05 May 2020

Now is the time to plan the recommissioning of your buildings water system post #coronavirus restriction. If you fail to do so you risk longer delays to opening or worse, run the risk of creating further health hazards from operating your water systems inc. Legionella outbreaks.

Planning for the Reopening of Premises - Recommissioning  of Hot & Cold Water Systems.

When restrictions are lifted and we begin returning to work, it will be important to recognise that, if premises were closed or only partially open, then additional measures. will need to be in place and undertaken. Fail to do so and you run the risk of creating further health hazards from operating your water systems.

The systems should be recommissioned as though they were new (ie thoroughly flushed, cleaned and disinfected) before returned to use.

Pg24. 2.5.2 - Buildings temporarily taken out of use (mothballing): HSE - HSG274 Part 2: Legionnaires’ disease The control of legionella bacteria and cold water systems

Download Reopening Premises Pack

Legal responsibilities for Health & Safety haven’t changed, including those applicable to the prevention of Legionella.

The time to consider a recommissioning plan is now.

A high demand for flushing, disinfection, sampling and other recommissioning work is predicted. Should you fail to plan ahead now you risk a longer delay beyond the loosening of government measures.

Whilst every water system should be given it’s own consideration, as a minimum you should look to:

Review Risk Assessment & Control Measures

If you haven’t already, now is the time to consider a plan for reopening your building. As part of this plan your legionella risk assessment should be updated. The impact of low occupancy or mothballing due to COVID-19 will have had a significant effect on risk and your review should document the additional measures you are implementing.

Flush / Avoid Stagnation

As a simple control measure, to avoid stagnation, flushing should have been implemented for the duration of low use. However, as a minimum expectation, before reopening your premises, systems should be thoroughly flushed with fresh mains water, with some additional measures required for larger systems i.e cleaning and disinfection.

Disinfection of Water Systems

If you operate a larger building or more complex water systems, e.g. a school, large office block or factory, then a disinfection of the water system will be required. High demand for disinfection services post restrictions means you should consider organising now to ensure works can be carried out in time or risk a longer delay beyond the lifting of government measures.


If your system requires recommissioning (most cases) you should consider sampling to indicate the effectiveness of your additional control measures or until control is restored.

Note! Whilst the measures above outline a minimum requirement of published guidance, these are not always 100% effective, other strategies maybe considered to regain control of your water systems. We recommend consultation with your Account Manager and to evaluate the specific options open to you.

Download Reopening Premises Pack

For more information on Reopening of Premises please call 0800 138 21 21 or use the form below

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