The grand old town of Butte (Why is there a toxic pit above me?)

I'm currently in Butte, MT for the Montana Class A Boys Basketball Tournament State Tournament which is about three hours from my home base of Polson. There's plenty of historical things to experience, and one of those things is the United States' largest Superfund site. Namely, a large lake of toxic water that is nestled above the town. It's called Berkeley Pit and it looks like this now...

Berkeley Pit was originally opened as an open pit mine in 1955, and shutdown in 1982. When they shut things down, they shut down pumps in surrounding mines and water seeped into the pit. Now the pit it 1,700 feet of toxic water and a source of tourism for Butte (??)

Just how alarming is the water seeping into the pit? Here's how it looked in 1984...

Notice a "slight" chance is water levels. It's not good water either and its going to cause some serious problems in a few years, according to Wikipedia....

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. 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.

So with that said, I will not be drinking any tap water in Butte.