Legionella risk assessments: how often should they be conducted?

When it comes to managing Legionella risk, regular assessment and monitoring are essential to keeping building users safe and maintaining compliance. But one of the most common questions we hear from duty holders and facilities managers is: how often should a Legionella risk assessment be carried out?

The answer depends on a number of factors – including the type of building, the complexity of the water system, and how the system is used – but there are clear guidelines to help steer your compliance.

The legal requirement

Under the Health and Safety at Work Act 1974 and the Control of Substances Hazardous to Health (COSHH) Regulations, all employers and building owners have a legal duty to assess and control the risk of exposure to Legionella bacteria.

This includes carrying out regular Legionella risk assessments to identify potential hazards and implement appropriate control measures. The Health and Safety Executive’s (HSE) Approved Code of Practice (ACoP L8) states that the assessment should be reviewed regularly and specifically when certain changes occur.

So, how often is “regularly”?

While there’s no fixed schedule set in law, ACoP L8 recommends reviewing the Legionella risk assessment at least every two years – or sooner if there are:

• Changes to the building or water system
• Significant alterations in usage or occupancy
• Reports of Legionella-related illness or non-compliance
• Evidence that current controls are no longer effective
• A change of responsible person or facilities management provider

In some higher-risk environments (such as healthcare facilities or sites with complex water systems), annual reviews may be appropriate.

What a review involves

A Legionella risk assessment review doesn’t always mean starting from scratch. However, it should still involve a competent person evaluating:

• Whether the original assessment is still valid
• If any new risks have been introduced
• Whether monitoring, cleaning and maintenance regimes are still effective
• The performance of temperature controls, flushing regimes, and dosing systems
• Staff awareness and training records

If the building or system has remained largely unchanged and existing controls are working well, a review might simply reaffirm that the current arrangements are still suitable.

Why timely reviews matter

Failing to carry out timely Legionella risk assessment reviews can lead to serious consequences, including:

• Increased risk of Legionnaires’ disease
• Non-compliance with legal duties
• Enforcement action by the HSE
• Damage to reputation and public trust
• Potential prosecution in the event of an outbreak

Keeping on top of your review schedule is a straightforward way to reduce risk and demonstrate proactive compliance.

How HBE UK can help

At HBE UK, we support organisations across the public and private sectors with expert Legionella risk assessments, reviews, and ongoing water hygiene monitoring. Whether you’re managing a school, hospital, office block or housing scheme, we tailor our services to the unique needs of your site and sector.

We offer:

• Initial and follow-up risk assessments
• Scheduled reviews based on your building profile
• Water sampling and temperature checks
• Written schemes of control and compliance documentation
• Staff training and support for responsible persons

When did you last review yours?

If you’re unsure when your Legionella risk assessment was last reviewed – or if you’ve recently had changes in your water systems or occupancy – it may be time to schedule a review.

Contact HBE UK today to arrange a consultation and ensure your Legionella control measures are current, effective, and fully compliant.