Which US Airlines Failed Water Safety Tests, Putting Passengers at Risk?
Key Points
- 1The 2026 Airline Water Study of 35,674 samples found 32 E. coli violations across 21 major and regional airlines between 2022 and 2025.
- 2Delta Air Lines and Alaska Airlines received the highest water safety scores, while Spirit Airlines, JetBlue, and American Airlines ranked lowest.
- 3Experts recommend passengers use bottled water for drinking and hand sanitizer over onboard tap water for handwashing.
- 4The EPA's Aircraft Drinking Water Rule (ADWR) requires disinfection and flushing of water tanks at least one to four times per year.
A new analysis suggests that airline water contamination remains a significant concern for flight passenger water safety. The study, conducted by the Center for Food as Medicine and Longevity, reviewed over 35,000 water samples. These samples were collected from various airline water systems between October 2022 and September 2025.
Researchers evaluated 10 major and 11 regional carriers. They assigned each a Water Safety Score from 0.00 to 5.00. A score of 3.5 or higher indicated relatively safe onboard water. The analysis found 32 E. coli violations airlines across the 21 carriers studied.
Water Safety Rankings and Findings
Delta Air Lines received the highest scores for water safety. Alaska Airlines and Frontier Airlines also ranked well in the study. Conversely, Spirit Airlines, JetBlue, and American Airlines placed at the bottom of the rankings. The presence of E. coli violations was the single largest factor lowering an airline's score. The study noted that 949 of the 35,674 samples tested positive for coliform bacteria, which is an indicator of potential contamination.
Charles Platkin, the study's lead researcher, emphasized that compliance with federal rules is the minimum standard. He stated that airlines should aim higher than the basic requirements. "Compliance should be the floor, not the ceiling," Platkin noted. He added that much of the regulatory data is self-reported by the airlines.
Regulatory Landscape and Airline Response
Potable water on U.S. airlines is jointly regulated. The Environmental Protection Agency (EPA), the Food and Drug Administration (FDA), and the Federal Aviation Administration (FAA) share oversight. The EPA Aircraft Drinking Water Rule (ADWR) was implemented in 2011. This rule requires air carriers to provide safe drinking water.
The ADWR mandates regular testing for coliform bacteria. It also requires disinfection and flushing (D&F) of water tanks. Depending on the sampling frequency, D&F must occur at least one to four times per year.
Carrier Statements
Delta Air Lines (which ranked highest) affirmed its commitment to quality. The airline stated that its high ranking reflects this commitment.
American Airlines told reporters its potable water program fully complies with EPA requirements. The carrier is reviewing the study's methodology. Spirit Airlines also confirmed its extensive testing and maintenance program. Spirit stated its procedures comply with the EPA's ADWR.
JetBlue noted that safety is its primary responsibility. The airline serves bottled purified drinking water on all flights. JetBlue follows processes from the EPA, FDA, and FAA for coffee and tea preparation.
Passenger Health and Precautionary Measures
The findings highlight the need for in-flight health precautions by passengers. Consuming contaminated water, even at low levels, can disrupt digestion. It can also weaken immune defenses. This risk is especially important for children and older adults.
Experts recommend simple steps to reduce risk:
- Choose bottled water over tap for all drinking purposes.
- Fill reusable bottles after clearing airport security.
- Use hand sanitizer instead of washing hands with commercial aviation water systems tap water.
These precautions help passengers ensure their own safety. They are necessary until all airlines consistently exceed minimum federal standards. The study serves as a critical reminder. Water quality varies sharply across different carriers.
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