The Taelemans´ Blog

The Berkeley Pit is a former open pit copper mine located in Butte, Montana, about a mile and a half wide and about 1,780 feet (540 m) deep. Once the pit was closed in 1982, groundwater started to fill the pit to the natural groundwater level. This has presented an environmental problem in that the water allows minerals in the ore and wall rocks to decay, releasing acid and finally resulting in water that is heavily acidic (pH level of 2.5) and loaded with heavy metals and dangerous chemicals (hence the color of the water).

Berkeley Pit, Butte, Montana | Location on map

The water contains so much dissolved metal that nowadays they actually mine the water as you can see on the picture below.

Berkeley Pit Water Processing Factory | Location on map

Check the map location to get a feeling of how large the pit really is.

PS: If you’re in Butte, go to the Derby Steak House. The steaks they serve are just amazing. Must have been the best steak I ate in my life.