Oregon's biggest city is sending eight million gallons of treated drinking water down the drain - because a man urinated into a city reservoir.
Portland authorities defended the decision, saying they did not want to send residents water laced, however infinitesimally, with urine.
But public health chiefs said urine was sterile in healthy people and that the urine in the reservoir was so diluted - perhaps a half pint in millions of gallons - that it posed little risk.
Some people in the city, in the suburbs and around the world condemned the big flush as an over-reaction, especially since animals such as ducks contribute waste routinely and, sometimes die in the water.
"More than one billion people worldwide do not have reliable access to clean drinking water, and here we are tossing away nearly eight million gallons of water just to appease the ignorant residents who believe their tap water will otherwise turn yellow," read one comment posted on The Oregonian's website.
Water from the city's five open-air reservoirs, all in parks, goes directly to customers. The reservoirs are due to be replaced by underground storage within a decade, a result of government requirements.
The reservoirs distribute water that flows from glaciers on Mount Hood. It is treated before it goes to the reservoirs for distribution, and then goes directly to consumers.
The reservoirs are drained twice a year for cleaning, and workers have found animal carcasses, paint cans, building material, fireworks debris and even the plastic bags people use to scoop up after their dogs, said David Shaff, administrator of the city water bureau.
Even so, Mr Shaff said, the "yuck" factor was the primary reason for the decision to drain the eight million gallons, at a cost of less than 8,000 dollars (£4,900) to treat it as sewage. "Nobody wants to drink pee and I don't want to deal with the 100 people who would be unhappy that I'm serving them pee in their water," he said.
Mr Shaff said the security cameras that caught piddler Josh Seater, 21, also showed that something still unidentified was thrown in the water, heightening concern about potential risks.