U.S. Airline Drinking Water Safety Scores, 2026 Study
Key points
- A New York based nonprofit scored 21 airlines for onboard water safety using federal Aircraft Drinking Water Rule compliance data
- Delta and Frontier scored highest among major airlines, while American and JetBlue scored lowest in the study
- GoJet led regional airlines, while Mesa scored lowest, and most regionals fell below the study's safer threshold
- The study says federal enforcement is weak, and civil penalties for rule violations appear rare
- Traveler guidance is to use sealed bottled water, skip coffee and tea made onboard, and use alcohol based hand sanitizer instead of lavatory water
Impact
- Onboard Drinks And Ice
- Plan to rely on sealed bottled water and skip coffee, tea, and ice if you want to minimize exposure to aircraft tank water
- Regional Jet Connections
- If your itinerary relies on regional affiliates, treat onboard water as higher risk, and pack your own hydration plan for tight connection days
- Health And Hygiene Choices
- Use alcohol based hand sanitizer when sinks are questionable, and avoid brushing teeth or rinsing contact lenses with aircraft water
- What To Pack For Flights
- Bring an empty bottle to fill post security, plus sanitizer, and consider buying sealed water before boarding on long flights
- Regulatory Oversight
- Airlines are required to sample, disinfect, and flush systems, but the study argues enforcement gaps can still leave quality uneven across carriers
A New York based nonprofit, the Center for Food as Medicine and Longevity, released its 2026 Airline Water Study, ranking 10 major and 11 regional U.S. airlines on the safety of drinking water served onboard. The study assigns each carrier a 0.00 to 5.00 Water Safety Score using five weighted criteria tied to federal Aircraft Drinking Water Rule compliance, including violations per aircraft, E. coli maximum contaminant level violations, indicator positive rates, public notices, and how often aircraft water systems are disinfected and flushed. If you fly frequently, or you depend on regional connections, the results matter because onboard water is used not only for drinking, but also for coffee and tea service, ice, and lavatory sinks.
The U.S. airline drinking water safety picture is uneven in the study's scoring. Delta Air Lines (5.00) and Frontier Airlines (4.80) earned Grade A scores, Alaska Airlines (3.85) and Allegiant Air (3.65) landed in Grade B, and Southwest (3.30), Hawaiian (3.15), and United (2.70) sat in the middle of the pack. Spirit (2.05), JetBlue (1.80), and American (1.75) ranked lowest among major airlines. On the regional side, GoJet (3.85) was the only carrier in the study's Grade B range, while most regionals scored in the Grade C to D bands, and Mesa (1.35) was the lowest at Grade F.
Who Is Affected
Passengers on U.S. carriers that operate aircraft with onboard drinking water systems are the primary audience for these findings, especially travelers who routinely accept tap water, coffee, tea, or ice inflight. The impact is amplified for travelers on regional jets, where water system maintenance, turnaround pressures, and third party servicing can vary widely, and where the study's results show most carriers below the score that the Center treats as relatively safe.
Travel advisors and corporate travel managers should also pay attention, because a small onboard health issue can turn into a trip disruption. If a traveler gets sick mid trip, the downstream costs show up fast, missed meetings, shortened itineraries, extra hotel nights, and last minute rebooking. Airlines and airports are affected indirectly too, because when passengers shift to buying sealed water in terminals, onboard beverage attachment rates can drop, and cabin crews may see more questions about what is safe to consume.
What Travelers Should Do
Make your next flight simple. Use only sealed bottled water for drinking, and assume that coffee and tea are made with aircraft tank water unless the crew can confirm otherwise. If you want hot drinks, consider buying them in the terminal after security and carrying them onboard, and skip ice in cups that are filled onboard.
Set a decision threshold based on flight length and complexity. For a short hop with no onward connections, your main goal is avoiding avoidable exposure, so sealed water and sanitizer usually cover it. For long haul travel, or for itineraries with tight connections where getting sick would blow up plans, tighten the standard further, fill a bottle after security, carry backup hydration, and treat onboard water as non essential even if the airline offers it.
Over the next 24 to 72 hours, monitor airline updates only if you see unusual cues inflight, such as non potable notices, disabled sinks, or crew announcements about water restrictions, because those can indicate a recent positive sample or a maintenance event under the rule. If you see a posted notice, take it literally, avoid using taps for drinking, teeth brushing, or hand washing, and use alcohol based hand sanitizer until you have access to clean running water off the aircraft.
How It Works
The federal Aircraft Drinking Water Rule requires airlines to manage aircraft water systems as regulated public water systems, including routine sampling for total coliform bacteria, defined corrective actions when samples are positive, and required public notification when passenger access is restricted or when required actions are missed. Under the rule's framework, a positive coliform result triggers follow up testing for E. coli, and airlines may need to disinfect and flush the system or shut it down depending on findings and timelines.
The travel system ripple starts at the source, the aircraft water tank and the equipment that services it. Aircraft take on water from many airports, sometimes multiple times per day, and the quality onboard can depend on the cleanliness of water cabinets, trucks, carts, and hoses used during servicing, not just the originating municipal supply. The next ripple is in the cabin, because the same water system supports beverage preparation and lavatory sinks, so a problem touches both consumption and hygiene behaviors on every flight that tail operates. The second order effects show up across connections and trip plans, as travelers respond by buying sealed water in terminals, skipping inflight service, and relying more on sanitizer, which changes what they need to carry, how they manage long connection days, and how they reduce the risk of a minor illness becoming a major itinerary disruption.
The study also highlights an oversight concern. While the Environmental Protection Agency provides the compliance system and public reporting for the rule, the Center argues that civil penalties for violations appear rare, which can leave travelers facing inconsistent real world outcomes even under a federal standard.