Managing Legionella - how much do you know?

05 November 2015

Legionnaires’ disease is a dangerous form of pneumonia that everyone can be susceptible to, all organisations need to be sure that they meet the relevant HSE guidelines to effectively manage the risks.

Legionella bacteria are found in water and will multiply when temperatures are between 25° and 45°C. It is contracted by inhaling airborne water droplets and although the elderly are particularly vulnerable, anyone can develop the disease.

Earlier this year, legionella bacteria was found in cooling towers at three schools in New York and in August, the city’s historic Opera House Hotel was identified as the source of a deadly outbreak that killed 12 people and sickened 128.


If you are a landlord, employer or someone in control of premises, it is important that you understand and mitigate the risks associated with Legionella. You are responsible for the health and safety of your tenants and employees and should take the necessary precautions to reduce the chances of exposure to the disease. Here are some ways that you can do that:

Temperature Control
The primary method used to manage Legionella is to operate water services at temperatures inhospitable for the bacteria. Hot water cylinders would therefore store water at 50°C or higher and cold, below 20°C.

Routine Checks
A routine inspection and clean is an obvious, but important part of preventing Legionella. If necessary, periodic water samples should be analysed.

Flush the Pipes
Stagnant water attracts Legionella growth, make sure all dead ends are removed and flush out outlets on a regular basis; particularly ones that are infrequently used.

System Design
When designing water systems, pre-empt the risks of Legionella by keeping pipe-work as short as possible, include adequate insulation and prevent contamination with lids and screens.

For a more in-depth overview, DTL recently published an in-depth whitepaper looking at the causes of legionella and strategies to prevent the disease in air conditioning and water systems - get your free copy here:

Click here to download your FREE legionella whitepaper

More information on DTL's legionella training solutions can be found by following this link. Alternatively, call us on 0800 876 6708.