Lamar Smith, a Texas Republican who chairs the House Science, Space and Technology Committee.
“Weeks after the spill, families and businesses who depend on the Animas River continue to deal with uncertainty and limited information,” Smith said Friday, as he called for EPA Administrator Gina McCarthy to appear before his committee for a hearing scheduled next month. “The EPA has an obligation to be forthcoming about what went wrong.”
Much of the text in the documents released Friday was redacted by EPA officials.
Environmental Restoration posted a brief statement last week confirming its employees were present at the mine when the spill occurred. The company declined to provide more details, saying that to do so would violate “contractual confidentiality obligations.”
A company dispatcher said no one was available for comment Saturday.
The St. Louis, Missouri-based company bills itself as the largest provider of emergency services for the EPA and is the agency’s prime contractor across most of the U.S.
The EPA has not yet provided a copy of its contact with the firm.
The spill’s aftermath has cost the EPA $3.7 million through Thursday, according to the agency.
Toxic water continues to flow out of the mine, although the EPA built a series of ponds so contaminated sediments can settle out before the water enters a nearby creek that feeds into the Animas River.
The agency said more work was needed to make sure there are no additional reserves of tainted water that could lead to another surge of contamination. Those efforts will include the removal of any blockages still holding back water inside the mine, according to the EPA.
Brown reported from Billings, Montana.
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