Legionnaires’ Disease

Landlords of residential accommodation have responsibilities for combating Legionnaires’ Disease.

Health and safety legislation requires that landlords carry out risk assessments for the Legionella bacteria which cause Legionnaires’ Disease and thereafter maintain control measures to minimise the risk. Most rented premises will be low risk but it is important that risk assessments are carried out and control measures introduced.

What is Legionnaires’ Disease?

Legionnaires’ Disease is a pneumonia like illness caused by the Legionella bacteria and can be fatal. The infection is caused by breathing in small droplets of water contaminated by the bacteria. The disease cannot be passed from one person to another.

Legionella bacteria are found in the natural environment and may contaminate and grow in water systems, including domestic hot and cold water systems. They survive low temperatures and thrive at temperatures between 20 – 45°C if the conditions are right. They are killed by high temperatures at 60°C or above.

Risk assessments

Landlords are under a duty to ensure that the risk of exposure to tenants, residents and visitors by Legionella is properly assessed and controlled.

Normally there is no reason why the landlord should not carry out this risk assessment himself/herself so long as they are competent. Usually there will be no need to employ a consultant. The assessment should be a straight forward simple exercise in ordinary domestic premises.

For most residential settings the risk assessment may well show the risks are low so long as simple control measures referred to in the next section are followed. This will apply to houses or flats with small domestic type water systems where the water turnover is high. Provided the risk assessment shows that the risks are insignificant and the control measures are being properly managed no further action would be necessary. It is important, however, to keep the assessment under review periodically in case anything changes to the system.

Control measures

Simple control measures will help manage the risk from Legionella and these should be maintained including:

• flushing out the water system by running all outlets for at least 2 minutes where the premises have not been used e.g. before letting the property or if the property has stood empty for a time
• avoiding debris getting into the system (e.g. making sure cold water tanks, if installed, have a tight fitting lid)
• setting controls so that the hot water is heated to and stored at 60°C
• the removal of any redundant pipe work
• advising tenants to regularly clean, descale and disinfect shower heads

Advice for tenants

Landlords are entitled to expect the tenants will play their part in ensuring control measures are maintained. Landlords should:

• inform tenants of potential risk of exposure to Legionella and its consequences
• tell tenants of any action which arises from the landlords risk assessment if appropriate
• tell tenants to inform the landlord/agent if the hot water system is not heating properly or if there are any other problems with the system
• tell the landlord/agent if the cold water system is not running cold
• tell tenants to keep the water turned over

Unoccupied premises

The risk from Legionella may increase if the property is unoccupied even for a short period. It is important that water is not left to stand in the hot or cold water systems. As a general rule, all outlets on hot and cold water systems should be used at least once a week for at least 2 minutes to maintain a degree of water flow and minimise the chances of stagnation. For long periods consider draining the system. Make sure that the system is flushed through when it is re-occupied by running all outlets for at least 2 minutes.

Further advice is available from the Health & Safety Executive. www.hse.gov.uk/legionnaires.