Tap water is making a comeback.

With a day's worth of bottled water — the recommended 64 ounces — costing hundreds to thousands of dollars a year depending on the brand, more people are opting to slurp water that comes straight from the sink.

The lousy economy may be accomplishing what environmentalists have been trying to do for years — wean people off the disposable plastic bottles of water that were sold as stylish, portable, healthier and safer than water from the tap.

Heather Kennedy, 33, an office administrator from Austin, Texas, said she used to drink a lot of bottled water but now tries to drink exclusively tap water.

"I feel that (bottled water) is a rip-off," she said in an e-mail. "It is not a better or healthier product than the water that comes out of my tap. It is absurd to pay so much extra for it."

Measured in 700-milliliter bottles of Poland Spring, a daily intake of water would cost $4.41, based on prices at a CVS drugstore in New York. Or $6.36 in 20-ounce bottles of Dasani. By half-liters of Evian, that'll be $6.76, please. Which adds up to thousands a year.

Even a 24-pack of half-liter bottles at Costco Wholesale Corp., a bargain at $6.97, would be consumed by one person in six days. That's more than $400 a year.

But water from the tap? A little less than 0.14 cent for a day's worth of water, based on averages from an American Water Works Association survey — just about 51 cents a year.

U.S. consumers spent $16.8 billion on bottled water in 2007, according to the trade publication Beverage Digest. That's up 12 percent from the year before — but it's the slowest growth rate since the early 1990s, said editor John Sicher.

Coca-Cola Enterprises Inc., the biggest bottler of Coca-Cola Co.'s Dasani, recently cut its outlook for the quarter, saying the weak North American economy is hurting sales of bottled water and soda — especially the 20-ounce single serving sizes consumers had been buying at gas stations.

"They're not walking in and spending a dollar plus for a 20-ounce bottle of water," said beverage analyst William Pecoriello at Morgan Stanley. Flavored and "enhanced" waters like vitamin drinks are also eating into plain bottled water's market share.

Pecoriello said Americans' concern about the environment was also a factor, driven by campaigns against the use of oil in making and transporting the bottles, the waste they create and the notion of paying for what is essentially free.

The Tappening Project, which promotes tap water in the U.S. as clean, safe and more eco-friendly than bottled water, launched a new ad campaign in May. The company has also sold more than 200,000 reusable hard plastic and stainless steel bottles since last November.

Linda Schiffman, 56, a recent retiree from Lexington, Mass., bought two metal bottles at $14.50 each for herself and her daughter from Corporate Accountability, a consumer advocate group, after she swore off buying cases of bottled water from Costco.

"I've been doing a lot of cost-cutting since I retired," said Schiffman, a former middle-school guidance counselor. "Additionally, I started feeling like this was a big waste environmentally."

Aware of those concerns, some bottled water makers are trying to address the issue.

Nestle says all its half-liter bottles now come in an "eco-shape" that contains 30 percent less plastic than the average bottle, and it has pared back other packaging. PepsiCo and Coca-Cola have also cut down on the amount of plastic used in their bottles.

While it is difficult to track rates of tap water use, sales of faucet accessories are booming.

Brita tap water purification products made by Clorox Co. reported double-digit volume and sales growth in May and have seen three straight quarters of strong growth.

Robin Jaeger of Needham, Mass., fills her kids' reusable bottles with water from the house's faucet. But she doesn't use water straight from the tap.

Her reverse-osmosis filter system costs about $200 every 18 months for maintenance — still cheaper than buying by the bottle.

Kennedy, the tap convert from Texas, has a filter built into her refrigerator. She also recently bought a reusable aluminum bottle made by Sigg, a Swiss company which has stopped selling its $19.99 metal bottles from its Web site, saying demand has swamped its supply.

While Brita is the dominant player in water filtration, according to Deutsche Bank analyst Bill Schmitz, sales of P&G's Pur water filtration systems are also growing. Sales from the Pur line have increased almost every month since mid-2007, said Bruce Letz, its brand manager.