Who is responsible for legionella control in commercial premises?
Responsibility for legionella control in commercial premises rests with the employer or person responsible for the business or undertaking, commonly referred to as the duty holder. They must assess and control the risk, appoint a competent person to manage necessary measures where appropriate, and ensure those arrangements are properly implemented and reviewed.
In practice, responsibility is held by whoever has sufficient control over the premises, work activities and water systems to prevent or manage exposure to legionella. This may be an employer, building owner, landlord, managing agent, occupier, facilities manager or another person with defined control. Where duties are shared, each party must understand its own responsibilities and coordinate with the others.
The duty holder is the person who has primary responsibility for health and safety in the business or undertaking. In an owner-occupied workplace, this will usually be the employer or business owner. In leased or multi-occupied premises, responsibility may be divided between the landlord, tenant, managing agent and facilities provider. The relevant question is not simply who owns the building, but who controls the parts of the water system and activities that could create or expose people to risk.
A landlord may control central plant, storage tanks, calorifiers, distribution pipework and maintenance arrangements, while a tenant may control outlets, local equipment or the way water is used within its occupied area. Contracts can allocate tasks, but they should clearly identify the systems covered, the work each party must undertake, access arrangements, reporting processes and what happens when a defect or elevated risk is found. Contractual arrangements do not remove the underlying legal responsibility of the person who controls the relevant risk.
What the responsible person must do
- Arrange a suitable and sufficient legionella risk assessment for relevant water systems.
- Identify sources of risk, including conditions that could allow legionella bacteria to grow or spread through aerosols.
- Put suitable control measures in place and ensure they are implemented consistently.
- Appoint a competent person, often called the responsible person for operational purposes, to help manage the control programme where appropriate.
- Provide suitable information, instruction and training to people carrying out monitoring, maintenance, cleaning or remedial work.
- Keep appropriate records demonstrating that risk controls, checks, actions and reviews are being managed.
- Review arrangements when there are changes to the building, occupancy, water services, equipment, procedures or risk profile.
The risk assessment should cover more than the visible outlets. It may need to consider incoming water, cold-water storage tanks, hot-water generation and return temperatures, dead legs, infrequently used outlets, showers, spray-producing equipment, thermostatic mixing valves, pipework configuration and areas with low or intermittent occupancy. The assessment should also consider people who may be more vulnerable to serious illness, such as those with certain underlying health conditions, and the likelihood that workers, visitors or other members of the public could be exposed.
The competent person does not necessarily have to be an employee. The duty holder can use suitably competent internal staff or appoint an external specialist. Competence involves having the knowledge, skills, experience and authority needed for the particular water systems and control tasks. The appointed person must have enough access to information, cooperation and resources to carry out the role effectively. Simply naming someone in a policy without giving them the ability to act is not a complete management arrangement.
External contractors can carry out work such as risk assessments, water testing, tank cleaning, disinfection, temperature monitoring support or remedial improvements. However, the duty holder should check that the contractor is appropriate for the task, provide relevant system information, review findings and ensure recommended actions are completed. A test certificate or contractor report does not, by itself, show that the overall legionella risk is being controlled.
Legal and guidance framework
Legionella control sits within general workplace health and safety duties. Depending on the circumstances, relevant requirements may include the Health and Safety at Work etc. Act 1974, the Control of Substances Hazardous to Health Regulations and the Management of Health and Safety at Work Regulations. In Great Britain, the Health and Safety Executive's Approved Code of Practice L8 and HSG274 provide the principal framework for managing and controlling legionella risks. An Approved Code of Practice is not itself legislation, but following it is a recognised way to help demonstrate that suitable precautions have been taken. Alternative measures may be acceptable where they provide an equivalent level of control.
The applicable guidance and enforcing authority can differ between parts of the UK, so businesses should confirm which requirements apply to their premises and activities. This is particularly important for organisations operating across more than one jurisdiction or managing buildings with complex ownership and occupancy arrangements.
Shared premises require documented coordination
Where several organisations occupy or manage a building, the parties should exchange relevant risk assessments, system schematics, monitoring records and maintenance information. They should agree who will manage common plant, who will investigate failures, how faults will be reported and who will communicate precautions to staff and visitors. The arrangements should also cover periods when areas are closed, partially occupied or brought back into use, because changes in water use can affect the risk profile.
Responsibility may also extend beyond routine monitoring. If a control check identifies unsuitable temperatures, poor circulation, contamination, scale, corrosion, stagnation or another deficiency, the duty holder must assess the significance of the finding and arrange appropriate corrective action. Depending on the issue, this could involve investigation, changes to operation, cleaning, disinfection, repairs, modifications or further sampling. Records should show the issue identified, the decision taken, the person responsible and how completion was verified.
How to establish who is responsible
- List every party with control over the building, water systems, maintenance and occupancy.
- Map the systems and areas for which each party is responsible.
- Check leases, service agreements, management contracts and site procedures for gaps or conflicting duties.
- Nominate competent people with defined authority and suitable training.
- Record the control scheme, monitoring programme, escalation route and review arrangements.
- Reassess the division of responsibility after refurbishment, changes in use, changes in occupancy or changes to plant and equipment.
Blue Fish Water Management Ltd supports businesses with legionella risk assessments, UKAS-accredited water testing, compliance audits, monitoring, training and remedial works. These services can help a duty holder obtain evidence about the condition and performance of a water system, but the business retaining control of the premises remains responsible for ensuring that the findings are acted upon and that its control arrangements remain effective.
Responsibility should be assigned according to control, not job title. In a commercial organisation, senior management should ensure that legionella control has clear ownership, suitable resources and a defined route for escalating significant findings. This provides oversight where day-to-day tasks are distributed between facilities teams, landlords, managing agents and specialist contractors.
A practical arrangement should show who receives monitoring results, who decides whether corrective work is necessary and who confirms that the work has been completed. Where a contractor reports a problem, the organisation responsible for the relevant premises or system should retain enough knowledge to understand the finding and challenge incomplete or unsuitable action. Clear governance helps prevent gaps when staff change, contracts are renewed or responsibility moves between different parties.
Clarify Your Legionella Control Responsibilities
If you need to clarify who holds responsibility for legionella control at your premises, speak to Blue Fish Water Management Ltd about reviewing your current arrangements and identifying any gaps.