The Difference Between Legionella Testing and a Legionella Risk Assessment

The Difference Between Legionella Testing and a Legionella Risk Assessment

If you're responsible for a commercial property, rental accommodation or another building with a water system, you've probably come across the terms Legionella testing and Legionella Risk Assessment. While they're often mentioned together, they aren't the same thing.

Understanding the difference is important because each has a different purpose and together, they form a complete water safety plan.

What Is Legionella?

Legionella is a type of bacteria that can grow in hot and cold water systems with the right conditions. It is most commonly associated with stagnant water, poor maintenance and unsuitable water temperature, particularly where water is stored in tanks or pipework.

If contaminated water droplets are inhaled, they can cause Legionnaires' disease, a potentially serious lung infection. Because of this, it's important for those responsible for buildings to manage the risk of legionella through appropriate monitoring and maintenance.

What Is a Legionella Risk Assessment?

A Legionella Risk Assessment is a professional inspection of a building's water system. Its purpose is to identify conditions that could encourage the growth of legionella bacteria in water and recommend ways to reduce the risk.

During the assessment, an assessor will inspect areas such as cold water tanks, outlets and pipework while considering factors including water temperature, system condition and how water is used throughout the building.

You'll then receive a report highlighting any potential hazards, along with recommended control measures to help keep the water system safe. Rather than looking for bacteria, a risk assessment focuses on preventing problems before they occur.

What Is Legionella Testing?

Legionella testing involves taking water samples from selected outlets and analysing them in a laboratory to check for the presence of legionella bacteria.

While testing can confirm whether bacteria have been detected in the samples taken, it only provides a view of the system at that moment. It doesn't explain why bacteria are present or identify issues elsewhere in the system.

This is why testing should be viewed as a supporting measure rather than a replacement for a Legionella Risk Assessment.

Do You Need Both?

Every building with a water system should have its risk of legionella assessed, as this is part of meeting your responsibilities under the Control of Substances Hazardous to Health (COSHH) Regulations. The Health and Safety Executive (HSE) provides guidance through ACOP L8, the Approved Code of Practice, which explains how duty holders should manage the risk.

However, routine legionella testing isn't required in every building. Whether testing is needed depends on the findings of the risk assessment and the type of water system being managed.

How Summit Environmental Can Help

Although they're often confused, Legionella testing and Legionella Risk Assessments have different roles. A risk assessment helps identify and control the conditions that allow bacteria to develop, while testing checks whether the bacteria are present at a particular time.

If your building is in need of an up-to-date assessment, Summit Environmental can provide professional Legionella Risk Assessments and expert advice to help you protect your water systems, comply with current guidance and reduce the risk of Legionnaires' disease.