What should a legionella management plan include?

A legionella management plan is a site-specific document that turns the findings of a risk assessment into an organised water-safety system. It should explain which water systems present a risk, who controls each part of the process, what precautions are required, how those precautions are checked, and what happens when performance falls outside the agreed limits.

Scope and system description

The plan should begin by defining the premises, water systems and activities covered. This may include hot and cold water services, storage tanks, calorifiers, showers, taps, thermostatic mixing valves, cooling systems, spa pools or other equipment that can generate aerosols. A schematic or asset register can show how water flows through the site and identify less-used outlets, dead legs, redundant pipework, temperature-controlled areas and equipment requiring special attention.

The description should reflect how the systems operate in practice rather than relying solely on design drawings. It should record changes such as extensions, alterations to occupancy, periods of low use, changes in water demand or the introduction of new equipment. These factors can affect water stagnation, temperature control and the likelihood of exposure.

Risk profile and control objectives

The plan should explain the significant risks identified for each system and the people who could be exposed. Consideration may be needed for residents, employees, contractors, visitors and people who are more susceptible to Legionnaires’ disease. The relevant factors can include age, underlying health conditions, access to showers or other aerosol-generating outlets, and the nature of the building’s use.

Control objectives should be specific enough to guide day-to-day work. For example, the plan may set out the required temperature performance at designated points, the need to prevent stagnation, the condition standards for tanks and calorifiers, and restrictions or precautions for equipment that cannot be adequately controlled. The objectives should be consistent with current HSE guidance, including the Approved Code of Practice L8 and the relevant parts of HSG274.

Defined duties and authority

Names or clearly defined job roles should be assigned to the dutyholder, responsible person, deputies, contractors and anyone carrying out operational checks. The document should state who can approve changes, isolate equipment, arrange corrective work, review results and escalate unresolved issues. Where duties are shared between a landlord, managing agent, facilities team and specialist contractor, the boundaries between those parties should be explicit.

It should also distinguish between people who carry out a task and those who verify that it has been completed correctly. This prevents important decisions being left to assumption and helps demonstrate that the organisation has suitable management arrangements.

Operational control scheme

The practical section should describe the routine measures used to keep the systems under control. Depending on the site, this could cover:

• temperature checks at representative outlets and relevant storage or heat-producing equipment;
• flushing arrangements for outlets that are infrequently used;
• cleaning, disinfection and inspection of tanks, calorifiers and associated components;
• removal or modification of redundant pipework and fittings;
• management of thermostatic mixing valves and other devices that affect temperature;
• precautions for showers, spray taps, humidifiers, cooling systems and other aerosol-generating equipment; and
• controls applied after periods of closure, reduced occupancy, maintenance or water-system interruption.

Each measure should identify the location, method, frequency and person responsible. It should also specify how a missed task is recorded and followed up. A general instruction to “monitor the system” is unlikely to be sufficiently useful unless the plan explains what is monitored and what result is acceptable.

Sampling, verification and records

Where water testing forms part of the control strategy, the plan should define why samples are taken, which outlets or systems are included, how samples are handled, and how results are interpreted. Testing should support the risk-based control approach rather than replace routine system management. The plan should identify who reviews laboratory reports and how findings are linked to corrective decisions.

Records should be organised so that an auditor or responsible person can trace the history of a system. Useful records may include asset information, inspection sheets, temperature logs, flushing records, cleaning and disinfection certificates, laboratory reports, maintenance documents, training evidence, incidents, corrective actions and formal reviews. The retention arrangements should be stated and records should be protected against unauthorised alteration or loss.

Incident and escalation arrangements

The plan should provide a clear route for dealing with failed temperatures, positive or concerning test results, contamination, equipment breakdowns, suspected exposure, complaints or an identified loss of control. It should set out who is informed, what immediate precautions may be necessary, when outlets or equipment should be taken out of use, and who determines when normal operation can resume.

Escalation should be proportionate to the risk and supported by written decision-making criteria. The procedure should include contact details for relevant internal roles and competent external advisers, while avoiding reliance on one individual. Where a suspected case of Legionnaires’ disease arises, the plan should support liaison with appropriate public health and regulatory bodies in accordance with current guidance.

Competence and communication

The document should identify the knowledge and practical competence required for each task. This includes understanding the systems, recognising abnormal conditions, taking reliable measurements, maintaining records and knowing when a matter must be referred. Induction and refresher arrangements should be linked to job responsibilities rather than treated as a one-off administrative exercise.

People using or maintaining the building may also need relevant information, particularly where access to outlets is restricted, equipment is isolated or remedial work affects normal use. Contractors should receive the system information needed to work safely and should provide suitable completion records for tasks they undertake.

Review and change management

A plan should be reviewed when monitoring identifies a weakness, after an incident, following significant maintenance or alteration, or when the building’s use changes. It should also be checked periodically to confirm that named roles, assets, control frequencies and escalation contacts remain accurate. The review should consider whether controls are working in practice, not simply whether paperwork has been completed.

Version control, approval dates and a record of amendments help show which arrangements applied at a particular time. A management plan is most effective when it remains aligned with the current water system and is used by the people carrying out the work, rather than kept as a static document.