As of May 5, 2017, the Pit’s water level was 5,339.30 feet above sea level. When water levels at one of the monitoring compliance points around the Pit reach the Critical Level of 5,410 feet, pumping and treating of Pit water will begin. Current projections estimate that the Critical Level will be reached around 2023. Full monitoring reports and data are […]

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1982-2013: 31 years since pumps stopped

Over 31 years ago economic factors led the Atlantic-Richfield Corporation, or ARCO, now a subsidiary of British Petroleum, to cease mining operations at the Berkeley Pit in Butte, Montana. Underground mining had come to an end seven years earlier, but the underground pumps had continued to operate, pumping groundwater out from the mines and the Berkeley Pit. The 1982 suspension […]

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The water level at the Berkeley Pit has been recorded every month for more than 23 years. In addition to that monitoring, scientists at the Montana Bureau of Mines and Geology have been sampling and analyzing water from the Berkeley Pit twice a year for its chemical composition and physical properties. In the Berkeley Pit, samples are taken from anywhere […]

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Geothermal Project Heats Up

The 10,000 miles of underground tunnels beneath Butte have filled with water since the closure of the Berkeley Pit and, in 1982, the shut-off of groundwater pumps that had dewatered the underground in the past. These waters are typically regarded as a liability, but a new project at Montana Tech is viewing the watery mines of Butte as a potential […]

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No More Chemocline

In the past, a chemocline was observed in the Berkeley Pit Lake. “Chemocline” refers to changes in the water chemistry at a certain depth. Pumping Pit water for copper extraction has caused the chemocline to disappear. For more on the chemocline and mining copper from Berkeley water, go HERE.

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