If you’re on a red-eye flight and feeling exhausted, think twice about ordering that cup of coffee before your next layover. Flight attendants usually refuse to drink any drink made from tap water on board, which includes plain coffee and tea. Why? The reason might alarm you.
In an interview with Business Insider, an anonymous flight attendant confirmed that even though the water tanks are cleaned from time to time, they aren’t necessarily cleaned very often — and therefore the water can usually get pretty dirty and stale. An study by the Environmental Protection Agency found that one in eight airplanes nationwide do not meet their standards for water safety, and that 12 percent of commercial planes tested positive for fecal bacteria in the tap water supply.
The Association of Flight Attendants-CWA confirmed with Business Insider that they do not believe the current regulations “go far enough” to ensure water safety. However, the trade association and lobbying group Airlines for America, which represents many large airlines, defended their water supply and hygienic standards:
“Airlines work closely with the Environmental Protection Agency to ensure that water received from municipalities for onboard systems is safe and to maintain that safety by following rigorous sampling and management requirements once received,” they told Business Insider in a statement. However, Airlines for America also added that “bottled water” is available to “meet customer preferences.”
Rancid tap water is just the tip of the in-flight iceberg. Here are 13 more Things Your Flight Attendant Won’t Tell You.