[AS.] A deposit of water reached by a hole sunk in the earth. The water in wells is of the same nature as that of springs. Many towns are supplied with water from deep wells which reach beds of sandstone, lying perhaps 500 or 1,000 feet below the surface. The water of shallow wells in towns is almost certain to contain sewage, which has passed from cess-pools or leaky drains through the soil and gravel or sand until it has reached the well. (See Artesian Well.)