Reopening Work Premises Safely

Maintenance of water systems in commercial buildings

Advice for building owners and managers

Irish Water continue to work with our Local Authority partners to maintain a safe and reliable public water supply that will continue as Covid-19 restrictions are eased and businesses begin to re-open. There are a number of steps that you can take to help ensure your water and wastewater systems in your business are safe before reopening. See below for information and advice or click on the link to view the full booklet.

View booklet

Protect public health

Protect public health

Serious water quality and public health hazards can develop in the water and cooling systems of buildings that have been closed or under-used for a period of time. You can reduce these risks and help protect the health of your staff, visitors and customers by ensuring you have a maintenance and reopening plan, specific to your building, in place.

If possible, water systems should be kept operational and fully maintained during periods of closure to minimise the risk of disease and infections when buildings reopen. As every building is different, with unique plumbing systems, building managers should get specialist advice if in-house expertise is not available. 

Legionnaires’ disease

Legionnaires’ disease

If water is left standing in plumbing systems and storage tanks for too long, harmful bacteria can grow and multiply, causing serious illness such as Legionnaires’ disease when re-used again. Legionnaires’ disease is a potentially fatal form of pneumonia and hospitalisation is generally required to treat symptoms. For advice, view the HSA's guidance on the Control of Legionella. For facilities such as healthcare settings and leisure centres, specialist advice is needed. Hospitality services may also require more detailed measures associated with water-using equipment. As an example, view the HSE's Checklist for Leisure Centres.

Find out more about Legionnaires' Disease

Other potential hazards

Wastewater systems

Wastewater systems, including toilets and shower rooms, that have not been used for several weeks must be checked to ensure they remain hygienically safe. Water trap seals under toilets and in drains, which prevent odours, insects and bacteria coming back up the pipework into your building, should be checked to make sure they have not dried out or come loose.

​Storage tanks

When buildings have been unoccupied for any length of time, there can be an increased risk of infestation by pests and vermin, which may result in biological contamination of water in storage tanks.

Lead in drinking water

In older buildings with lead pipes and fittings, small amounts of lead can dissolve in water that has been sitting in the pipes for long periods. Lead in drinking water is a recognised health concern and even low levels can affect human health. Similarly, particles in old metal pipes can settle in stagnant water and become disturbed when re-used.

Find out more

Checking for leaks

When your business reopens, it may be a good opportunity to check for and repair leaks on your premises. Water can be very destructive, whether it seeps from a loose fitting or gushes from a burst pipe. By finding and fixing leaks at an early stage, you could prevent costly damage and repairs later. 

Find out more

Check for and clear blocked drains

Fats, oils and grease (FOG) generated during the preparation of food and washing up processes can cause blockages that, if left untreated, could result in flooding and damage to your business. Severe blockages can cause sewers to overflow into business premises, public areas and rivers resulting in environmental and public health hazards.

Find out how to check for and clear blockages

Your drinking water quality

We carry out regular testing and monitoring of all public water supplies in Ireland to ensure the water quality is of an acceptable standard, as set out in the European Union Drinking Water Regulations 2014 legislation.

Check your water quality

Your drinking water quality

Bringing your water systems and devices safely back into use

  • Flush water pipes by running taps until the water temperature is constant and mains water is drawn through the system
  • Clean all drinking water outlets with suitable disinfectants
  • Flush all toilets, and run water through sinks and shower basins, to ensure that the water trap seal is replenished in the u-bends
  • Inspect all storage tanks and cisterns, and drain, clean, disinfect and refill as necessary;
  • Clean shower-heads with disinfectant and flush water through until clean, with a minimum temperature of 60°C for hot water showers
  • Empty hot water tanks and refill with water heated to 70° C for at least an hour before use
  • Replace filter cartridges in water filters and clean & disinfect the cartridge holder according to manufacturer’s instructions, then run water through to flush clear
  • Check pumps on the building’s water/wastewater system to ensure that they are operating correctly
  • Check sewer & drains and clear any blockages promptly
  • On-site wastewater treatment systems should be checked to ensure they are operating correctly

Please note, sampling and monitoring of water quality should be continued after the water systems have been cleaned to ensure the water is clean and safe to use.

Frequently Asked Questions

Businesses are charged for all water that they use. Irish Water would not be able to determine what was used to flush the system in addition to normal business use.

We are only able to advise that there is an increased risk on water quality that could lead to illness, however, because each building is different and we don’t know your circumstances, we can only offer general guidance in our advisory note. If you require further assurance about the safety of the water systems in your premises, please seek specialist advice from qualified professionals.  

It is good maintenance practice to conduct regular checks on the water and wastewater infrastructure within your premises, especially during closures, to mitigate against issues that could delay reopening.   

If possible, to reduce the risk of disease and infections after a period of building closure, we would advise you to keep the water systems operational and fully maintained while the building is closed. This will reduce the need to take special measures to ensure the water systems are safe before reopening.    

We would advise you to ensure all fittings and fixtures, such as taps, sprinklers, hot-tubs, fountains etc., are thoroughly cleaned before being brought back into use and that pipes and tanks are flushed of standing water. You may also consider whether certain types of fixtures (such as water fountains or ornamental pools) need to be brought back into service immediately.

Particular basic measures for consideration may include:

  • Flush water pipes by running taps until the water temperature is constant and mains water is drawn through the system
  • Clean all drinking water outlets with suitable disinfectants
  • Flush all toilets to ensure that the water trap seal is restored
  • Inspect all storage tanks and cisterns, and drain, clean, disinfect and refill as necessary
  • Clean shower-heads with disinfectant and flush water through until clean, with a minimum temperature of 60°C for hot water showers
  • Empty hot water tanks and refill with water heated to 70° C for at least an hour before use
  • Replace filter cartridges in water filters and clean & disinfect the cartridge holder according to manufacturer’s instructions, then run water through to flush clear

Specialist advice is required for healthcare, swimming pools, leisure centres, gyms, saunas and similar facilities. Equally, food and drink production and hospitality services may require more detailed measures associated with water-using equipment.

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