Safety regulators worldwide agree that a Legionella risk assessment is the first step to a solid water safety plan. In the UK, it’s also a legal must.
This article explains what’s involved in a Legionella risk assessment, who can do it, why the right skills matter, how often it needs updating, and how it helps keep workplaces safe.
What is Risk Assessment for Legionella?
A Legionella risk assessment is a process for identifying and managing the risks of Legionella bacteria in water systems. In the UK, carrying out these assessments is legally required to keep facilities safe and control the risk.
This is part of the duty of care to protect people from potential exposure to water droplets that may carry Legionella bacteria, which can lead to serious illnesses like Legionnaires’ disease. While it’s not possible to eliminate the bacteria completely, the focus is on keeping levels low and manageable through proper water treatment. Regular checks of water outlets, such as taps and showers, are also important to reduce risks associated with Legionella bacteria and maintain safe conditions.
Promoting Legionella Safety in the Workplace
A Legionella risk assessment is key to keeping water systems safe. It helps spot and evaluate risks unique to each building.
The Health and Safety Executive (HSE) says these assessments aren’t a one-off job. According to their guidance (ACOP L8 and HSG274), they must be reviewed and updated regularly.
Is Your Legionella Risk Assessment Sufficient to Protect Your People?
The type of Legionella risk assessment you need depends on your specific setting. Every assessment should fit the specific environment, considering the complexity of the water system and pipework, who uses it (e.g., a tenant), and their potential risks.
For example, a small office with a simple kitchen and bathroom setup will have a much less complicated water system than a large hospital with sprawling infrastructures.
For the office, a basic assessment by someone with a good understanding of Legionella risks might be enough. In contrast, the hospital’s large and complex water system needs a more detailed review. This should be handled by professionals experienced in Legionella control and up-to-date with current guidelines.
How Often Should You Review a Legionella Risk Assessment?
According to the HSE’s ACoP L8, the assessment should be reviewed whenever there’s a reason to think it’s no longer valid. This could include:
- Changes to the water storage system or how it’s used
- Changes to how the building is used
- New information about risks or control measures
- Checks showing that current measures aren’t working
- Changes to key staff
- A case of Legionnaires’ disease linked to the system
Other points worth thinking about:
- How the water is stored and its quality
- Whether key risks are shifting over time
- How risks are being managed as safely as possible
- Resources and how they’re being prioritised
- How risk management issues are being escalated
How to Use Your Legionella Risk Assessment
This should be included in your Water Safety Plan, a key document explaining how to operate, maintain, and clean your water systems properly. The assessment might point out risks that can be removed entirely. It could also suggest practical steps to improve water hygiene and ensure your systems meet the required standards.
One critical factor is ensuring that hot water stays above 20°C and cold water below it to reduce the risk of Legionella growth. Facilities should regularly test the temperature of stored water in cylinders and cold water tanks, as well as monitor outlet points such as taps and showers.
Good Communication is Key to Successful Water Safety
Smaller businesses might only need one person to manage water management, as simple measures can often keep things running smoothly. For larger or more complex operations, it’s usually a team effort.
A Legionella risk assessment is a key part of the process, but it’s not a one-off task. It needs to be done by someone with the right skills and reviewed regularly to stay current. This ongoing approach helps keep cold and hot water storage systems safe and avoid future issues.
Expert Legionella and Water Safety Solutions – Comfort Services Group
At Comfort Services Group, we specialise in Legionella and water safety solutions. We want to help business owners and workplace managers keep their hot and cold water systems safe and compliant.
Our team simplifies managing your water systems while protecting everyone on the premises. Contact us today to learn how we can support you with reliable water safety services.
FAQs
Is it a legal requirement to have a Legionella risk assessment?
In the UK, employers, landlords, and anyone responsible for premises must carry out a Legionella risk assessment. This is required under the Health and Safety at Work Act 1974 and the Control of Substances Hazardous to Health Regulations (COSHH).
What is a Legionella management plan?
A Legionella management plan helps you reduce risks in your water systems. It is a practical guide that explains what to do and who is responsible. This plan includes policies and procedures to keep Legionella under control. It follows the guidelines set out in the Approved Code of Practice L8.
How many employees are needed for a Legionella risk assessment?
The number of people needed for a Legionella risk assessment depends on the size and complexity of the water system. Often, one skilled person is enough. However, larger or more complex buildings may require additional help. Extra team members might be needed to inspect large systems, collect samples, or set up control measures.
What is a safe level of Legionella bacteria?
Legionella bacteria in water systems is never safe. Even a tiny amount can be potentially fatal. If the conditions are right, it can grow quickly and spread, creating serious health risks, including Legionnaires’ disease, which is a potentially fatal form of pneumonia caused by the inhalation of small droplets of contaminated shower or tap water containing Legionella.
We are proud to share our experience and knowledge and take pride in offering this to all clients when required. If I, or one of the team can help then please schedule a meeting via the office or get in touch via one of our social media platforms.
- Top 10 Best Legionella Risk Assessment Companies in the UK (2026) - June 24, 2026
- Coagulation and Flocculation in Water Treatment: What’s the Difference? - April 7, 2026
- What is the Chain of Infection and How to Break It? - March 27, 2026
