Testing a Distributed Monitoring System for EBMUD’s Water Mains

The bay area has several active seismic faults. In order to supply water for its 1.4 million customers, the East Bay Municipal Utility District (EBMUD) must maintain pipe infrastructure that cross these hazards. Researchers at SRG have been working with EBMUD to develop a monitoring system for the most critical pipes in the east bay’s water supply network. Recently, a bending test was conducted at EBMUD’s Oakport storage facility to test the system. A 50’ long, 22” diameter HDPE water main was instrumented and bent by gravity loading. The strain induced by bending was measured along the entire length of the main, allowing for the deformed shape to be calculated with high precision. The monitoring system is made up of a UC Berkeley-developed distributed fiber optic strain sensor, a robust sensing cable, and a rapid attachment technique designed for in-trench deployment during pipeline construction. The test was a success, and the system will be used to monitor a new large diameter pipeline that will cross the Hayward fault. The field installation is scheduled for 2021.