Passenger aircraft carry tanks of drinking water for use by crew and passengers in flight. The source of drinking water on planes usually is the municipal water supply of the airport where the water is boarded. Water is loaded into aircraft tanks via pipes and hoses from a public water source, or from water tanker trucks.
In the United States, several government agencies share responsibility for the safety of drinking water on airliners.
The Federal Aviation Administration (FAA) oversees maintenance for all parts of the aircraft, including the potable water system.
The Food and Drug Administration (FDA) has jurisdiction over "culinary water" - ice, for example - and the pipes, tankers, or other points at which aircraft obtain water at airports.
The Environmental Protection Agency (EPA) regulates water quality in public water systems, thus it regulates the systems that supply water to airports. EPA also is responsible for the safety of the drinking water on board the aircraft.
Over a period of several months in late 2004, the United States Environmental Protection Agency (EPA) carried out water quality sampling on commercial passenger aircraft. They tested water from galley taps, water fountains, and lavatory faucets.
In two rounds of sampling, a total of 327 randomly selected domestic and international passenger aircraft were sampled. Of those, 49 aircraft (about 15%) were found to be positive for coliform bacteria.