I have a friend who says you should never drink the water on a plane and you should pass on ice cubes as well. He claims that they reuse the water tanks and never clean them so they could be infested with bacteria. I found an article from Travel + Leisure reporting on which airlines have the cleanest and which have the dirtiest water (from an analysis performed by the Center for Food as Medicine and Longevity).
According to the study, American Airlines ranked lowest among major U.S. carriers for in-flight water quality. In the ranking American sat at the bottom with a Grade D score, indicating water that failed to meet strong standards under the EPA’s Aircraft Drinking Water Rule.
Other major airlines that scored poorly included:
- JetBlue — also Grade D, signaling water quality concerns.
- Spirit Airlines — not far behind, likewise receiving a D grade.
These lower scores reflect issues such as higher levels of contaminants, more frequent violations, and less consistent cleaning and flushing of water systems. With these airlines, you should buy your own water at the airport!!
On the flip side, some airlines performed surprisingly well:
- Delta Air Lines topped the list with a perfect score—earning a Grade A for clean, safe in-flight water.
- Frontier Airlines, despite its budget profile, also earned an A, narrowly trailing Delta.
- Alaska Airlines and Allegiant Air received B grades, indicating generally good water quality.
Other mid-tier carriers such as Southwest and Hawaiian Airlines landed in the C range.
✈️ What’s Behind the Rankings?
The study’s methodology evaluated airlines on key water safety factors, including:
- Number of violations per aircraft
- Contaminant levels (such as E. coli)
- Frequency of disinfection and flushing
- Public health notifications
Airlines that rigorously maintain and clean water systems tend to score better. In contrast, those that do not consistently flush tanks or monitor water quality closely see lower scores.
💡 Tips for Travelers
Whether you’re flying for business or pleasure, there are simple precautions you can take to protect yourself:
✔ Drink sealed bottled water rather than water from the tap or coffee/tea made onboard.
✔ Buy your own bottled water at one of the airports shops. You’ll avoid relying on aircraft water altogether.
✔ Use hand sanitizer rather than washing hands in airplane bathrooms, where water quality may be questionable.
Experts in the study even recommend skipping hot drinks made onboard since they’re often mixed with tap water.