Legionella Risk Assessment
BioSweep UK provides professional Legionella risk assessments to help landlords, employers, property managers and dutyholders identify, assess and manage the risks associated with Legionella bacteria in water systems.
Our assessments are undertaken in accordance with the Health and Safety Executive's Approved Code of Practice L8 (ACoP L8) and relevant HSG274 guidance. We inspect water system arrangements, identify potential risk factors and provide clear, prioritised recommendations to support effective water hygiene management and compliance with applicable health and safety duties.
We work across residential, commercial and managed properties, including offices, hotels, educational facilities, healthcare settings and other premises with water systems requiring assessment.
Why a Legionella Risk Assessment is Essential
Legionella bacteria can grow in man-made water systems when conditions are favourable. If contaminated water droplets become airborne and are inhaled, they can cause Legionnaires' disease, a potentially serious form of pneumonia.
Factors that can increase the risk of Legionella growth include:
Water Temperature: Water held within the temperature range that encourages bacterial growth, particularly between 20°C and 45°C.
Stagnation: Infrequently used outlets, dead legs and sections of pipework where water movement is limited.
Storage & Distribution: Poorly maintained water tanks, calorifiers and associated distribution systems.
System Condition: Scale, sediment, corrosion and biofilm that may support bacterial growth.
Inadequate Controls: Insufficient temperature management, maintenance, monitoring or water hygiene procedures.
A professional Legionella risk assessment helps identify these hazards, evaluate the level of risk and establish appropriate control measures.
The assessment should reflect the design, use and complexity of the water system. Even relatively straightforward domestic installations may require consideration of Legionella risks, although the assessment and control measures should remain proportionate to the circumstances.
Legal Duties & Compliance
UK health and safety legislation requires relevant dutyholders to assess and control the risks associated with exposure to Legionella bacteria in water systems.
The Health and Safety Executive's Approved Code of Practice L8 (ACoP L8) and supporting HSG274 guidance explain how these responsibilities can be managed.
Depending on the premises and water system, dutyholders may need to:
Identify & Assess Risks: Undertake a suitable and sufficient assessment of potential Legionella exposure.
Appoint Responsible Personnel: Ensure competent individuals are responsible for managing water hygiene risks.
Implement Control Measures: Establish appropriate arrangements to prevent or control identified risks.
Monitor & Maintain Systems: Carry out proportionate inspections, maintenance and monitoring.
Maintain Appropriate Records: Document significant findings, control measures and monitoring activities where required.
Review the Assessment: Reassess risks when there is reason to believe the existing assessment is no longer valid, including relevant changes to the water system or its use.
Failure to manage Legionella risks appropriately may result in enforcement action under applicable health and safety legislation.
BioSweep UK provides structured Legionella risk assessments with practical, prioritised recommendations to help dutyholders understand their responsibilities and manage identified risks.
Our Legionella Risk Assessment Process
BioSweep UK undertakes structured Legionella risk assessments in accordance with HSE ACoP L8 and relevant HSG274 guidance, tailored to the design, complexity and use of each water system.
1. Water System Survey
Our assessor examines accessible water system components, including storage tanks, calorifiers, distribution pipework and outlets, where applicable. We review the system layout, operation, maintenance arrangements and potential exposure points.
2. Risk Identification & Evaluation
We assess factors that may encourage Legionella growth or increase the risk of exposure, including:
Hot and cold water temperatures and the effectiveness of temperature control.
Stagnation, infrequently used outlets and dead legs.
Water storage conditions, sediment, scale and corrosion.
System design, circulation and accessibility for maintenance.
Existing monitoring, cleaning and water hygiene procedures.
Potential exposure to contaminated aerosols.
For temperature-controlled systems, cold water should generally be maintained below 20°C, stored hot water at 60°C or above, and hot water should reach at least 50°C at outlets within one minute, subject to the applicable guidance and system requirements.
3. Risk Rating & Prioritised Recommendations
Identified risks are evaluated and documented, with practical recommendations for appropriate control measures, maintenance, monitoring or further investigation.
4. Structured Risk Assessment Report
Following the assessment, we provide a report detailing:
Water system observations and relevant findings.
Identified hazards and risk ratings.
Existing control measures and areas requiring attention.
Prioritised recommendations for managing identified risks.
Supporting information to assist dutyholders with their water hygiene responsibilities.
Our assessments provide a documented basis for managing Legionella risks. The dutyholder remains responsible for implementing and maintaining appropriate control measures.
