News
Asarco: Dust a one-time event
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| Mario Aguilar | Green Valley News Asarco has started using a co-polymer on the sides of its tailing piles, giving the embankment a greenish hue, as seen from Interstate 19. |
By Tim Hull
Special to the Green Valley News
Workers at the Asarco Mission Mine have added a dust-suppression chemical to the towering slag piles north of Green Valley after wind-blown tailing filled the Santa Cruz Valley air last week, company officials said.
Mine employees were building a 15-foot to 20-foot berm on top of the tailing impoundments when high winds whipped up the remains of hard-rock mining and sent them billowing across the valley, obscuring views and adding particulates to the air.
Asarco spokesman Doug McAllister said the incident was a rare occurrence that likely won't happen again.
"In the process of (building the berm), we had a high-wind situation," McAllister said. "This was a one-time construction event; it shouldn't have happened."
To keep the tailing on top of the impoundments, the Mission Mine has applied an acrylic co-polymer to the sides of the piles, turning them an otherworldly green.
It's the same chemical the company used on its slag piles in Hayden, where Asarco was fined $77,500 over a 2005 blowing dust incident.
McAllister blamed the Hayden incident on the companywide strike from July to November 2005, saying that with no workers on hand to apply dust suppressant the tailing there dried and became airborne.
The fallout from the strike eventually sent Asarco into Chapter 11 bankruptcy proceedings.
The company said it spent more than $1.2 million this year applying the co-polymer to its tailing ponds in Hayden.
The Mission Mine operates under the jurisdiction of the federal Environmental Protection Agency as it is located on land leased from the Tohono O'odham nation.
While McAllister said that the dust incident last week did not violate the mine's air quality permit, EPA officials said that remains to be seen.
Colleen McHugh, with EPA's District 9 office in Tucson, said the Pima County Department of Environmental Quality forwarded several citizen complaints about the dust to her office.
She is in the process of talking to tribal and company officials about the incidents to determine if the mine violated its permit, a process which will probably take several weeks, she said.
Tim Hull is a freelance writer.
Workers at the Asarco Mission Mine have added a dust-suppression chemical to the towering slag piles north of Green Valley after wind-blown tailing filled the Santa Cruz Valley air last week, company officials said.
Mine employees were building a 15-foot to 20-foot berm on top of the tailing impoundments when high winds whipped up the remains of hard-rock mining and sent them billowing across the valley, obscuring views and adding particulates to the air.
Asarco spokesman Doug McAllister said the incident was a rare occurrence that likely won't happen again.
"In the process of (building the berm), we had a high-wind situation," McAllister said. "This was a one-time construction event; it shouldn't have happened."
To keep the tailing on top of the impoundments, the Mission Mine has applied an acrylic co-polymer to the sides of the piles, turning them an otherworldly green.
It's the same chemical the company used on its slag piles in Hayden, where Asarco was fined $77,500 over a 2005 blowing dust incident.
McAllister blamed the Hayden incident on the companywide strike from July to November 2005, saying that with no workers on hand to apply dust suppressant the tailing there dried and became airborne.
The fallout from the strike eventually sent Asarco into Chapter 11 bankruptcy proceedings.
The company said it spent more than $1.2 million this year applying the co-polymer to its tailing ponds in Hayden.
The Mission Mine operates under the jurisdiction of the federal Environmental Protection Agency as it is located on land leased from the Tohono O'odham nation.
While McAllister said that the dust incident last week did not violate the mine's air quality permit, EPA officials said that remains to be seen.
Colleen McHugh, with EPA's District 9 office in Tucson, said the Pima County Department of Environmental Quality forwarded several citizen complaints about the dust to her office.
She is in the process of talking to tribal and company officials about the incidents to determine if the mine violated its permit, a process which will probably take several weeks, she said.
Tim Hull is a freelance writer.
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