LEGIONELLA RISK ASSESSMENTS

Legionella is the bacteria that can contaminate your water supply and expose your tenants to legionnaire’s disease.

A Legionella bacterium is naturally present within water supplies in all properties. This bacterium enters domestic water system via mains supply. Due to the conditions within domestic properties the bacterium increases in growth. Many factors which increase the growth are the temperature of the water, nutrient sources (Scale, sediment, corrosion, algae, micro-organisms and materials) and the stagnation of water.

Contaminated water is aerosolised by showers and taps, meaning the inhalation of tiny droplets is drawn deep into the lungs which can cause a severe form of Pneumonia.

Unfortunately there has been a high rate of hospitalisation cases from residential properties, including a 12% mortality rate. Recently the Health and Safety Executives clarified that all landlords are responsible for the assessment and control of legionella. They have put severe penalties in place; these punishments can be imposed even in the case of risk without tenant’s becoming ill.

A Legionella risk assessment is a legal requirement and it’s the assessment of the water system that identifies the pipework and individual assets. In order for Landlords to abide by the legal requirements, a risk assessment is needed to be carried out; this lasts two years unless a significant change has been made to the water system and or use of the building has changed, however on the back of the risk assessment it may be recommended to monitor certain risks as a precaution at a specific frequency.

The risk assessment should be a living document which must be reviewed regularly to ensure it remains up to date. The landlord is responsible for identifying if the water systems are likely to create a risk of exposure by assessing if:

Water is stored or re-circulated in the system,
The water in all or some parts of the system may be between a certain temperature,
There are deposits that support bacterial growth,
If the produced water droplets can be dispersed.

We understand that sometimes properties are vacant for a period of time, this is a factor that can lead to the development of legionella bacteria growth, and so before a tenant moves in we can flush the system as a simple control measure that can help manage the risk of exposure and if the property was to be vacant for a while then we can drain the system also. We can also ensure that all redundant pipework is removed. Where there are difficulties gaining access to occupied properties, appropriate checks can be made alongside mandatory visits such as the gas safety inspection.