Des Moines Sewer Project Underscores Commitment To Infrastructure, Flood Control

November 2012, Vol. 67, No. 11

H&W Contracting LLC, based in Sioux Falls, SD, was awarded the sewer separation contract with construction beginning in early spring 2011. The first phase from Water Street along Court Avenue and north up to Grand Avenue was completed on schedule last fall. The open-cut method identified for the majority of the project was influenced mostly by cost. Yet there were also locations along the sewer alignment in which open-cutting the pipe was not feasible; hence, five trenchless installations were completed along the project.

Rognes Excavating worked with RTL Equipment, also based in Ankeny, IA, to secure a Doosan crawler excavator to complete the trenching and installation of the 66- and 54-inch reinforced concrete pressure pipe (RCPP) sewer. The RCPP along Court Avenue is all 66-inch-diameter, while the pipe diameter reduces at 2nd Avenue to 54 inches for the remainder of the upstream system.

“There were confined space and lane width considerations given that this is a high-traffic, often-congested downtown area,” says Doug Rhodes, sales representative with RTL Equipment, Ankeny, IA. “We recommended the Doosan DX235LCR excavator for the job mainly because of its zero clearance capabilities. This excavator has just three inches of overhang and has the ability to maneuver within inches of construction barriers. The DX235LCR also has extended vertical reach that requires repositioning of the excavator less often, and is capable of loading spoil into high-frame truck boxes.”

Subsurface exploration was extremely critical. As a result, there were no delays due to utility conflicts. Communication was also an important component to the project’s success. Contractors, businesses and media were kept informed continuously, not just about specifics of the project -- the what, where and when -- but also of progress and delays. Aesthetically, the walls surrounding the station complement the design of a river-view kiosk situated directly across the street adjacent to the Court Avenue bridge. Kamp explains this is one of the unique components of the project overall.