Thinking about asking for coffee or tea on a plane? Think again. According to a study from Hunter College’s NYC Food Policy Center, airplane water tanks on planes are poorly maintained, which could result in toxic bacteria being found in airline beverages. The study of 11 air carriers, including JetBlue and Delta, analyzed water tank maintenance procedures.

“Planes come in, [and the tanks are] not being emptied and cleaned because there is no time for that. The water tank is being filled on top [after] each usage. Whatever would be on the bottom stays there and sits there,” Charles Platkin, a professor of nutrition and the executive director of the Food Policy Center, told The New York Post.


Standards for drinking water on US flights are set by the EPA’s aircraft drinking water rule, which depends on information supplied by the airline industry and requires water tanks to be cleaned a mere four times a year.

“[The rule] was instituted because there were issues with coliform, which is a broad class of bacteria. I don’t want to freak anybody out, but it’s feces. [In 2004,] the EPA did a test of airlines and found 15 percent of the aircraft tested positive for coliform,” says Platkin. Also, a 2015 study of airline water quality reported in the International Journal of Environmental Research and Public Health revealed that the water tanks are “conducive for microbial growth.”

Still, even after new regulations, a year after the new standards were implemented, one out of every ten airplanes still tested positive for the presence of coliform in their water. The Airline Food Study released this year revealed that not much has improved. Water tanks still go uncleaned for extended periods of time.

Delta and United say they use a high-tech ozone disinfection process four times a year to clean their water tanks. A spokesperson for an airline trade group told the LA Times that “rigorous sampling and management requirements” are regularly met. However, Platkin believes that the self-reporting “sends up a red flag.”

Given that airlines are routinely streamlining procedures to get planes in the air, Platkin wonders if water potability is high on the list of priorities. “They barely clean the planes in my opinion. I’m sure something that’s hidden like the water is something that’s not a huge priority.”

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To avoid infection with E. coli and other pathogens, avoid brewed airline beverages, stick to bottled water and refreshments and skip the ice in your drink. It is also essential to use hand sanitizer after coming into contact with hard surfaces or using the restroom. Platkin says that “it’s good to bring hand sanitizer just to be on the safe side until this is all sorted out and we look into it a little deeper.”