The risks presented by Legionella bacteria in water systems were in the headlines again in February, following inquest findings which highlighted the failures that led to the death of 68-year-old Terry Brooks at Bath’s Royal United Hospital in July 2015.
Mr Brooks died from pneumonia caused by Legionella following a 24-day stay at the hospital’s cancer ward, according to The Bath Chronicle.
Subsequent investigations revealed that water samples taken from the ward in question the day before Mr Brooks’ death were contaminated with Legionella. Tests also confirmed that three homes he could have visited around the same time were free of the bacteria, and expert opinion also ruled out two pubs he had visited in the weeks before his death as likely sources of infection.
Broken pump
The head of estates at the hospital, Brian Gubb, told the inquest on 8 February that in the investigations following the tragedy, it was discovered that the temperature of water in a hot water return pipe was between 35C and 40C – below the minimum 60C normally specified to minimise the risk of Legionella bacteria. The source of the problem was later revealed to be a broken water pump in a water loop feeding a section of the ward, which had meant the water wasn’t being returned to the boiler frequently enough to keep it at the required temperature.
Such an error had been made possible, it seems, by the estates department not being in possession of up-to-date diagrams of its water system, so it was unaware either that this area of the ward had its own water loop, or that the broken pump existed, or how long it had been broken.
Monthly water temperature checks, which were carried out at a kitchen sink at the other end of the ward, had not revealed the problem.
Preventative measures
The incident seems to highlight the need for vigilance with respect to this issue, on the part of estate managers, as well as manufacturers and specifiers of equipment.
Commenting on the lack of access to the original water system diagrams which had led to the incident, Chris Meir of Andrews Water Heaters suggested Building Information Modelling (BIM) will play an increasingly important role in helping avoid such incidents, ensuring that key information on the design of a system is easily to hand.
He also pointed to anti-Legionella functionality in water heaters as a measure that can further help avoid disaster.
