Magna residents will breathe easier in a few months when the last parts of the giant Kennecott tailings pond are wet, according to the company's manager of environmental quality.
Peter W. McCallum told members of the Utah Air Conservation Committee Wednesday that a new pipeline has been installed to control dust that sometimes blows from the tailings mountain, which is 150 feet high and covers 5,000 acres.Just to make sure, said Burnell Cordner, director of the Utah Bureau of Air Quality, "We are going to install a monitoring site down in that housing development where the citizens are most affected."
The monitor will be financed by a $10,000 settlement reached with Kennecott after the state accused it of violating clean-air regulations.
When Kennecott was shut down and not pumping much slurry onto the pond, the top of the enormous hill began to dry out. The surface is not entirely soaked, even though Kennecott is again producing copper.
About 240 acres remain dry.
During windstorms, powdery tailings fly into a nearby subdivision. They fill the air, cutting visibility and aggravating asthma symptoms for those with the disease.
These particulates are so fine they can lodge in the lungs, and they sometimes violate federal clean-air standards.
A study showed no danger of silicosis, said a consultant, Dr. Attilio D. Renzetti Jr. of the University of Utah Health Services Center.
But he added, "I have a lot of telephone calls from patients whose asthma is exacerbated by the dust." Whenever the wind blows strongly, people with a dust sensitivity suffer, as do some who wear contact lenses.
McCallum said the company has enough underground ore to keep mining at the present rate and technology for 30 years.
A $7.5 million pipeline system was completed in July, he said. The 18 miles of pipes move slurry around the pond, wetting the areas that cause problems.
A snow vehicle also shoves slurry "rivers" about, as further control. Such vehicles are necessary because trucks would sink into the shaky tailings.
Environmental studies by Kennecott show that a significant decrease will occur in windblown dust, McCallum told the Deseret News.
Is Magna's dust problem licked? "I think we need a few more months, but I think we've got the system in place that will significantly reduce the dust and bring us into compliance with the standard," he said.
In addition to the pipe system, Kennecott has stabilized the high rim of the pond by planting trees, grass and shrubs. "Over the past 20 years we've planted some 10,000 trees," he said.
McCallum said 1,000 more will be planted soon.
Slides shown to the committee displayed an apple tree, bushes, grains, Russian olive, tamarisk and other plants, which hold the soil in place.
The pond stretches upward at a rate of 4 feet per year, so by the expected demise of Kennecott's operations, it should be 270 feet high. By that time, more plantings would have stabilized larger areas of the rim.
B.P. America, Kennecott's parent company, is experimenting to determine which plants will grow best in the tailings pond once the company shuts down. McCallum told the committee that reclamation will continue on the pond, to permanently control the dust, for five to 10 years after the closure.
Asked whether Kennecott is bonded to ensure compliance, he said, "We're self-bonded." A committee staffer pressed for an explanation, and he said that means the company sets aside money for the reclamation and promises to do the work.
He said that when the plant finally closes, if residents wish they can keep an actual pond going by adding water. Water on one part of the pile is 15 feet deep.