Reviving Reliability: Safeguarding the Waukegan Effluent F-3 Force Main

The Waukegan Effluent F-3 Force Main (Force Main) in Illinois, responsible for transporting treated effluent into the Des Plaines River just next to Lake Michigan, has been under proactive condition assessment by the North Shore Water Reclamation District (NSWRD) for two decades. Constructed in 1976, the pipeline has experienced catastrophic failures in 1996 and 1998, prompting repeated condition assessments with varying techniques. The latest condition assessment in December 2022 included an electromagnetic assessment, visual and sounding inspections of the prestressed concrete cylinder pipe (PCCP) and 95 carbon fiber reinforced polymer (CFRP) repairs, remaining useful life analysis, and incorporation of structural risk curves and priorities from a third-party engineering firm. Out of the 1,261 inspected pipes within the pipeline, 68 were identified with distress with 21 being newly compromised and 28 showing an increase in distress since 2018. This paper presents the assessment methods, results, recommendations for both short-term and long-term management of the Force Main, and how NSWRD is using this guidance to ensure the force main’s continued reliability.