AWWA JAW59059

Several environmental conditions, such as aggressive soil, use of dissimilar materials, and stray electrical currents, can cause metal water mains to corrode. This corrosion has been documented to occur as soon as five years after a metal water main has been installed. The authors explore various ways utilities around the world attempt to protect their ductile-iron water mains from leaks and breaks. Protective methods include coating, wrapping, or some form of cathodic protection. During the course of their research, the authors learned that the success or failure of a given protective method often depended on a specific set of circumstances. They learned that corrosion engineers, utilities, and pipe manufacturers have distinctive schools of thought about which method provides the most protection. Because of the variety of experiences reported by professionals in the water industry, the authors recommend that a comprehensive study be performed under a variety of conditions to help determine which protective method works best with ductile-iron pipe for a specific environment. Includes 55 references, tables, figures.