In 2007, WSSC began adding Acoustic Fiber Optics (AFO) to detect the sounds associated with pre-stressed wire breaks on PCCP sections while the pipelines are in service. Once installed, the AFO system continuously monitors the integrity of all the pipes and provides notification to trained personnel if a potential problem is detected in any pipe section.
WSSC has a total 145 miles of PCCP ranging from 36” – 96”. As of 2018, 100 miles of WSSC’s PCCP is monitored with AFO, making it the longest, active monitoring system in the United States. The Commission also conducts planned inspections. PCCP ranging from 48” – 96” is inspected every 5-6 years. Pipe that is 36” – 48” is inspected every 7-8 years.
Because the design of the pipe, AFO is effective only for PCCP, not for other types of pipe in the system such as ductile iron or cast iron.