Legionella risk assessment from Pathology Management Services

Risk Assessment

Legionella Risk Assessment

Is it a legal requirement to have a Legionella Risk Assessment?

Organisations or Self Employed individuals who provide residential accommodation or who are responsible for the water system(s) in their premises, are responsible for ensuring that the risk etc exposure to Legionella in those premises is properly assessed and controlled. All water systems require an assessment of the risk which they can carry out themselves if they are competent or employ somebody who is.

Managing the Risk

As an employer or person in control of the premises (Landlord) you must appoint someone competent to help you meet your Health and Safety duties and take responsibility for controlling any identified risk from exposure to Legionella bacteria. A competent person often known as the responsible person, is someone with sufficient authority, necessary skills, knowledge of the systems and experience. The appointed person could be one, or a combination of:


One or more workers

Someone from outside the business

How often should I test and monitor Legionella from my water system?

It depends on the system you have in place and the outcome of the Risk Assessment. For open systems such as Cooling Towers, Evaporation Condenser, Spa pools etc routine testing should be carried out at least quarterly. However there may be circumstances where more frequent sampling may be required.

There may be other circumstances where Legionella testing is necessary e.g. where there is doubt about the efficacy of the control regime or where recommended temperatures or disinfection concentration are not being consistently achieved.

Where does it come from and how do people get it?

Legionella bacteria is widespread in natural water systems e.g. rivers and ponds. The conditions are rarely right for people to catch the disease from these sources. Outbreaks of the illness occur from exposure to Legionella in purpose built systems where water is maintained at a temperature high enough to encourage growth e.g. Cooling Towers, Evaporation Condensers, Hot and Cold water systems and Spa pools.

People contract legionnaires disease by inhaling small droplets of water (aerosols) containing the bacteria. Certain conditions increase the risk

Water temperature in some or all parts of the water system may be between 20 – 45c suitable for growth

Water is stored and/or recirculated

There are deposits that can support bacterial growth, provides a source of nutrients e.g. rust, scale and biofilms

What is the purpose of a Legionella Risk Assessment?

Identify any risks in your water system

The competent person should understand the water system and associated equipment

What should the Legionella Risk Assessment include?

Your Risk Assessment should include:

Management responsibilities, including the names of competent person and a description of your system

Potential sources of risk

Any controls in place to control the risks

Monitoring, inspection and maintenance procedures

Records of the monitoring results, inspections and checks carried out

A review date – There no guidelines in the revised HSE ACOP on how frequently you should review the Risk Assessment but annually would be ideal or if the design of the water system has changed earlier

Simple control measures can help control the risk

Flushing out systems prior to letting the premises

Avoiding debris getting into the system

Setting correct temperatures

Make sure any redundant pipework is identified and removed

How much does a Legionella Risk Assessment cost?

The typical cost depends on the size of the premises. Our assessors undertake assessments of all types of building and water systems including offices, manufacturing sites, warehouses and public buildings.

For a Legionella Risk Assessment quote please call 0161 643 5330.





You can contact us at this address:

Pathology Management Services
Rose Mill
Union St
M24 6DD

Tel: 0161 643 5330
Fax: 0161 653 3647
email: path.man@hotmail.com

Opening Hours:

8am until 5pm - Monday - Friday
7.30am until 10am Saturday and Sunday

*Clients are requested to telephone the laboratory prior to arrival