Council’s and Housing stock – how to manage Legionella

by Charlie Brain, on 20-05-2022
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This blog attempts to answer a conundrum regularly pondered by Councils, housing associations and private landlords…. “do our 1000’s houses need a Legionella Risk Assessment?”  The regular response they may well receive from a health and safety or indeed, a Legionella consultant, will probably be “yes and no”. This blog aims to give practical steps landlords should take to meet their legal responsibilities.

Legionella - The Law and Regulations

If you are a landlord, you have a legal responsibility under the Health and Safety at Work Act (HSWA) to ensure your tenant is not exposed to health and safety risks. COSHH Regulations further explain that we are required to control the risk from a range of hazardous substances including biological agents, Legionella being an example. This is achieved by identifying risks, assessing those risks, and implementing any necessary control measures - sound familiar?


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Furthermore, ACoP L8 Approved Code of Practice requires landlords of domestic premises to assess the risk of exposure to Legionella to their tenants. More detailed information is given in HSG 274 Part 2 pages 45-47 as well as the HSE website .


There is much published guidance on what to do, however, it still seems to leave organisations with little practical advice on how to tackle it, starting with Legionella risk assessments.


Legionella Risk Assessment

HSG 274 Part 2 states “All water systems require a risk assessment but not all systems require elaborate control measures. A simple risk assessment may show that there are no real risks from legionella, but if there are, implementing appropriate measures will prevent or control these risks.”


If like many organisations, a specialist water hygiene company is commissioned to assess your properties, you could seek their help, although this may come at a less than reasonable cost to assess all residential properties.


The term “simple risk assessment” could be interpreted in many different ways, perhaps it means, short? i.e., a single page? Maybe, God forbid, not meeting all the detailed requirements of BS 8580-1 and the Legionella Control Association?


Completed internally by the Health & Safety Team? Completed by the same person conducting your energy survey?


What is deemed reasonable but sufficiently compliant could be debated at length, which sometimes results in this ‘prickly thorn’ left un-grasped. If starting from scratch, it is more important to find out what risks (water systems) you have, rather than the “risk” they represent via a detailed risk assessment.


It is suggested by the HSE that these types of property represent a “low risk” of Legionella to its users, which is why organisations concentrate resources on more complex water systems in buildings with more susceptible users.


It is also not unreasonable to suggest that organisations have not grasped this “prickly thorn”, because these properties will never be inspected or investigated. Well, the HSE has stated that they, nor Local Authority inspectors would actively inspect domestic premises or ask landlords for proof of a risk assessment. “However, if a tenant were to contract Legionnaires' disease from the water system in their home, the landlord may be liable to prosecution under HSWA, and would have to demonstrate to a court that they had fulfilled their legal duty, so it is important that they assess and control the risks”.


So, are you willing to play the game of chance or are willing to pay for Legionella Risk Assessments of your entire property stock? I hope your answer is, “somewhere in the middle”? If it is, let’s get started…


ACTION 1 – Identify Legionella Risks 

The risks, in this case, are water systems, be it, cold water tanks, hot water immersion heaters or showers. The first task is to categorise your property stock, this may well already exist?


The second task is to find out what water systems these properties have, this information may also exist already in the servicing or maintenance schedules or even refurbishment works?


This information could start to be pulled together on a spreadsheet.


ACTION 2 – Assess Legionella Risks 

As explained above, a “simple” risk assessment template could be devised internally, which an employee could carry out, if they have knowledge of the typical water systems installed.


Similarly, if the type of water system is generally known, then a desktop exercise of the property stock, including a scoring method of water system type and known occupant susceptibility could be devised.


This is known as a Property Risk Screen. Bunching similar properties together by “risk” could allow you to devise a schedule of risk assessments over the course of several years, thus managing budgets and resources.


HSG 274 Part 2 advises to do just this, initially assessing a representative proportion of similar properties, eventually assessing the entire housing stock in a rolling programme.


