Local bans are unlikely to stop bottled water overtaking soda pop as Americans' preferred beverage by the end of the decade, the chairman of Nestle Waters North America said Thursday.

Speaking to reporters in Washington, Kim Jeffery forecast that "within the next five or six years," bottled water would become "the number one beverage in America" as consumers turn away from carbonated soft drinks.

He acknowledged efforts by environmental activists to ban the sale of bottled water on college campuses, after the affluent Boston suburb of Concord this year became the first US city to ban bottled water.

But he played down the impact of such campaigns -- which allege that water in disposable plastic bottles is harmful to the environment and no better than tap water -- on overall sales.

"The category grew seven percent this last year. It was the highest growth rate we've had in six years," said Jeffery, adding that carbonated soft drink sales fell by one percent during the same period.

"These trends are continuing and, in fact, they are starting to accelerated because carbonated soft drink consumption has really fallen on hard times."

Seventy percent of growth in the bottled water industry in the past 10 years has been at the expense of soda pop, he said, adding that if colleges do ban bottled water, students will likely just go off campus to stock up.

More than 90 colleges in the United States, including some prestigious Ivy League campuses, have so far either banned water in disposable bottles or restricted their use, according to the Mother Nature Network blog.

Some schools are giving students reusable metal bottles to fill up at designated water fountains.

Nestle Waters North America, a unit of Swiss food conglomerate Nestle, accounts for half the entire bottled water business in the United States with such brands as Poland Spring, Deer Park and Nestle Pure Life.

It also imports European brands such as Perrier and San Pellegrino.

Jeffery, at the helm of Nestle Waters since 1992, cited two groups opposed to bottled water -- Corporate Accountability International and Food & Water Watch -- as "not solution-based organizations."

"They would prefer that we not have a license to operate our business," he said scornfully. "We have nothing to talk about with these two organizations."

A Food & Water Watch researcher sitting at the back of the press event said that Nestle's own corporate annual reports detail a decline in bottled water sales, but Jeffery said her numbers were wrong.

Corporate Accountability International is spearheading an ongoing campaign to get national parks in the United States such as the Grand Canyon to stop selling water in disposable bottles to tourists.

The sale of bottled water in single-serve sizes in Concord, population 17,000, took effect on January 1 after a three-year campaign that focused on reducing waste and fossil-fuel use.

Jeffery attributed the popularity of bottled water to changing lifestyles as more and more Americans try to cut down their calorie intake to ward off obesity, diabetes and other health concerns.

Speaking at a table in the National Press Club that had two small bottles of Nestle Pure Life and a large metal pitcher of tap water, he said that most consumers see both types of water as complementary.

"Over 50 percent of bottled water consumers drink both bottled water and tap water," he said. "To suggest we should just drink tap water, and not bottled water, is a false choice. We actually need the availability of both."