Managing Legionella – how much do you know?

Waterborne diseases pose a significant threat to public health, and among them, Legionnaires' Disease is a serious and potentially fatal illness. Legionella, the bacteria responsible for causing this respiratory infection, can thrive in various water systems. Therefore, all organisations need to be sure that they meet the relevant HSE guidelines to effectively manage the risks.

Legionella bacteria are found in warm water environments such as cooling towers, hot tubs, and plumbing systems and will multiply when temperatures are between 25° and 45°C. When contaminated water droplets are inhaled, individuals can contract Legionnaires' disease, leading to pneumonia-like symptoms. To effectively manage Legionella, it's crucial to first understand its habits and potential breeding grounds.

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:

Identify At-Risk Environments

Legionella thrives in stagnant or warm water, making cooling towers, hot water tanks, and air conditioning systems common breeding grounds. Additionally, places like hospitals, hotels, and long-term care facilities, where individuals may have compromised immune systems, are at higher risk. Identifying and regularly monitoring these environments is crucial in preventing Legionella outbreaks.

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.

However, a recent update to Part L of Building Regulations (Conservation & Power) now emphasises that, for heating systems, flow temperatures should not exceed 55°C, and ideally, they should be kept below this threshold.

While this change brings about several advantages in terms of energy efficiency and environmental impact, it also introduces a new consideration for those that manage secondary hot water systems heated by them — the increased risk of Legionella bacteria formation in hot water systems due to decreased hot water flow, return and distribution temperatures. You can find out more about these changes here.

Routine Checks A routine inspection and clean is an obvious, but important part of preventing Legionella. If necessary, periodic water samples should be analysed. How often depends on the system and the outcome of any risk assessment. Further guidance can be found here on the HSE’s website.

Flush the Pipes Legionella can multiply in hot and cold water systems. Stagnant water attracts Legionella growth, so ensuring all dead ends are removed and all outlets are flushed out at least weekly, will help to reduce the risk.

System DesignWhen 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, please visit the HSE website: https://www.hse.gov.uk/healthservices/legionella.htm

As a business, the best way to ensure you are fulfilling your duties and managing the risk effectively is to ensure at least one of your employees is trained in Legionella management. RelyOn offer a number of Legionella courses which can be viewed here.