Developing a Comprehensive Risk Management Strategy for a Community-Focused Combined Sewer Overflow Long Term Control Plan

Combined Sewer Overflow (CSO) Programs vary greatly in cost and complexity for each municipality. The City of Omaha (City) CSO Program is identified to have a cost of approximately 1.7 Billion in 2008 dollars. The Substantively Complete Long Term Control Plan (SCLTCP) was submitted to the Nebraska Department of Environmental Quality on October 1, 2007 identifying the proposed control strategy for the 29 CSO outfalls in the Combined Sewer System (CSS). Projects identified in the SCLTCP include a six-mile-long, 13.5 foot diameter tunnel for conveyance and equalization storage of combined sewage flow; a stormwater conveyance tunnel; three high-rate treatment facilities; two storage tanks; and over 3,500 acres of sewer separation.The risk management strategy for the projects identified in the Program uses a three-pronged approach to ensure compliance with all Program objectives. The analysis identifies risk events, opportunities, and mitigation strategies for all major items that could result in delayed implementation of the final Long Term Control Plan (LTCP) to be submitted in October 2009. The ultimate benefit of a comprehensive risk management strategy is implementing the LTCP to meet required program deadlines within estimated program costs. This is realized first and foremost by identifying all of the risks associated with the program. A well-developed, comprehensive risk management strategy leads to more accurate assessment of overall project costs and schedule, and a clear understanding of confidence that can be attributed to the results.