As occupants return, Legionnaires’ disease risk emerges
Legionella bacteria can proliferate in stagnant pipework – an important health and safety fact to remember for FMs, as occupants return to work.
Facility managers must be diligent to ensure they minimise the risk of a Legionnaires’ outbreak when restarting facilities that have been partially or fully shut down as a result of COVID-19 measures, says a release from HydroChem.
As buildings are reoccupied and pedestrian activity increases, it is important water systems are properly recommissioned and tested to mitigate Legionella risks that may have developed during the shutdown.
“Ideally, facilities should have placed their cooling water systems into hibernation, providing ongoing disinfection to minimise the risk of Legionella growth within pipework,” says HydroChem CEO Nicholas Duncan. “If not, the managers of those facilities must take additional precautions on restarting their cooling systems,” he adds.
“Buildings that have been partially or fully shut down for more than a week are likely to have stagnant water in the pipework that distributes water to taps, showers and ice machines. This water presents a risk of propagating Legionella. We also need to be especially mindful of people at a higher risk of contracting Legionnaires’ disease – such as people who are immunocompromised or have pre-existing health conditions.”
HydroChem recommends all water systems are flushed before use and Legionella testing is conducted to identify any compromised systems.
Australia has experienced Legionnaires’ outbreaks associated with cooling tower systems, such as the Melbourne Aquarium case in 2000, and with water distribution systems, such as at Wesley Hospital in 2013. HydroChem’s release has recommendations for each system:
Water cooling systems
- Water cooling systems should be in ‘hibernation’ not shutdown.
- If not in hibernation, all pipework and equipment must be fully drained.
- Prior to start-up of any cooling water system, a cooling tower clean must be conducted and care must be taken to disinfect all system water.
Water distribution systems
- Prior to facilities being open for use, all water outlets should be flushed for at least three minutes each.
- Legionella testing should be conducted to ensure pipework has not been colonised by Legionella during periods of stagnancy.
Legionnaire’s disease presents similar symptoms to COVID-19 such as fever, cough, shortness of breath and, potentially, fatal pneumonia.