What are Legionella Risk Assessments?

While a leaking water tank or faulty water booster pump can be inconvenient, they pose minimal risk to human health. The same cannot be said for Legionella growth in your water system. Inhalation of this deadly disease can cause serious illness. 

All employers, landlords or premises managers have a legal duty to understand and manage the risks associated with Legionella within their property or workplace. This includes ensuring that a Legionella Risk Assessment of all water systems is carried out on a regular basis.

Many people choose to leave their Legionella Risk Assessments to the water hygiene experts. H2O Comply can help you control the risks presented by Legionella and other water-borne bacteria. Here’s our guide to Legionella and Legionella Risk Assessments, so you know what to expect from your water hygiene specialist.

What are Legionella bacteria?

A natural, common type of bacteria found in freshwater environments, Legionella can be a potentially serious health concern in the event it grows and spreads across man-made water systems such as your showerhead, taps, hot water tanks or heaters. Inhalation or absorption of the bacteria could lead to the development of Legionnaires disease, an often fatal form of pneumonia. 

Ideal conditions for Legionella growth

Legionella occur naturally and can be found in a range of natural and artificial water systems, such as lakes, rivers, and soils. They can also be found in mains water supplies, albeit in low numbers, so it is likely they’ll find their way into buildings’ water systems.

The low amounts of Legionella in freshwater are usually not problematic, but Legionella can pose a health risk when they make their way into buildings’ water systems and multiply. Legionella bacteria require iron to grow, so thrive in nutritious environments created by things like rust, sludge, scale, algae, and other bacteria. 

Legionella grows best between 20°C and 45°C. They can be killed rapidly at temperatures above 60°C, and they do not multiply at temperatures above 50°C or below 20°C. However, they can remain alive until the temperature rises to a suitable level for multiplication, unless they are dealt with.

What does a Legionella Risk Assessment involve?

A Legionella Risk Assessment will include a review of your previous assessments and your current records to ensure that all recommendations of remedial works or maintenance have been acted upon.

A typical assessment will also involve an assessor taking a close look at all water sources and systems on your property, with a specific focus on areas where water is stored or where there is the potential for aerosols to be created.

Based on the findings produced by this legionella testing, a report will be prepared. This report will outline any recommendations of what you need to do to lessen or lower the Legionella risk. Find out more about what the report consists of below.

When to conduct a Legionella Risk Assessment

The Approved Code of Practice L8 states that a Legionella Risk Assessment should be carried out “regularly and specifically when there is reason to suspect it is no longer valid.”

As a general guide, it is often recommended that you should carry out a Legionella Risk Assessment whenever there is any change in circumstances relating to your water system. This could include:

●     A change in the use of the building in question

●     A change in the water system itself

●     Updated legislation relating to Legionella Risk Assessments

●     Changes to key employees within the company

●     When there has been a reported case of Legionnaires’ disease

What’s included in a Legionella Risk Assessment report?

The report may vary slightly between water hygiene specialists, but they will usually contain the same or similar information. When H2O Comply carries out a Legionella Risk Assessment, we produce a concise, detailed report which comprehensively covers the following:

Any samples collected are analysed by a UKAS-accredited laboratory for TVC, E-Coli, Coliform and Legionella. We provide a written plan for the management, prevention and control of identified risks of Legionellosis, including a schedule for regular inspections, water analysis, temperature checks and record-keeping.

H2O Comply also offers Legionella Risk Assessment Monitoring and Inspection. These site inspections and visits provide an ideal opportunity to update the existing risk assessment and ensure the ongoing accuracy of the written report, accounting for any changes you have made. With our Legionella Risk Assessment Reviews, the original plan, recommendations, and control measures are regularly reviewed and discussed in order to ensure that they remain efficient and cost-effective.

How can I help to maintain excellent water quality?

Making sure your water system is sanitised and free of bacteria is extremely important. Here are some key ways to maximise your water quality and keep your water system protected against Legionella.

Carry out regular maintenance

Regularly using and maintaining your water system should help prevent it from becoming an ideal environment for Legionella. Frequent inspections and maintenance can help you avoid encouraged Legionella growth. Using all taps, showers, and other water-related appliances regularly can also reduce the chances of stagnant water in your system.

Check disinfectant levels

Disinfectants such as chlorine, stabilised silver hydrogen peroxide, and ultraviolet light can help regulate Legionella by killing enough of bacteria to make your water system safe again. However, processes such as heating and filtering can reduce the disinfectant levels in your water system, so it’s important you regularly check disinfectant levels and increase them if they are too low.

Check and adjust water temperatures

Legionella bacteria thrive in temperatures between 20°C and 45°C. They do not multiply at temperatures above 50°C or below 20°C and can be killed quickly at temperatures above 60°C. In order to make sure Legionella can’t thrive in your water system’s temperatures, it’s important to keep cold water cold and hot water hot. While they won’t multiply, legionella can still survive in these temperatures, so it’s important you keep the water temperature consistent and take other precautions.

Prevent stagnant water

Poor water flow and/or minimal usage can result in stagnant water within your water system, encouraging biofilm growth and issues such as rust, scale, sludge, and algae. It can also reduce water temperature and disinfectant levels. Put simply, stagnant water can create the perfect environment for Legionella to survive and multiply. It is important to identify the areas within your water system that might be prone to stagnant water and take steps to ensure this does not happen.

Need a Legionella Risk Assessment? H2O Comply’s Water Hygiene Experts Can Help

If you’re worried about Legionella in your water system, H2O Comply can help. We are a team of specialist water treatment engineers you can trust, providing everything from Legionella testing, Risk Assessments and monitoring to microbiological sampling and pipework chlorination.

If you choose us for your Legionella Risk Assessment, our specialists will conduct a thorough survey of any water systems and water distribution services within your property and provide a fully compliant, site-specific report of your water system upon completion. This will provide a range of recommendations as to how you can reduce or eliminate risk of Legionella growth and keep your water system safe.

Contact us today to find out more about our services.