Legionella Risk Assessments

Legionella is a form of bacteria found in water droplets and is responsible for Legionnaires’ disease, a potentially fatal form of pneumonia. The disease is contracted through inhalation of infected water droplets, not through drinking contaminated water. Legionella risk assessments are carried out to identify the risk legionella poses to occupants and visitors in a given building. This enables the ‘responsible person’ to make decisions as to the best course of action for monitoring, managing, and where possible, preventing the risk.

Where can Legionella be found?

Legionella is commonly found in man-made water systems including:

  • cooling towers and evaporative condensers
  • hot and cold water systems
  • spa pools

The legionella bacteria often thrive in certain environmental conditions. The legionella risk is greater when:

  • water temperatures are between 20-45 °C
  • the system uses stored or re-circulated water
  • the system can create and/or spread inhalable droplets, e.g. air conditioning
  • where sources of nutrients are present, e.g. rust, scale

Why do you need legionella risk assessments?

Legionella risk assessments are enforceable under The Control of Substances Hazardous to Health (COSHH) Regulations 2002 and The Health & Safety at Work Act etc. 1974. Failure to carry out a legionella risk assessment where required can result in prosecution.

Businesses need to control these risks by implementing measures detailed in the Approved Code of Practice and Guidance document L8 – Legionnaire’s diseases: the control of Legionella bacteria in water systems.

To prevent exposure to the legionella bacteria, duty holders must properly manage, maintain and treat the water systems in their premises.

The L8 guidance requires risk assessments to be:

  • carried out by a competent person
  • used to determine the appropriate maintenance regime for each property
  • reviewed if a system is substantially altered
  • reviewed periodically, in any event, every two years

It also requires records of the risk assessment, maintenance regime and any testing carried out to be recorded in writing and kept, possible electronically, for five years.

How can Stroma Tech help?

We are experienced in carrying out legionella risk assessments and act for a number of clients with significant property portfolios. Our services include:

  • Assessment and physical examination of every water system and outlet on the premises (providing access is granted)
  • Issue of a detailed, fully illustrated report, detailing the risks found (photographs and full schematic diagram included) and outlining possible remedial works for minimising/ eliminating these risks
  • Testing for legionella, especially in the problem areas highlighted
  • Production of a comprehensive, straightforward monitoring and management strategy, which is in accordance with guidance document L8
  • Assistance with the implementation of this strategy
  • Provision of treatment records and certification for proof of compliance
  • Provision of legionella control log books to enable ongoing monitoring

Why Stroma Tech for legionella risk assessments?

  • Our in-house Chartered Health and Safety Consultants are members of IOSH (CMIOSH) and the OSCHR Register – Water Management Society, Cooling Towers
  • Experienced in carrying out a full range of legionella risk assessments across a variety of building types and industries
  • Full nationwide coverage

Contact Stroma Tech for further details on Legionella Risk Assessments and for more information on how we can help you. Feel free to call us and speak to a member of the team, or complete our quick contact form.

Complementary services

Stroma Tech also offer a range of complementary Health and Safety Services including:


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