Simultaneous Leaks in York-Peel Feedermain at Two River Crossings: Investigation and Repair

The York Peel Feedermain (YPFM) is a critical watermain comprised of 1,800 mm (72 in.) diameter prestressed concrete cylinder pipe (PCCP) that is owned and operated by the Regional Municipality of York (Region) and supplies approximately 30% of the water demand for the Region. In 2022, two leaks were identified through leak detection on the YPFM, one near the West Humber River crossing and another near the East Humber River crossing. Before these two leaks, YPFM had experienced five other confirmed leaks that the Region repaired, including a pipe failure in 2009 just west of the East Humber River crossing that resulted in removal and replacement of several pipe pieces. The purpose of this paper is to present the investigation, analysis, and repair of the PCCP near the leak locations at East and West Humber River. Investigation included internal inspection of PCCP in the YPFM near the two 2022 leak locations, external investigation of PCCP removed in 2009, study of the steel cylinder of a pipe segment removed in 2021, and laboratory testing. Analysis included review of past studies that were performed during localized pipe replacements and pipe–soil-interaction finite element analysis of the pipeline. Repairs for the two 2022 leaks were performed using internal Carbon Fiber Reinforced Polymer (CFRP) that was designed to resist all internal and external loads including longitudinal demands from thrust and thermal loads with special details at the leak locations and at locations of suspected settlement.