A stray voltage detection and isolation system. The stray voltage detection portion of the system includes a water delivery system electrically isolated from an electrical transmission system of an electric utility. Meters measure an electrical characteristic between a first test-point that is electrically connected to the water delivery system and a plurality of second test-points. The second test-points are at earth grounds at locations electrically connected to the first test-point. The location of a source of stray voltage can be determined by evaluating differences in the measured electrical characteristics. The stray voltage isolation portion of the system electrically isolates a water delivery system. A controller maintains an air gap between a water source and a first storage tank or between the first storage tank and a second storage tank. The second storage tank provides the electrically isolated water.