Study details slope stability

The rate of rise of water levels in the Berkeley Pit and connected monitoring points is affected by many factors, including rain and snowfall and occasional ‘sloughs’ or ‘slumps’ of material from the Pit’s sidewall slopes. The most recent slough occurred on February 8, 2013. An estimated 820,000 tons of material from the southeast wall collapsed into the Pit. Montana […]

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In 2010 EPA interviewed local citizens and reviewed the status of Butte area Superfund sites as part of a required five-year review (the full review report is available here). Five-year reviews determine whether remedies or other response actions are protective of human health and the environment in compliance with a site’s decision documents. Methods, findings, and conclusions are documented in […]

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The Montana Bureau of Mines & Geology (MBMG) developed this computer model showing Butte topography and the corresponding underground tunnels from the years of historic underground mining. The red dots at the surface and red lines below represent vertical shafts, and the colored lines under the surface represent the horizontal levels of the mines. The graphic does not illustrate stopes […]

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Berkeley Pit slough

On February 8, 2013 material from the southeast wall of the Berkeley Pit collapsed into the Pit water in what is known as a rotational slump or slough. Such sloughs are relatively common in open pit mines. For example, a similar slough occurred at the Berkeley Pit in 1998. The recent slough was about 550 feet wide and caused an […]

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In past years, many visitors were curious about the waterfall visible from the Pit Viewing Stand. Montana Resources pumped water out of the Berkeley Pit, then removed the copper from that water before returning it to the Pit (click here for more information on mining copper from Pit water). The waterfall was created by this returning water. However, this activity […]

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