Legionella Risk Assessment in Water System
Hi,
I am looking for a sample Water risk assessment for Legionella in Water supply system.
Can anyone provide a guidance / sample to conduct legionella risk assessment.
Many thanks,
Things to consider regarding legionella to compare against your specific water system using a risk x likelihood matrix are:
- tendency to form droplets and aerosols e.g. still water would be low and aerosol or a lot of spray would be higher risk
- conditions of water e.g. potable, sterlised (UV, RO etc. will give a different risk rating), or known to be contaminated would be higher risk
- water temperature (one of the most crucial factors to consider) if the water is in the danger zone it will be higher risk (zone is approx. <20°C and approx. >50°C
- water flow rate e.g. legionella likes stagnant water so this would be a higher risk on the rating
- other factors such as population, density and susceptibility of exposed individuals
The total rating after adding all these risk ratings can be interpreted to then determine control measures and testing frequency
Thanks,
Would you be able to provide more accessible template?
Hygienic design inspection is so crucial for water system to see if the system is vulnerable for legionella or not ( if you have seasonal production ( risk of still water) rusted containers , dead legs , improper piping slop , improper PM of filters specially carbon and sand filters your system is vulnerable )
Visual inspection and backwash checking ( color , nature after backwash) can give you an idea for Risk assessment.
I have found some legionella cases due to poor condition of water system ( Hygienic design )