Well, except for that time 20 years ago when a Texaco drilling rig punctured the top of the salt dome (and Diamond Salt Mine) and sucked down a lake, a barge or two, a 5 million dollar oil platform, a few trucks and other miscellany, in just a few hours time. Luckily, all of the saltminers were evacuated in time and the few fisherman in the lake were able to escape, unharmed. http://members.tripod.com/~earthdude1/texaco/texaco.html Other than that, yeah, it's environmentally friendly. :)