A collaborative approach to preventing Legionella

25 April 2025

Maintaining water hygiene and regularly flushing infrequently used water outlets is crucial for preventing Legionella. Effective prevention relies on a strong partnership between Estates and every department.

Close-up illustration of a colony of Legionella bacteria, showing their characteristic elongated, cylindrical shape.

What are legionella?

Legionella are bacteria that can grow in water systems and, if inhaled, can cause a serious lung infection called Legionnaires' disease. Preventing their growth requires a team effort, with Estates ensuring safe water delivery and departments playing a crucial role in maintaining water quality at the point of use.

Four main principles make for good legionella management:

Keep hot water hot.
Keep cold water cold.
Keep the system clean.
Keep water moving (flushing of little used outlets).

What Estates does

Estates is responsible for:

Ensuring hot and cold water are supplied at the correct temperatures.
Maintaining the cleanliness of the main water systems leading to your departments.
Managing the flushing of water outlets in communal areas, especially during periods of low occupancy.
Offering expert guidance and support for any work affecting departmental water systems.
Addressing reported issues of contamination or scaling in water outlets.

What departments need to do

Departments play a vital role in maintaining water safety by:

Identifying all water outlets that are not used at least weekly.
Implementing and consistently carrying out a weekly flushing schedule for these outlets.
Keeping a record of when each infrequently-used outlet is flushed, especially during University shutdowns.
Immediately reporting signs of contamination or heavy scaling on taps and outlets through MyCampus.
Always consulting Estates before any work is done on your department's hot and cold water systems.

A laboratory water tap showing a heavy accumulation of dark, possibly organic, material and scale at the outlet.

Image: This image, taken in April 2025, shows a laboratory tap with a significant buildup of contaminants and scale. Outlets with this type of contamination can harbour nutrients that promote the growth of bacteria, including Legionella. If you observe similar conditions, please report them on ‘My Campus’ for cleaning and disinfection.

Appointed Person Legionella and Training

Each department using water supplies beyond communal areas must appoint a Legionella Appointed Person to maintain a list of water outlets and act as the primary contact. This includes responsibility for regular flushing and risk assessment of departmental water-using equipment like wave machines, test rigs and ultrasonic baths. This appointment must be recorded in the Responsible Persons Register on riskNET. Training is available for this role, with instructor-led training taking place in May.

Work with the Estates Division to ensure water safety on your premises and involve them early when installing new water equipment. If your department lacks a Legionella Appointed Person and you have questions, email safey@ucl.ac.uk

Where can I get further information

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