In the last 18 months, bottled water has come under some of the most virulent attacks experienced by any consumable products.

It’s been denounced as unnecessary, expensive and wasteful by newspaper op-ed writers, bloggers and politicians. The U.S. Conference of Mayors passed a resolution in June criticizing it, and municipalities in America and elsewhere have banned it from their offices.

Packaging is one of the biggest points of contention, with the Conference of Mayors resolution stating that “plastic water bottles are one of the fastest growing sources of municipal waste.” According to one estimate, 40 million plastic water bottles are discarded daily.

The industry is aggressively defending itself on two fronts. It emphasizes that the polyethylene terephthalate (PET) used in most water bottles is the most easily recyclable of all plastics. And it’s lightweighting those bottles, to the point where some of them feel more like water balloons.   F&BP

Nestlé SA

Nestlé Waters has been very aggressive in material reduction, downgauging its single-serve water progressively over the last few years. Its newest half-liter bottle, Eco-Shape, has 30% less plastic than the average water bottle of comparable volume. The company has a big portfolio of packaging sizes, ranging from 11-ounce Aquapods to 5-gallon water-cooler bottles.

Groupe Danone

Danone, producer of Evian, has also been actively lightweighting its polyethylene terephthalate (PET) bottles. Danone has pledged to start producing 750-milliliter and 1-liter bottles with up to 25% post-consumer recycled PET. Evian also is known for its artistic, limited-edition bottle designs, including teardrop shaped glass and artist-designed labeling.

Coca-Cola

Coca-Cola greatly augmented its water portfolio with last year’s $4 billion purchase of Glacéau’s vitaminwater. Its Dasani was the top-selling U.S. bottled water brand in 2007, with a 14% market share. Water bottles will form a big part of Coke’s drive to step up its PET recycling, which includes building what is billed as the world’s biggest bottle-to-bottle PET recycling plant.