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 estimated 820,000 tons of material to collapse into the Pit. Montana Bureau of Mines & Geology (MBMG) monitoring showed that the water level in the Pit lake rose about 0.6 feet as a result of the slough. For comparison, over the past several years the water in the Berkeley Pit has risen about 0.65 feet per month.
Current projections still estimate that water levels at one of the surrounding monitoring compliance points for the Berkeley Pit system will reach the Critical Level (5,410 feet) around 2023.
Pumping and treating of Berkeley Pit water will be required when water levels at any of these compliance points reach the Critical Water Level. Currently, the highest water level is in the Pilot Butte shaft to the north of the Pit. As of June 2013, the Berkeley Pit water level was 5,310.89 feet above sea level, and the water level in the Pilot Butte shaft was 5,335.72 feet above sea level, or about 75 feet below the critical level.
No. Butte residents don’t need to worry about flood insurance in regard to the Berkeley Pit and connected underground mine workings. The Berkeley Pit and connected tunnels act as a sink that collects groundwater in the area. Water levels in the Berkeley Pit and associated mine shafts are currently 175 to 200 feet below the rim of the Pit.
The lowest point on the Pit rim, on the east side near the Montana Resources concentrator, is 5,509 feet above sea level. As of June 2013, the Berkeley Pit water level was 5,310 feet, and the highest water level in the system, in the Pilot Butte shaft, was 5,335 feet.
Under the management plan for the Berkeley Pit, these water elevations will always be maintained at levels 100 feet or more below the rim. This will be accomplished by pumping and treating Berkeley Pit water. Pumping and treating will start when the water level at any one of the monitoring compliance points reaches the critical level of 5,410 feet. The Montana Bureau of Mines & Geology (MBMG) monitors water levels at all compliance points, as well as at several other monitoring sites, on a monthly basis. Based on the rate the Pit is filling now, that should happen around 2023.
The elevation of the Metro Storm Drain near the Pit at Texas Avenue and Continental Drive is 5,470 feet, about 60 feet above the highest water level allowed for the Berkeley Pit system.
For further comparison, a monitoring well at Greeley School has an elevation of 5,503 feet, about 93 feet higher than the critical level. The current water level in this well is 5,462 feet, about 52 feet higher than the critical level. This difference in water levels tells us that groundwater is flowing toward the Pit, and will continue to do so after the waters in the Berkeley Pit and connected mines reach their highest allowed levels.
In other words, water is flowing into the Berkeley Pit, and the Pit will be managed so that water is always flowing into it. Butte residents can rest easy knowing that the Berkeley Pit is not going to overflow, and that there is no need for flood insurance due to the Pit or underground mines.
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 between three to nine different depths and analyzed for various dissolved chemicals.
Water quality conditions, such as temperature, pH, specific conductance, and dissolved oxygen, are also measured at five- to ten-foot intervals from the surface to a depth of 600 feet. These same conditions are also measured at a depth near the Pit bottom.
In past years, the Berkeley Pit was a chemically layered system, which means that the chemistry of the water changed with depth. The brownish-red water at the surface was actually the least contaminated water in the pit, and the lower layer the worst water quality. The color changed as well, going from brownish-red on top to bluish-green at the bottom.
At a certain depth, the chemistry of the water changed so rapidly that it formed a chemical boundary scientists refer to as a chemocline. Water above the chemocline was chemically lighter, in other words, less dense, than the water below. The layering of the two waters is similar to oil floating on water. The water above the line was also less acidic (higher pH), with lower concentrations of metals.
Due to mixing in the Berkeley Pit lake over time, this previously layered system disappeared around 2012, and the Pit water has since become more uniform.
Summary of 2012 (published in March 2013) monitoring data related to the Butte Mine Flooding Consent Decree, which includes the Berkeley Pit and associated workings, from the Montana Bureau of Mines & Geology.
Quality: HD Title : Be Afraid Release : 2017-04-01. Language : English. Runtime : 99 min. Genre : Thriller, Science Fiction. Stars : Brian Krause, Kevin Grevioux, Louis Herthum, Jaimi Paige, Callie Thorne, Jared Abrahamson.
Not long after John Chambers and his family arrive at their new home in a small country town of Pennsylvania, John begins to experience sleep paralysis. Lying there paralyzed, trapped within his own nightmare, other-worldly beings visit John. They are entities which exist in the darkest shadows of the night and can only be seen out of the corner of one’s eye. These encounters begin to haunt John, transforming to complete terror as he discovers the entities’ sole purpose… the abduction of his seven year old son. In the end, John will uncover the town’s horrific secret, a portal on his land, and make one last attempt to save his son before the shadow people permanently take him away to their world.
The Berkeley Pit will never overflow. In 1994 the EPA established the Critical Water Level (the maximum level the water will be allowed to reach) at 5,410 feet above sea level, which is one hundred feet below the rim.
Water levels are regularly monitored at the Pit, in historic underground mines, and in wells surrounding the Pit. Failure to keep the water below 5,410 feet would result in steep fines for the companies responsible for the site, BP-ARCO and Montana Resources.
In addition to careful monitoring, the Horseshoe Bend Water Treatment Plant was constructed to make sure water in the Pit remains below 5,410 feet. Pit water will be pumped, treated, and discharged when the level nears the critical point.
Even if the water was allowed to rise unchecked, it would still never reach the rim. The groundwater flow would reverse direction and, instead of flowing toward the Pit, as it does now, the water would flow away from the Pit, underground into the sandy aquifer beneath Butte’s valley.
Due to the underground flow, Pit surface water would never reach the rim. Considering the federal orders, potential fines, and frequent monitoring, Pit water will not rise unchecked.