Understanding the Risk

Legionella bacteria thrive in stagnant or slow-moving water between 20°C and 45°C. They can be found in various water systems, including:

• Showers and shower heads
• Taps and pipework
• Toilets
• Hot water cylinders and cold water tanks
• Any other water features in the property

People become infected by inhaling small droplets of contaminated water (aerosols), not by drinking the water.

Landlord's Legal Duty: Risk Assessment

Under the Health and Safety at Work etc. Act 1974 and the Control of Substances Hazardous to Health Regulations 2002 (COSHH), landlords are considered to be in control of the premises and have a duty to:

• Identify and assess sources of Legionella risk: This involves carrying out a Legionella risk assessment.
• Prevent or control the risk: Implement measures to manage any identified risks.

Important: For most domestic rental properties, the risk is usually low, and a simple risk assessment can often be carried out by the landlord themselves. However, if you are unsure or the property has a more complex water system (e.g., a large hot water tank, multiple shower units), consider engaging a competent professional.

What a Legionella Risk Assessment Involves

A Legionella risk assessment should:

• Identify potential sources of exposure: Look at all water systems in the property.
• Assess the risk: Consider factors like water temperature, stagnation, and presence of sludge/scale.
• Identify who is at risk: Consider vulnerable Contract Holders (e.g., elderly, those with weakened immune systems).
• Propose control measures: Recommend actions to minimise or eliminate the risk.
• Record findings: Document the assessment and any actions taken. While not legally required to be written down for low-risk properties, it's good practice.
• Review regularly: The assessment should be reviewed periodically (e.g., every two years), or if there are significant changes to the water system or the property's use.

Controlling the Risk: Simple Measures

For most domestic properties, simple, common-sense measures can effectively control Legionella risk:

• Temperature Control:
  • Keep hot water hot: Ensure hot water is stored and distributed at a temperature high enough to kill Legionella (e.g., above 60°C in the cylinder, and delivered at taps above 50°C within one minute).
  • Keep cold water cold: Ensure cold water is stored and distributed at a temperature below 20°C.
• Flushing Seldom-Used Outlets: If a property is vacant for a period (e.g., between Contract Holders) or if a tap/shower is rarely used, flush it through for a few minutes before use to remove stagnant water. Advise Contract Holders to do this if they return from a holiday.
• Cleaning & Descaling: Regularly clean and descale shower heads and taps to prevent the build-up of biofilm and scale, where bacteria can multiply.
• Removing Dead Legs: Identify and remove any redundant pipework ('dead legs') where water can stagnate.
• Maintaining Water Systems: Ensure all water systems are in good repair and free from leaks.

Consequences of Non-Compliance

Failure to manage Legionella risk can lead to serious health consequences and legal penalties:

• Serious Illness: Contract Holders or visitors could contract Legionnaires' disease, which can be severe or even fatal.
• Prosecution: Landlords can face prosecution under health and safety legislation, leading to significant fines and potential imprisonment.
• Civil Claims: You could face civil claims for damages if a Contract Holder becomes ill due to your negligence.