BEDFORD HILLS, N.Y. — Bottled water is on the fast track for growth. For the first time, Americans on average drank more bottled water in 2006 than milk and almost as much as beer, according to Beverage Digest. Average per capita consumption of bottled water grew from 11 to 21 gallons between 1996 and 2006. Meanwhile, milk consumption dropped from 22.7 to 19.5 gallons during the same period, while beer consumption was stable at 21.8 gallons. If the trend continues, bottled water consumption may surpass that of tap water in a few years.