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 conducts planned inspections. Once initial inspections are complete, re-inspection for each pipe section occurs every five to seven years. By the end of calendar year 2016, all of WSSC's 77 miles of PCCP water transmission mains 48 inches and larger will be equipped with continuous AFO-monitoring technology. Thirteen miles of PCCP mains 36 inches and larger have AFO-monitoring and WSSC continues installation on the remaining PCCP mains (36”+).
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.