Legionella Compliance

The first step in any risk management process is production of a professional risk assessment and Legionella management is no different. A written risk assessment is required for all commercial building with a water supply, where five or more people are employed.

A Legionella Management Plan prevents exposure to bacteria that causes legionellosis.

Where risk assessment shows there to be a foreseeable risk of exposure to bacteria, it is then necessary to implement ongoing controls to mitigate the risk highlighted within the assessment. This usually takes the form of a Legionella Management Plan and would include the following;

  • Weekly flushing of infrequently used services

  • Monthly temperature monitoring of sentinel outlets
  • Quarterly descaling and disinfection of shower head
  • Six monthly tank inspections
  • Annual review
  • Awareness training
  • Tank cleaning and disinfection

A site specific log book is created based on the report findings and water system detailed in the risk assessment setting out the controls necessary and appropriate forms for creation of an audit trail.

A full reassessment should be completed every two years, in addition to:

  • Change to plant / water system or its use
  • Change to use the of the building
  • New information about risks / control measures
  • Tests indicate control measure are ineffective

Legionella Risk Assessment

Based on the HSE’s Approved Code of Practice (ACOP L8), a written risk assessment is required for all commercial buildings that have a water supply and where five or more people are employed.

As set out in the guidance, the person on who the statutory duty falls is required to have ‘access to competent help in assessing the risks’. This involves the engagement of an external water consultant to produce a risk assessment, which should identify and evaluate all potential sources of risk, review how exposure to bacteria can be prevented, or where prevention is not possible, exposure can be controlled.

A Legionella Risk Assessment involves a trained engineer visiting a premises and making an objective assessment of the water system’s potential to be colonised by Legionella bacteria and the various factors favourable for their continued growth.


The new ACOP L8 has been published: Legionnaires’ disease: The control of legionella bacteria in water systems. Approved Code of Practice L8 (Fourth edition) Published 2013:

Available Now: http://www.hse.gov.uk/pubns/books/l8.htm

When the new ACOP L8 was released recently, there was the associated guidance HSG274 which came in three parts:

  1. Cooling systems
  2. Hot and cold water systems
  3. Other risk systems

The hot and cold guidance was an interim document awaiting review and this has now been completed. The final version of the hot and cold guidance can be found at www.hse.gov.uk

For more information on how this affects the way in which you govern water hygiene and legionella control, please contact a member of the team on 0800 0741237.

Solutions we offer:
Legionella Management

At Nemco, we understand that every water system is different, and therefore so are the needs and constraints of varying companies and organisations.

In light of this, all management programmes are tailored to meet the needs of the client and range from completion of weekly flushing for unmanned sites, to on-site training of maintenance staff.

Contact us today to find out how we can support your organisation with a Legionella Management programme.

Solutions we offer:
Legionella Risk Assessment

At Nemco, our expert team provides detailed Legionella Risk Assessments to meet the HSE’s guidelines. As part of a thorough risk assessment, all areas of the water system are inspected including loft spaces and void areas.

Following the on-site assessment, a report is produced together with remedial recommendations and schematics drawings. Advice is provided for those buildings where the risk of exposure to Legionella is possible, in order to mitigate such risks.

Contact us regarding Water Hygiene

Call us : 0800 0741237
Email : info@nemco-utilities.co.uk