Can existing maintenance procedures support Legionnaires’ disease prevention risk controls?

Existing maintenance procedures can support Legionnaires’ disease prevention when they are deliberately linked to the site’s water safety arrangements, rather than treating water hygiene as an incidental part of general building maintenance. A maintenance schedule may provide a useful framework for inspections, servicing and corrective work, but it is suitable only if it addresses the risks identified for the particular water system and produces reliable evidence that the required controls are operating.

Many planned maintenance programmes are designed primarily to protect asset performance, occupant comfort or business continuity. Those objectives do not automatically control the risk of Legionella. A boiler service, for example, may confirm that equipment operates correctly without demonstrating that the wider hot and cold water system is being managed in accordance with its water safety requirements. The maintenance procedure should therefore state which water hygiene risks the task is intended to control and what constitutes a satisfactory result.

A useful review should examine the full maintenance process, including:

• the assets and outlets included within the schedule, with no relevant parts of the system left outside the inspection regime;
• the frequency and method of each task, including the reason for the chosen interval;
• the competence, supervision and instructions provided to employees or contractors;
• the actions required when an inspection identifies a defect, inaccessible component or failed control;
• the arrangements for verifying that corrective work has been completed effectively; and
• the way maintenance information is communicated to the person responsible for water safety.

Maintenance should also cover work that changes the condition or operation of a water system. Installation, refurbishment, alterations to pipework, replacement of valves, changes to outlet types and periods when parts of a building are closed can all affect the control strategy. A change-control process helps determine whether the risk assessment, written control scheme, monitoring arrangements or operating instructions need to be revised before the altered system is brought back into use.

Work on a system can temporarily increase risk even where the finished installation is technically sound. Procedures should explain how the system is made safe before work starts, how components are handled and protected during the task, and what checks are required before outlets or equipment return to service. Where contractors are used, their method statements and completion information should be checked against the site’s water hygiene requirements rather than accepted solely as evidence that the engineering work is complete.

Preventive maintenance is generally stronger when responsibilities are clear at each stage. The person overseeing water safety should know who carries out routine tasks, who reviews results, who authorises remedial work and who decides whether unresolved defects require escalation. A procedure that says an issue should be “reported” without identifying the recipient, timescale or follow-up method may not provide effective control in practice.

Records should allow an auditor or responsible person to reconstruct what happened. Depending on the system and risk assessment, useful information may include the date of the task, the asset or area inspected, the person completing it, findings, measurements where applicable, defects raised, actions taken and the date of verification. Records should distinguish between a task being scheduled and the control actually being completed. Missing entries, repeated unresolved defects or unexplained changes in results can indicate that a maintenance procedure is not functioning as intended.

Maintenance arrangements should be reviewed after incidents, significant defects, changes to occupancy or building use, alterations to plant and pipework, or evidence that an existing control is not effective. The review should consider whether the procedure itself is unsuitable, whether it is being applied inconsistently, or whether the system has developed a risk that was not previously recognised. This is different from simply increasing the frequency of a task: more frequent work will not correct an unsuitable method or unclear responsibility.

Testing can provide useful verification, but it does not replace effective maintenance or other operational controls. A satisfactory test result represents the position at the time of sampling and should be interpreted alongside system condition, monitoring results, maintenance findings and the site’s risk assessment. Conversely, an adverse result should trigger a structured investigation rather than an isolated sampling exercise with no examination of the underlying maintenance process.

For a business or property operator, the practical test is whether existing procedures enable the organisation to identify water-system risks, act on defects, manage changes and demonstrate that actions were completed competently. If they do, they may form part of the Legionnaires’ disease prevention control scheme. If they focus only on mechanical servicing or reactive repairs, they are unlikely to provide sufficient assurance without being expanded and formally integrated with the site’s water safety arrangements.

Blue Fish Water Management Ltd can help organisations assess whether their maintenance approach aligns with legionella prevention requirements, identify gaps and establish proportionate monitoring, documentation and remedial actions for their water systems.