The Environmental Protection Agency ordered U.S. airlines to inspect the water systems on each aircraft in a final rule issued Tuesday.
U.S. airlines must have a sampling plan for coliforms (digestive-tract bacteria) and a water system operation and maintenance plan within 18 months for each existing aircraft and within the first calendar quarter of initial operations for new aircraft.
Airlines must conduct a self-inspection of each aircraft’s water system at least once every five calendar years.
They also must perform routine disinfections and flushes of aircraft water systems and routinely test for coliforms. Any coliform-positive sample must be further analyzed for the presence of E. coli.
In addition, the EPA said it may conduct compliance audits.
The new rule provides details about corrective action, public notification and monitoring.
"This rule is a significant step forward in protecting people's health when they travel," said Peter Silva, assistant administrator for the EPA’s Office of Water. "EPA has taken this step to make sure the public has drinking water that meets standards, both in the air and on the ground."
Airlines are already complying with similar standards on inspections and sampling under interim orders issued by the EPA in 2005. The interim orders were given in response to tests that showed bacteria in some aircraft water samples.
The EPA's final rule applies to onboard water systems only. The Food and Drug Administration is responsible for regulating airport water systems.
Click here for more information about the EPA's final rule.