Legionella Risk Assessments
in Hampshire

What is a Legionella Risk Assessment?

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A Legionella risk assessment is a legal requirement under the Health and Safety at Work Act and HSE ACOP L8for landlords, employers, and anyone responsible for water systems. Its purpose is to identify and control the risks of Legionella bacteria, which can cause the potentially fatal illness Legionnaires’ disease.

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The assessment provides a structured review of your water systems, highlights areas of concern, and recommends control measures to ensure compliance and protect health.

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The Full Scope of a Legionella Risk Assessment

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A comprehensive assessment will cover:

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1. Review of Site and Duty Holders

   • Identifying the responsible person(s) and duty holders under health and safety law.

   • Reviewing management procedures already in place.

2. Survey of Water Systems

   • Inspection of hot and cold water systems, tanks, calorifiers, showers, outlets, and any other relevant equipment (e.g. cooling towers, spa pools).

   • Assessing system design and condition.

3. Water Temperature Checks

   • Testing sentinel outlets (nearest and furthest taps/showers).

   • Ensuring cold water is below 20°C and hot water reaches 50°C+ within one minute.

4. Identification of Risks

   • Detecting areas where water stagnation could occur (dead legs, infrequently used outlets).

   • Noting scale, corrosion, biofilm, or debris in tanks and pipework.

   • Checking insulation and tank integrity.

5. Assessment of Occupants and Vulnerable Groups

   • Determining if building users are at higher risk (e.g. elderly, immunocompromised, hospital or care home residents).

6. Evaluation of Current Control Measures

   • Reviewing existing maintenance, flushing, cleaning, and monitoring regimes.

   • Checking record-keeping practices.

7. Recommendations for Control

   • Outlining practical measures to remove or reduce risks, such as:

     • Removing redundant pipework

     • Cleaning and disinfecting tanks

     • Adjusting temperatures

     • Installing or servicing TMVs

     • Setting up ongoing monitoring schedules

8. Compliance Documentation

   • Providing a full written report, including:

     • Risk findings

     • Photographic evidence

     • Temperature records

     • Action plan and timescales

   • Serving as an auditable record for HSE inspections.

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The Process of Carrying Out a Legionella Risk Assessment

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1. Initial Consultation – Discussion with the client to understand building type, water systems, and compliance needs.

2. On-Site Survey – A competent assessor inspects all relevant systems, takes temperature readings, and records system details.

3. Data Collection – Information gathered on system design, condition, and management practices.

4. Risk Evaluation – Risks are analysed against HSE guidance (ACOP L8 & HSG274).

5. Report Production – A clear, detailed report is issued, outlining risks and recommended remedial works.

6. Implementation Support – The assessor or water hygiene company can provide remedial works, training, and ongoing monitoring services.

7. Review and Updates – Risk assessments should be reviewed:

   • Every two years as a minimum

   • After significant system changes

   • Following changes in building use or management

   • After detection of Legionella in testing

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Why is the Process So Important?

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• Ensures legal compliance with HSE guidance.

• Protects the health of occupants from Legionnaires’ disease.

• Identifies risks early before they become serious issues.

• Provides documented evidence of compliance for audits and inspections.

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✅ A Legionella risk assessment is the foundation of water safety compliance. It gives duty holders the knowledge and plan they need to manage risks effectively and protect people from harm.