SALT LAKE CITY — The view of the southwestern Salt Lake Valley will be undergoing a major facelift over the next few years — a $100 million facelift.
Rio Tinto Kennecott has launched a five-year project that is aimed at rehabilitating and enhancing the aesthetic appearance of the mountainside altered by decades of mining activity in one of the world's largest open pit copper operations.
The facelift, dubbed the Alternative View Construction Project, is underway on the south- and east-facing rock piles along the Oquirrh Mountains. The project is expected to mitigate potential flood danger in the mine area that can occur after heavy rains as well as improve the overall look of the granite faces of the mountains that create the western boundary of the Salt Lake Valley.
Over the next two years, crews of more than 100 engineers and workers will remove waste rock material across the nearly 3-mile upper swath of the mine property, said Rio Tinto Kennecott environmental engineer Zeb Kenyon.
Once removed, material will be re-graded at an angle that will allow for revegetation of the newly altered surface, he said. The project will include the construction of new walls and stormwater basins that will be engineered and constructed to handle a minimum of a 100-year, 24-hour storm event — a much higher tolerance than the 10-year, 24-hour storm capability that currently exists.
Future reclamation of the newly placed material will create long-term benefits by improving the aesthetics of the base of the valley facing waste rock piles, reduce water infiltration and erosion, and improve surface water management, Kenyon said. The project also provides options for work that could extend the long-term life of the mine that could take the operation through 2029 and enable further reclamation of the historic waste rock piles, he added.
“While this work will be more visible compared to what we do inside the mine, we are committed to minimizing impacts and maintaining all regulatory compliance,” Kenyon said.
Michael Piercy, general manager of construction for Rio Tinto Kennecott, said waste rock is the uneconomic material that is moved out of the way and placed in engineered and permitted facilities — enabling access to metal-bearing ore.
He said the project, which is scheduled for completion in 2020, will not only help with water management on the property, but will also give the community a rejuvenated and more aesthetically pleasing view as they peer to the west everyday.
“What the community will ultimately see is a mountain come back to life,” Piercy said. “It will have natural grasses (similar vegetation) on it. It will look similar to what the mountain would have looked like at one point in its life.”
He also noted that as the area is re-seeded and begins to grow, the amount of dust will significantly diminish and the overall air quality in the immediate area and across the valley will improve greatly.
The project was spurred, in part, by a major seismic event that happened more than two years ago.
On April 10, 2013, a massive slide on a northeast slope created havoc in the main mining area. The slide was large enough to register a magnitude 2.4 at the University of Utah seismograph station. It knocked out Kennecott's visitors center, buried 13 large hauling trucks, large containers holding 83,000 gallons of diesel fuel, 13,000 gallons of various types of oil, 5,000 gallons of coolant and grease, a steel container full of thousands of pounds of explosives, and it buried two-thirds of the bottom of the pit.
Because of safety equipment that had already been installed to monitor the movement of the cliffs and soil in the mine, company officials were already aware of a pending problem before the slide came down and all employees were able to get out of the area prior to the event.
Just 17 days later, the mine was able to resume operations on a reduced scale using a single lane road down to the lower pit that included 13 switchbacks. Today, the mine is operating in a manner similar to the way it was prior to the slide, said Rio Tinto Kennecott spokesman Kyle Bennett.
The mine is now nearly fully operational again, he said. And from the company's perspective, they are putting that incident behind them and moving on.
"This is one such opportunity to show that we are continuing to invest in the (mine), and we think that we have a long and exciting future," Bennett said.
Email: [email protected], Twitter: JasenLee1