In addition to the systems most likely to cause legionella (evaporative cooling systems, hot and cold water systems and spa pools), there are several other systems that could be a source for legionella bacteria growth. These include:
- humidifiers
- air washers
- emergency showers
- eye wash sprays
- indoor ornamental fountains
- aqueous tunnel washers
Any water system is potentially a reasonably foreseeable legionella risk if it has any of these factors:
- the presence of legionella bacteria in the system water
- where the water temperature may be between 20-45°C
- a means of creating and/or spreading breathable droplets (aerosols)
- it stores and/or re-circulates water
- it is likely to contain a source of food for the organism, such as contaminants from the surroundings or process including the presence of sludge, rust, scale, organic matter or biofilms
The actions you need to take with regard to these sorts of other risk systems are set out in Part 3 of Legionnaires' disease: The control of legionella bacteria in other risk water systems.
You must carry out a risk assessment as described in Legionnaires’ disease: what you must do to decide whether further actions are needed. These systems and any others found to present a risk should be maintained in a clean state and monitored on a regular basis, where appropriate.
There is also a duty to maintain records of all maintenance carried out, together with monitoring results.