How to Manage Water Systems during COVID-19

Practical Advice on How to Manage Water Systems during COVID-19

The legal responsibility for legionella control lies with the Dutyholder, but your water management should provided you with expert advice to assist you in compliance.  Each Dutyholder must make their own determination for each circumstance but the following principles should be considered when making decisions on what to do to control legionella during the COVID-19 outbreak:

What if your building is currently unsafe to access or access cannot be permitted due to COVID-19 restrictions? – How do I review my Legionella Risk Assessment and manage my current compliance obligations?

Consider carrying out a desk based Legionella Risk Assessment with a competent person to outline current risks and provide sensible solutions.

What could a Desk Based Assessment involve?

The desk based assessment will identify areas of elevated risks and will also recommend and detail appropriate, site specific control measures to take immediately, short term and post COVID-19 lock down.

There should be a collaborative approach with the Water Safety Consultant / Duty Holder / Responsible Person / Site Competent Person and Water Treatment Contractors to include:

  • Access to previous Legionella Risk Assessment and schematics (or as fitted drawings).
  • Access to records (temperature, sampling, cleaning records etc)
  • Video Conference / Telecommunication to review current previous risk assessment (if present)
  • Identification of system changes / building changes / operational changes / user changes

Appropriate control measures can be discussed and formally presented by the Water Safety Consultant in writing and as part of the desk based assessment report.

Confirm who is going to complete all the actions and agree on reasonable timescales for completion.

One of the many problems facing DutyHolders at present is low water use due to reduced building occupancy.  Water is currently not being used in its usual volume, increasing the risk from Legionella and other waterborne pathogens.

If the building is still partially in use take additional measures to keep the remaining occupants safe:

  • If possible, drop stored water levels in tanks to maintain <24 hours storage
  • Flush to simulate use – weekly flushing may not be sufficient
  • Monitor temperatures to ensure thermal gain in cold water is controlled
  • Consider other short term measures to keep remaining occupants safe such as point of use filters at designated locations with other areas shut off

Buildings that are temporarily shut down (mothballed) should follow the guidance in HSG274 Part 2 paragraphs 2.50-2.52:

  • Do not drain down pipework
  • If possible, remove sources of heat and external thermal gain
  • Lock off, place signage on doors and otherwise advise potential users that the system has been taken out of use
  • Have a plan in place for recommissioning the water system

For all of the work above there should be a task risk assessment in place to ensure operatives are working safely.

Recommissioning Water Systems following a site shutdown

Unfortunately, there is increased potential for outbreaks of Legionnaires’ disease following the COVID-19 lockdown period if carefully considered actions are not taken.

  • When buildings reopen following the lifting of COVID-19 restrictions, it is essential that water systems are not simply put straight back into use.
  • Small, simple hot and cold water systems should be flushed through with fresh mains water and tested after flushing.
  • Larger buildings such as those with tanks, showers, calorifiers and more complex pipework, are likely to need more extensive flushing followed by cleaning and disinfection. This should be followed up with sampling to prove the efficacy of the disinfection procedure.
  • As per HSG274 part 2, samples should be taken 2-7 days following recommissioning and not on the day of disinfection. Follow up samples may need to be considered as part of the recommissioning plan.