Is bottled water a wasteful, expensive habit that contributes to global warming, or is it a healthy alternative to soft drinks for people on the go?

For Darlene Jones, the answer is simple: drinking bottled water is a wasteful habit.

“It’s not necessary,” said the Napa woman, as she carried a bag of junk mail to a recycling bin on Second Street.

Robert Arguel, on the other hand, prefers bottled water to tap water.

The U.S. postal service clerk, holding a bottle of water purchased at Costco, said he does not like its taste of tap.

Americans drank close to 8.3 million gallons of bottled water in the United States in 2006 — a 9.7 percent increase over the previous year, according to the Beverage Marketing Corp.

While bottled water industry representatives argue they offer a safe and healthy alternative to sodas, others question the practice of buying, drinking and importing bottled water.

“You pay so much for convenience,” said Erin Farnand, a water quality analyst for the city of Napa, adding that 1,000 gallons of Napa tap water cost only $3.75.

The city’s water is continuously monitored to meet state and federal water quality standards, she said.

An increased number of environmental activists, grass roots groups and public officials, including San Francisco Mayor Gavin Newsom, have said that drinking bottled water contributes to the emission of greenhouse gases because the water has to be transported. They also note that plastic bottles fill landfills; that the bottled water industry saps aquifers; and that selling water undermines efforts to make safe drinking water a fundamental human right.

In June, Newsom signed a directive to have San Francisco gradually stop buying bottled water. In rural west Marin County, home to the Point Reyes National Seashore, a group of residents have begun a campaign to eliminate the use of plastic bottles and plastic bags, explained Jack Kramer, a member of the grass roots effort. The group encourages businesses to sell stainless steel water bottles that can be refilled with water. They also want to find money to install public water fountains in downtown Point Reyes.

In Napa County, the Napa County Transportation and Planning Agency’s executive director decided to stop buying bottled water earlier this year to save money and cut down on the emission of greenhouse gases.

“We allow convenience to drive us,” said NCTPA Executive Director Jim Leddy.

Supervisor Bill Dodd, a NCTPA board member and former Culligan executive, said he still prefers “high quality” water, though he’s fine with NCTPA’s decision to no longer buy bottled water.

“If I need a beverage I can bring my own,” Dodd said this week.

Other public agencies, including Napa County, American Canyon, Calistoga, Yountville and St. Helena continue to offer bottled water at public meetings. The city of Napa’s elected officials drink tap water from a blue pitcher and use recyclable cups, Napa City Clerk Sara Cox said Tuesday. St. Helena City Clerk Delia Guijosa said the city offers bottled water because the city is rationing its potable water supply.

Chris Canning, a representative for Calistoga Beverage Company, said his company offers a healthy alternative to carbonated soft drinks that caters to Americans’ active lifestyle.

“We strongly encourage recycling,” Canning said, noting the company has nothing against tap water drinkers.

Kevin Miller, recycling manager for the city of Napa, said plastic bottles used for bottled water are recyclable.

Preventing the waste in the first place is always the best option, Miller also wrote in n e-mail. Reuse, followed by recycling, are the next best options environmentally, he said.

Plastic container recycling lags behind aluminum and glass recycling. Still, the city’s recycling and composting facility shipped out almost 9 million 20 ounce plastic bottles for recycling in 2006, according to Miller.