> I read something recently about surface water in mountainous areas
 > being very mineral-rich, ...

That's surprising. Where would the water pick up minerals? Maybe the article
applied only to a particular region, perhaps an area with geothermal vents
bringing mineral-rich water from the depths.

A couple of data points from my own experience. New York City's water is
very soft and comes mainly from surface runoff from upstate watersheds.
South Bend, IN, gets its water from wells, and the stuff is so hard that, if
you boil the water in an open pan, you get a film of mineral scale on _top_
of the water.

Bill Dooley