In the past, I’ve covered the topic of whether it’s gross to drink airplane coffee, given that it’s brewed with water from the aircraft’s tanks. One certainly wonders how clean all of those systems are. Along those lines, an interesting study has just been released, which might make you think differently about how you use water on planes… at least on some airlines.
In this post:
Study ranks water safety across several airlines
The Center for Food as Medicine and Longevity has released an airline water study, which reveals that the quality of water varies significantly by airline, and claims that many airlines provide passengers with potentially unhealthy water. This is specifically in reference to aircraft tank water, which is used in the lavatories, and to brew coffee and for hot water.
Before we discuss the relative airline rankings, let me share the recommendations that are provided, in order to be “extra safe,” as it’s described:
- NEVER drink any water onboard that isn’t in a sealed bottle
- Do not drink coffee or tea onboard
- Do not wash your hands in the bathroom; use alcohol-based hand sanitizer containing at least 60% alcohol instead
This study ranked the quality of water provided in the tanks onboard flights, during a three year study period, from October 2022 through September 2025, and used over 35,000 samples. Each airline was given a “Water Safety Score” (ranging from 0.00 to 5.00), based on five weighted criteria.
These include violations per aircraft, maximum contaminant level violations for E. coli, indicator-positive rates, public notices, and disinfecting and flushing frequency. A score of 3.50 or better indicates that the airline has relatively safe, clean water, and earns a Grade A or B.
So, how do the major US airlines compare? According to the study, here’s how each airline was graded, ranked from best to worst:
- Delta Air Lines: 5.00 (Grade A)
- Frontier Airlines: 4.80 (Grade A)
- Alaska Airlines: 3.85 (Grade B)
- Allegiant Air: 3.65 (Grade B)
- Southwest Airlines: 3.30 (Grade C)
- Hawaiian Airlines: 3.15 (Grade C)
- United Airlines: 2.70 (Grade C)
- Spirit Airlines: 2.05 (Grade D)
- JetBlue: 1.80 (Grade D)
- American Airlines: 1.75 (Grade D)
My take on this study about airplane tank water
I don’t think any of us expect the water in airplane tanks to be particularly clean. However, at least personally, I am a bit surprised to see such a huge variance in terms of cleanliness between airlines. I suppose some airlines really do take this a lot more seriously than others?
Another thing I find interesting is that the Environmental Protection Agency (EPA) has an Aircraft Drinking Water Rule (ADWR), which despite the name, includes rules surrounding water in airplane tanks (even though all airlines make a point of noting it’s not potable).
The study slams the EPA for not enforcing its rules, and for only rarely issuing penalties for airlines that do a poor job following regulations. That seems like fair criticism, if the difference in water quality between airlines is really that extreme.
I find this study to be interesting, but what should we actually do with this information? Should we literally just not even wash our hands on any airline? Am I supposed to sacrifice my Emirates A380 first class showers?!? 😉
Even though I’m a selective germaphobe, I put this info in the category of “interesting” and “eek,” but I’m not sure it’ll really impact my decisions going forward.
I guess my uneducated take here is that there’s a difference between an interesting study that covers best practices, vs. something we should actually actively be concerned about. Billions of airline passengers are enplaned every year. How many people suffer any sort of negative results from drinking coffee or tea or washing their hands?
Of course I’d never just drink cold water from the plane’s tanks, but it doesn’t seem to me like anything to be particularly worried about. And I suppose if that’s the case, maybe I would’ve just been better off not knowing this, since American is the airline I fly most? After all, ignorance is bliss!
Bottom line
I don’t think anyone will be surprised to learn that the water in aircraft tanks isn’t consistently of great quality. Perhaps what’s most surprising is how big the variance is — among US airlines, Delta leads the pack, while American is in last pace (which, come to think of it…).
The study recommends never drinking water directly from the plane’s tanks (which is unarguably good advice), but also suggests not having airplane coffee or tea, and not even washing your hands on airplanes. Everyone can do with this information as they please…
What do you make of this study, and does it impact your approach to using water from airplane tanks?
Alex, I'll take things that never happened after washing hands with warm water and soap on an airplane for $500.
“Why aircraft water can be questionable:
On most commercial aircraft, the water you’d get from:
A. The lavatory tap.
B. Hot beverages (tea/coffee).
The water comes from onboard water tanks that are:
• Filled on the ground
• Stored for hours or days
• Connected to relatively complex plumbing.
While airlines are required to disinfect and test these systems, investigations and inspections over the years have found that:
...
“Why aircraft water can be questionable:
On most commercial aircraft, the water you’d get from:
A. The lavatory tap.
B. Hot beverages (tea/coffee).
The water comes from onboard water tanks that are:
• Filled on the ground
• Stored for hours or days
• Connected to relatively complex plumbing.
While airlines are required to disinfect and test these systems, investigations and inspections over the years have found that:
• Cleaning schedules vary by airline and aircraft.
• Tanks and pipes are harder to keep pristine than household plumbing
• Biofilm (bacterial buildup) can occur if maintenance slips.
This doesn’t mean the water is dangerous—but it does mean it’s not consistently fresh”.
"(even though all airlines make a point of noting it’s not potable)." If this is the case then why are airlines EVER serving water from the tank? Not being able to wash our hands? Seriously? so yea use the bathroom and go back to your seat without washing. That makes sense. We all know that seat isn't getting a full cleaning before the next flight. Terrible advice telling people not to wash their hands. Just...
