The Center for Food as Medicine and Longevity reviewed more than 35,000 aircraft water samples from 2022–2025 and found 32 E. coli violations affecting 21 airlines. A score of 3.5 or higher was considered relatively safe; Delta and Alaska ranked highest while Spirit, JetBlue and American ranked lowest. Researchers say compliance with federal rules should be a minimum, and experts recommend filling bottles after security, buying sealed water and using hand sanitizer instead of airplane tap water.
Study Finds 32 E. coli Violations in Airline Water Systems — What Travelers Should Do
Flight passengers warned as airline water systems test positive for contamination
A new analysis of aircraft water systems raises concerns about onboard tap water safety and offers practical tips for travelers. The Center for Food as Medicine and Longevity, a New York City research group, reviewed more than 35,000 water samples collected from airlines over a three-year period (2022–2025).
The Center for Food as Medicine and Longevity, based in New York City, recently reviewed airline water systems over a three-year period.(iStock)
What the Review Found
The study evaluated both major and regional carriers, scoring them on contamination violations, detections of E. coli, maintenance practices and the frequency of water-system cleaning. Investigators set a threshold score of 3.5 or higher as indicative of relatively safe onboard water; scores below that were flagged as potentially unhealthy.
Results indicated that Delta Air Lines earned the strongest marks for water safety, with Alaska Airlines also performing well.
Across the review period analysts recorded 32 E. coli violations affecting 21 different airlines. Delta Air Lines and Alaska Airlines earned the highest water-safety scores, while Spirit Airlines, JetBlue and American Airlines were ranked toward the bottom of the list.
Rather than drinking water provided on the flight, passengers may reduce risk by filling reusable bottles after clearing security or purchasing bottled water, experts advise.
Expert Views and Recommendations
"Compliance should be the floor, not the ceiling," said Charles Platkin, the researcher who led the analysis, noting that much of the underlying data used by carriers can be self-reported.
Registered dietitian Nicolette M. Pace advised simple, practical precautions: fill reusable bottles at airport water stations after clearing security, purchase sealed bottled water on board, and use hand sanitizer rather than washing with airplane tap water when possible. She warned that even low-level contamination can upset digestion and weaken immune defenses, and urged extra caution for children, older adults and people with weakened immune systems.
The analysis placed Spirit Airlines, JetBlue and American Airlines at the bottom for water safety.
Airlines' Responses
Several carriers contacted for comment said their potable water programs comply with the Environmental Protection Agency’s Aircraft Drinking Water Rule and undergo routine testing and maintenance. Spirit Airlines emphasized progress in recent years and ongoing reviews of procedures. American Airlines said a recent EPA audit found no significant issues and that it is evaluating the study’s methodology. Delta highlighted its commitment to safe, potable water, and JetBlue said it serves bottled purified water on all flights and follows EPA, FDA and FAA guidance for coffee and tea preparation.
Practical Tips for Travelers
- Fill a reusable bottle at a trusted water source after passing security.
- Buy sealed bottled water when boarding if you have concerns.
- Use alcohol-based hand sanitizer instead of rinsing with onboard tap water.
- If you have a weakened immune system, consider avoiding tap water on flights entirely.
While airlines report compliance with federal rules, the study’s authors argue that meeting minimum standards should be the baseline — and that passengers reasonably expect safe water for drinking and handwashing on every flight.
Help us improve.
