by April Scheinoha
Several breaches have led raw sewage to be discharged into a county ditch that travels to the Red Lake River in Pennington County. As part of its consent agenda Tuesday, Sept. 4, the Thief River Falls City Council approved starting the process of fixing the affected wastewater force main.
The council approved a $64,400 contract with Advanced Engineering and Environmental Services for preliminary engineering of the project. In September 2017, AE2S provided an estimated cost of $2.93 million. That amount didn’t include improvements to Lift Station 9.
Installed in the early 1970s, the current force main has experienced major corrosion caused by the combination of the acidic wastewater inside the force main and the hot soil in which the force main is encased. The pipe then leaked into County Ditch 70, which travels to the Red Lake River. The city plans to replace the wastewater force main in 2019. That time frame was selected, so the project would be completed before the nearby Digi-Key storm water outlet project and the nearby West Side Flood Damage Reduction Project.
As part of the force main project, a new PVC force main will be installed. In a memorandum to the council, Water Systems Superintendent Wayne Johnson wrote that the new pipe will resist corrosion and will be placed in sand to extend its life.