How long should water be flushed from the line before collecting a sample?

Flushing water from the line for 2-5 minutes before collecting a sample is important to ensure the water quality is representative of the supply. This practice allows for the removal of stagnant water that may have been sitting in the pipes, which can contain contaminants or compounds that alter the water’s chemistry or microbiological integrity.

Flushing for this duration helps to clear any build-up or material that may have accumulated and ensures that the sample reflects what is being supplied from the source rather than remnants from the plumbing system. This is a critical step in monitoring and testing water quality to ensure safety and compliance with health standards.

Other durations may not adequately remove the stagnant water or could potentially lead to elevated concentrations of certain parameters due to insufficient flushing. Therefore, the chosen time frame of 2-5 minutes strikes a balance that is effective for accurate sampling without being excessively long, which might waste water or lead to changes in temperature or chemical composition during the flushing process.