What Canadian airlines are saying after study claims water on many U.S. flights 'potentially unhealthy'

Passengers can be at ease while travelling on Canadian carriers, some of the country’s major airlines say, after a new study claims many U.S. airlines are using “potentially unhealthy water” for coffee, tea and hand-washing.

Air Canada, Flair Airlines, and Air Transat told National Post that they adhere to water safety guidelines. (WestJet did not immediately respond to National Post’s request.)

For the 2026 Airline Water Study , researchers tested water provided on flights between October 2022 and September 2025. They observed 10 major airlines and 11 regional airlines. The findings by Center for Food as Medicine & Longevity were released in late December.

“Airlines often respond to our findings by saying they comply with U.S. Environmental Protection Agency (EPA) guidelines. But the public should understand that all of this data is self-reported by the airlines, and enforcement depends on their accurate reporting and follow-through,” Dr. Charles Platkin, the study’s author and the executive director of the Center for Food as Medicine & Longevity, told National Post.

“More importantly, compliance should be the floor, not the ceiling — and this study examines whether airlines are actually doing enough to protect passengers and treat them with care while onboard. What does care look like? It means passengers can drink a cup of coffee or tea without hesitation, wash their hands with confidence, and trust that clean, safe water is available throughout their flight.”

Researchers warned travellers to “never drink any water onboard that isn’t in a sealed bottle,” and to stay away from coffee or tea offered on flights. They also said that an alcohol-based sanitizer should be used instead of washing hands in an airplane bathroom.

“Airplane drinking water is stored in onboard tanks and distributed through plumbing to galleys and lavatories,” the study says. “These systems can face stagnation, temperature fluctuation, and maintenance complexity, all of which can contribute to microbial contamination risk or persistent hygiene challenges.”

Airlines were given a score out of five followed by a letter grade based on a variety of factors, including whether or not coliform bacteria or E. coli were found in the water, and the frequency of disinfecting and flushing an aircraft’s water tank. Coliform can be an indicator that “suggests potential fecal contamination or inadequate disinfection.” A grade of A or B indicated that “an airline has relatively safe, clean water,” according to researchers.

The highest scoring major airlines were Delta Air Lines and Frontier Airlines, which both received a Grade A.

Following close behind were Alaska Airlines and Allegiant Air, which both received Grade B. Trailing further behind were the major airlines that received a Grade C, which included Southwest Airlines, Hawaiian Airlines and United Airlines.

But the lowest scoring major airlines, according to the study, were Spirit Airlines, JetBlue, and American Airlines. They all received a Grade D.

Regional airlines in the study struggled in comparison to the major airlines, with nearly all of them — except for GoJet Airline — needing to improve their water safety.

At the top of the list, GoJet received a Grade B. Meanwhile, Piedmont Airlines, Sun Country Airlines and Endeavor Air received C grades.

The Grade D group was the largest for the regional carriers, featuring SkyWest Airlines, Envoy Air, PSA Airlines, Air Wisconsin Airlines, Republic Airways and CommuteAir. The lowest grade received by any airline across the entire study was an F, given to Mesa Airlines.

Canadian airlines, meanwhile, reassured travellers of their water safety standards. Wes Cruickshank, who is the VP of Maintenance at Flair Airlines, said that Flair follows “rigorous standards for onboard water safety.”

“All potable water is sourced from approved airport facilities, routinely tested, and maintained through regular sanitation, with aircraft potable water systems. Additionally, Flair has a Potable Water Control Program,” he said. “Onboard coffee and tea are instant and prepared fresh using potable water, and bottled water is available for purchase onboard.”

A spokesperson for Air Transat said that the potable water on its aircrafts is safe and “regularly tested to meet strict standards, in full compliance with Canadian and provincial regulations.”

A spokesperson for Air Canada told National Post that Canadian airlines are governed by the Department of Health Act’s Potable Water on Board Trains, Vessels, Aircraft and Buses Regulations.”

“Our potable water management program, which exceeds the requirements governing the airline industry, is regularly audited by the Public Health Agency of Canada,” said the airline.

As of 2011, the Aircraft Drinking Water Rule came into effect in the United States, requiring airlines to test water tanks for coliform bacteria and possible E. coli, the study explains. There were a total of 35,674 sample locations tested for coliform across all of the airlines in the study. “Of these, 949 locations (2.66 per cent) tested positive for total coliform,” according to the study. E. coli was present at 50 locations.

Platkin said access to clean water isn’t a luxury, it’s a basic expectation. “And while getting someone safely from point A to point B is essential, how passengers are treated during that journey matters too,” he said. “Airlines should focus not only on meeting minimum requirements, but on doing better and showing greater care for the people they serve. Passengers deserve that.”

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