I found an article about things airline employees know about flying you should know. I was interested because I used to work as ground crew and I knew a lot of them already, but this one was new to me:
Is this true? Both that it is known by employees, and is it in fact true that there are inches thick layers of grime in the tanks?
The inches of slime bit is probably an exaggeration, but according to an NBC investigative report, the EPA in 2012 found that 12 percent of commercial airplanes tested positive for coliform bacteria (NBC for some reason also felt compelled to point out that this was close to 1 in 10… apparently they think that 12 percent is too difficult of a number for their audience to grasp). The NBC report, being an NBC report, is as you would expect, a bit overhyped and sensationalist. But the EPA does apparently consider the findings to be significantly high. The NBC report also mentioned that the EPA first began to focus on this problem in 2004 and apparently not much has changed since then.
The EPA also has stated that it does not have any confirmed reports of anyone getting sick from airplane water.
The bit about the tanks never being cleaned is false. However:
The tanks have to be stainless or anti-microbial plastic to prevent corrosion so slime really couldn’t accumulate in them. And there have been no reported outbreaks of illness from people who consumed contaminated water on airplanes, so it seems like it would be a minor concern, if it was a concern at all.
Frankly, I would be more concerned with a passenger suffering from the norovirus getting on board and not thoroughly washing their hands while touching everything in their path. You are likely to grow ill from that.
I’m curious about NBC’s report. 12 percent isn’t a particularly high number depending on how much effort is made to draw an uncontaminated sample. For domestic well water labs see bacteria in a higher percentage of samples provided by home owners. In most of those cases it is error in the sampling process and not the well water.
The tanks are sanitized with bleach regularly. It’s not unusual for any tank or pipe to accumulate sediment. This doesn’t make them harmful. If you’re drinking water on a plane it is going to be bottled water anyway.
People tend to be far too concerned about the cleanliness of water, so it’s hardly surprising people in the airline industry avoid it. If those same people worked for a cities DOW or in a bottling plant they might end up dying of thirst. Most water comes from the ground. It isn’t pristine source from the heavens. Water is some dirty stuff. Dirty does not mean unhealthy.
Well, you might want to dwell on the following question a bit: when was the last time the pipes leading to your home were scrubbed down and disinfected? Never, right? The town might occasionally send an extra jolt of chloramine through, but that’s not going to do anything for the sediments and calcium deposits. So if you looked at a cross section of the pipes, you’d probably be more sanguine about the airline drinking water.
The deHavilland Comet entered service in 1952. And if you give them ‘nearly’ 60 year old, the SAS Caravelle entered service in 1955 and the 707 entered service in 1958. So 60 years ago isn’t quite the ‘stone knives and bearskin’ era of commercial travel you would think.
Of course, none of them are still in commercial service!
I worked on the US Air Force C-9 which was a version of the DC-9. It had potable water. It was tested frequently and bleach ran though the system every so often. We also drained the tank and lines a lot especially when it was going to be below freezing. Sure didn’t want water pipes breaking inside an aircraft!
My grandpa used to have a water cooler with a large glass tank on top, which had developed moss along the inner walls that had tendrils a couple inches long waving in the water. I’m sure he drank from it every day for several decades.