How often should a Legionnaires disease risk assessment be reviewed?
A Legionnaires’ disease risk assessment should be reviewed regularly, typically at least every two years, and sooner if circumstances change. An earlier review is needed after alterations to the water system or building, changes in use or occupancy, evidence that control measures are ineffective, or a suspected case or outbreak of Legionnaires’ disease.
A review of a Legionnaires’ disease risk assessment is a formal check that the assessment still reflects the water system, the way the premises are used and the effectiveness of its control measures. It should not be treated as an administrative exercise or as a document that remains valid simply because it has been signed and filed.
The review should be proportionate to the complexity and risk of the system. A straightforward domestic hot- and cold-water system may require a different level of scrutiny from a large healthcare, industrial, hospitality or commercial site with multiple outlets, storage tanks, showers, thermostatic mixing valves or other higher-risk features. The assessment should clearly explain the reasoning behind the review frequency and identify who is responsible for carrying it out.
During a review, the competent person should compare the written assessment with the system as it exists in practice. This normally includes checking:
- the current schematic or description of the water system;
- plant, storage vessels, outlets and areas that may encourage stagnation;
- temperature control arrangements and the operation of relevant equipment;
- cleaning, disinfection, servicing and maintenance records;
- temperature monitoring, sampling results and other control records;
- any recurring deviations, outstanding remedial actions or access difficulties; and
- whether staff understand their duties and are following the written control scheme.
Monitoring records are particularly important because they show whether the precautions described in the assessment are working consistently. A single acceptable result does not by itself demonstrate effective control. The reviewer should consider patterns over time, missed checks, unexplained temperature changes, repeated faults and whether corrective actions were completed and verified.
The review should also consider whether the people exposed have changed. Some occupants may be more susceptible to serious illness, and a change in the use of a building can alter how often outlets are used, how long water remains in parts of the system and how much oversight is needed. These factors may justify strengthening the control scheme even where the physical installation has not changed.
Where the assessment remains suitable, the review should still be recorded. The record should identify the date, the person undertaking the review, the evidence considered, any limitations, the conclusion reached and the date or circumstances for the next review. If amendments are required, the revised assessment and control measures should be issued to the responsible people, with relevant staff briefed on what has changed.
A review is different from routine monitoring. Daily, weekly or monthly checks provide evidence about operational control, whereas the risk assessment review considers whether the overall approach remains appropriate. Routine checks cannot replace a formal review, and a new assessment may be needed where the existing document no longer represents the system or its risks.
Blue Fish Water Management Ltd can support organisations with legionella risk assessments, water testing, compliance audits, system monitoring and remedial works. Its approach can help bring together assessment findings, operational records and technical evidence so that the review produces a practical, documented basis for ongoing water safety management.
A Legionnaires’ disease risk assessment should be reviewed whenever a change could alter the route of exposure or the effectiveness of water-system controls. The review may focus on the affected part of the system rather than repeating every element unchanged, provided the reasoning and boundaries are documented.
Examples include bringing a previously unused area back into service, replacing water-heating equipment, changing outlet arrangements, introducing new processes that use water, or altering responsibility for maintenance. The review should establish whether the change affects temperatures, flow, stagnation, access, cleaning requirements or the people using the premises. Any new actions should be assigned to named responsible people and tracked to completion.
Need help reviewing your Legionnaires’ disease risk assessment?
If your Legionnaires’ disease risk assessment is due for review or circumstances have changed, speak to Blue Fish Water Management Ltd about assessing whether it remains suitable and identifying any necessary updates.