I found this sign over the waterless urinal at the Woods Hole Oceanographic Institute (where I am hanging out this summer) difficult to parse (or follow).
Ordinarily I wouldn't devote a blog post to this kind of thing but believe it or not, this month's Wired has an excellent article on the science, economics and considerable politics of waterless urinals. Here's one bit:
Plumbing codes never contemplated a urinal without water. As a result, Falcon’s fixtures couldn’t be installed legally in most parts of the country. Krug assumed it would be a routine matter to amend the model codes on which most state and city codes are based, but Massey and other plumbers began to argue vehemently against it. The reason the urinal hadn’t changed in decades was because it worked, they argued. Urine could be dangerous, Massey said, and the urinal was not something to trifle with. As a result, in 2003 the organizations that administer the two dominant model codes in the US rejected Falcon’s request to permit installation of waterless urinals. “The plumbers blindsided us,” Krug says. “We didn’t understand what we were up against.”
One thing that does annoy me is the claim that these urinals "save" 40,000 thousand gallons of water a year. Water is not an endangered species. With local exceptions, water is a renewable resource and in plentiful supply. At the average U.S. price, you can buy 40,000 gallons of water for about $80.