If your building has been closed or with reduced occupancy during the coronavirus (COVID-19) outbreak, water system stagnation can occur due to lack of use, increasing the risks of Legionnaires’ disease.

The serious Legionnaires’ disease, as well as the similar but less serious conditions of Pontiac fever and Lochgoilhead fever, are caused by legionella bacteria, which are widespread in natural water systems such as rivers and ponds. However, the conditions are rarely right for people to catch the disease from these sources. Outbreaks of the illness occur from exposure to legionella growing in purpose-built systems where water is maintained at a temperature high enough to encourage growth, such as cooling towers, evaporative condensers, hot and cold water systems and spa pools used in all sorts of premises (work and domestic).

Employers, the self-employed and people in control of premises, such as landlords, have a duty to identify and control risks associated with legionella.

The HSE has issued guidance specific to risks associated with the coronavirus pandemic. It advises that you should review your risk assessment and manage the legionella risks to protect people when the water system is reinstated or returned to use.

The guidance looks in detail at the following areas:

• Hot and cold water systems;
• Cooling towers and evaporative condensers;
• Commercial spa pools and hot tubs;
• Methods of control;
• Changing control methods – risk to operators;
• Personal protective equipment (PPE) required for cleaning water systems; and
• Getting specialist help.

You may need advice from a competent person and/or specialist to help you identify and implement suitable controls for legionella.

The HSE recognises that getting specialist help may be difficult during the coronavirus outbreak. If you’re unable to appoint someone with the appropriate authority and competence to oversee the risk controls of water systems, you must consider stopping operation of the systems.

You can find out what Legionnaires’ disease is, where it comes from, how people get it and symptoms and treatment by reading the HSE guidance What is Legionnaires' disease?.