EPA plans concrete bulkhead for Red and Bonita mine in 2015

Bonita Mine acid mine drainage
Bonita Mine acid mine drainage

From The Durango Herald (Mary Shinn):

Representatives from several government agencies, including the EPA, informed La Plata and San Juan county commissioners last week that the Red and Bonita mine will be plugged to help stem the flow of metals.

“This is a worthwhile investment,” said Steve Way, on-scene coordinator for the EPA.

The EPA plans to pay for the large concrete bulkhead, which could cost between $750,000 and $1.5 million, Way said earlier this year.

The Red and Bonita Mine is a major source of metals such as cadmium, zinc, iron and aluminum that have been flowing into Cement Creek and are responsible for killing off native fish and other species, the researches told local commissioners.

“We really need to do something about this before it gets worse,” said John Ott, general manager of Animas Water Co.

While his well water is in good shape, as a farmer on the Animas River below Bakers Bridge, he said he is disturbed by the pollution.

In 2003, the Sunnyside Gold Corp., the last major mining operation in Silverton, stopped treating the water in Cement Creek.

Then in 2006, the Red and Bonita started leaking high levels of metals after the American Tunnel was plugged in several places, which raised the water table, said Peter Butler, co-coordinator of the Animas River Stakeholders Group.

In recent years, the EPA and other agencies have come together to assess if plugging the mine would significantly reduce pollution. They found it contributes some of the highest levels of heavy metals year-round to Cement Creek and leaks about 300 gallons of polluted water per minute, Way said. A plug would help, but it would not eliminate all the seeping metals.

The mine was active for only a few years in the late 1800s, and miners carved out only 2,000 feet of tunnels below the surface that the EPA and the Colorado Division of Reclamation, Mining and Safety could explore in 2013. After mapping the mine, scientists don’t believe the tunnels are connected to any other systems where polluted water could find an outlet.

The scientists also reason that the bulkhead could reduce the amount of pollution any potential water-treatment plant would have to process if one is installed. The Animas River Stakeholders Group has been researching treatment plant options, but it could be very expensive to maintain.

“Treating water, that is a forever decision,” Way said.

However, a valve will be built into the bulkhead, so that if it causes problems, it could be opened back up. To what degree the plug may raise the water table and how the water would be dispersed is unknown, Way said.

While this would be an EPA project, it will not require Superfund listing. It would be a short-term project by a different branch of the agency.

More Animas River watershed coverage here.

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