Legionella risk assessments evaluate water sources for the bacteria that causes Legionnaires’ disease. Water sources require monitoring for the presence of the Legionella pneumophilia bacteria and must undergo thorough Legionella risk assessments to ensure that they are not a danger to the public.

Legionnaires' disease is a potentially fatal form of pneumonia caused by inhalation of small water droplets containing the Legionella pneumophilia bacteria. These bacteria are naturally found in lakes, ponds, and streams, and at low levels are extremely unlikely to cause Legionnaires’ disease, but in favorable conditions the concentration of bacteria can increase, making the Legionnaires’ risk much higher. For this reason, water system managers are responsible for Legionella monitoring and must conduct Legionnaires' disease risk assessments to ensure the risk to the public is strictly controlled.

Legionella risk assessment services

Element is a trusted Legionella risk assessment and testing company, with highly experienced scientists and lab technicians throughout the world. Our experts can provide you with a clear and concise Legionnaires' disease risk assessment, as well as guidance and peace of mind knowing that you comply with all relevant legal requirements.

Element also offers Legionella and Total Viable Count (TVC) water sampling to indicate heterotrophic organisms' total level (fungi, yeasts, molds, and bacteria) within a sample. TVC sampling indicates general contamination within a system, determining if further investigation or remedial action is necessary.

In the UK, our team of qualified occupational hygienists, all of whom are members of the British Occupational Hygiene Society, carry out Legionella risk assessments following the Health & Safety Executive's Approved Code of Practice (ACOP) L8, and their supporting Health and Safety Guidance HSG274.

In the US, Element’s Lafayette, LA, laboratory provides environmental analytical and bioassay testing services, offering clients one-stop access to testing for several programs, including NPDES GMG 290000, NCP Product Schedule testing and Legionella testing. Element offers Legionnaires' disease risk assessment and risk mitigation services and provides clients access to a highly qualified team of environmental experts. Our lab uses the Legiolert testing method for comprehensive Legionella monitoring.

Element also offers ISO 17025 accredited Legionella testing services in our Dubai (UAE), Doha (Qatar), and Dammam (Saudi Arabia) laboratories, and can provide certain Legionella testing services through our Mumbai (India) and Singapore facilities.

Legionella risk assessment report

Our occupational hygienists produce Legionella bacteria risk assessment reports that outline the risk of exposure to Legionella from the hot and cold water systems and recommend the necessary control measures and water treatment programs to minimize the risks of exposure to Legionella.

The Legionella risk assessment report will be customized to the site but will typically be structured as follows:

  • Executive Summary (including any remedial control actions or requirements for on-going management, Legionella monitoring, or training)
  • Introduction
  • The Control of Legionella Bacteria in Water Systems
  • Assessment Procedure
  • Description of Water Systems
  • Appendix 1 Risk Assessments
  • Appendix 2 Asset List and Temperature Measurements
  • Appendix 3 Photographs
  • Appendix 4 Schematics
  • Appendix 5 HSG274 Part 2 and Part 3 Checklists
  • Appendix 6 Example of Monitoring Check Sheets and Procedures
  • Appendix 7 Example of Written Preventative Scheme

For more information about our Legionella risk assessment services, contact us today.

Legiolert Testing Method

  • Units - MPN/100 mL, (MPN – Most Probable Number)
  • Reporting limit – 10 MPN/100 mL
  • Holding time – 30 hours from collection to incubation
  • Sample volume – one 100 mL sterile container containing sodium thiosulfate to neutralize up to 5 mg/L chlorine (the same container that we use for fecal coliform)
  • Storage – Refrigerate at a temperature < 10°C, but not frozen, during transit to the laboratory.


Our team of over 6,000 Engaged Experts in North America, Europe, The Middle East, Australia, Asia and Africa are ready to help you.

Contact The Element Team