The 2026 Airline Water Study conducted by the Center for Food as Medicine and Longevity has revealed notable disparities in water quality across numerous airlines. The research, spanning three years from late 2022 to late 2025, tested water samples from 21 airlines—comprising both major and regional carriers—for bacteria indicators such as coliform and E. coli. The results showed that only Delta and Frontier received a top grade of A, while American Airlines ranked at the bottom with a D, indicating poor water safety standards. Regional carriers were generally found to have worse results than national airlines.
The study highlighted that out of over 35,000 samples, nearly 950 tested positive for coliform bacteria, with violations mainly tied to E. coli maximum contaminant levels. Based on these findings, the researchers recommended that passengers should only consume bottled water on flights and avoid washing hands in onboard bathrooms due to water contamination concerns. Additionally, they advised against drinking coffee and tea made with onboard tap water, emphasizing the risk of ingesting potentially contaminated water during flights.
While the findings raise health and safety concerns, some travelers, including the author, expressed reluctance to change their routines, especially since coffee drinking is perceived as an essential part of airline travel. The study’s concluding advice is to avoid using tap water for beverages or hygiene purposes onboard when possible, thus highlighting ongoing safety issues with airline water supplies.
