Legionella bacteria are found in natural and man-made systems and thrive at temperatures between 25C and 45C. Although easily killed by disinfectants, water systems especially in large buildings frequently have stagnant areas, e.g. tanks and "dead legs", where disinfectants introduced by the water undertaker no longer have effect, so water systems where temperatures are inadequately controlled will harbour Legionella bacteria.
If the legionella bacteria were to remain uncontrolled it may create a risk of Legionellosis, which is a form of pneumonia, to building occupants who may be susceptible because of age, illness, immunosuppression, smoking, etc.
Water quality in the University is managed by Estates and Facilities with assistance from Schools and Directorates.