Legionella could lurk in the water supplies of school buildings, and some measures to keep people in schools safe from coronavirus may even increase risks from deadly illnesses caused by the bacteria.

Legionella, usually Legionella pneumophila, is the bacteria that causes Legionnaires’ disease, a respiratory condition. It can form in stagnant water and then disperse through the air and be inhaled when, for example, a shower or tap is turned on. It can be fatal in one in 10 cases, according to the US Centres for Disease Control and Prevention.

To protect against the spread of coronavirus, many school buildings have been unoccupied since March. Their bathrooms, cafeterias and sports facilities have gone unused. While low occupancy in schools is typical during summer breaks, many are open for summer school and other activities. Experts worry that water was left to stagnate in plumbing during lockdown, and that schools don’t have plans or effective guidance from health authorities for dealing with the effects of prolonged shutdowns.

But stagnant water in unused drinking fountains or sink plumbing could be a good reservoir in which the bacteria could grow. Shower heads like those found in locker rooms are also common places for Legionella to proliferate. 

Environmental Efficiency has completed a total of 15 legionella assessments in recent times:

  • 12 pre-COVID; 3 post-COVID
  • All three post-COVID had positive results.  Only 1 of 12 pre-COVID had tested positive.
  • The trend in positive results post-COVID seem to follow;
    • Insufficient care in monitoring the internal condition of cold-water storage tanks (CWST). A build-up of sediment and rusting of internal support bars.
    • Insufficient insulation of hot and cold-water pipes to outlets behind the walls, particularly the hot pipes heating up the cold bringing it >20oC, then being left stagnant over the lockdown.
    • Boilers being left off during the period, with stagnation in the system. 
    • Use of non-WRAS approved fittings used in water tank design. E.g. corrugated metal covering used as a lid for CWST, metal support bars, steel CWST, Inlet/ outlets being to close to each other.

For Legionella enquiries, please contact our office: 01 276 1428 or email rsutcliffe@enviro-consult.com

Author: George Byrne.