Legionella Risk Assessments Across Different Sectors
BioSweep UK provides professional Legionella risk assessments for landlords, employers, property managers and dutyholders across residential, commercial and specialist environments. Each assessment is tailored to the water system, property use and associated risks.
Landlords & Residential Property Managers
Assess Legionella risks within rental properties and managed residential buildings.
Support landlords and managing agents in understanding their water hygiene responsibilities.
Provide proportionate recommendations based on the property and water system.
Commercial Premises & Offices
Assess hot and cold water systems within offices, workplaces and commercial buildings.
Identify potential hazards and review existing water hygiene controls.
Provide documented findings to support facilities management and regulatory responsibilities.
Hotels, Leisure & Hospitality
Assess water systems within hotels, guest accommodation and leisure facilities.
Consider risks associated with stored water, distribution systems and infrequently used outlets.
Support dutyholders with prioritised recommendations and water hygiene management.
Schools, Colleges & Educational Facilities
Assess water systems within educational premises, including areas subject to seasonal or intermittent use.
Identify potential stagnation, temperature-control and maintenance concerns.
Provide practical recommendations to support ongoing risk management.
Healthcare, Care Homes & Managed Facilities
Assess relevant water systems within care homes, healthcare premises and other managed environments.
Consider system complexity, occupancy and the vulnerability of those potentially exposed.
Provide structured reporting to support appropriate water hygiene controls and management decisions.
This coverage supports duty holders across a range of property and operational settings.
Why Choose BioSweep UK
BioSweep UK provides professional Legionella risk assessments to help landlords, employers, property managers and dutyholders identify and manage water hygiene risks.
HSE-Aligned Assessments: Risk assessments undertaken in accordance with ACoP L8 and relevant HSG274 guidance.
Experienced Assessors: Competent personnel with practical knowledge of water systems, Legionella risk factors and appropriate control measures.
Property-Specific Assessments: Evaluations tailored to the design, complexity, occupancy and use of each water system.
Clear, Prioritised Reporting: Structured reports identifying potential hazards, existing controls and recommended actions.
Practical Compliance Support: Guidance to help dutyholders understand their responsibilities and implement appropriate risk management arrangements.
Nationwide Service: Legionella risk assessments for residential, commercial and managed properties throughout the UK.
Authoritative Guidance
Legionella risk management in the UK is supported by guidance published by the Health and Safety Executive (HSE).
The following resources explain the responsibilities of dutyholders and provide practical guidance on assessing and controlling Legionella risks:
HSE ACoP L8 – Legionnaires' Disease: The Control of Legionella Bacteria in Water Systems
The Approved Code of Practice outlines the legal framework and practical guidance for managing Legionella risks in workplace water systems.
HSG274 – Legionnaires' Disease: Technical Guidance
HSG274 provides detailed technical guidance on controlling Legionella risks, including hot and cold water systems, evaporative cooling systems and other risk systems.
HSE – Legionella and Legionnaires' Disease
Official information covering risk assessment, prevention, control measures and dutyholder responsibilities.
HSE Approved Code of Practice L8 – The control of Legionella bacteria in water systems
HSE HSG274 Technical Guidance
Health & Safety at Work etc. Act 1974
Need a Legionella Risk Assessment?
Whether you're responsible for a rental property, commercial premises, hotel, care home or managed building, BioSweep UK can help you identify and assess Legionella risks within your water systems.
Our professional assessments follow HSE ACoP L8 and relevant HSG274 guidance, providing clear findings and prioritised recommendations to support your water hygiene responsibilities.
Tell us about the property, its location, the type of water system and whether you have an existing Legionella risk assessment. Our team can advise on the appropriate next steps.
Identifying and assessing Legionella risks within water systems
Related Water Hygiene Services
A Legionella risk assessment identifies potential hazards and recommends appropriate control measures. Depending on the water system, its condition and the findings of the assessment, microbiological water sampling may also be recommended.
BioSweep UK provides complementary water sampling services, including analysis for Legionella, Pseudomonas, total viable counts (TVC) and selected bacterial indicators through independent laboratories.
Explore our related services to understand how we can support your water hygiene management requirements.
Where appropriate, Legionella risk assessments are supported by our water sampling services, with independent laboratory analysis using UKAS-accredited test methods where applicable.
Where findings identify a requirement for further action, decontamination services may also be provided where appropriate.
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