Legionnaires disease can cause serious illness and even death, it was named after the 1st major recorded outbreak at a conference/gathering in the United States.
The bacteria are present in all water and become an issue when the right conditions for them to proliferate exist. These are; an ideal temperature and some stagnation, the perfect temperature is mid to high 30 degrees C.
Approved Code of Practice (ACOP) L8 recommends that an initial Legionella risk assessment is carried out and then a suitable water management scheme is put in place and followed. This will include monitoring of outlets and water tanks and may include regular water sampling and disinfections. The Legionella risk assessment needs to be carried out to BS8580 by a competent, i.e. trained, person.
The bacteria is ingested by human beings in the form of an aerosol and then infects the lungs, the symptoms are similar to flu and also Covid 19. The mild illness is called Pontiac fever and will generally be flu-like and may dissipate without treatment. The more serious illness can involve hospitalisation including ICU and even death. Public Health England confirms there were 503 cases of Legionnaires’ Disease in 2019 for England and Wales – an average of almost 10 cases a week. (Latest available data).
The most common sources are from showers or other equipment, such as cooling towers, that produce an aerosol. Stagnation is also a major factor in increasing the risk, to mitigate this any low use/seldom used outlets should be run off weekly. Temperature monitoring is also advisable, both of these actions MUST be recorded.
In summation: A current Legionella risk assessment and appropriate water hygiene management and monitoring scheme will prevent the bacteria proliferation within the systems and therefore significantly reduce the risk to Staff and public health. Steve Dillon (Advanced WMSoC Legionella Risk Assessor) Managing Director Stokefield Water Treatment Ltd