Bottled water is a huge industry, and a profitable one. Last year it netted $10 billion in the US, but there are signs that the industry is slowing. Restaurants have turned away from pricey bottled water, and consumers have returned to tap water to save money. Nestlé is a huge player in the sector: its bevy of brands, which includes Perrier and Poland Spring, captures about 40% of the market. But recently Nestlé’s sales have taken a hit.