For some it is "dirt", for others it is registered as a contaminated site. By law, soil is the upper layer of the earth's crust with its functions in the natural balance, excluding groundwater and water beds. It is not only an important basis of life and habitat for humans, animals, plants and soil organisms, it is also used by humans in a variety of ways as a deposit for raw materials, an area for settlement and recreation and ultimately as a disposal area for waste.