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Legionella Risk Assessment

Conducting and complying to a Legionella Risk Assessment (LRA) is required by law. The Health and Safety at Work Act (1974) states that the ‘Duty Holder’ has a duty of care for anyone using or occupying their buildings.

An LRA should be in place at all times and continually reviewed and updated. When significant alterations are made to the building a new LRA may be required OR if changes occur in the building that influence the risk factor, reviews should be carried out more frequently. The building’s responsible person could carry out this assessment if appropriately qualified, however it is often recommended an external water hygiene specialist completes this for them.

Should you require advice or quotations for legionella risk assessments please contact one of our team at

What is Legionella bacteria?

Legionella bacteria is a microorganism that lives in natural water, such as lakes and rivers. However they can also be found in man-made water systems given the right conditions.  Its ideal conditions are at temperatures between 20-45°C (77°F–113°F) and in water that it’s rich in nutrients. If these conditions arise, there is a potential that legionella can grow and spread.

What is Legionnaires’ disease?

Legionnaire’s disease is a severe and potentially fatal disease that is contracted through water droplets in the air. It is caused by the airborne pathogen Legionella bacteria and has pneumonia-like effects.

Check for Legionella now!

What is a Legionella risk assessment?

So, what does all this have to do with your legal water hygiene obligations as a business owner? You will have to undertake a Legionella Risk Assessment to assess the risk of legionella bacteria spread throughout your water systems. The frequency of any subsequent assessment will be determined by the legionella risk assessment as well as the client’s legionella policy.

A legionella risk assessment should contain both a physical inspection of the water system/s at your premises, as well as a consultation with the responsible people in this process. Firstly, the assessor will review any previous legionella risk assessments and determine if the outcomes were acted on appropriately. Then, they will tour the site to identify how and where water is stored and distributed, and the risks involved with current measures. Based on both aspects, a report will be drawn up and any recommendations to reduce or remove the risk of legionella bacteria will be documented along with a schematic drawing of the associated water systems.

The report will consider the following 6 areas, but not limited to:

  • The susceptibility of the building’s occupants, specifically vulnerable users
  • A description of all water systems assessed
  • An assessment of the risk associated with any water system identified
  • An assessment of the current lines of communication
  • An assessment of the current control measures in place
  • A description of any additional risks that should be addressed

When should a Legionella Risk Assessment (LRA) be conducted?

If you are the business owner, or legionella Duty Holder, it is crucial you understand the legal requirements as well as the responsibility to your employee’s health.

For a handy quick guide to the role of the duty holder Legionnaires’ disease A brief guide.

Whilst it is no longer a legal requirement to carry out a Legionnaires risk assessment every 2 years, it is still recommended. It is also recommended to carry out LRAs more frequently if there are any changes or updates to your water systems. The Approved Code of Practice L8 (ACoP L8) recommends a LRA “when there is reason to suspect it is no longer valid”.

If your building is inhabited or often used by high-risk users such as the elderly you may need to carry out an LRA more frequently. Additionally to this, the other reasons you may need an LRA include any changes to:

  • Significant water system alterations or additions
  • Changes in the lines of communication
  • The tenancy of the building changing
  • Relevant legislation changes
  • The risk level of Legionella bacteria ie. positive sample results

Who is the Legionella responsible person?

Since an LRA is a legal requirement, it must be carried out or authorised by your business’s responsible person. However, most businesses find that no one in their workforce is “suitably informed, instructed and trained and their suitability assessed” to carry out the assessment. This person must be confident that the business is compliant and ultimately is responsible for the prevention of Legionella bacteria growing or spreading.

If you are responsible for a more complex building it is definitely advisable to contact an experienced water hygiene specialist to ensure the assessment is done correctly and meets legal requirements.

What should you expect from a Legionella risk assessment (LRA)?

A LRA helps you better understand the risks of your water system and provides recommendations to help reduce or remove those risks. From an LRA, many business owners separate tasks into which are urgent and need addressing immediately and those that are non-urgent but would help the overall water hygiene process.

Choosing the right provider to carry out your LRA is crucial, as some businesses such as ourselves, will help you understand each task and reassure you from experience.

How much does a Legionella risk assessment cost?

The cost of a Legionnaires risk assessment will depend on the complexity of the building and its water systems. If you’re looking for a loose guide, typically an assessment for a simple building and water system would cost £250-£500. However, if the assessment is more complex they could cost much more, an Aquastat representative will be able to provide an accurate cost for your requirements . The easiest thing to do is give us a quick call to discuss your requirements.

Helping You Keep Your People Safe

Any water system can harbour bacteria growth in the right conditions, leading to Legionella bacteria growth.

The conditions in which bacteria is encouraged to multiply include:

  • Temperature between 20-45°C
  • Presence of rust, sludge, scale and organic matter
  • Stagnant or stored water

Legionella bacteria is one such bacteria that can thrive in water, causing legionnaires disease – a potentially fatal type of pneumonia.

All businesses are obliged to deliver a safe environment; however an unhealthy environment isn’t always obvious. Often the only symptoms your building will show you are:

  • Lukewarm water from taps
  • Bad tasting, or smelling water
  • Staining or discolouration around ventilation systems
  • Stains on ceiling tiles
  • Employees suffering with itchy or dry eyes

Aquastat dedicated teams deliver over thousands of risk assessments per year across all industries throughout the UK. We know that creating a healthy work place can contribute to:

  • Higher productivity
  • Higher staff retention
  • Reduced staff absenteeism

Our check-up is a simple, quick and easy way to see if you can better protect your staff and building from water, air and fire risks.

Aquastat teams are experienced in the design, supply, installation and maintenance of cost-effective water treatment solutions across various sectors, including but not limited to:

  • Local and Regional Government
  • Education
  • Retail and Leisure
  • Food and Beverage
  • Hospitality and Leisure
  • Hospitals and Healthcare
  • Manufacturing
  • Pharmaceuticals & Cosmetics
  • Industrial and Commercial

In all cases, Aquastat differs from traditional approaches in using an open, flexible and nimble approach to create the right team to make a rapid difference to their clients’ businesses.