How should a hot water pre-flush sample be collected?

Collecting a hot water pre-flush sample correctly is crucial for obtaining accurate data in Legionella assessments. The recommended method involves filling the sample bottle immediately after opening the hot water valve. This approach ensures that the water collected is representative of the conditions within the system at the point of sampling.

By filling the bottle right away, you capture the water that has been in the hot water line for some time, which can contain a concentration of Legionella organisms if present. This method reflects the immediate conditions of the water in the plumbing system just as it flows out of the tap, thereby allowing for a more precise evaluation of the potential for Legionella growth and presence.

Using other methods, such as waiting for a specified duration or prior cold water collection, might not provide an accurate picture of the hot water conditions. Waiting could allow for changes in temperature and sampling conditions that may affect the Legionella levels present in the water. Therefore, immediate collection is paramount for effective assessment and management of the risk of Legionella in plumbing systems.