Innovative Risk Management for a Sewer Tunnel Rehabilitation

The Beach Interceptor Tunnel in Laguna Beach, California was constructed in 1954 and contains a gravity sewer pipeline critical to the South Coast Water District system. The tunnel is in deteriorated state that is endangering the sewer pipeline. Interceptor flow averages 4.73 million liters per day and failure of the pipeline would result in discharge of untreated sewage onto the beach and a potentially catastrophic environmental event. Emergency repairs were completed to a short interval of the tunnel and the District is preparing to rehabilitate the entire tunnel and replace of the pipeline. Because the project represents a very large capital investment, the District is proactively identifying and addressing protection of the environment, potential public impacts, securing additional easements and access, and planning to complete five years of construction without interruption to service. Additionally, the District has implemented an innovative project risk management strategy that includes early contractor involvement coupled with a Target Price contract. Details of key District strategic risk management actions: emergency repairs completed to a short section of the tunnel, CEQA certification of the project, and adoption of Early Contractor Involvement and a Target Price Construction Contract are reviewed and lessons learned identified for application to future sewer interceptor rehabilitation projects.