Innovative Risk Management for a Sewer Tunnel Rehabilitation

摘要

The Beach Interceptor Tunnel in Laguna Beach, California was constructed in 1954 and contains agravity sewer pipeline critical to the South Coast Water District system. The tunnel is indeteriorated state that is endangering the sewer pipeline. Interceptor flow averages 4.73 millionliters per day and failure of the pipeline would result in discharge of untreated sewage onto thebeach and a potentially catastrophic environmental event. Emergency repairs were completed to ashort interval of the tunnel and the District is preparing to rehabilitate the entire tunnel and replaceof the pipeline. Because the project represents a very large capital investment, the District isproactively identifying and addressing protection of the environment, potential public impacts,securing additional easements and access, and planning to complete five years of constructionwithout interruption to service. Additionally, the District has implemented an innovative projectrisk management strategy that includes early contractor involvement coupled with a Target Pricecontract. Details of key District strategic risk management actions: emergency repairs completed toa short section of the tunnel, CEQA certification of the project, and adoption of Early ContractorInvolvement and a Target Price Construction Contract are reviewed and lessons learned identifiedfor application to future sewer interceptor rehabilitation projects.