KLM Royal Dutch Airlines tests the water quality in its aircraft’s water systems on a regular basis, though this is not required by law. A test for the presence of legionella bacteria was added some while ago, though this KLM initiative was again undertaken on a voluntary basis only, and followed recent discoveries of these bacteria at several locations in the Netherlands.
For the first time since testing began, legionella bacteria have been found in the water system of one KLM aircraft. The level, though higher than normal, is still negligible in terms of constituting a health hazard for passengers and crew.
People cannot be infected by drinking the water in which the bacteria is present. Infection only occurs among persons who inhale moisture or vapor originating from water containing the bacteria. The pressure on potable water carried by aircraft is too low to cause the water to vaporize when a water point is opened. Neither is the water vapor originating from heating water for the hot water system in any way a health hazard, since high temperatures kill the bacteria.
KLM has nevertheless reported the incident to aircraft manufacturer Boeing and to the Dutch health and aviation authorities. In its report, KLM suggests that an official test procedure should be created, since the airline considers that the same situation could occur on the aircraft of any other airline worldwide.
KLM has immediately ordered water quality testing to be intensified throughout its worldwide route network without waiting for potential initiatives by Boeing or the Dutch health and aviation authorities. Any suspect aircraft water systems will immediately be disinfected and cleansed.