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Chalky white residue left from dripping taps

I am an artist who works with time based sculptures and have recently witnessed a phenomena in relation to a leaking tap, attached to what I believe is a copper or brass water pipe, possibly quite old.I would like to integrate the phenomena I witnessed into an artwork but I am not exactly sure of the chemistry underlying the phenomena and hope that a correspondent of finishing.com may be able to help me.

The phenomena is outlined as follows:

The dripping water collected in to a ceramic bowl, but when the bowl overflowed onto the floor the water turned a chalky white colour as it formed a puddle on the floor, absolutely opaque.The flooring was a polyurethane covered concrete. When the water evaporated a white residue remained.

Any advise on the underlying chemistry and possible ways to duplicate such phenomena, would be most appreciated.

Yours sincerely,

Todd Robinson
artist - Sydney, New South Wales, Australia
2003

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2003

Water has salts of various types dissolved in it. For example, sea water has about 6 percent sodium chloride salts. When the water evaporates, the salts don't evaporate. So, over time, the salt residue can become more and more concentrated. The Dead Sea and the Great Salt Lake are large examples of this phenomenon. But even city water, although it has much less salt than sea water, still has salts in it. The most common of these is calcium.

You can probably accelerate the process by dissolving calcium chloride salt into the water.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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Do you have "hard water"? If so, the deposit is calcium carbonate.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2004