Identification of Water Pipe Material Based on Stress Wave Propagation: Numerical Investigations

Water utilities have been struggling to replace their aging infrastructure and have increasingly faced crisis related to the presence of lead pipelines that can affect the health of many communities across the United States. Replacement of lead pipelines is a daunting task because often their location is unknown and technologies to discover such hazardous water lines are unreliable. Driven by these needs, the researchers have explored nondestructive evaluation (NDE) strategies based on ultrasonic stress waves as a tool to discover lead pipelines. While such approaches present great potential, the complexity of wave propagation must be understood to develop an effective NDE strategy. This paper discusses the theoretical foundation and complexities of this approach by showing how stress wave propagation is quite different in pipelines of different materials such as lead, steel, copper, and PVC, which are the common materials used to provide drinking water to households. In particular, different stress wave speeds allow for the identification of different pipeline materials. The simulations presented in this study suggest how ultrasonic stress waves could be deployed in the coming years to help discover and replace lead pipelines.