Where on Earth? - October 2010

Clues for October 2010:
1. This former open pit mine is more than 1.5 kilometers across and more than 500 meters deep, and has become a tourist attraction.
2. After mining activity was suspended in 1982 and pumps were turned off, the pit began to flood from natural groundwater seeps. It now contains a pool of highly acidic water laden with heavy metals — the largest pit of contaminated water in its host country.
3. The still-rising water level in the pit is expected to reach the water table by about 2020. Fears that the contaminated water will then flow back into the aquifer and enter surface waters have prompted large-scale efforts to clean up the site. Meanwhile, extremophile species of fungi and bacteria have adapted to the harsh conditions, some of which may be useful in cleanup operations.
Name the mine and its location.
Scroll down for the answer
Answer: After mining activity at Berkeley Pit in Butte, Mont., was suspended in 1982, groundwater began to seep in, eventually forming a deep pool of highly acidic, metals-laden water. Fears that the water level could top the water table by 2020 and then flow into the aquifer are fueling large-scale cleanup operations. Photo by Matthew Sabetta. 
October winners
Anne Andersen (Bemidji, Minn.)
Scott Bouma (Missoula, Mont.)
Matt Falter (Reston, Va.)
Ryan W. Fandray (Monroeville, Pa.)
Bruce Karinen (Salt Lake City, Utah)
James Phipps (Cosmopolis, Wash.)
Bayard D. Rea (Casper, Wyo.)
Roger C. Steininger (Reno, Nev.)
Michael Watson (Yucaipa, Calif.)
Nick Wigginton (Washington, D.C.)

To submit your photographs to our Where on Earth? contest, send them via e-mail to

23 Oct 2010