The water supplied to your home by the water company must meet the standards set in the Water Supply (Water Quality) Regulations 2000. The standards are strict and the water company is monitored by the Drinking Water Inspectorate (DWI) who carry out regular tests to ensure that the water quality meets the required standards.

Things that we do in our homes can affect the water quality and even encourage bacteria growth.

Legionnaires’ disease is a kind of pneumonia that can kill. It can affect anybody, but mainly affects people who are vulnerable or elderly because they have a lower immune system.

The disease is caused by a bacterium called Legionella pneumophila, and other related bacteria. These live in rivers, lakes and reservoirs, usually in low numbers. They can also live in purpose-built water systems such as hot and cold water systems, storage tanks, pipework, taps and showers.

If conditions are favourable, the bacteria may grow, creating conditions in which the risk from Legionnaires’ disease increases, so it is especially important to control the risks.

The risks tend to be higher in larger water systems but bacteria can also live in smaller water supply systems, ones usually used in homes.

Legionella can survive in low temperatures, but thrive at 20°C to 50°C. Temperatures of 60°C and over will kill Legionella.

If you have a domestic hot water storage tank, a combination boiler or a multi point heater in your home, the thermostat should be set at 60°C. This will be checked and set by the heating engineer when the heating and hot water systems have their annual service. DO NOT reduce this setting as bacteria can multiply at lower temperatures.

If you are away from home for long periods (for example holidays or hospital stays of 2 weeks or more) the water in your system can deteriorate if unused. When you return home, heat up your system to the normal temperature and open each tap and run for at least 5 minutes.

If you have a shower fitted, clear your shower head regularly to remove scale and run for 5 minutes if it’s not been in use regularly.