What records should support legionella compliance?

A defensible legionella compliance record is a clear, dated audit trail showing how water-system risks were identified, controlled, checked and corrected. It should allow a duty holder, auditor or enforcement officer to understand the system, the control measures in place, who carried out each task, what the results were and how deficiencies were addressed.

1. Responsibility and governance

Keep a written record of the person or organisation with overall responsibility for legionella control, together with the people carrying out operational tasks. Where duties are delegated, the record should state the scope of each person’s role, their authority to act and the arrangements for reporting concerns. Meeting notes, management reviews and internal audit findings can also demonstrate that water safety is being actively overseen rather than treated as a one-off assessment.

2. System information and asset records

Records should describe the water systems covered by the control arrangements. Useful supporting information includes:

• an up-to-date schematic or written description of the hot and cold water systems;
• the locations of tanks, calorifiers, heaters, pumps, outlets, thermostatic mixing valves and other relevant components;
• identification of infrequently used outlets, areas with low or intermittent occupancy, and parts of the system that may create stagnation;
• details of changes, extensions, alterations or decommissioned equipment; and
• an asset register linking each item to its inspection, maintenance and monitoring history.

This information is particularly important where buildings have been modified or where responsibility has changed. A temperature result or sample result is difficult to interpret if the location and equipment it relates to cannot be identified.

3. Control-scheme records

The written control scheme should explain the precautions selected for the particular system, the limits used to judge performance and the action required when those limits are not met. It should be version-controlled, dated and reviewed when the system, use of the premises, responsible personnel or risk profile changes.

Supporting documents may include procedures for temperature control, outlet flushing, cleaning and disinfection, tank inspection, monitoring, sampling and escalation. The record should distinguish between a planned task, a completed task and a task that was missed or found to be ineffective.

4. Monitoring and inspection logs

Routine logs should record the date, location, reading or observation, name of the person completing the check and any action triggered by the result. Depending on the system, this may include hot-water storage and distribution temperatures, cold-water temperatures, flow and return temperatures, sentinel outlets, tank condition, cleanliness, insulation, access arrangements and signs of stagnation.

Electronic records can be suitable, provided they are protected from unauthorised alteration and retain an audit trail. Handwritten sheets should be legible and corrections should not obscure the original entry. Blank fields, unexplained identical readings and undated entries weaken the evidential value of an otherwise complete log.

5. Flushing, cleaning and maintenance evidence

Where outlets are flushed because they are seldom used, records should identify the outlet, the date, the person responsible and any problem encountered. Records for cleaning and disinfection should set out the scope of the work, method used, relevant measurements, completion date, person or contractor undertaking the work and any post-work verification.

Planned and reactive maintenance records should cover faults affecting legionella control, such as failed thermostats, defective pumps, damaged insulation, blocked strainers or problems with storage tanks. Include work orders, inspection reports, parts replaced and confirmation that the system was returned to an acceptable operating condition.

6. Sampling and laboratory records

Water-testing records should connect each result to the premises, system, outlet or equipment sampled and the date and time of collection. They should also show the sampling method, sample identification, laboratory report, interpretation of the result and any action taken.

Retain evidence that samples were handled and tested appropriately, including chain-of-custody information where relevant. A laboratory result should not stand alone: its significance depends on the sampling location, the purpose of the test, recent system activity and the control response that followed.

7. Training and competence records

Keep evidence that people undertaking legionella-related duties have been given suitable instruction and are competent for the work assigned to them. Records may include course details, dates, assessment results, refresher training, supervised practical work and relevant experience.

Training records should be matched to responsibilities. For example, a person recording temperatures needs different evidence from someone designing a written scheme, interpreting laboratory findings or carrying out cleaning and disinfection.

8. Incident, escalation and remedial-action records

Any significant control failure, suspected exposure, positive or concerning test result, complaint, equipment failure or extended interruption to control measures should have a documented response. Record:

• what was identified and when;
• who was informed and what decisions were made;
• temporary precautions introduced;
• investigation findings;
• remedial work completed; and
• the checks used to confirm that the issue was resolved or brought under effective control.

Open actions should remain visible until they are closed, with an owner and target date. Simply noting that an issue was reported does not demonstrate that it was managed.

9. Review, retention and accessibility

Records should be retained in line with applicable health and safety requirements and the organisation’s documented arrangements. Current versions should be readily accessible to those responsible for managing the system, while superseded documents should be clearly marked so that they cannot be mistaken for current instructions.

A periodic records review should check for missing readings, overdue tasks, unresolved defects, inconsistent asset references and changes that have not been reflected in the risk assessment or written scheme. Records are most useful when they are maintained as part of normal water-system management, rather than assembled retrospectively before an audit.

Where a specialist carries out risk assessment, testing, monitoring or remedial work, the duty holder should retain the resulting reports and make sure they are incorporated into the site’s own control records. Responsibility for maintaining an effective compliance system remains with the duty holder, even when individual tasks are delegated.