(4 credits available)
To ensure that water systems are managed to minimise the risk from legionella bacteria.
Has an assessment of the asset’s water systems been performed to identify the potential risk of exposure to legionella bacteria and, if so, are management processes in place to prevent or control the risk?
|Credits||Answer||Select all that apply|
|0||A||Question not answered|
|1||C||Guidance on minimising legionella risk is provided to residents|
|3||D||A full risk assessment and management process is in place|
|Criterion||Assessment criteria||Applicable answer|
Guidance should cover the following topic:
Guidance can be included as part of the Home User Guide, but can also be repeated at appropriate times, e.g. during summer holiday season.
A competent person has performed a risk assessment that identifies and assesses the risk of exposure of asset users to legionella bacteria from the asset’s water systems and any required prevention or control measures. All water systems that present a potential risk from legionella bacteria must be assessed, including, but not limited to:
A water system includes all equipment and components associated with that system, e.g. all associated pipework, pumps, feed tanks, valves, showers, heat exchangers, quench tanks, water softeners, chillers, etc.
Where the risk assessment identifies that prevention or control measures are necessary, the following must be in place:
Where a risk assessment shows that risks are low and that no prevention and control measures are required, it is not necessary to demonstrate compliance with this criterion (subject to compliance with criterion 4).
|4||The risk assessment must be reviewed periodically, especially following any changes to the water system(s) or changes to the asset’s operation that may result in significant changes to water use within the asset, e.g. change in number of users or change in use of space(s).||D|
Legionella prevention and control measures
Prevention and control measures include, but are not limited to:
- Avoiding water temperatures between 20°C and 45°C and conditions that favour the growth of legionella bacteria and other microorganisms.
- Avoiding water stagnation which may encourage the growth of biofilm.
- Avoiding the use of materials that harbour bacteria and other microorganisms or provide nutrients for microbial growth.
- Controlling the release of water spray.
- Maintaining the cleanliness of the system and water in it.
- Using water treatment techniques, e.g. biocides, chlorination, heat.
- Ensuring the correct and safe operation and maintenance of the water system.
|-||The evidence below is not exhaustive, please also refer to the ‘BREEAM evidential requirements’ section in the scope of the Guidance for appropriate evidence types which can be used to demonstrate compliance.|
|1||A copy of the guidance provided to residents|
|2||Documentation in accordance with criterion 2.|
Genus of bacteria that can cause infection (Legionellosis) through the inhalation of contaminated water droplets or aerosols, which can range in severity from a mild, febrile illness (Pontiac fever) to a rapid and potentially fatal pneumonia (Legionnaires’ disease).
A person that has sufficient authority, competence and knowledge of the asset to ensure that all operational procedures are carried out in a timely and effective manner, and has such ability, experience, instruction, information, training and resources to enable them to carry out their tasks competently and safely. In particular, they should know the:
- Potential sources of legionella bacteria and the risks they present;
- Measures to adopt, including the precautions to take to protect the people concerned, and their significance;
- Measures to take to ensure that the control measures remain effective, and their significance.
Legionella and water systems guidance
Guidance on the risk assessment and control of legionella bacteria in water systems include:
- American Society of Heating, Refrigerating and Air-Conditioning Engineers; ANSI/ASHRAE Standard 188-2018 Legionellosis: Risk Management for Building Water Systems; 2018.
- American Society of Heating, Refrigerating and Air-Conditioning Engineers; ASHRAE Guideline 12- 2000 - Minimizing the Risk of Legionellosis Associated with Building Water Systems; 2000.
- British Standards Institution; BS 8580‑1:2019 Water quality – Risk assessments for Legionella control – Code of practice; 2019.
- The Chartered Institution of Building Services Engineers; CIBSE TM13: 2013 Minimising the risk of Legionnaires' disease; 2013.
- European Centre for Disease Prevention and Control; European Technical Guidelines for the Investigation, Control and Prevention of Travel Associated Legionnaires' Disease; 2017.
- World Health Organisation; Legionella and the Prevention of Legionellosis; 2007.
© Copyright Building Research Establishment Ltd 2021