I'm on record as recommending that you avoid bottled water largely because you don't know if the water you're drinking from that bottle really comes from a healthy source or from the tap. Unless, of course, it's absolutely necessary.

Today's warning from the EPA about the poor water quality on a surprising number of drinking water systems on domestic and foreign commercial aircraft randomly tested over the past two months is probably one of those exceptions. Those drinking systems on commercial airplanes were grounded because they were contaminated with potentially harmful bacteria.

In fact, EPA suggested passengers with compromised immune systems -- usually the elderly, very young or those who are sick -- not wash with water from the tap or drink beverages that are brewed or mixed on flights, like coffee or tea.

Airlines defended aircraft water quality and said the government's conclusions were drawn from samples taken from only a fraction of the thousands of aircraft in the fleet.

But EPA had good reasons to worry. Look what they found:

• More than 12 percent, or 20 aircraft, tested positively for total coliform bacteria.
• Water on two planes contained E.coli, a potentially deadly bacteria commonly associated with food poisoning.

Total coliform and E.coli is an indicator that other pathogens may be present.

Yahoo News September 20, 2004