- January 16, 2025
- Posted by: Zoe Jones
- Category: Business, Legionella, Legionella Control Association, News, Water Safety

Legionella bacteria are a serious concern for businesses across the UK. They can cause Legionnaires’ disease, a potentially fatal form of pneumonia, through the inhalation of water droplets contaminated with the bacteria. This makes Legionella risk assessments an essential component of water safety management for businesses, healthcare facilities, hotels, and any establishment with a water system.
In this article, we will cover everything you need to know about Legionella risk assessments, including why they are necessary, the steps involved, and how to ensure your business stays compliant and safe.
What is Legionella?
Legionella is a bacteria found naturally in water and soil. While most species pose minimal risk, the Legionella pneumophila species is most commonly associated with Legionnaires’ disease. This disease occurs when Legionella bacteria grow in water systems, such as cooling towers, hot tubs, air conditioning units, and plumbing systems, and are inhaled as a fine mist or aerosol.
Symptoms of Legionnaires’ disease can include fever, chills, shortness of breath, and cough. While it can be treated with antibiotics, it can be fatal if not caught early, particularly for those with weakened immune systems, the elderly, or individuals with underlying health conditions.
Why Is a Legionella Risk Assessment Essential?
A Legionella risk assessment is a crucial step for identifying, evaluating, and controlling the risks associated with Legionella bacteria in water systems. According to the Health and Safety Executive (HSE) guidelines, employers have a legal responsibility under the Control of Substances Hazardous to Health (COSHH) Regulations 2002 to manage the risks posed by Legionella. Failure to comply with these regulations can lead to legal penalties, costly fines, and even reputational damage for your business.
The primary goal of a Legionella risk assessment is to ensure that appropriate measures are in place to prevent Legionella bacteria from multiplying and becoming a health risk to employees, clients, and visitors.
Who Needs a Legionella Risk Assessment?
A Legionella risk assessment is required by any business or organization that has a water system where the risk of Legionella growth could occur. This includes:
- Healthcare facilities (hospitals, care homes, clinics)
- Hospitality and leisure establishments (hotels, spas, swimming pools)
- Industrial and commercial properties (factories, offices, warehouses)
- Schools and universities
- Public buildings (libraries, government offices, community centers)
If your business operates with any type of water system, you are responsible for ensuring that it is safe and free from Legionella contamination. A risk assessment will help identify areas of concern and put safeguards in place.
Key Steps in a Legionella Risk Assessment
- Appoint a Responsible Person
The first step in conducting a Legionella risk assessment is to appoint a responsible person. This individual should have sufficient knowledge and authority to carry out the assessment and implement control measures. This could be an in-house health and safety officer or an external expert. - Identify the Water Systems and Potential Risks
The risk assessor will identify all the water systems on your premises, including cooling towers, water tanks, showers, and air conditioning systems. They will assess factors such as water temperature, stagnation, and access for maintenance. High-risk areas where Legionella bacteria could thrive will be pinpointed. - Evaluate the Likelihood of Legionella Growth
Certain conditions make water systems more prone to Legionella growth, such as:- Warm temperatures: Legionella thrives in water temperatures between 20°C and 45°C.
- Stagnant water: Water that is stagnant or sits idle for long periods can promote bacterial growth.
- Water droplets or aerosol formation: Systems that create water droplets, like cooling towers or showers, are higher risk.
- Assess the Control Measures
The risk assessor will examine the current control measures in place. This includes reviewing your water safety management plan, water treatment processes (such as disinfection), and temperature control. The assessor will determine whether your current procedures are sufficient or if improvements are needed. - Recommend Control Measures and Action Plan
If any risks are identified, the assessor will recommend specific actions to mitigate those risks. These could include:- Regular water system flushing to prevent stagnation
- Adjusting water temperatures to keep hot water above 60°C and cold water below 20°C
- Regular cleaning and maintenance of water tanks and pipes
- Installation of water treatment systems (such as chlorination or UV treatment)
- Increased monitoring and testing to detect Legionella contamination
- Review and Update the Risk Assessment Regularly
A Legionella risk assessment is not a one-time task. Water systems should be regularly monitored and assessed to ensure they remain safe. The risk assessment should be updated whenever there are significant changes to the water system, such as system modifications or building renovations, or if there is an outbreak of Legionnaires’ disease.
How Often Should a Legionella Risk Assessment Be Done?
The frequency of Legionella risk assessments will depend on the nature of your water systems and the level of risk. As a general guideline, risk assessments should be reviewed at least year or whenever there are significant changes to your water system. In addition, regular water sampling and testing should be performed, particularly in high-risk areas.
Benefits of Regular Legionella Risk Assessments
- Legal Compliance: Regular Legionella Risk Assessments ensure your business is compliant with health and safety regulations, reducing the risk of legal penalties.
- Protection of Health: By identifying and controlling the risks, you protect the health and safety of your employees, customers, and visitors.
- Operational Continuity: Preventing Legionella outbreaks ensures your business continues to operate smoothly without costly shutdowns or disruptions.
- Improved Reputation: Demonstrating that you take water safety seriously can enhance your business’s reputation, fostering trust with employees, customers, and stakeholders.
How Water Hygiene Services Can Help
At Water Hygiene Services, we specialise in providing thorough and reliable Legionella Risk Assessments for businesses of all sizes. Our team of water hygiene experts conducts detailed inspections of your water systems, identifies potential risks, and implements tailored solutions to mitigate them.
We offer comprehensive risk assessments, including water testing, system inspections, and ongoing monitoring to ensure your systems remain safe and compliant. With our expertise, you can have peace of mind knowing that your business is fully protected from the risks of Legionella contamination.
We work with a range of clients across all industries including healthcare including NHS, education establishments, private offices and more.
Why Choose Water Hygiene Services?
With over 20 years of expertise in the water hygiene industry, Water Hygiene Services has earned a reputation for providing trusted, high-quality solutions to businesses across various sectors. We are proud to be a member of the Legionella Control Association, which guarantees that our services meet the highest industry standards and regulatory requirements.
Our long-standing partnerships with major clients demonstrate our commitment to delivering consistent, reliable results. Businesses trust us because we understand the complexities of Legionella management and have the knowledge and experience to provide tailored solutions that ensure safety and compliance.
When you choose Water Hygiene Services, you’re choosing a proven partner that prioritises your business’s health and safety with a professional, customer-focused approach.
Get in Touch Today
If you need a Legionella risk assessment or want to learn more about how to safeguard your water systems, contact Water Hygiene Services today. Don’t leave the safety of your business to chance. For more information, contact us or email the team today.