INFILTRATE, ALSO INFILTRATION

(1) The flow of a fluid into a substance through pores or small openings; to cause a liquid to permeate a substance by passing through its interstices or pores. It connotes flow into a substance in contradistinction to the word Percolation, which connotes flow through a porous substance. Also the process whereby water passes through an interface, such as from air to soil or between two soil horizons. (2) The technique of applying large volumes of waste water to land to penetrate the surface and percolate through the underlying soil.