"(even though all airlines make a point of noting it’s not potable)." If this is the case then why are airlines EVER serving water from the tank? Not being able to wash our hands? Seriously? so yea use the bathroom and go back to your seat without washing. That makes sense. We all know that seat isn't getting a full cleaning before the next flight. Terrible advice telling people not to wash their hands. Just means way more germs for the next person. I would be interested if you find any information out there about water quality on international carriers . For example I have had jamaican blue mountain coffee on Singapore first class. I suspect they may not be pulling the water to make high end coffee out of their tank but who knows. Are there some airlines that make coffees and teas with bottled water? This is a useful article for travelers thank you.
“GreAAt is what we’re going for”
“You(r high chances of getting sick) are why we fly”
What a joke of an airline
glad you covered the article,
The point is not really whether you should drink water from airplanes or take a shower onboard (if you can find one) but that there is a difference in the compliance of US airlines.
and US airlines do not say that water is not potable specifically because of this rule. Airplane water is supposed to meet the same standards as water supplied from a public source on the ground.
There...
glad you covered the article,
The point is not really whether you should drink water from airplanes or take a shower onboard (if you can find one) but that there is a difference in the compliance of US airlines.
and US airlines do not say that water is not potable specifically because of this rule. Airplane water is supposed to meet the same standards as water supplied from a public source on the ground.
There is no other way to make hot beverages other than with water from the tanks of the aircraft; coffee makers have additional filters and if there were really a disease risk, it would be very obvious given how much coffee airlines serve.
The doctor is right below- wash with soap and water and then use sanitizer. And use hand lotion of your hands are dry and/or cracking.
"wash with soap and water"
It's not just wash with soap and water, but how you wash is vital.
I've seen people just wet their hands, do a quick lather and rinse.
Digging in to the study left me confident that drinking coffee and washing my hands is not an unsafe endeavor. Especially on an A graded airline. While I appreciate any intent to improve drinking water safety on air carriers I get the feeling there is some click baiting happening with a title using “Disgusting” in the article. The study explains the flushing procedures and lists actual instances per carrier, many had zero results for E...
Digging in to the study left me confident that drinking coffee and washing my hands is not an unsafe endeavor. Especially on an A graded airline. While I appreciate any intent to improve drinking water safety on air carriers I get the feeling there is some click baiting happening with a title using “Disgusting” in the article. The study explains the flushing procedures and lists actual instances per carrier, many had zero results for E Coli. Improvements to be made, sure. Weighing the cons of consuming plastics in bottle water, yep.
yea I am becoming more convinced that plastic water bottles aren't the safest either. Its just soo difficult to keep up with all the potential things that can cause issues.
I've drunk the water in the pitchers that the cabin crew serve aside from coffee and tea in all classes to rinsing my mouth from the tap after brushing my teeth.
And I'm still here, never got sick.
The best thing you can do is to take care of yourself in your day-to-day life by eating right, getting physical activity and focus on your mental well-being which a lot of people tend to overlook.
At...
I've drunk the water in the pitchers that the cabin crew serve aside from coffee and tea in all classes to rinsing my mouth from the tap after brushing my teeth.
And I'm still here, never got sick.
The best thing you can do is to take care of yourself in your day-to-day life by eating right, getting physical activity and focus on your mental well-being which a lot of people tend to overlook.
At the same time. it's 2026 already, so you would think that technology would be incorporated by now such as filtration systems, et.al.
I'm not disputing the findings but really curious, like you, as to how this can vary so much? Water at airports is all the same for everyone when filled into tanks. Is there a cleaning of these tanks and lines more at one airline versus another? That's the only thing I could imagine.
One thing: I would like to see which aircraft from each airline were utilized for the testing. If there are disparities in aircraft age or models where, say, Delta had a propensity of newer aircraft being tested versus American where they leaned more to older frames, that could prove a difference I assume. I doubt the water testing authorities are all that familiar with the difference between aircraft and how it might affect testing.
As a physician, I advocate you still wash your hands with soap and water, and then perhaps use hand sanitizer after if you wish. Norovirus and c diff are two examples of common pathogens that hand sanitizer alone won’t take care of.
Just curious what kind of doc are you as I've always had a curiosity in medicine especially in surgery; I always had a fascination with laparoscopy, robotics, and other advancements.
I use hand sanitizer as a last resort where there is no water source like going to a food court, that's where I tend to use Purell fragrance-fee hand sanitizing wipes. And I moisturize after.
Oh and btw, I never use those hand dryers! Paper...
Just curious what kind of doc are you as I've always had a curiosity in medicine especially in surgery; I always had a fascination with laparoscopy, robotics, and other advancements.
I use hand sanitizer as a last resort where there is no water source like going to a food court, that's where I tend to use Purell fragrance-fee hand sanitizing wipes. And I moisturize after.
Oh and btw, I never use those hand dryers! Paper towels are good enough for me, I use the paper towel to hold the door handle and throw it out.
This is good advice if you can do it--which almost nobody can. Actually washing hands, with soap, for the length of time needed to combat norovirus is rare in real life, and I think it's nearly impossible in an airplane sink with spring-loaded handles. There's even a recent trend toward removing hand-washing sinks from hospitals, because real-world sanitizer compliance is so much higher than real-world hand-washing compliance.
I hate to be fatalistic, but I think...
This is good advice if you can do it--which almost nobody can. Actually washing hands, with soap, for the length of time needed to combat norovirus is rare in real life, and I think it's nearly impossible in an airplane sink with spring-loaded handles. There's even a recent trend toward removing hand-washing sinks from hospitals, because real-world sanitizer compliance is so much higher than real-world hand-washing compliance.
I hate to be fatalistic, but I think defending yourself from norovirus in an airplane lav is pretty much impossible. (Well, maybe with careful use of disposable gloves, but that'd be weird.)