DENVER (AP) — The U.S. Environmental Protection Agency says it plans to return to the Gold King Mine in southwestern Colorado this spring or early summer to resume preliminary cleanup work after it inadvertently triggered a 3-million-gallon spill of wastewater there in August.
Longer-term remediation at the site north of Silverton could be months or years away, even though local officials and Gov. John Hickenlooper have signed off on a Superfund cleanup.
The spill tainted rivers in Colorado, New Mexico and Utah.
Here is a look at where things stand:
WHAT'S HAPPENING NOW
Harsh conditions at the site, which is about 11,000 feet above sea level, prevent cleanup work over the winter.
A temporary treatment plant has been cleaning up water flowing from the mine since October. The plant cost $1.8 million.
The EPA has spent at least $17 million at the site.
When the weather improves this spring or early summer, the EPA plans to stabilize the entrance to the mine and install a temporary steel structure about 60 feet inside the tunnel to control any surges in the wastewater still flowing out, spokeswoman Nancy Grantham said this week.
The structure could also hold back water inside the mine if the level rises, and instruments would allow the EPA to remotely monitor the level, Grantham said. The structure could be removed and then replaced for any work deeper in the mine.
As of October, the EPA said wastewater was draining from the mine at about 560 gallons per minute.
The EPA is considering Superfund status for the Gold King and 47 other mining sites in the Bonita Peak Mining District north of Silverton, which would free up millions of dollars in federal funds for an extensive cleanup. The EPA estimates that about 5.4 million gallons of acidic mine waste flows from those sites each day, eventually reaching the Animas River.
Local officials and Hickenlooper endorsed a Superfund listing in February.
Long-term cleanup work could still be months or years away.
The first step, which could occur in late March or early April, is for the EPA to propose a Superfund listing. That would be followed by a 30- or 60-day public comment period, depending on how much public interest the EPA expects. After the comments are reviewed and answered and any changes are made to the proposal, the EPA could formally add the site to the Superfund this autumn.
If the area is designated a Superfund site, the EPA would begin a detailed investigation of pollution sources and develop a list of feasible cleanup alternatives. The EPA already has contracts in place to start that work, Grantham said.
"In the case of the Bonita Peak Mining District, we expect to move quickly into the investigations needed to begin identifying appropriate clean up actions," she said in an email.
Federal agencies and the local Animas River Stakeholder Group have already done some of the investigation work. The EPA has also pledged to listen to what local residents have to say.
Long-term cleanup work would begin once the EPA chooses an alternative.
If conditions threaten another blowout like the one in August, the EPA can take emergency action without waiting for Superfund designation.
In about a third of the Superfund sites involving hard-rock mining operations, the EPA took early action to address imminent threats before formally declaring them Superfund sites, Grantham said.
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