The City of Ihlen is located on a rock shelf in southwestern Minnesota. The city’s sanitary sewer was installed as a force-main grinder pump system. Each home had an outside grinder pump installed and the sewage was force-mained to a mound system on the edge of town.
The biggest challenges came in the areas of geology and Mother Nature. Specifically, the pipes needed to be installed in an area with large,
shelf rock just 2 to 4 feet below the surface – in a region that experiences deep winter freezes. Digging down to the rock, we routed the sewer line around any protruding points and installed pipe and trenching insulation, which has kept it from freezing. To minimize cost and traffic interruptions, a directional drill was used for all road crossings.
Project was completed September 1997.