Wired for Success: The Evolution of a Utility’s Large Diameter Force Main Asset Program

In 2003, the Middlesex County Utilities Authority (MCUA) implemented an asset management program to manage its most critical underground asset—the 102-in. prestressed concrete cylinder pipe (PCCP) Sayreville Relief Force Main (SRFM)—following two failures that occurred within the first 21 years of the force main being commissioned. At the heart of the program is the acoustic fiber optic (AFO) monitoring of the individual pipe sticks in the SRFM, which provides accurate and reliable real-time monitoring and alerts of the wire wrap breaks as they occur. The AFO monitoring data is accessed through a GIS-based web-portal. The AFO monitoring system has proven to be a powerful tool, allowing for live monitoring of the SRFM, tracking of historical data and repairs, and identifying broken wire wrap activity of interest that helps identify when pipes need repair. Additionally, the SRFM is inspected on a routine basis using visual and sounding techniques and electromagnetic technology. To determine the structural consequence of the broken wire wraps, structural analysis was performed using the American Water Works Association (AWWA) standards and nonlinear, three-dimensional finite element analysis (FEA). These analyses determine the pipe repair intervention limits. Since 2003, the MCUA has used the program to implement proactive, fully structural repairs on 41 pipes in the SRFM. As the world’s only known wastewater AFO monitoring system, the MCUA has been at the forefront of current PCCP management strategies. In combination with a robust inspection program, the MCUA has been able to anticipate pipes requiring intervention, thus preventing another catastrophic failure.