A frequently overlooked fact, but one that is becoming of increasing concern, is the effect that the drinking water delivery system can have on the quality of water received at the tap. Deterioration of aging water supply systems can result in pipeline failures, pressure losses, fire hazards, damaged streets, human health concerns, and economic losses. The cumulative effects of inadequate maintenance and repair and a pipe's local environment can contribute to leakage losses of up to 40 percent and over 2 breaks/km/year. Twenty percent of the waterborne disease outbreaks in the United States have been associated with distribution system failures. Coupled with these water quality considerations is the fact that delivery systems can account for up to 80 percent of the cost of water supply. There is an infinite number of complex problems relating to drinking water distribution system reliability.