What is the minimum flow rate for line flushing before samples are taken?

The minimum flow rate for line flushing before samples are taken is established to ensure that the water in the lines is adequately moved and that any stagnant water, which may contain contaminants, is flushed out. A flow rate of 2.5 feet per second is typically seen as sufficient to effectively clear the lines of any debris, sediments, or biofilms that may have accumulated.

Using a flow rate lower than this could potentially leave behind stagnant water, which would compromise the reliability of the water quality samples taken afterward. A flow rate of 2.5 fps is often used as a standard in the water treatment industry to ensure that the system is adequately flushed before sampling, resulting in a more accurate representation of the water quality in the distribution system.