The City of Topeka, Kan., had scheduled the repair of several hundred feet of deteriorating reinforced concrete pipe (RCP) sanitary sewer line at its South Kansas River pump station in the fall of 2013. Rather than undertake a costly replacement that would close the pump station and interrupt the high water flow during excavation, the city looked into optional rehabilitation and slip-lining methods. Its intent was to install a liner to restore the structural integrity of the original 78-in. diameter pipe and prevent failures while reducing the groundwater infiltration into the system.
Given the 18 ft of cover over the existing reinforced concrete pipe, SPR PE pipe liner supplied by Contech Engineered Solutions and SEKISUI Chemical Co. LTD was the selected material of choice for this project. This system allowed the city to reline the system completely from one access hole. The SPR PE pipe lining system consists of a single strip of steel reinforced HDPE profile that is progressively wound into the existing pipeline by a mobile winding machine positioned at the base of an access chamber. The edges of the profile are fusion-welded together by the winding machine, forming a continuous watertight liner.
The reline installation was conducted under live flow, which reduced the need for bypass pumping of the sanitary sewer effluent; this is an advantage of SPR PE over other reline technologies. The equipment and pipe profile were placed through a 22-in. manhole opening, and the project subcontractor, SAK Construction LLC, was able to line the entire 453 linear ft of the deteriorating RCP with the steel-reinforced SPR PE profile in only three days.
“Contech’s SPR PE pipe liner ended up being the most cost-effective solution for this project because the liner could be installed without modifying the existing structures to access the pipe,” said Andy Wright, P.E., of Bartlett & West. “The live flow installation was another advantage that reduced the project’s bypass pumping time and, subsequently, the overall cost.”