Drinking water systems left stagnant due to prolonged inactivity can lead to poor water quality and the growth of microorganisms such as legionella bacteria, which can be harmful to health when taps get turned on again.
It is the legal duty of those in control of premises such as offices, shops, cafes, restaurants and public buildings such as community centres, leisure centres, libraries and museums to reduce the risks of exposure to legionella bacteria and to make sure their water supplies are safe.
Those responsible for reopening buildings are advised to follow Water UK’s guidance on recommissioning water systems. This includes advice to ‘flush’ the water system with fresh water to replace all water inside the building’s pipework and appliances.
Larger buildings, with storage tanks, showers and more complex pipework, are likely to require more extensive flushing followed by cleaning and disinfection.
Anyone with a complex plumbing system should have a competent person oversee the work.
The guidance advises employing approved plumbers registered with WaterSafe to make changes or repairs. This is because they have specific training in the Water Supply (Water Fittings) Regulations and Scottish Byelaws, to make sure they meet the strict legal requirements for installing water pipes and fittings.
Download Water UK’s guidance on recovering drinking water supplies in buildings and networks after prolonged inactivity:
The CIPHE has produced guidance on mitigating the risk of building water systems post Covid-19:
For further advice on managing risks associated with Legionella visit:
Contact your water retailer for more information. Water retailers can access specialist advice on how to support their clients and the specific issues affecting them from their designated wholesale supplier contact point.