The Kennecott tailings could expand on the southeast corner, bringing them closer to the Magna houses
Magna • The tailings ponds for Rio Tinto Kennecott cover almost 9,000 hectares on the western edge of Salt Lake County.
These tailings ponds and the mine’s sometimes difficult relationships with surrounding communities have resulted in the operation establishing a dominant presence in Magna.
While long-time residents agree that their effects have lessened over the years, dust can obscure visibility on strong windy days. The industrial sprinklers just aren’t enough to disperse the particles in the air.
Now, while Kennecott works to dig deeper and extend the life of the Bingham Canyon mine to 2040, the Company is considering expanding the eastern portion of the historic South Dam to accommodate 100 million tonnes of tailings.
Some environmental activists worry that this eastern extension is closer to homes in Magna and have raised concerns about air and water quality. But for those responsible for the underground community, the picture is more complex and keeping the mine running is also a top priority for them.
“A lot of people in our city work for Kennecott,” said Magna Mayor Dan Peay. “They need to have a place to store their backlog if they want to continue.”
The project would affect 539 acres, including 327 acres of the existing South Dam, 39 acres of an existing canal and closed sediment pond, and 173 acres with no prior tailings deposits.
This would be enough to store the tailings piles for two years, which together with the remaining space in the north impoundment would sustain copper flow through 2040.
Peay trusts Kennecott to take the necessary precautions to keep the site safe and recognizes all of the work and impact the company has made at Magna.
Still, he understands his constituents’ concerns.
“Like everyone else, I probably wish they wouldn’t,” he said. “However, it is their property and they have the right to do what they want with their property.”
Kennecott has an operating northern tailings dump near Interstate 80. From State Road 201, motorists can see the southern tailings pile, which has not received an active tailings pile since 2001. It is dry and being recultivated.
For decades, before Kennecott drained the southern site in the 1980s, he hid that the southeast corner of his tailings pond could fail in a major earthquake and send a “soupy sludge” to Magna.
Attention is now turning to this area again. After remedial work is completed and the north dam is constructed, Kennecott hopes to work on this southeast corner to improve its stability by strengthening its walls and expanding them for the planned eastward expansion.
If the project receives federal approval, the homes near SR-201 (aka 2100 South Freeway) and 8000 West would again become neighbors of active tailings pads.
what’s in the dust
In mid-April, when Molly Blakowski drove past the dumps on her way back from the Saltair boat harbor, she found a dusty scene amidst the high winds.
“Since we were right next to the Kennecott tailings, visibility on the road was pretty limited,” she said. “It was really uncomfortable and difficult to breathe and really experience something uncomfortable.”
The visit prompted Blakowski, a graduate student in Utah State University’s Department of Watershed Sciences, to reflect on the levels of PM2.5 and PM10 people breathe near the mountains.
Dust generated from tailings dumps at many mining operations is rich in heavy metals, so it may also be enriched with metals like copper, lead and zinc, she said.
According to Paula Doughty, the company’s tailings and water services manager, Kennecott’s tailings piles are of better quality than some of its counterparts. They do contain metals, but the latest environmental study found the levels are reproducible in many backyards.
“It’s very comparable to Western soils from a metal standpoint,” Doughty said. “The only thing slightly higher is copper.”
Still, Blakowski worries about what’s in that metallic-flavored dust.
“Regardless of chemical composition, exposure to elevated levels of particulate matter poses an acute health hazard,” she said. “But if that dust is then enriched with heavy metals, there may be additional health concerns associated with exposure.”
Advocates like Friends of Great Salt Lake are also concerned about a possible expansion of an industrial operation that is dumping some waste, including selenium, into water bodies that reach the Great Salt Lake.
However, Doughty is not concerned about the quality of the water Kennecott is sending into the Great Salt Lake.
“We’re heavily regulated,” she said. “It meets all of our permit requirements. And we hit those pretty easily. The only challenge we have is strong winds. It’s going to stir that up and so we’re going to have suspended solids.”
In those cases, she said, her team stops the discharges until the solids settle. In addition, Kennecott reduces dust generation by keeping the sprinkler system on the tailings piles on at all times except during heavy rain.
“Our air quality permit requires that we conduct taps at every location on the dam at least once every four days,” Doughty said. “So we’re going to rotate where we need to and where we can to meet that requirement.”
Location, location, location
Friends of Great Salt Lake executive director Lynn de Freitas said it was “unfortunate” that Kennecott could not find a better place to store its waste products that would not impact the wetlands and air quality near the lake.
“Kennecott has extensive holdings in the Oquirrh Mountains and there are some abandoned mines there,” de Freitas said. “That would be a logical place.”
De Freitas also worries that dust suppression methods may be ineffective, especially if the ponds are adjacent to a growing metropolitan area already struggling with air pollution.
“Kennecott has been evaluating various options to expand the storage of its tailings piles on its properties,” said Laura Ingersoll, Rio Tinto’s senior advisor to the company’s community and social performance team. The company concluded that the eastward expansion would be the one that best minimized the environmental impact.
“The area where the expansion will go was an area that was previously industrialized. [like] Treated water channels, sediments, ponds, roads, pipelines, equipment storage,” she said. “The residence closest to the East Tailings expansion area is approximately 1,100 feet away and separated by SR-201.”
Environmental impacts are checked
Whenever a project could impact U.S. waterways and wetlands, the Army Corps of Engineers steps in to review it.
Because Kennecott’s plans would cover 44.86 hectares of water including wetlands, the Corps prepares an environmental impact statement that considers factors such as aquatic resources, air and water quality, and socioeconomic aspects such as jobs.
Although there have been public announcements, the expansion of the tailings pile has remained a relatively unknown process for the community. Although some residents and non-profit organizations submitted comments, only one person attended the scoping meetings.
“That was a little disappointing,” said Nicole Fresard, senior regulatory project manager for the Corps, “because you want to hear from the public whenever you’re working on projects of this type.”
As with most environmental impact statements, the alternative of no action is considered. The Corps will also consider on-site and off-site alternatives. The option that has the least impact on the community is likely to prevail.
“What Kennecott would most like to do isn’t necessarily what they will ultimately do,” Fresard said, “because the project may change as the EIS process progresses.”
The public comment period ended in April. However, the Corps will continue to evaluate additional inputs as it develops the analysis. A final study can be completed in two years.
Alixel Cabrera is a Report for America Corps member and writes for The Salt Lake Tribune on the status of communities on the west side of the Salt Lake Valley. Her donation to complement our RFA grant helps ensure she continues to write stories like this. Please consider making a tax-deductible gift of any amount today by clicking Here.
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