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Legionella - keeping existing risks in mind as well as preparing for the new ones

As we respond to the challenges of managing remobilisation through COVID-19, especially with our water systems and services, we do not want to be looking to reduce the risk of one respiratory infection, while potentially increasing it for another. So, as well as the hygiene and social distancing measures you are putting in place, reviewing your Legionella management must be a component of your return to work strategy.

Whether owner occupier, landlord, managing agent or tenant, knowing your water systems and services remain safe, is central to the re-occupation of your workplace. While some premises may have stayed largely operational throughout the “lockdown”, others may have had little or no usage. So, in assessing how best you manage your systems you need to know what has been happening.

There is no blanket approach that will fit all circumstances or individual buildings, so your site specific, water management system and risk assessment are the key documents you need to initially review. In doing so, look at any high-risk areas or recommendations made, that have not been completed and how these may materially affect your management now.

Check your recent records (at the very least the last 6 months), to confirm the systems have been under control or where issues have occurred what they were, (temperature, flushing cleanliness etc.). These could also manifestly affect how you need to develop your plan for demonstrating ongoing compliance.

Assess the likely level of occupancy against the water systems and services installed and you have responsibility for. In tenanted buildings some floors may become completely vacant, where others might have more limited or no reductions in staff. Apply your approach to these areas accordingly and discuss with your landlord or tenants what they have been doing, so you have a complete understanding of the current condition of your water systems.

For buildings that have been fully operational or, for example, with amended schemes to increase flushing due to reduced occupancy, and where the records continue to indicate control, it is likely to be business as usual. Those premises that may have been closed and the water systems not used for the last two months or more, are much more likely to need disinfection and a review of their management prior to reintroduction/re-occupancy.

Items you should have or should be considering include:

  • Have you reviewed your Legionella risk assessment? Is it still valid/up to date? Have any remedial actions and changes been documented? This should be reviewed at each stage of re-occupation to capture any additional risks introduced.
  • Have you assessed likely time frames and levels of occupancy against the water systems and services installed (and you are responsibility for) and any necessary works that need to occur prior to re-occupation?
  • Have you reviewed your water management system to reflect changes in activity and clearly documented any additional control measures introduced/removed?
  • Have all planned preventative maintenance tasks been carried out at the correct frequency e.g. flushing, temperature checks, shower de-scaling, tank and plant inspections with remedial actions documented?
  • If any cold-water tanks or water heaters were temporarily by-passed, have these been re-commissioned and re-instated? Do these require a clean and disinfection?
  • Do you need to confirm the availability/projected lead times of your water treatment company to complete any disinfections in line with your timescales for re-commissioning the building i.e. domestic water systems/cooling towers?
  • Are hot water units set correctly to make sure that hot water is supplied within parameter at periods of higher demand (as occupants will be washing their hands more frequently)?
  • Are there any dead legs on the water systems from lack of occupancy/temporary isolations? Have these been flushed, or removed? Coffee machines, water dispensers, dishwashers and ice machines may have been left as dead legs and could need cleaning prior to re-commissioning.

Other considerations:

  • Have vending machines and other drinking water dispensers that may have been out of use over lockdown been appropriately cleaned and re-stocked prior to reintroduction?
  • Have you reviewed and confirmed your cleaning company's cleaning procedures (where applicable) to make sure that vending machines, water dispensers and kitchen taps are cleaned with cross-contamination minimised?
  • Have drainage and sanitation facilities been checked to make sure they are in good working order i.e. water filled, free of blockages and undamaged for example?

Greg Davies SIIRSM, Director of Market Development, Assurity Consulting.

Greg is a degree-qualified microbiologist and registered expert witness, who has worked for over 30 years in health, safety and environmental compliance management covering aspects including Legionella, health and safety, fire, asbestos, building environment quality and sustainability. He chaired the CIBSE committee that revised TM13 and was the author of the original IWFM good practise guide to risk management. Greg currently chairs the IWFM Sustainability Special Interest Group and has been a committee member of the IIRSM London Group for the last two years.


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