Airline tap water (so, tea and coffee, too) is “filthy,” says one flight attendant

Precautions abound for ensuring a healthy flight—like not falling asleep during takeoff or landing to protect your ears. Now there’s a reason to avoid inflight water: One flight attendant opened up about the cleanliness of the tap served onboard. Spoiler alert: She said it’s so dirty, she won’t even take a sip.

“I just don’t always trust the cleanliness of the aircraft,” a flight attendant of a major airline for 20 years named Jenny told Time.

A 2015 study found 1 in every 8 planes don’t meet the standards for water—that means everything made from it is affected, including tea and coffee.

And her stance isn’t so shocking: A 2015 study found 1 in every 8 planes don’t meet the standards for potable water, which is news that affects everything made using the H2O as well, including tea and coffee. And even though major airlines claim they meet the standards, water tanks are reportedly rarely cleaned—and that’s nothing new. In 2004, it was discovered that 15 percent of the water samples taken from 327 planes contained coliform, the bacteria found in feces. Um, ew?

In light of the completely filthy findings, Time reports that airlines have had to clean out their tanks and make sure their water is free of bacteria a minimum of once a year since 2011. But…later tests revealed the tap water still remains dirty.

“We only truly clean once a year,” Jenny said. “I’ve been on planes that are constantly running. It’s almost like a subway in New York. We know things are dirty in the system, and it takes a little while to clean it out.” Again: Um, ew?

So maybe until airlines start putting a bigger focus on the cleanliness of their water, stick to the bottled stuff and sparkling cans instead.

Here’s how 10 wellness pros stay healthy while traveling. And by healthy, that also means sane.