{"id":9851,"date":"2017-07-02T00:47:19","date_gmt":"2017-07-02T04:47:19","guid":{"rendered":"http:\/\/tusentakk2.com\/wordpress\/?p=9851"},"modified":"2017-07-02T00:47:19","modified_gmt":"2017-07-02T04:47:19","slug":"pits-june-22-2017","status":"publish","type":"post","link":"http:\/\/tusentakk2.com\/wordpress\/2017\/07\/pits-june-22-2017\/","title":{"rendered":"Pits & Mines — Butte, Montana; June 22, 2017"},"content":{"rendered":"

This last winter, while still in Bonaire, Barb and I read two interesting books by Timothy Egan.  So interesting, that they have influenced our travel plans as we head west.  One, Lasso the Wind: Away to the New West<\/strong>, is a social history, with each chapter dedicated to a particular site in the western states.  One of the chapters is about the rape of the environment in Butte, Montana.  We vowed to see for ourselves.  This posting is about that visit.<\/p>\n

(The other book is The Big Burn<\/strong>, and that will relate to a later post in our blog.)<\/p>\n

Berkeley Pit<\/span><\/h1>\n

From Wikipedia, the free encyclopedia<\/em><\/p>\n

The Berkeley Pit<\/strong> is a former open pit copper mine located in Butte, Montana, United States. It is one mile long by half a mile wide with an approximate depth of 1,780 feet (540 m). It is filled to a depth of about 900 feet (270 m) with water that is heavily acidic (2.5 pH level), about the acidity of cola or lemon juice.[1]<\/sup><\/a> As a result, the pit is laden with heavy metals and dangerous chemicals that leach from the rock, including copper, arsenic, cadmium, zinc, and sulfuric acid.<\/p>\n

The mine was opened in 1955 and operated by Anaconda Copper and later by the Atlantic Richfield Company (ARCO), until its closure on Earth Day 1982. When the pit was closed, the water pumps in the nearby Kelley Mine, 3,800 feet below the surface, were turned off, and groundwater from the surrounding aquifers began to slowly fill the pit, rising at about the rate of one foot a month.[1]<\/sup><\/a> Since the pit closure in 1982, the level has risen to within 150 feet of the natural groundwater level.<\/p>\n

The pit and its water present a serious environmental problem because the water, with dissolved oxygen, allows pyrite and sulfide minerals in the ore and wall rocks to decay, releasing acid. When the pit water level eventually reaches the natural water table, estimated to occur by around 2020, the pit water will reverse flow back into surrounding groundwater, polluting into Silver Bow Creek which is the headwaters of Clark Fork River. <\/span>The acidic water in the pit carries a heavy load of dissolved heavy metals. In fact, the water contains so much dissolved metal (up to 187 ppm Cu) that some material is mined directly from the water.<\/p>\n

In the 1990s plans were devised for solving the groundwater problem. Water flowing into the pit has been diverted to slow the rise of the water level. Plans have been made for more extensive treatment in the future. The Berkeley Pit has since become one of the largest Superfund sites.<\/p>\n

The pit is currently a tourist attraction, with an adjacent gift shop. A $2 admission fee is charged to go out on the viewing platform.<\/p>\n

From other sources:<\/em><\/p>\n

Butte is the largest U.S. Environmental Protection Agency (EPA) Superfund site in America. It is their job, along with the Montana Bureau of Mines and Geology and other groups, to maintain it as a terminal sink and keep the pathogens contained to help the public stay safe and healthy.  Water levels in the East Camp\/Berkeley Pit system will not be allowed to exceed the established Safe Water Level (SWL) of 5,410 feet<\/p>\n