Who
The dutyholder (landlord) is responsible for ensuring a legionella risk assessment is carried out. The dutyholder can appoint a competent person or persons to undertake the risk assessment and take day-to-day responsibility for controlling any identified risk from legionella bacteria, known as the ‘responsible person’.
What
Check competence
The dutyholder should check that the appointed responsible person has sufficient authority, competence and knowledge of the installation to ensure that all operational procedures are carried out effectively and in a timely way.
Carry out a legionella risk assessment
All systems require a legionella risk assessment. Where the assessment demonstrates there is no reasonably foreseeable risk or that risks are insignificant and unlikely to increase, and are properly managed, no further assessment or measures are needed. Examples:
(a) in a small building without individuals especially ‘at risk’ from legionella bacteria (people over 45, smokers and heavy drinkers, people suffering from chronic respiratory or kidney disease, diabetes, lung and heart disease or anyone with an impaired immune)
(b) where daily water usage is inevitable and sufficient to turn over the entire system;
(c) where cold water is directly from a wholesome mains supply (no stored water tanks);
(d) where hot water is fed from instantaneous heaters or low volume water heaters (supplying outlets at 50 °C);
(e) where the only outlets are toilets and wash hand basins (no showers).
Prepare a written scheme
If a risk has been identified, a written scheme should be prepared for preventing or controlling it. In particular, the written scheme should contain the information about the water system needed to control the risk from exposure.
Review the legionella risk assessment
The legionella risk assessment should be reviewed regularly in case of any changes to the system and specifically if there is reason to suspect it is no longer valid and make any necessary changes as a result of that review {If anyone tells you this should be reviewed annually, ask them to show you the regulation or HSE guidance that says so}. This may result from, e.g.:
(a) changes to the water system or its use;
(b) changes to the use of the building in which the water system is installed;
(c) the availability of new information about risks or control measures;
(d) the results of checks indicating that control measures are no longer effective;
(e) changes to key personnel;
(f) a case of legionnaires’ disease/legionellosis associated with the system.
Further Reading:
Legionnaires’ disease – The control of legionella bacteria in water systems
The Control of Substances Hazardous to Health Regulations 2002 (as amended) in particular regulations 6,7,8,9 & 12
Legionnaires’ disease – Part 2: The control of legionella bacteria in hot and cold water systems