But if the water systems are generally known and are indeed classed as “simple systems”, “simple control measures” could start to be applied.


ACTION 3 – Control Measures


HSG 274 Part 2 gives advice on what simple control measures could be applied to these types of water systems, these are;

  • Flushing out the system before letting the property;
  • Avoid 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 calorifier to ensure water is stored at 60 °C);
  • Making sure any redundant pipework (i.e. dead legs) identified is removed;
  • Advising tenants to regularly clean and descale showerheads.


Your current control scheme for your larger properties will be larger and more complex than this, so it may be comforting to read these more basic measures. It may also be the case that you are already doing these, just not documenting them.


ACTION 4 – Implementation


Now that you have a property list, perhaps an idea of the types of water systems included and now the control measures that need to be applied, let’s look at each one and see how they can be implemented;


Control Measure


Flushing out the system before letting the property

  • Whether it is an entire property or an individual flat, is there a process already in place i.e. cleaning regime, that a water system flushing task can be added to? And importantly recorded?

  • Outlet flushing is not a highly skilled task, which can easily be trained in-house. See our video here for an introduction.

  • This could also apply to advising tenants to flush outlets after a period of no use i.e., after holidays, in a tenant’s handbook or article.

Avoid debris getting into the system (e.g., ensure the cold water tanks, where fitted, have a tight-fitting lid);


  • Where cold water tanks are fitted and known, could a simple inspection be carried out during an annual maintenance/service visit? Or during a pre-letting flushing task (above).

  • Could cold water tank inspections be tied in with Legionella Risk Assessments?

  • Even better would be to remove the cold water tank and pressurise the water system.

Setting control parameters (e.g., setting the temperature of the calorifier to ensure water is stored at 60 °C);

  • Check the hot water cylinder during an annual maintenance/service visit for storage temperature.

  • Advise tenants not to alter the temperature setting in a tenant’s handbook or an organisation magazine article.

Make sure any redundant pipework identified is removed;

  • Ensure any refurbishment work is carried out to standard using competent contractors who would not leave any dead ends or deadlegs.

  • Any redundant pipework should be highlighted in a Legionella Risk Assessment that can then be removed.

  • Supply washing machines with a cold feed only, as many hot feeds are left as a deadleg.

Advising tenants to regularly clean and descale showerheads.

  • Advise tenants to clean their showerheads in a tenant’s handbook or organisation magazine article.

Outside taps and garden hoses

  • An additional consideration should be to advise tenants to flush outside taps during times of low or no use i.e. winter.

  • Also, to disconnect and drain down garden hoses after use. This could be part of a tenant’s handbook or organisation magazine article.


ACTION 5 – Records and Review 

Private landlords are not necessarily required to keep records of the above tasks, unless there are five or more employees, but it would be a good idea to keep them, especially as an electronic file. Councils, Local Authorities and Housing Associations should, however, keep these records as they would with other properties.


There is no need to review the risk assessment unless there has been a change to the water system. A check to see if any changes have occurred which require different controls can be undertaken during routine maintenance/service visits. Download our Free Risk Assessment Review Tool for further assistance.



Most water systems in domestic settings are considered basic and the risks associated with them are considered low, owing to regular water usage and turnover. But even low risks must be managed to keep them that way. Mis-managing an inherently low-risk system, can create a high-risk situation, just think of not servicing your car, or indeed, driving your car recklessly.


To identify all water systems in the entire housing stock may seem a gargantuan task which may put you off starting, but it is important to start doing something. The implementation suggestions above will help prove risks are being managed and should be where to start.


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.

Editor’s Note: The information provided in this blog is correct at the date of original publication – May 2022.

© Water Hygiene Centre 2022


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About the author

Charlie Brain

Charlie started the Water Hygiene Centre as a trainee risk assessor back in 2010, since then he has developed professionally from risk assessor, project manager and is now a Senior Consultant. During this time he has taken ownership of our risk assessment method and development of our bespoke reporting platform and has been key in our UKAS accreditation to 17020.

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