UKAS Accredited Legionella Sampling: What You Need to Know

Wondering about Legionella sampling in your hospitality establishment? It’s a common belief that Legionella sampling is a must for Legionella control in domestic hot and cold-water systems. But the truth is, microbiological monitoring isn’t typically required for compliance with current guidelines.

However, Legionella sampling becomes necessary in high-risk scenarios or when existing controls fail. For instance, if maintaining temperature control proves consistently challenging or disinfection concentrations fall short, alternative precautions, such as weekly microbiological sampling, may be warranted.

When Is Legionella Sampling Required?

In high-risk settings such as hospitals, taking Legionella samples is obligatory. Specific guidance on microbiological monitoring can be found in BS 7592:2008 – Sampling for Legionella Bacteria in Water Systems.

It’s important to note that Legionella testing alone does not ensure compliance with The Control of Legionella Bacteria in Water Systems (ACoP L8), issued by the Health and Safety Executive.

Compliance begins with:

• A Legionella risk assessment
• Implementation of a control scheme based on the assessment findings

Understanding Legal and Regulatory Context

While ACoP L8 guidelines are not statutory, they are enforceable under:

• The Health and Safety at Work Act 1974
• COSHH regulations

A Legionella risk assessment determines:

• Actions required for compliance
• Ongoing monitoring schedules (e.g. temperature monitoring or biological monitoring where necessary)

How Long Do Legionella Sample Results Take?

Legionella samples must be analysed at a UKAS-accredited laboratory.

• Standard culture method: 10-day incubation period
• Expedited methods: Results available in as little as 24 hours

Where Should Legionella Samples Be Taken?

Sampling should follow BS 7592 guidelines, taking into account the complexity of the water system.

Key principles include:

• Representing water flow throughout the entire system
• Avoiding sampling solely from downstream areas
• Using a clear sampling plan that defines locations and sample types

Cold Water Systems

Samples should be taken from:

• Mains entry point
• Storage tanks
• Sentinel outlets (nearest and furthest outlets)

Hot Water Systems

Samples should be taken from:

• Outlets close to the calorifier
• Sentinel points on each branch or loop

How Are Legionella Samples Collected?

The sampling plan will specify whether pre-flush or post-flush sampling is required.

Technicians use strict aseptic techniques to minimise contamination and ensure accurate results, including:

• Using sterile bottles
• Avoiding contact between bottles and potential contaminants
• Maintaining appropriate hygiene throughout the sampling process

What Happens If a Legionella Sample Tests Positive?

If a sample tests positive, there is no need to panic.

Dantek should be contacted for guidance on the appropriate next steps. Actions will depend on the results, but may include:

• Re-sampling
• Reviewing existing control measures
• Disinfecting the water system where necessary

Key Takeaway

Legionella sampling is not a standalone solution. Achieving and maintaining compliance requires a comprehensive approach, including:

• Legionella risk assessments
• Effective control schemes
• Ongoing monitoring

Stay informed, stay compliant, and speak to Dantek for expert support with Legionella control in your hospitality establishment.