Why Airline Drinking Water Quality Varies Significantly Across Carriers

A new study reveals significant differences in the airline drinking water quality provided to passengers and crew. This variability raises concerns about passenger health and safety across the air travel industry. The 2026 Airline Water Study, conducted by the Center for Food as Medicine and Longevity, found that many carriers may be providing unhealthy water. This practice could violate the federal government's ADWR, or Aircraft Drinking Water Rule.

Regulatory Compliance and Findings

The Aircraft Drinking Water Rule (ADWR) was implemented in 2011. Its primary goal is ensuring a safe drinking water supply on all aircraft. The US Environmental Protection Agency (EPA) is the key regulator for onboard water systems. The Food and Drug Administration (FDA) regulates the water sources at airport watering points. The study analyzed compliance data from October 2022 through September 2025. It ranked 10 major and 11 regional US airlines based on five weighted criteria. These criteria included violations for E. coli and the frequency of tank disinfection.

The Water Safety Scorecard

The research assigned a “Water Safety Score” from 0.00 to 5.00. A score of 3.5 or better indicates relatively safe, clean water. Delta Air Lines and Frontier Airlines earned the top scores. Delta Air Lines achieved a perfect 5.00, earning a Grade A. Alaska Airlines followed closely in third place.

Conversely, some major carriers scored poorly. American Airlines received the lowest score among major airlines at 1.75 (Grade D). JetBlue was also identified as having one of the worst scores. The report noted that nearly all regional airlines need significant improvement. The sole exception among regional carriers was GoJet Airlines.

In total, researchers analyzed 35,674 water samples. Of these, 2.66% tested positive for total coliform bacteria. Total coliform bacteria is an indicator of potential contamination. The study also identified 32 breaches for E. coli.

Challenges in Water Tank Cleanliness

The ADWR mandates specific maintenance for water tank cleanliness. Airlines must take water samples to test for coliform bacteria and E. coli. They must also disinfect and flush the water tank. This procedure must be done four times annually. Alternatively, an airline can disinfect once per year. However, this option requires monthly testing instead. Failure to comply triggers corrective actions. This includes restricting public access to the water system.

Aircraft manufacturers like Boeing design these systems. However, the responsibility for maintenance falls entirely on the air carriers. The logistics of loading water at multiple global airports presents a constant challenge. This is a critical factor in maintaining aviation health regulations.

Industry Impact and Regulatory Oversight

Contaminated water poses a serious health risk. Contaminants can range from bacteria to heavy metals. For frequent flyers, this impacts gut health and overall metabolic function. The findings are relevant globally, not just in the US. Many international locations lack comparable oversight. The European Union Aviation Safety Agency (EASA) and the US Federal Aviation Administration (FAA) must work with the EPA on these issues. Greater transparency and uniform standards are needed.

One key finding was the lack of enforcement. The US Environmental Protection Agency rarely levies civil penalties. This is despite numerous documented ADWR violations. This lack of consequence may reduce the incentive for airlines to prioritize system maintenance. The study urges passengers to reduce risk. Recommendations include choosing sealed bottled drinks. Passengers should also avoid coffee or tea made with onboard water. This story is important commercial aviation news and highlights a major operational challenge. Read more industry updates at flying.flights. The data underscores the need for airlines to invest in advanced filtration. This will ensure consistent provision of truly safe drinking water.