Take a few ounces of water. Garnish with an elegant bottle and a large price tag. Convince Americans it’s cool. Somehow, in the 1990s, a French company called Perrier did that, and now, America is getting soaked.

Today, Evian has surpassed Perrier in sales; it’s now the chic French water of choice. It costs more than gasoline – about $5 a gallon – and if you’d rather wear it than drink it, you can pay $10 for a 5-ounce aerosol can (ingredients: “aqua” and nitrogen).

Then there are Aquafina, Dasani, and the dozens of new brands of bottled water that have jumped into this billion-dollar business, including bizarre ones like Venus, the Water for Women, and Trump Ice, with the Donald scowling on the label. I’d have to be very thirsty to buy that.

Water comes out of public fountains for free. It comes out of your tap for pennies. Why buy it in bottles?

“Because it tastes better,” people told us. So ABC News ran a taste test. We put two imported waters, Evian and Iceland Spring, up against Aquafina (America’s best-seller), American Fare (Kmart’s discount brand), and some water from a public drinking fountain in the middle of New York City.

We asked people to rate the waters bad, average, or great. Many said one of the waters was bad. Which one? Why, monsieur, that would be Evian, the most expensive, which came in last in our unscientific test. Evian had no comment. The water our testers like most came from Kmart: American Fare ranked first in our unscientific test, and it costs a third of what Evian costs. (Maybe that’s why “Evian,” spelled backward, is “naive.”) Aquafina ranked second. Poland Spring came in fifth.

Tied for third were the water from Iceland and the New York tap water – water that may have come as much as 100 miles through the antique pipes of New York before emerging from that water fountain. Even people who said they didn’t like tap water liked it when they weren’t told it was tap water. Of course, your local tap water may not be as tasty, but you owe yourself a taste test before you squander more money on the bottled stuff.

For a show on the Showtime cable channel, satirists Penn and Teller got a trendy California restaurant to let them fool customers with a “water steward.” Like a wine steward, he had lots of fancy bottles, and most diners said they loved their elegant waters. “Oh, yeah, definitely better than tap water!” said one. But tap water is just what it was – the “water steward” filled the fancy bottles using the hose on the restaurant’s patio.

If taste doesn’t justify the price of bottled water, maybe “purity” does. Some people have the notion that bottled water is healthier than tap. We sent some bottled and tap water samples to microbiologist Aaron Margolin, of the University of New Hampshire, to test for the bacteria that can make you sick, like E. coli. “There was actually no difference between the New York City tap water and the bottled waters that we evaluated,” he said.

Some people worry about traces of chemicals, like chlorine, fluoride, copper, and iron. There’s a lot of misinformation suggesting tiny levels of pollutants injure people. They don’t. Small amounts of chemicals are usually not only harmless, they even put them in vitamin pills.

Many scientists have run tests that find tap water is as good for you as bottled waters that cost 500 times more. I even asked the man the bottled-water association recommended we interview, Dr. Stephen Edberg, of Yale University’s School of Medicine, “Is bottled water healthier than tap?” He gave me this sparkling gem: “I wouldn’t say, uh, it’s healthier than tap water. I mean, uh, it’s both, they both provide, uh, water.”

That’s right: All those companies that charge you an arm and a leg are selling you, uh, water. I can’t argue with that. They certainly are selling you water.

If you buy bottled water because you think it’s healthier than tap, test after test shows no evidence of that. And if you buy fancy brands because you think they taste better, you’re probably just buying hype.

Mr. Stossel is co-anchor of ABC News’s “20/20.” ©2005 By JFS Productions Incorporated.