Asset Management of a Failing 36" Ductile Iron Sewage Force Main

Two failures within a two year timeframe on a 36-inch ductile iron sewage force main installed in 1983 has raised serious questions on the expected life and risks associated with this underground asset. With proper design and installation a life expectancy of at least 60 years should have been expected for this pipeline. The cost for the repair of each break was between $50,000 and $75,000. In addition, a sanitary sewer overflow (SSO) resulted from each of these failures, which is a violation of the operating permit with the State of Wisconsin. To help determine the condition of the pipe, Pure Technologies was hired to perform a leak survey using their proprietary SmartBall® (Pure Technologies). The results of this survey are one of the tools being used to determine the current condition of the asset, in line with a defined asset management approach. This paper will outline the asset management approach being taken to assess the condition of the 36-inch ductile iron force main and the repair, rehabilitation and replacement strategies being considered for the pipeline asset.