Mayor Luke Ravenstahl would love to reduce the city's reliance on bottled water, but as long as the plumbing in the City-County Building remains in its current condition, city employees will quench their thirsts at the water cooler.

The U.S. Conference of Mayors passed a resolution Monday encouraging cities to stop using taxpayer money to buy bottled water because it is expensive and generates substantial waste.

Mr. Ravenstahl is a member of the conference but did not attend its annual meeting in Miami this week.

His spokeswoman, Joanna Doven, said the mayor supports green initiatives, but the water coming from taps on Grant Street isn't always something you'd want to drink.

She said that the pipes in the 91-year-old building turn some tap water a nasty shade of orange and that it's not very tasty.

The conference's resolution cites the "high-quality, safe drinking water" available in American cities as one reason to reject the bottled variety.

But Pittsburgh pays Atlanta-based Crystal Springs about $26,000 a year to keep its office coolers stocked with five-gallon bottles of purified water, according to the controller's office.

Ms. Doven said that sometime in the future, the mayor would like to upgrade the City-County Building to a LEED-certified green structure, but that until then, the water situation would probably remain the same.

Allegheny County government also pays about $30,000 a year for water in its offices countywide, said Kevin Evanto, spokesman for Chief Executive Dan Onorato.

Mr. Evanto said that in addition to water coolers, the county pays for filtration systems in the County Courthouse, which was built in 1884 and has lead plumbing pipes.

"The amount of money we spend on bottled water is very small," Mr. Evanto said. "We use city water; it's just filtered."

He said the county doesn't plan to get rid of bottles completely, but that over the last several years it has been increasing its use of filters and decreasing the amount of bottled water it buys.

More than 60 cities and towns nationwide have taken measures to keep the amount of bottled water they buy to a minimum.

San Francisco Mayor Gavin Newsom, who drafted the conference's resolution, issued an executive order in June 2007 that phased out water coolers in city offices and prohibited city purchasers from buying single-serving bottled water unless absolutely necessary.

Mr. Newsom's order has become a model for cities around the country, according to Deborah Lapidus, an organizer with Corporate Accountability International, a nonprofit group that advocates for social responsibility in the corporate world.

The group's Think Outside the Bottle campaign has worked to promote public water supplies in lieu of bottled water for 2¹/₂ years.

A fact sheet from CAI says that it costs cities more than $70 million a year to dispose of plastic water bottles and that production of plastic water bottles used more than 17 million barrels of oil last year.

Ms. Lapidus was at the conference's meeting this week promoting Mr. Newsom's resolution and asking mayors to co-sponsor it. She said 18 mayors signed on to the resolution, which passed with a unanimous vote.

Among the co-signers was Philadelphia Mayor Michael Nutter, who currently has no plans for reducing bottled water use, though a spokesman said that he has always been in favor of promoting municipal water.

On Monday, the International Bottled Water Association, a trade group that represents water bottlers worldwide, issued a statement calling the resolution erroneous and saying that it "is not in the public interest and could discourage consumers from drinking bottled water."