Legionella Sampling Techniques

It is important to highlight that there is no statutory requirement to carry out routine legionella sampling to domestic water systems. However where water temperatures cannot be controlled within the desired range, routine legionella sampling can be a valuable tool in managing the risk of legionella.

Aqua Legion UK Ltd supports each client by formulating and implementing bespoke water sampling strategies specific to each individual client and budget.

It is recommended that samples only be collected by operatives who are suitably trained to carry out such work in a safe manner.

In basic terms the following procedures are adhered to by Aqua Legion UK when sampling for legionella or any other waterborne pathogen.

  1. Personal safety precautions are always used to prevent breathing any aerosols, generating aerosols or mists of water and appropriate PPE is used when necessary.
  2. All our samples are obtained using sterile, screw-capped plastic bottles treated with Sodium thiosulphate, added to the bottle as a preservative and halogen (chlorine)-neutralizing agent in line with UK Standards.
  3. Using the most modern centrifugal techniques we are able to collect just 500ml of water sample to obtain UKAS accredited results. However 1 Litre samples are collected where necessary.
  4. When sampling cooling towers, whirlpool spas or fountains, etc we are constantly looking for evidence of biofilm formations and areas which may encourage bacterial growth and proliferation.
  5. It is also normal procedure to record any biocide used in water treatment when collecting water samples and this includes recorded the residual chlorine concentration in the mains water supply.
  6. All samples are submitted to UKAS accredited laboratories and tested via a traceable standard.
  7. All samples are submitted to our laboratories within 6 hours of collection and leaving any given site.
  8. Depending on the investigation a sample may be collected immediately upon opening the tap this is known as the first draw off. A second sample may then be taken after a few minutes of flushing to identify the distribution system water quality.
  9. In order to ensure all our samples are collected and transported using the highest standards we stick to a strict protocol set out in our own company procedures and in line with British Standards and UKAS requirements