Dwr Cymru Welsh Water
Business Customers The impact of COVID-19 How to restore your drinking water system

How to restore your drinking water system

At Welsh Water, our most important responsibility is supplying 1.4m homes and businesses with safe and clean drinking water 24 hours a day, 365 days a year. During the COVID-19 pandemic, we’ve been doing everything we can to maintain people’s water supply and protect our customers, by delivering over 900 million litres of clean water every day.

As part of our role, we carry out 300,000 water tests every year and work with customers to ensure it’s of a high quality. The UK Government social restrictions placed on businesses and other organisations since 23rd March has seen many buildings and sites close for a prolonged period. In turn, this impacts water quality, as many drinking water systems (including water storage tanks and pipes) within buildings will have been left standing during the lockdown.

Standing water can result in:

  • The water in internal plumbing systems becoming warmer
  • Microbiological growth (such as bacteria) in the water
  • An increase in plumbing metals seeping into the water

All of this can adversely affect the quality of drinking water and potentially pose a risk to people’s health. So it’s important that building owners, landlords, managers or operators of a Refill scheme take certain steps before the building is reoccupied.

Follow these steps to safely recommission the water system in your building:

  1. If your water is supplied from storage, empty and refill your storage cisterns with water direct from the incoming supply, before the taps are flushed.
  2. Run all the taps in your building or site individually (also known as flushing), starting with the tap nearest to where the water enters the building and moving systematically to the ones furthest away, until the water is clear and feels cool to touch.
  3. You need to make sure that when you carry out flushing you reduce the risk of water droplets becoming airborne so e.g. remove showerheads, slowly open taps and close the lid on toilets before the first flush. Safety considerations should be made for those carrying out the flushing including providing the appropriate PPE such as a mask to prevent inhalation of water droplets.
  4. Make sure all your appliances are thoroughly flushed before they’re used too, being careful to follow the manufacturer’s instructions.
  5. If you have any internal filters or water softeners, check they’re working correctly as outlined in the manufacturer’s instructions. Consult with the manufacturer regarding the risk of microbial growth on filters or softener resins if they have been sitting unused in water for a significant period of time - you may be advised to replace
  6. Think about equipment connected to the water supply outside of the building e.g. jet washers and flush them safely and in accordance with manufacturers guidance.

For larger buildings

For larger buildings such as those with tanks, showers, calorifiers (also known as indirect-fired water heaters) and more complex pipework, as well as following the above steps, you’ll also probably need to carry out more extensive flushing followed by cleaning and disinfection. If your plumbing system is complex, make sure you have a competent person to oversee this work. When you’re ready to recommission your water supply, make sure it’s in-line with your water safety management plan, including pressure testing all of your systems.

Need more information?

To find out how to make sure your building’s drinking water is safe to drink, please click here to view a briefing note which contains links to further guidance and advice from government and regulators.

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