December 6th, 2017

A standing sample is a sample of the first water that comes out of the tap that could have been “standing” in the pipe and not flowing whereas a “flushed sample” is a sample of water that has had a chance to flow before taking water from the tap or fountain.

While lead is generally not found in water from municipal drinking water plants, it may be present in the distribution piping with the streets and in certain facilities (schools) with older pipes, solder and fixtures, especially buildings built prior to 1990. Flushing of plumbing has been proven to decrease the amount of lead in drinking water in these cases. Facilities are required to take samples of the drinking water from the drinking fountains and taps before and after they flush the plumbing. A comparison of the flushed sample results versus the standing sample results consistently shows that flushing significantly reduces lead in drinking water.