Protecting Residents from Legionnaires’ Disease

by Peter Gunn, on 28-01-2020
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115 - Protecting Residents - Correctly SizedShould we be concerned?

Legionellosis risks from hot and cold water systems in most residential settings are generally considered to be low owing to regular water usage and turnover. It’s also true to say that not all systems require elaborate control measures and simple, proportionate and practical actions are often all that is required to minimise risks for residential occupants of any age or vulnerability.

Legionellosis risks from hot and cold water systems in most residential settings are generally considered to be low owing to regular water usage and turnover. It’s also true to say that not all systems require elaborate control measures and simple, proportionate and practical actions are often all that is required to minimise risks for residential occupants of any age or vulnerability.

Residential landlord’s wishing to ensure the safety of their residents and take a practical and proportionate application of health & safety regulations and other Legionella guidance should note that whilst there is a duty to assess the risk of exposure to Legionella bacteria this does not always necessitate an in-depth, detailed risk assessment.


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The flip side of these statements in a residential setting, may be that many occupants remain either completely unaware or indifferent to Legionellosis risks as they go about their day to day lives. Public Health England’s monthly surveillance reports for Legionnaires' disease frequently show a majority of Legionnaires’ disease cases derived from community settings, as opposed to travel abroad or healthcare. However, we have no data on the proportion of these cases and whether they may originate from domestic properties, rented or otherwise. All we can say, is that it is possible or even likely that some of these cases come from domestic properties.

A newborn baby was victim to a Legoinnaires' disease outbreak at a Pimlico appartment block early this year.

Both landlords and residents [tenants] have a role to play in risk minimisation and we have set out the background responsibilities and the type of simple practical tasks that can and should be undertaken routinely.

HSE guidance acknowledges that in many residential settings Landlords have a legal responsibility to ensure the health and safety of their tenants by keeping property safe and free from health hazards.

What is a landlord?

Anyone who rents out a property (or even just a room) they own for a period of less than 7-years in duration. The following list is not exhaustive, but landlords include:


What is required?

The Health & Safety Executive [HSE] provide advice on their website in respect to Legionella and landlords’ responsibilities. In a nutshell, all systems require a risk assessment in the first instance. The situation was clarified following the publication in 2013 of the fourth edition of the Health & Safety Executive’s Approved Code of Practice [ACOP] “Legionnaires’ Disease, The Control of Legionella Bacteria in Water Systems”, L8. However, while the ACOP was updated, it didn't change or alter the responsibilities placed on landlords who have always had a duty to carry out risk assessments and manage the risk from Legionella bacteria to their tenants.


Risk Assessment

The water systems in many single residential properties are simple and unlikely to represent a significant risk when used regularly. Likewise control measures are also likely to be simple without the need for convoluted ongoing interventions. The information on the Health & Safety Executive’s website states:

“The practical and proportionate application of health and safety law to landlords of domestic rental properties is that whilst there is a duty to assess the risk from exposure to Legionella to ensure the safety of their tenants, this does not require an in-depth, detailed assessment”.

All systems should be assessed but the programme of assessment should be reasonably practicable. This may mean, in the first instance, undertaking a desktop appraisal of risk to identify properties that could represent an increased risk, for example:

  • properties in which the typical occupants may be of increased susceptibility to infections (e.g. sheltered housing schemes or hostels);

  • larger and more complex properties and water systems (e.g. multi-dwelling units, HMOs etc.)

  • features of the water system design that increase the likelihood of bacterial colonisation (e.g. the presence of hot or cold water storage tanks);

  • the age of construction and/or subsequent refurbishments; this may indicate properties in which plumbing is unlikely to comply with current standards.

Of course, there may be other reasons why one property represents a higher risk than another and there is no substitute for an inspection of site water services when it comes to determining the actual risk. Risk assessment of a sample of sites can provide a representative cross-section of the properties to identify the priorities for the future programme of assessments and control measures.


Control Measures

The HSE’s ACOP L8 states that:

All systems require a risk assessment, however not all systems will require elaborate control measures. A simple risk assessment may show that the risks are low and being properly managed to comply with the law. In such cases, you may not need to take further action, but it is important to review your assessment regularly in case of any changes in your system, and specifically if there is reason to suspect it is no longer valid”; and “Other simple control measures to help control the risk of exposure to Legionella include:

  • flushing out the system prior to letting the property;
  • avoiding debris getting into the system (e.g. ensure the cold water tanks, where fitted, have a tight fitting lid);
  • setting control parameters (e.g. setting the temperature of the hot water cylinder (calorifier) to ensure water is stored at 60°C);
  • make sure any redundant pipework identified is removed;
  • The risk is further lowered where instantaneous water heaters (for example combi boilers and electric showers) are installed because there is no water storage.”

Persons undertaking the control measures and any other work on the plumbing systems should be trained in the risks from Legionella bacteria and competent to undertake the work.


What Residents (or Tenants) need to know

The HSE state – "Tenants should be advised of any control measures put in place that should be maintained eg not to adjust the temperature setting of the calorifier, to regularly clean showerheads and tenants should inform the landlord if the hot water is not heating properly or there are any other problems with the system so that appropriate action can be taken".

‘"here showers are installed, these have the means of creating and dispersing water droplets (aerosols) which may be inhaled causing a foreseeable risk of exposure to Legionella. If used regularly (as in the majority of most domestic settings) the risks are reduced, but in any case, tenants should be advised to regularly clean and disinfect showerheads. Additionally, ‘Report faults with the system so that appropriate action can be taken’".


Additional actions for properties left vacant

The management of void properties and their re-occupation process will also have an impact on the risk to residents. Again, the HSE’s advice remains: ‘"t is important that water is not allowed to stagnate within the water system and so there should be careful management of properties left vacant for extended periods (eg student accommodation left empty over the summer vacation). As a general principle, outlets on hot and cold water systems should be used at least once a week to maintain a degree of water flow and minimise the chances of stagnation. To manage the risks during non-occupancy, consideration should be given to implementing a suitable flushing regime or other measures such as draining the system if it is to remain vacant for long periods".

In Summary

All rental properties require a Legionella risk assessment. For landlords with only a small number of properties undertaking risk assessments, or commissioning them, should not be an onerous proposition. However, landlords or agents with responsibility for a large number of properties require a robust plan for the management of the risk from Legionnaires’ disease. Whilst Landlords may not have a mandatory obligation under law to provide residents with information relating to risks associated with domestic water systems, the HSE are clear in their view and advise that “landlords should inform their tenants about the action taken to control the risk from Legionella bacteria and advise them how they should be maintained".


If you have questions regarding the issues raised above or you would like to speak with one of our consultants please click here to get in touch.

Editors Note: The information provided in this blog is correct at date of original publication - January 2020.

Image by Photo Mix from Pixabay 

© Water Hygiene Centre 2020


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About the author

Peter Gunn

Peter has been acting as an AE [water] and providing competent help services to multiple public sector and public services client in both the Midlands and North of England since 2004, and working within Legionellosis risk management since 1997. Peter currently acts as AE [water] for 11 large public services client’s including University’s, Councils, Healthcare and Constabularies.

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