Rio Tinto Kennecott has started a project on the outer face of the Bingham Canyon Mine that will enhance the aesthetics visible from the Salt Lake Valley and provide optionality for mine-life extension.
The Alternative View Construction Project is occurring on the south and east facing waste rock piles. The long-term improvement in the appearance and performance of the waste rock piles and associated stormwater management systems will be possible by constructing enhanced surface and groundwater infrastructure in advance of placing new material from inside the mine at the base of the outer toe of the existing piles.
The material will be regraded at an angle allowing for revegetation of the surface. In addition, the project will include the construction of new cut-off walls and stormwater basins that will be engineered and constructed to handle a minimum of a 100-year, 24-hour storm event.
The work on this project is anticipated to be completed by the end of 2020. A comprehensive fugitive dust control plan is in place that utilizes water trucks, and construction impacts will be minimized as practical.
Terms of reference
Angle of repose
The term angle of repose refers to the steepness of the waste rock slopes. In the Alternative View Construction Project, the slope angle will be reduced to improve seismic stability, water drainage and to aid vegetation growth as the slopes are reclaimed.
A cut-off wall is part of a water collection system designed to protect water that seeps down from waste rock piles from infiltrating the water supply. They stop any contaminated water from moving farther downstream and collect the water for treatment. The existing walls, built in the 1990s, will be replaced and moved farther east. The cut-off walls are built 20-40 feet deep down to the bedrock.
Reclamation means working to restore the land to a more natural setting, similar to what the land may have looked like before mining. As part of the Alternative View Construction Project, waste rock would be added to the existing piles to reshape the piles. The waste rock will be placed in terraces or levels. As each terrace is completed, the slope can be graded, covered in topsoil and seeded with native plants. Although the whole process of waste rock placement, grading, planting and finally the re-growth of the slopes will take many years, the final result will be a mountainside that looks more like the surrounding natural slopes and blends in to the Oquirrh Mountain Range.
Waste rock, also called overburden, is the rock material removed during mining but considered uneconomic to process. Kennecott deposits waste rock in large, piles that can be seen from the valley. Currently, the overburden rock is deposited on top of the southern piles, east side piles or in Bingham Canyon.
Work on this project is similar to the work conducted everyday inside the Bingham Canyon Mine and is under the same regulatory oversight. Read more here.
To engage with us on this project, send an email to firstname.lastname@example.org or call (801) 204-2000.