Before taking a bacteriological sample, it is important to:

In the process of collecting a bacteriological water sample, flushing the service line before taking a sample is crucial for obtaining accurate results. This step ensures that stagnant water, which may have different characteristics from the source water, is cleared from the line. Service lines can contain bacteria or other contaminants from being idle, leading to inaccurate test results if not properly flushed. By allowing fresh water from the supply to flow through the line, you can ensure that the sample reflects the true quality of the water being supplied to consumers.

For thoroughness, it's worth noting that while letting water run for a few minutes and ensuring clean sampling procedures are important, these methods do not specifically address the concerns associated with stagnant water in the service line. Testing water temperature, although relevant in other contexts, doesn't play a direct role in preparing for a bacteriological sample. Therefore, flushing the service line stands out as the best practice to guarantee the integrity of the sample being collected.