As an employer, facilities manager or landlord, it’s your responsibility to take actions in order to control the risks associated with the Legionella bacteria. As a duty holder, you are required to make an assessment of the risks or hire someone who is competent to do so, and take steps to implement an effective control regime.

It is essential that you have a thorough knowledge of your building’s water system, any equipment where water may accumulate, and any areas where conditions may be right for the bacteria to thrive and multiply.

Effective control measures

To ensure you fulfil your responsibilities with regard to legionella prevention, check the HSE’s Approved Code of Practice. Your basic responsibility is to avoid water temperatures and conditions where legionella – and other micro-organisms – can grow. This includes ensuring the water temperatures are either too hot or too cold for the Legionella bacteria, keeping the system clean and making sure that any unused piping systems are removed.

Assessments are, of course, especially vital in buildings used by people who have suppressed immunity as this will make them particularly vulnerable to any threats from the bacteria.

Extra care also needs to be taken when you have an open system, e.g. spa pools, cooling towers, evaporative condensers, etc., and additional testing is advised.

How do you know if your precautions are working?

The absence of an outbreak of Legionnaire’s disease is not an indication that your legionella control regime is adequate. The only sure way of knowing is to test the water for the presence of bacteria, in addition to taking measures to prevent an outbreak.

Regular testing will supplement your maintenance and control methods, giving you peace of mind that your precautions are effective at the same time as demonstrating that you are taking steps to control the bacteria.

Our advice is to test annually – unless circumstances such as changes to the water system or HSE advice require additional testing – to ensure that you have complete confidence that your legionella control regime is working effectively. If you would prefer testing to be carried out by a specialist company with fully qualified engineers, contact us for more information.