Legionella and landlords' responsibilities

Legionnaires' disease is a potentially fatal form of pneumonia caused by the inhalation of small droplets of contaminated water containing legionella. All man-made hot and cold water systems are likely to provide an environment where legionella can grow.

You can find more information on what Legionnaires' disease is and typical symptoms.

What is a landlord?

A landlord is anyone who rents out a property they own under a lease or a licence that is shorter than 7 years. Landlords' duties apply to a wide range of accommodation, occupied under a lease or a licence, which includes but not exclusively, residential premises provided for rent by:

local authorities
housing associations
private sector landlords
housing co-operatives
hostels

What you must do under the law

The law is clear that if you are a landlord and rent out your property (or even a room within your own home) then you have legal responsibilities to ensure the health and safety of your tenant by keeping the property safe and free from health hazards.

Section 3(2) of the Health and Safety at Work Act (HSWA) makes provision for relevant health and safety legislation to apply to landlords to ensure a duty of care is shown to their tenants regarding their health and safety.

Landlords, under section 53 of HSWA, are regarded as being self-employed. If you rent out a property, you have legal responsibilities to ensure you conduct your undertaking in such a way that your tenant(s) are not exposed to health and safety risks.

The Control of Substances Hazardous to Health Regulations (COSHH) provide a framework of actions to control the risk from a range of hazardous substances, including biological agents (such as legionella), to identify and assess the risk, and implement any necessary measures to control any risk.

The Approved Code of Practice Legionnaires' disease: The control of legionella bacteria in water systems (L8) has guidance on the requirements of the HSWA and COSHH for employers and those with responsibilities for the control of premises, including landlords.

Assessing and controlling the risks

The practical and proportionate application of health and safety law to landlords of domestic rental properties is that while 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.

The risks from hot and cold water systems in most residential settings are generally considered to be low owing to regular water usage and turnover. A typical 'low-risk' example may be found in a small building (such as a housing unit) with small domestic-type water systems, where:

daily water usage is inevitable and sufficient to turn over the entire system
cold water is directly from a wholesome mains supply (no stored water tanks)
hot water is fed from instantaneous heaters or low volume water heaters (supplying outlets at 50°C), and where the only outlets are toilets and wash hand basins

A simple assessment may show there are no real risks and these are being properly managed so no further action is needed. It is important to review the assessment in case anything changes in the system.

Implementing simple, proportionate and appropriate control measures will ensure the risk remains low. For most domestic hot and cold water systems, temperature is the most reliable way of ensuring the risk of exposure to legionella bacteria is minimised – keep the hot water hot, cold water cold and keep it moving. 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 (for example, ensure the cold water tanks, where fitted, have a tight-fitting lid)
setting control parameters (such as 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.

What your tenants need to know

Tenants should be advised of any control measures put in place that should be maintained, for example they should:

not adjust the temperature setting of the calorifier
regularly clean showerheads
inform you as 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

Where 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 they are 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.

Instantaneous electric showers pose less of a risk as they are generally cold water-fed and heat only small volumes of water during operation.

Additional actions for properties left vacant

It is important that water is not allowed to stagnate within the water system, so there should be careful management of properties left vacant for extended periods (such as 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.

Who can assess the risk?

In most cases, the actions landlords need to take are simple and straightforward so compliance does not need to be burdensome or costly. Most landlords can assess the risk themselves and do not need to be professionally trained or accredited. However, if they do not feel competent, or inclined to do so, they can arrange for someone to do it on their behalf.

Most landlords are able to:

understand the set of risks of running a hot and cold water system in a way that provides the above conditions
implement cheap, simple and effective physical control measures required to minimise the risk of the system becoming colonised with legionella and other microorganisms

Testing (or sampling) the water system for legionella

Testing or sampling for legionella (sometimes referred to as microbiological monitoring) is not usually required for domestic hot and cold water systems, and is only needed in very specific circumstances. There is relevant information in Part 2 of Legionnaires' disease: Technical guidance.

Testing for legionella should not be confused with temperature monitoring, which is a reliable method for confirming the water system is under control. Health and safety law does not require landlords to obtain or produce a 'legionella test certificate'.

Keeping a record of the risk assessment and reviewing it

Landlords are not necessarily required to record the findings of the assessment (this is only a statutory duty for employers where there are 5 or more employees), but you may find it wise to keep a record of what has been done for your own purposes.

The law does not prescribe that the risk assessment be reviewed on an annual or biennial basis. It is important to review the assessment periodically in case anything changes. However, where there are difficulties gaining access to occupied housing units, appropriate checks can be made by carrying out inspections of the water system, for example during mandatory visits such as gas safety checks or routine maintenance visits.

Are domestic properties proactively inspected?

HSE and local authority inspectors do not proactively inspect domestic premises or ask for evidence that landlords have carried out 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. They 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.