A Legionella Risk Assessment forms the backbone of protecting your water system against legionella bacteria. Legionella bacteria is dangerous. When breathed into the lungs, it can cause Legionnaires’ disease, a potentially fatal form of pneumonia. Risk assessments are used to identify risks and potential concerns with water systems that could cause legionella bacteria to proliferate. Acting on its analysis can help organisations stay legionella-free, protecting both employees and the general public.
What is a Legionella Risk Assessment?
Legionella breeds in water that has poor flow or is kept within a certain temperature range. The risk assessment will therefore analyse how the water is flowing and how it is stored. Regular risk assessments are required for regulatory compliance.
A qualified risk assessor undertakes a legionella risk assessment. The assessor will visit the site, assess the system and create a water schematic. This schematic will record where each tap, water tank, toilet and other water assets are in a particular building. They will be looking to check that every asset is accounted for and that the internal water system is in good working order.
Alongside this, they will monitor the temperature of water at specific points in the water system. Especially in storage features such as tanks where water is still. They will also be looking for any visible signs of biofilm, dirt and slime within these storage assets.
Assessors may take samples of water from different parts of the system and send them for laboratory testing to confirm if legionella is present.
What is the Risk Assessment looking for?
Legionella risk is dictated by two key factors: temperature and flow.
Water systems which lack proper flow are at a higher risk from legionella. The regular usage of water assets such as taps and showers keeps the water flowing through and reduces the risk of stagnation.
If certain assets are used less often: for instance, if there is one part of a hotel which is used less often, or a shower in an office/warehouse which is rarely used, the water is stagnant and at risk of breeding legionella.
One of the biggest threats to a water system comes from “dead-legs”. Parts of the water system which connect to the main feed but do not have an asset to purge the branch. For instance, if a tap has been removed but the pipework remains with no other way to drain the water. “Dead-legs” are usually left behind during building renovations and are classic breeding grounds for legionella.
Taking the Temperature
Another key element of a legionella risk assessment is to record the temperature of water throughout the water system.
Legionella thrives in warm water- with temperatures of 20°C – 45°C being the perfect environment for it to breed in. Storing water below 20°C ensures the legionella bacteria is dormant, and storing it above 60°C eliminates it. Because of this, assessors will record temperatures at specific points throughout the system.
If water is being stored or used at the wrong temperature, there is a higher chance of legionella being present.
Next Steps
Once the risk assessment is complete, it will identify the risks associated with the system and the severity of these risks, including how to rectify them. Risk assessments undertaken by Legionella Management Solutions include a complete review and breakdown of the findings with your Assessor to ensure you fully understand our findings and what your next steps should be.
If the risk assessment identifies high areas of risk, a list of remedials works will be suggested to the customer to eliminate these risks.
If the samples come back positive, Legionella Management Solutions will complete a Legionella Positive Action Plan (LPAP) which includes guidance and instructions on how to combat the results. Further samples will then be taken to ensure the bacteria has been eliminated.
Legionella Risk Assessments are therefore a key tool for any organisation looking to keep their water systems functional, clean and safe. They arm an organisation with the facts about their system and give them a strong understanding of their risk factors.