The Art of Managing Contracts: Insights from the City of Toronto Ashbridges Bay Treatment Plant Outfall

Toronto Water’s Ashbridges Bay Treatment Plant Outfall (ABTPO) project will be the largest wastewater treatment plant effluent outfall in Canada. This paper discusses contract administration challenges encountered throughout the ABTPO construction phase. Project-specific construction management approaches, issues, and lessons learned are explored, including quality, schedule, risk and claims management, as well as the application of a Dispute Review Board (DRB). Owner and Consultant perspectives discuss how claims were successfully resolved for ABTPO. Contract administration insights for major disputes are presented, including a stuck bucket during shaft secant pile installation, three separate Differing Site Conditions (DSC) events involving unexpected adverse ground conditions with water inflows at greater than 400 lpm during Tunnel Boring Machine (TBM) tunnelling, and off-shore work claims involving riser installation DSC and marine weather conditions (e.g., adverse wind and waves). Lessons learned from successfully resolving these claims are also presented.