Saturday 26 March 2011

The Berkeley Pit


The Berkeley Pit is a former open pit copper mine located in Butte, Montana, USA. 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). As a result, the pit is laden with heavy metals and dangerous chemicals that leach from the rock, including arsenic, cadmium, zinc, and sulfuric acid.

The mine was opened in 1955 and operated by Anaconda Copper and later by the Atlantic Richfield Company, until its closure in 1982. When the pit was closed the water pumps in the nearby Kelly shaft 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. Since the Berkeley Pit closure in 1982, the level has risen to within 150 feet of the natural groundwater level.

3 comment(s):

Anonymous said...

It's just a hole in the ground...not a toxic waste dump. I admit that I don't know the details, but if natural elements (including some heavy metals) leach out of the rocks, well, they must be natural.

For sure, zinc is NOT hazardous.

Also, as far as 2.5 pH levels go (stated in blog as heavily acidic)...please don't ever drink Coke or Pepsi...they both have the same pH level. OMG

Gerard, did you copy and paste this, or did you think about it first? I thought so.

Bill

Gerard said...

For your information: The acidic water in the pit carries a heavy load of dissolved heavy metals. In fact, the water contains so much dissolved metal that some material is mined directly from the water.

In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0. Solutions with a pH less than 7 are said to be acidic. And you're right, the pH of regular Coca Cola is about 2,6

In 1995, a small flock of migrating snow geese landed in the Berkeley Pit water and died, with 342 carcasses recovered.
Necropsies by the State of Montana showed their insides were lined with burns and festering sores from exposure to high concentrations of copper, cadmium, and arsenic.

So, the Berkely Pit IS a toxid waste dump, not just a hole in the ground.

Monkey106 said...

Case dismissed, Bill. Nice one Gerard!