Legionella bacteria in natural and manmade water sources is the cause of the devastating Legionella Disease, which can cause respiratory and lung problems, kidney disease, and pneumonia and may be fatal if not treated immediately.
The bacteria thrive in warm water, particularly if it has been sitting stagnant in unused or little use pipes and outlets. Where there has been a build-up of rust, scale, sludge and Biofilms (tiny micro-organisms), there is more potential for Legionella to be present.
Why test for Legionella?
Legionella is not visible to the naked eye but when inhaled or consumed, it can result in a serious illness. If tests are not carried out and the bacterium is left to grow and spread, Legionella can reach dangerous levels.
The types of water systems at risk from Legionella include:
- Hot and cold water systems are found in just about every building.
- Sprinklers and vehicle wash systems.
- Fountains and water features are found in gardens, including naturally occurring ponds and streams.
- Spa and swimming pools.
- Spray humidifiers, air washers and wet scrubbers.
- Water cooling systems and towers, and evaporative condensers.
It is also a legal requirement for business owners, employers, landlords and property managers to regularly assess, test and mitigates the risk of Legionella in their building’s water systems as part of the Health & Safety Act 1974 and TR19 guidance.
When should Legionella testing be done?
There are certain conditions when it is highly recommended to test for Legionella. These are:
- A high-risk area or building where there is an increased vulnerability, such as hospitals, care homes and healthcare centres.
- A water system that has been identified as, or suspected as, a case of an outbreak of Legionella.
- A building that has a water system, i.e. pipes and outlets, that have not been used, or infrequently used, for a period of time, such as an empty rental property or business premises.
- A water system that is being, or has recently been, treated with biocides and the hot water is either stored or distributed at lower temperatures.
- As part of the limits of a control programme, i.e. disinfectant or temperature concentrations being used, that has not been consistently monitored and managed.
Legionella testing should be carried out according to L8 standards and done by professional experts in Legionella, like Swiftclean who are members of the Legionella Control Association.
How often should the water be tested for Legionella?
The regularity of Legionella testing largely depends on the type and size of the water system, its level of use and whether there is any potential risk due to a change in circumstances, such as a building standing empty for a period of time.
For water systems that have a low use, i.e. the water system is only in use for 6-8 hours a day, testing should be done every 12 months. For medium use – 10-12 hours a day – plan to test every 6 months and for water systems that have a high use (14-16 hours a day), such as hotels, leisure centres and schools, it’s better to test every 3 months to ensure absolute safety.
Regular testing demonstrates to regulators that there is a comprehensive Legionella control programme in place to ensure that the water systems are assessed and monitored to avoid any potential risk.
