A recent study in the USA by the Hunter College NYC Food Policy Center in conjunction with DietDetective.com revealed that the quality of drinking water varies wildly by airline and many provide passengers with water that is not safe to drink.
The 2011 Aircraft Drinking Water Rule (ADWR) requires US airlines to provide passengers and crew with safe drinking water. The 2019 Airline Water Study ranked 10 major and 13 regional airlines by the quality of water provided on their flights. Airlines were rated from 0 to 5 based on water quality, positive tests for E. coli and coliform bacteria and other ADWR violations. A score of 3 or more indicates water safe to drink.
The study found that only 3 major airlines passed the test Allegiant and Alaska Air with 3.3, followed closely at 3.1 by Hawaiian Airlines. Nearly all the regional airlines, with the exception of Piedmont Air, had poor Water Health Scores and a large number of ADWR violations.
Seven of the 10 the major airlines failed the test.
Three of the top 4 US airlines by passenger numbers scored less than 2!
- American Airlines scored 1.5
- Delta Airlines scored 1.6
- Southwest Airlines scored 2.4
- United Airlines scored 1.2
With scores like this you should avoid drinking any water, even tea or coffee, and if possible, even use your own bottled water to wash your hands.