Addressing Rehabilitation Challenges for the Underwood Creek Force Main

Abstract

This paper discusses the challenges associated with the rehabilitation design and construction of the 36-inch ductile iron pipe (DIP) Underwood Creek force main. Based on the condition assessment and risk analysis, the Milwaukee Metropolitan Sewerage District (MMSD) minimized the risk of continued pipe failures by rehabilitating the force main. The rehabilitation design was based on a review of the currently available technologies and methods to identify those that appeared to be feasible. The four methods selected for further evaluation were cured-in-place pipe (CIPP) (for pressure), swagelining, tight liner (rolldown), and fold and form rehabilitation technologies. The final design documents included the use of two methods, CIPP and high density polyethylene (HDPE) liner, allowing the contractor to select the method and provide MMSD with the most cost-effective solution. The challenges that were addressed included minimizing the number of pits for construction of the liner because of location and constraints, the need to minimize impacts on the Underwood Creek Parkway and crossing a railroad and highway. This paper also discusses the challenges associated with implementing the design during construction and the coordination with many stakeholders, including the full reconstruction of a U.S. Highway 45 interchange by the Wisconsin Department of Transportation (WisDOT), and the construction of overhead high voltage trans¬mission lines by the American Transmission Company (ATC).