Water Sampling

How do you test for legionella in water?

A trained specialist measures samples from your taps and outlets. Personal protective equipment (PPE) is worn, and sample containers are sterilised to ensure an accurate measurement is taken where no contamination of the samples has occurred.

There are various methods and customer requirements, but we can take the first sample immediately, without any disinfection or flushing of the tap and without the tap having been used for several hours. Temperature measurements are also taken, and the sample of water is mixed with a biocideneutralizing agent in a container. 

The collection method is then repeated to take a second sample after the tap has been flushed, disinfected in-line with site health and safety requirements, and the temperature is stable.

Disinfection involves removing any fittings and using a flexible plastic Pasteur pipette, wash bottle, or other appropriate means to inject disinfectant inside the nozzle of the tap until it runs out. Two minutes should be allowed for the disinfectant process to take place. All of this must be done while wearing protective goggles.

After sampling, the containers are then labelled with unique identifiers and testing details such as date, time, and location of the sample site. They’re then kept at ambient temperatures and protected from sunlight while they’re transported for storage and analysis. For legionella water testing and the measurement of other bacteria, samples are tested within 48 hours for accurate analysis.