Residential Water Services

Legionella risk assessments for water systems across the UK

If you are looking for experienced engineers to carry out legionella risk assessments, get in touch with the team at Chiltern Water & Environment. Our service areas include the Midlands, Buckinghamshire, Hertfordshire, Bedfordshire, North London and across the UK.

Assessing the risk for residential landlords and small commercial enterprises (shops, holiday lettings and small offices)

All landlords and those responsible for small commercial water systems are legally required to assess the risk from legionella to anyone using or exposed to their water system. This is to prevent tenants contracting the potentially fatal Legionnaires disease from water in their home.

The HSE is now strongly encouraging landlords and all Duty Holders to ensure they have a legionella risk assessment in place. They have recently revised the Approved Code of Practice (ACoP L8) 'Legionnaires' disease: The control of bacteria in water systems' and published the Health & Safety Guidance 274 ‘The control of legionella bacteria in hot and cold water systems’, which includes clarification with regard to residential landlords' responsibilities. This guidance is free to download from the HSE website: (specifically refer to 2.138 to 2.146 in HSG274 and para 25 in ACoP L8).

Within this guidance, it has been recognised that the risk is normally low, so the requirements are a little different than for larger and more complex water systems. At Chiltern Water & Environment, we have adapted our services accordingly, to provide cost-effective services that reflect these requirements.
Water quality assessment

What is Legionnaires' disease?

Legionnaires' disease is caused by legionella bacteria and is a potentially fatal form of pneumonia that particularly affects people already at risk due to age, illness or immunosuppression. Legionella bacteria can also cause less serious illnesses. Normally cold or flu type symptoms occur, before developing to full pneumonia in more serious cases. Infection normally occurs by breathing in small water droplets containing the bacteria, e.g. from showers, water features or hoses.

The Legionella bacterium is often present in natural sources of water, but can quickly multiply to harmful levels in domestic water systems if not maintained or designed properly. 

Although the occurrence of the infection at home is rare, Chiltern Water & Environment has assisted several clients in the past with this issue.

What is your responsibility as a resident? 

As per the updated HSE ACoP L8 & HSG274 guidance, in premises with small domestic-type water systems and where there is regular water usage, the risk is likely to be low. However, a simple risk assessment is required to assess and demonstrate low risk.

The ACoP L8 guidance stresses the importance of a competent person carrying out this risk assessment. Although it may be possible for landlords to assess the risk themselves, if you do not feel sufficiently competent, ACoP L8 guidance indicates a competent contractor should be used. If issues are identified, then remedial actions and ongoing control measures may be necessary (but this is unlikely for most residential systems).

Our service for landlords, small commercial units and offices

Chiltern Water & Environment provides tailored simple risk assessments for residential landlords and small commercial enterprises carried out by experienced competent surveyors. Since 1991, we have been carrying out legionella risk assessments on a wide range of different water systems. For larger water systems, we provide full legionella risk assessments compliant with BS8580.

However, to meet with the demand for residential risk assessments, we have developed a new simple risk assessment, as per ACoP L8 and HSG274 guidance. This assesses whether a water system is compliant with the requirements in paragraph 25 of ACoP L8, which describes low risk systems. The risk assessment is completed on-site by one of our trained, competent and experienced surveyors. If issues are identified, then we can take water samples to determine if legionella is present, (as per BS7592 requirements). On an average, 1-5% of all domestic water systems in the UK have legionella present. A report is completed by hand on-site which can be left with you or posted.
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Ongoing control measures

In the likely event that the system is found to be low risk, then no further action will be required, other than to regularly review the risk assessment. If issues are identified, we will provide recommendations in our report to advise you and can provide further support if required.
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For legionella risk assessments in Buckinghamshire, the Midlands, North London and across the UK,
call Chiltern Water & Environment today on
01844 347 678
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