A couple of years ago, sellers of bottled water noticed a problem. Shoppers had become increasingly wary of plastic bottles, which were painted as wasteful and environmentally damaging. Environmental worries were singled out for causing bottled water sales to slip. In response, beverage companies have tried to wrap their brands in a shroud of environmental responsibility by making bottles lighter and using less plastic. The environmentally conscious packaging could not stop the bottled-water segment from shrinking last year, thanks to a troubled economy. But in muted good news for Coca-Cola, PepsiCo and other drinks companies, criticism of bottled water on environmental grounds has quieted. Last year, Atlanta-based Coca-Cola Co. unveiled a new plastic bottle made partially from plants. The Dasani bottle, made from a blend of petroleum-based materials and up to 30 percent plant-based materials, is now rolling out in select markets. The Eco-Fina half-liter bottle for PepsiCo's Aquafina brand uses 50 percent less plastic than a similar package made in 2002. Meanwhile, Nestle Waters is touting its next-generation Eco-Shape bottle as one of the lightest half-liter plastic bottles available today. It weighs 9.3 grams on average and uses about 25 percent less plastic than the Eco-Shape bottle launched in 2007. It uses 60 percent less plastic than the company's original half-liter bottle from the mid-1990s. At around 10 grams, some water bottles on the market today are 'practically water balloons,' said Tom Lauria, International Bottled Water Association spokesman. Niagara Bottling LLC, which bills itself as the largest private label water producer in America, sees 'lightweighting' as a way to keep its prices low. Niagara now has the fastest lines and the lightest bottles in the industry, chief executive Andy Peykoff boasted last month at a Beverage Digest conference in New York. 'There is a growing long-term sensitivity to wastefulness,' beverage consultant Tom Pirko said. 'It is now part of the menu of consumer psychology. Almost nobody is as wasteful as they once were. The ship is definitely headed toward sustainability.' Jeremiah McWilliams writes for The Atlanta Journal-Constitution. E-mail: Jeremiah.McWilliams@ajc.com. 