A rush of cold air greets Glenn Yost as he opens the door to the old mine. The shaft inside, abandoned for more than 40 years, is full of cool, crystal clear water, which brings a grin to Yost's face.

"Do you feel how cold that is?"

A few feet away, the water trickles out from a natural spring. Yost walks to the stream and comes up with a handful of water.

"See how clean that is?"

A pipe, a few feet from Yost and the stream, uses gravity to send water to a small facility, about a mile away.