The operators of any premises occupied by people, whether employees or visitors, have a duty to ensure that the space is free from hazards.
This is both a moral and legal duty, with multiple HSE and worker safety regulations dictating what steps are legally necessary to ensure the safety of specific environments. One of the many environmental factors that require attention is water sources. Here, we look at why a water management strategy is crucial for Legionnaires’ prevention.
What is Legionnaires’ disease?
Legionnaires’ disease is a severe kind of atypical pneumonia that is often fatal. It’s caused by inhaling water droplets that contain high concentrations of the bacteria Legionella pneumophila. The bacteria is commonly found in a lot of natural water sources, but it is rarely found in high enough concentrations to cause illness.
However, when specific environmental conditions are present, the bacteria can proliferate to dangerous levels. Water management is crucial in order to ensure that those conditions do not occur.
What conditions promote Legionella pneumophila growth?
The bacteria that cause Legionnaires’ disease proliferate under specific conditions. They typically thrive in stagnant water between around 20-45C, although they can also thrive in water that’s re-circulated in the same system.
Certain deposits in the water system can also support bacteria growth, by providing necessary nutrients; these include scale, biofilms, rust, and sludge. A water management strategy is crucial in order to identify and prevent these kinds of environmental conditions from occurring in the first place.
How is Legionnaires’ disease spread?
Legionnaires’ disease is transmitted when an individual inhales droplets (aerosols) with high concentrations of Legionella pneumophila. These droplets can enter the air from a wide variety of different sources. These include taps, showers, swimming pools, and (as it famously occurred in the first identified case in 1976) air conditioning units.
A water management strategy will facilitate the identification of all potential places where aerosols could potentially enter the air, in turn allowing for effective risk management.
Water management for Legionnaires’
There are a number of strategies that can be implemented to minimise the risk of Legionnaires’ disease. One of these is the use of temperature control devices; the key is to ensure that hot water is stored at a minimum temperature of 60 C, with cold water stored at a maximum of 20 C. Devices should be installed in all water storage locations to ensure that these minimum and maximum temperatures are maintained.
Duty holders also have certain obligations. These include ensuring that formal Legionella risk assessments are conducted at regular intervals, generally by external providers.
Duty holders also need to appoint a ‘competent person’, an individual with sufficient Legionella training and knowledge to ensure that legal compliance is maintained at all times. It’s crucial for duty holders to keep records on all measures that are taken to monitor and protect against Legionnaires’ disease.
Whichever approach you decide to take to water management, ensure that you cross-reference any advice with leading resources such as the detailed studies and guides on the Water Hygiene Centre website.