Facilities managers need a clear view of how water systems operate, where conditions may support Legionella growth and how well current controls are working. A Legionella risk assessment provides that view by examining the system itself, patterns of use and the records that show how the site manages water hygiene.
For duty holders, the assessment supports responsibilities under UK health and safety law. HSE guidance requires employers and people in control of premises to identify and assess sources of risk, manage those risks and keep suitable records. A useful assessment should give facilities teams a basis for deciding what to monitor, what needs attention and how to plan future work.
Why a Legionella risk assessment matters for facilities teams
Legionella can multiply in man-made water systems when conditions support growth. HSE highlights factors such as water temperatures between 20°C and 45°C, stored or recirculated water, nutrients including scale and biofilm, and systems that can produce water droplets that people may inhale.
Facilities managers need to understand how those factors apply to the building they manage. A straightforward hot and cold-water system may need a different control approach from a hospital, care home or large multi-site estate. Occupancy, outlet use, system design and the susceptibility of building users can all affect the level of management required.
A good assessment gives the team a documented view of current conditions. It should identify existing controls, explain any gaps and set out clear recommendations for the people responsible for taking action.
What should a Legionella risk assessment include?
HSE states that an legionella risk assessment should cover management responsibilities, a description of the water system, competence and training, identified risk sources, existing controls, monitoring and maintenance procedures, records and arrangements for review.
The assessor should connect this information with what is actually happening on site. That means reviewing current drawings and schematic information, temperatures, storage and recirculation, low-use outlets, signs of stagnation, the condition of tanks and pipework, maintenance history and the people who could face greater susceptibility to infection.
Site records should support the inspection, but the assessor also needs to verify that they still reflect current conditions. Refurbishment, redundant pipework, changes in occupancy and altered patterns of use can all change how a water system operates.
Understanding system design, temperatures and water use
The site inspection should establish how hot and cold water moves through the building. This includes storage vessels, calorifiers, distribution pipework, outlets and other systems that could create exposure to contaminated aerosols.
Temperature control remains a common method for managing risk in hot and cold water systems. HSE advises keeping cold water below 20°C where possible, storing hot water at 60°C or above, and distributing it so that it reaches at least 50°C within one minute at outlets. Healthcare premises generally use 55°C at outlets. The assessment should check performance against the control approach set for that system.
Water use also matters. Infrequently used outlets can allow water to stagnate, so the assessor should identify low-use areas and review any flushing arrangements. This can apply to spare rooms, changing facilities, seasonal areas, vacant units and parts of larger estates with changing occupancy.
Reviewing current controls, competence and site records
The assessment should establish how the current control scheme works in practice. Facilities teams need to know which checks take place, who completes them and what happens when results fall outside the agreed control parameters.
Relevant evidence may include temperature logs, flushing records, cleaning and descaling records, maintenance history, previous assessments and sampling results where sampling forms part of the control approach. The assessor should also review responsibilities, including the person appointed to manage a legionella risk and the competence of staff involved in the control regime.
Where staff need more knowledge of their water hygiene responsibilities, legionella awareness training can support the control programme and help teams understand the procedures they are expected to follow.
This review can identify where responsibilities need clarification, procedures need updating or the monitoring programme no longer reflects current site conditions. It also gives facilities managers stronger information for planning maintenance and allocating resources.
Turning assessment findings into practical actions
A useful report should tell facilities managers what requires attention and why. Recommendations may cover changes to monitoring, repairs, removal of redundant pipework, cleaning, descaling or updates to site procedures. Where physical changes are required, we can also support sites with remedial works based on the issues identified.
If the assessment identifies a significant risk that needs ongoing management, the duty holder should have a written control scheme. HSE guidance says this should describe the system, responsibilities, control measures and the checks used to confirm that the scheme remains effective.
Support with the next stage of water hygiene management
If your water system has changed, site records contain gaps or you need an up-to-date view of current risk, Safety First Group can carry out a legionella risk assessment and provide clear recommendations for your facilities team. We can also support the follow-up actions identified through the assessment, including ongoing monitoring, sampling, remedial work and staff training.
How the assessment informs monitoring and water sampling
The findings should shape the next stage of the control programme. They can define temperature checks, inspection routines, maintenance requirements and other monitoring activity based on the risks present at the site.
Where a site needs external support for scheduled checks, our legionella monitoring service can support the monitoring regime set for the water system.
The assessment can also identify when water sampling would provide useful additional information. Routine Legionella sampling is not usually required for hot and cold water systems. HSE states that testing may be necessary when there is doubt about the effectiveness of the control regime or when recommended temperatures or disinfectant concentrations are not being achieved consistently.
This distinction helps facilities managers avoid treating sampling as a substitute for system management. Sampling can support decisions in the right circumstances, while ongoing temperature control, inspection, maintenance and record keeping remain central to managing many hot and cold water systems.
For multi-site estates, assessment findings can also improve consistency. Facilities managers can compare recurring issues, plan monitoring requirements across the portfolio and prioritise maintenance according to the condition and use of each system.
Keeping the assessment current
A Legionella risk assessment needs regular review, particularly when there is reason to think it no longer reflects the site. Changes to the water system, building use, occupancy or control arrangements can affect the findings and may require the assessment or control scheme to change.
Keeping the assessment current gives facilities teams a stronger basis for future planning. Managers can use the findings to schedule monitoring, organise remedial work, brief contractors and provide evidence when budgets or maintenance priorities need approval.
Plan the next step with Safety First Group
We support facilities managers, estates teams and duty holders with Legionella risk assessments and the follow-up services that may form part of an effective control programme. If you need to review the condition of your water systems or update an existing assessment, contact our team to discuss your site and the most appropriate next step.