What is Legionella?

Legionella is a dangerous form of bacteria, the presence of which can cause Legionnaire’s disease; a potentially fatal form of pneumonia caused by the inhalation of small droplets of contaminated water.

Legionella is commonly found in purpose-built water systems, such as cooling towers, evaporative condensers, hot and cold water systems and spa pools. In other words, all man-made hot and cold water systems have the potential to provide a favourable environment for Legionella to grow.

It is therefore important to be aware of common areas of exposure to Legionella and best practices for preventing the spread of bacteria in order to protect the health of tenants and staff in the building.

Who needs a Legionella risk assessment?

If you are a landlord or responsible for the upkeep and maintenance of your premises, then you are under a legal obligation to carry out a Legionella risk assessment.

The law is also clear that under the Health & Safety Work Act 1974, you have legal responsibilities to ensure the health, safety and welfare of your employees at work.

If you are a landlord, check out our landlord’s guide to legionella risk assessments.

What does a Legionella risk assessment involve?

The purpose of a Legionella risk assessment is to identify potential sources of Legionella bacteria growth, as well as assess the risk of Legionnaires’ disease. The assessment is important for many reasons. Not only is it a legal requirement for businesses and landlords, but it acts as a source of information when implementing an action plan in addressing the control measures of Legionella within the premises.

A Legionella risk assessment involves several steps, outlined below.

Identifying potential sources of contamination

This will involve a comprehensive evaluation of all water systems and sources, including cooling towers, hot tubs, showers and water storage tanks.

2. Assessing the risk of exposure

Consider a number of factors when assessing the risk of exposure. For example, the number of people who use the water systems, the frequency of use etc. It is also worth noting that those over the age of 50, smokers, or those with respiratory health issues are more at risk of contracting Legionnaires’ disease. Therefore, considering the health and age of your tenants/customers is wise.

Implementing Control Measures

Once the review of potential sources of contamination and risk levels is made, control measures must be implemented to further limit the risk of Legionella bacteria. This may include regular maintenance of water systems, including cleaning and disinfecting, or monitoring the water temperatures to ensure they remain at a controlled level.

Record keeping

Once the assessment is completed, it is the management’s responsibility to record all monitoring results, inspections and details of checks carried out on the premises.

Who can conduct a Legionella risk assessment?

As the employer/landlord, it is your responsibility to appoint the person or persons responsible for conducting the assessment. It can be yourself, one or more of your employees or someone outside of the business.

However, if you decide to employ a third-party contractor to conduct the assessment, it is still your responsibility or the responsibility of the appointed employee to ensure that the assessment and work are carried out to the required standards.

How often should a Legionella risk assessment be conducted?

All systems require a risk assessment, however not all systems will require elaborate control measures. A simple risk assessment may show that the risks are low and being properly managed to comply with the law. In such cases, you may not need to take further action, but it is important to review your assessment regularly in case of any changes in your system, and specifically if there is reason to suspect it is no longer valid.

The frequency of assessment may also be increased by circumstances such as:

• Changes to the water systems installed
• Changes to how the water systems are used
• Changes to the building’s occupants or their health status
• Changes to the management of the water systems

HSE’s ACoP L8 – The Control of Legionella Bacteria in Water Systems

The most relevant guidance and legislation on Legionella is the L8 Approved Code of Practice (ACoP). Within this code of practice, conducting a Legionella risk assessment is the starting point in Legionella risk management.

The document also offers guidance on implementing control measures and the responsibilities of the duty holder.

LCA Registered/h3>

By adopting the above prevention methods, you can reduce the risk of preventing the presence and growth of Legionella proliferation as well as the risk of Legionnaires’ disease. However, if you require any assistance in carrying out Legionella risk assessments, remedial works and monitoring, we are LCA registered certified and therefore well placed to assist our clients.