Can one water hygiene risk assessment approach suit every organisation?

A single template is not suitable for every organisation. A sound water hygiene risk assessment should use the same underlying principles, but the investigation, evidence, control measures and management arrangements must be proportionate to the water systems and the risks created by each premises.

The important distinction is between a consistent method and an identical assessment. A consistent method provides a reliable way to identify hazards, assess risk, assign responsibilities and record actions. An identical assessment may overlook important differences between a small office, a residential block, a manufacturing site and a building used by people who may be particularly vulnerable to infection.

What determines the appropriate approach?

The organisation’s size is relevant, but it is only one consideration. An assessment should take account of:

• the type, age and configuration of the premises;
• the incoming water supply and internal distribution system;
• hot and cold water storage, heating and distribution arrangements;
• showers, taps, outlets, thermostatic mixing valves and other points of use;
• infrequently used outlets, vacant areas and sections of pipework with limited flow;
• temperature control, circulation and the potential for stagnation;
• occupancy levels, patterns of use and periods when parts of the building are unoccupied;
• maintenance, cleaning, monitoring and remedial arrangements; and
• the responsibilities of the owner, employer, facilities team, landlord, managing agent or contractors.

This means that a compact building can still require a detailed assessment if its water system is complex or poorly understood. Conversely, a larger organisation with several similar premises may be able to use a standard management framework, provided each site is checked and site-specific differences are properly recorded.

The core principles can remain consistent

Most organisations need the assessment to establish how water systems operate, where conditions could allow Legionella to multiply or spread, who could be exposed, and which controls are necessary. It should also identify the people responsible for managing those controls and explain how their performance will be checked.

These principles should not change simply because the assessment is for a different sector. What changes is the depth of investigation and the detail needed to make the findings useful. A basic visual review may be appropriate for a straightforward system with clear records and few outlets. It would not be an adequate substitute for asset-level examination where the system includes multiple storage vessels, secondary circulation, complex plant or a history of control difficulties.

Different organisations create different exposure patterns

In a conventional office, water use may be concentrated around kitchens and washrooms, with relatively limited hot water storage. The assessment may therefore focus on outlet use, temperature management, seldom-used facilities and responsibilities shared with a landlord or managing agent.

A residential building may require consideration of individual dwellings, communal facilities, stored water, shower arrangements, void properties and the division of duties between the freeholder, property manager and occupants. Access arrangements and evidence that controls have been completed can be as important as the physical condition of the system.

Industrial and commercial premises may have process water, changing facilities, welfare areas, large distribution networks or specialist plant. Their assessment may need to distinguish domestic water systems from other water uses and examine how production, maintenance shutdowns and engineering modifications affect control measures.

Premises occupied by people who may be more susceptible to illness require particularly careful consideration of exposure and control. The assessment should reflect the occupants, the services provided and the consequences of control failures rather than relying solely on the size of the building.

Proportionality does not mean reduced rigour

A proportionate assessment is not one that provides less information simply to reduce cost or paperwork. It is one that gathers enough reliable evidence to support decisions. For a simple system, that may mean a concise description, clear schematic information, outlet checks and a practical control schedule. For a complex system, it may require detailed asset identification, inspection of plant and storage, review of historical records, representative temperature measurements, examination of dead legs and confirmation that written procedures match the installation.

The assessor should be able to explain why particular areas were included or excluded. Assumptions should be recorded rather than left implicit. If drawings are incomplete, the report should identify that limitation and recommend how the system information can be improved. Where access was not possible, the affected areas and the implications for the findings should be stated clearly.

The organisation’s management structure also matters

Two buildings with similar plumbing may need different management arrangements if one has an in-house facilities team and the other relies on several contractors. A useful assessment should define who acts as the responsible person, who carries out routine checks, who reviews results, who authorises remedial work and who receives escalation when controls are not met.

It should also consider competence. People carrying out monitoring or maintenance need suitable instruction, access to the relevant information and a clear understanding of what to do when readings or conditions are outside the expected range. Contractor activities should be coordinated so that servicing, refurbishment and alterations do not undermine existing controls.

When a standard framework can work

An organisation with multiple premises may use common policies, forms, monitoring schedules and reporting arrangements. This can improve consistency, but it should not remove the need for a site-specific assessment. A group-level procedure should be supported by local information covering the actual system, responsible personnel, risks, control measures and outstanding actions at each location.

Standardisation is most useful for governance and record-keeping. It should not be used to assume that every building has the same pipework, usage, occupancy, maintenance history or risk profile.

When the approach should become more detailed

A fuller assessment is generally appropriate where there is uncertainty about the system, extensive stored or circulated water, complex plant, significant periods of low use, frequent changes to the building, previous control failures, poor records or a population that could be more vulnerable to infection. It may also be necessary after refurbishment, changes in occupancy, alterations to water services, prolonged closure or the discovery of conditions that could affect water quality.

Blue Fish Water Management can help organisations establish a risk-based assessment and supporting water hygiene arrangements suited to their premises. The objective is not to impose the same document on every client, but to produce findings that are technically justified, understandable to those managing the building and capable of being translated into effective monitoring and corrective action.