A process in which solid particles with a density greater than water settle out of the water phase due to gravity.

In a pumping station it is important to have benches at the bottom to insure that sedimentations and other suspended material are being guided to the inlet of the pump instead of settlements at the bottom of the pumping station.

In a discharge pipe it is important to insure a velocity high enough to avoid sedimentations in the pipes. The EN 1205 norm define min. 1 m/s in horizontal pipes and min. 0.7 m/s in vertical pipes. For a grinder pump or a pump with a cutter, sedimentations up to 0.6 m/s are acceptable.