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Legionnaires' disease is contracted by breathing in large numbers of the legionella Pneumophila bacteria. These bacteria are widespread in the environment and are able to thrive in warm water conditions. They can be found in water systems, such as hot water tanks, cooling towers and large air conditioning systems. They are more likely to be found in complex plumbing systems.
Water suppliers treat drinking water with chlorine to kill off bacteria. However, they can continue to thrive in plumbing systems which are not installed or maintained correctly, which is why WaterSafe urges homeowners and businesses to only choose qualified and knowledgeable plumbing businesses.
Top tips to avoid problems with Legionnaires' disease include:
Only use a qualified plumber
Ensure suitable fittings are used (Reg 4 compliant)
Keep the design of plumbing systems simple
Design a system so water is regularly turned over and does not stagnate
Ensure hot and cold water are kept at the correct temperatures
Businesses should follow the advice within the HSE approved code of practice L8 to ensure they meet their legal duties under the Health and Safety at Work Act 1974 to manage risks from legionella bacteria.
In May 2020, Water UK published guidance to building owners, landlords and managers on recovering buildings and networks after prolonged inactivity during Covid-19 to avoid risks of adverse water quality and potential risks to health – including legionella bacteria.