Water main failures are very expensive for municipalities because they typically result in expenses associated
with repair costs, flood damage, and loss of revenue to affected businesses. Water main failures also interrupt
the operation of vital services, such as medical care and fire-fighting operations. Currently, millions of dollars are spent annually by the water utility industry and by municipalities on the repair of failed components of the water distribution infrastucture, such as components that are made from gray cast iron or "gay iron" pip and ductile cast iron of "ductile iron" pipe. The rate of municipal water main failures is expected to increase as the existing cast iron infrastructure continues to age. The cost of repairing damages caused by broken water mains (and subsequent flooding damage) may become an important item in many municipal budgets. It is important to develop a corrosion program to prevent catastrophic failures of water mains. This paper presents a plan
consisting of several phases including preassessment, indirect assessment, direct assessment, and integrity
assessment of failed water mains. We will elaborate on the failure mechanisms, failure analysis protocols, and
corrosion mitigation strategies for water mains that experience breaks. Water main breaks are mainly due to
corrosive soil, pipe material, galvanic action, stray current corrosion, or microbiological induced corrosion (MIC). This paper provides an overview of corrosion issues commonly experienced by water main pipes, presents specific case histories involving graphitic corrosion, galvanic corrosion, stray current corrosion, and MIC. In this paper, we will introduce a graphitization sensor for condition assessment of water mains. This sensor can identify the location and extent of graphitization on water main.