Can landlords use an existing legionella risk assessment after a property changes?

An existing assessment can remain part of the property’s compliance records, but it is only suitable for continued use where a competent review confirms that it accurately describes the current premises, water systems and management arrangements. If the review identifies material changes or gaps, the assessment should be updated or replaced before it is relied upon.

A change of landlord or managing agent does not automatically invalidate the document. However, the new dutyholder should obtain the complete assessment and supporting records, understand the control scheme, and confirm who is responsible for each action. Responsibility cannot be assumed to have transferred simply because the document remains at the property. The landlord should be able to demonstrate that the assessment has been considered and adopted as part of the current management arrangements.

Changes that normally require a detailed review include:

• Alterations to hot or cold water services, including new outlets, showers, storage tanks, calorifiers, boilers or other equipment.
• Changes to pipework, water storage, circulation or insulation.
• Unused outlets, capped branches, dead legs or sections of system that have been taken out of service.
• Refurbishment, conversion or a change in the property’s layout.
• A change from single occupancy to multiple occupancy, or a change in the type of tenant or resident.
• Periods of vacancy, low water use or changes to how the building is occupied.
• A change in the contractor, caretaker, managing agent or person carrying out monitoring and remedial work.
• Evidence of temperature control problems, stagnation, contamination, repeated faults or previous legionella findings.

These changes can affect how water is stored, heated, distributed and used. They can also alter exposure, particularly where tenants have limited control over the water system or where occupants may be more vulnerable to illness. A risk assessment should therefore consider both the physical system and the way the property is actually managed.

The review should check more than the date on the document. The reviewer should compare the assessment with the property as it exists, inspect relevant plant and outlets, and confirm that the system description and schematic information are accurate. They should consider water storage and distribution, outlet use, temperature control, access for inspection, cleanliness, maintenance arrangements and any identified control measures. Where the assessment refers to records, those records should be available and consistent with the current arrangements.

The reviewer should also confirm that the named responsible person and contractors are still appropriate, that monitoring frequencies remain suitable, and that abnormal results or remedial actions have been dealt with. A document may appear comprehensive but still be unsuitable if it refers to a previous layout, former equipment or arrangements that are no longer followed.

A new assessment is more appropriate where the existing one is incomplete, cannot be verified or no longer reflects the system. This may apply after substantial plumbing or heating works, a major change of use, installation of new water plant, or a change that creates a different pattern of occupancy and exposure. A new assessment may also be sensible where the original assessment was not produced by someone with suitable knowledge and experience, or where important supporting evidence is missing.

Not every minor change requires the entire assessment to be rewritten. For example, a small alteration may be dealt with through a documented amendment if the competent reviewer confirms that the existing findings and control measures remain suitable. The record should clearly identify what changed, when it was reviewed, who carried out the review and whether any further action is required. A revised assessment should be issued where the changes affect the findings or control scheme.

Landlords should retain a clear audit trail. This should normally include the current risk assessment, previous versions where relevant, records of review, monitoring results, maintenance and cleaning records, information about remedial work, and evidence that identified actions have been completed. Tenants and contractors should receive the information they need to carry out their responsibilities, including instructions for reporting faults, prolonged non-use or changes to the system.

The assessment should also be reviewed when there is reason to suspect that it is no longer valid, when control measures are not working effectively, or when new information about the risks becomes available. A calendar-based review is useful, but it should not replace a review triggered by a significant change or an incident.

In practice, a landlord should not ask only whether an existing document is still within its review date. The more important questions are whether it describes the current system, whether the control measures are being implemented, and whether the person responsible can provide evidence of ongoing management. If the answer to any of these is uncertain, the assessment should be reviewed by a competent person before it is relied upon.

Blue Fish Water Management Ltd can support landlords with the review of existing assessments, water hygiene monitoring and remedial recommendations where the assessment no longer reflects the property’s circumstances.