Is Airplane Water Safe To Drink On U.S. Flights?

If your TikTok feed is anything like mine you’ve probably seen a number of videos from current and former airline staff warning you about the water on board your next flight. But are these “warnings” about tap water onboard flights in the U.S. accurate?

Being curious, I decided to take a look at the Aircraft Drinking Water Rule (ADWR) report data collated and published by the Environmental Protection Agency (EPA) to reveal which airlines are most likely to fail water tests, and how many take a failed test to clean up their act.

Reviewing ADWR report data, I’ve focused on the presence of E.Coli and Coliform in routine and follow-up test results of both galley and lavatory tap water from November 2019 to November 2022.

Drinking water on flights data points

• One in 20 (4.96%) of water samples taken from passenger planes since November 2019 have recorded positive traces of E.Coli and/or Coliform, rising to 6% in 2022 so far.
• Sky West Airlines (115) recorded the most E.Coli and/or Coliform samples since November 2019.
• The majority of tests (61.54%) on Trans States Airlines planes recorded positive samples of E.Coli and/or Coliform, the highest of any airline.
• More than one in six (17.00%) of Spirit Airlines’ water tests since November 2019 have recorded a positive sample E.Coli and/or Coliform.
• Since the start of 2022, Spirit Airlines (40), Jetblue Airways (38), American Airlines (28), Commute Air (27), and United Airlines (22) have recorded the most samples of E.Coli and/or Coliform in tests
• To date, in 2022, 100% of routine tests on Allegiant Air and United Airlines aircraft have recorded the presence of E.Coli and/or Coliform in samples.

Can I drink the water on board a flight in the U.S.?

Since November 2019, nearly one in 20 (4.96%) water samples from U.S. passenger planes have recorded positive traces of E.Coli and/or Coliform; with this figure increasing to 6% since the start of 2022.

Overall, 852 of the 17,179 water tests conducted by the EPA showed traces of E.Coli and/or Coliform, with 283 positive test results reported since the beginning of the year.

One in 20 U.S. passenger planes failing water tests might not sound a lot, however, when you consider many airlines operate thousands of flights per year, do you really want to be on a plane that could make you sick?

Which airlines have the worst water quality?

Across the three years of sample data analysed, Trans States Airlines planes recorded positive samples in nearly two-thirds of their tests (61.54%), the highest of any airline. Behind Trans States Airlines, in second place are CommuteAir (24.46%), and Avelo Airline (22.73%). 

As with any percentage, the results above don’t take into account fleet sizes, meaning they can be slightly exaggerated. Below, the analysis focuses on which airlines have failed the most water tests, broken down by the total number of tests and how many routine samples have shown contamination.

Since November 2019, Sky West Airlines recorded the most positive samples of E.Coli and/or Coliform in water samples (115), followed by Spirit Airlines (101) and American Airlines (87). 

However, when we look at routine tests only, results showed that Sky West Airlines still failed the most (95), followed by American Airlines (74) and Spirit Airlines (68). Why is this important? Well, after a positive routine test airlines are expected to clean and flush their water systems to remove contaminants and ensure water onboard is pure.

As the results suggest, some airlines appear to be better at cleaning their water systems than others.

Airlines recording the most E.Coli and/or Coliform samples since November 2019

Which airlines are best (worst) since the start of 2022?

Since the start of 2022, 50% of tests performed on United Airlines and Allegiant Air planes have found E.Coli and/or Coliform in the water provided to customers in either the galley or in the lavatories. Results show that United and Allegiant have only passed follow-up tests.

During 2022, United Airlines and Allegiant Air have (so far) faced 22 and 1 routine water sample tests respectively, failing all of them. However, follow-up test data (after the systems are cleaned) showed a 100% pass rate…so at least we know they can clean the systems well, when asked.

Airlines recording the highest rate of E.Coli and/or Coliform samples during 2022

As the results above show, many of the worst-performing airlines have only been tested and/or failed a few times. Again, this is likely a mixture of scheduling and fleet sizes.

Analysing which airlines have failed the most tests this year, it is revealed that Spirit Airlines (40) failed the most water tests during 2022, followed by Jetblue Airways (38) and American Airlines (28).

Results from 2022 show that Spirit Airlines have failed the most routine tests (27) this year, followed by American Airlines (25), with JetBlue Airways and CommuteAir (23) as the joint third worst for failed routine tests.

Airlines recording the most E.Coli and/or Coliform samples during 2022

Should you drink the water on flights in the U.S.?

As to whether you should drink the water on flights, that’s entirely up to you. However, from my perspective, I’d probably say you should avoid it where possible, and use a hand sanitiser after going to the toilet and washing your hands to be extra cautious.

Overall, the data from this study forms part of the Aircraft Drinking Water Rule (ADWR), its intention being to ensure that safe and reliable drinking water is provided to aircraft passengers and crew. But as the results show things probably could be better in some instances.

What should you drink on board flights in the U.S.?

Now that’s a huge question. Being from the UK, you might expect me to suggest an alcoholic beverage, however, I’m less keen on those inflight these days.

From personal experience, and in the process of writing this page, I’ve found that bottled water (without ice) is typically the best. Not only is easy for the cabin crew to serve – few bubbles to worry about and less mess if it spills – it also helps with the dehydration you can experience when flying.

It’s recommended that you drink about 250 millilitres (just over 1 cup) of water per hour when flying. This helps to keep avoid dehydration and, for those on long-haul flights, can help fight against jet lag.

I’m very aware there’s a bit of irony that within a post discussing whether it’s safe to drink the water on flights I’ve then said to drink (bottled) water. However, that can be pretty expensive, well in relation to what it would cost on the high street or in a normal shop.

Looking to save at the airport? Read my tips on cutting costs at the departure lounge and duty-free

To get around high duty-free/departure lounge costs for water, it’s worth taking an empty reusable bottle and filling it up via a water station or asking a vendor (restaurants are best) within the departure gate to fill up your bottle. 

Not only is taking an empty water bottle within the rules of *most* airport security, but it also helps reduce waste and can save you quite a bit if you tend to drink quite a bit before, during and after a flight.

Need a new water bottle? Here’s my list of some of the best around.

Methodology

Data from this study was sourced directly from the Environmental Protection Agency (EPA) and their Aircraft Drinking Water Rule (ADWR) compliance reports between November 1st, 2019, and November 24th, 2022. For analysis of 2022 data, figures were analysed between January 1st, 2022, and November 24th, 2022.

Analysis within this study combines samples from both the galley and lavatories of aircraft. 

Figures shown highlight both the overall number of tests and routine tests performed on aircraft belonging to each airline. Typically, after contamination is found during routine tests airlines are expected to clean the water systems onboard the plane, with a follow-up test used to show that E.Coli and/or Coliform is no long contaminating onboard water supplies.

Percentages shown are based solely on figures and aircraft reported by the EPA, meaning, only a fraction of each airline’s fleet have been tested and results should be viewed as indicative only.

Sources 

This study was first posted in July 2022.

This work is licensed under a Creative Commons Attribution 4.0 International License.

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