What is the optimum well design for the prevention of contamination?

The only way to design a well to prevent water contamination is to seal it so that water can enter only through the bottom section. Dug wells need to be covered with a permanent cover through which a pump is installed to draw water. All wells should have a platform around them that is at least 1 meter wide, one which water will not penetrate. This platform ought to be sloped in such a way that any spilled water runs off away from the well. (See Figs. A and B on inside of front and back manual covers.)

These and other measures are described in more detail in the design section for the different types of wells (pp. 23 and 124).