CORVALLIS - As a hydrologist and professor of the Oregon State University Institute of Water and Watersheds, Todd Jarvis thinks a lot about H2O.

Normally, water is considered a healthy thing, one of the ingredients to a healthy life and a healthy planet. Drinking down a cool bottle of water after a workout seems like one of the best things you can do for your body. But what Jarvis wanted to know was, what does bottled water do to the planet?

The answer is surprising.

"There's a carbon footprint from the cradle to the grave" for bottled water, Jarvis said. From the manufacturing of plastic bottles to the transportation of water to the disposal of empty water bottles, it takes a lot of oil and water to get bottled water into the hands of consumers. And it costs those consumers a lot of money.

"This resource, this commodity is something that really exemplifies how oil and water mix," Jarvis said, during a presentation on bottled water and the environment Wednesday afternoon at OSU. His presentation was part of a week of sustainability events being held on campus.

Americans spend $20,000 a minute every day buying bottled water. They consume about 8.2 billion gallons a year, compared to 41 billion gallons of worldwide consumption. Their reasons are varied: convenience, concerns about safety, taste.

But with between 25 and 40 percent of all bottled water containing nothing more than treated tap water, is it worth the cost, to both the planet and the average budget? While Jarvis won't tell anyone to stop drinking bottled water, he argued that the benefits of tap water overshadow the costs of bottled water.

There are more than 700 brands of bottled water sold in the United States. It's a $10.8 billion industry, and the most popular brands cost between $3.30 and $3.80 a gallon. In Corvallis, drinking straight from the tap costs around 5 cents a gallon. By adding a filter onto the faucet, the cost increases to around 15 cents per gallon.

The environmental cost of making plastic water bottles is 21.4 million barrels of oil, and 72 billion gallons of water, and that's before any water is put into the bottles. Once the water is bought and consumed, about 125 million bottles are thrown away every year in Oregon alone.

Jarvis' conclusion: "Bottled water isn't worth the price," he said.

For those staunch bottled-water supporters, Jarvis suggests looking for water that is labeled as purified, rain or well water, and says supporting local bottled water companies at least reduces the amount of travel the water makes, and keeps the money in the local economy.

Tap water can be made to taste better by putting it in a container in the fridge overnight. That allows the chlorine to evaporate and eliminates the chemical taste.

"North American tap water," Jarvis said, "is the best you can get."