The City of Hiawatha is a northern suburb of Cedar Rapids and part of the greater Cedar Rapids Metropolitan Area. The City was in need of two significant solutions to their sanitary sewer system in order to stabilize infrastructure and plan for future community growth.
The first would address routine breakage issues within a portion of sanitary sewer force main located along Mitchell Drive between North Center Point Road and the lift station positioned at the end of the drive. This had become a consistent headache for City staff, wasting precious time and resources to continuously repair the broken force main. MSA had been partnering with the City since 2010, and was brought in to design for replacement of the deteriorated main. The answer was the construction of 1,523 linear feet of new sanitary sewer force main, expanded from 6- to 8-inch diameter for increased capacity.
Two significant private businesses are located along Mitchell Drive – a millwright manufacturer/contractor as well as a larger printer and lettershop business. Both needed to retain full access to business and shipping operations during the course of installing the new force main. In addition, there were a number of existing utilities located along the construction path. MSA decided that a horizontal directional drilling method would best solve both of these challenges. Directional drilling allowed the contractor to avoid existing underground utilities and locate the new force main either under or between potential conflicts. It also minimized impacts on private business access along the route.
The second issue addressed the need for an extension of sanitary sewer gravity main to an undeveloped parcel of land located along Edgewood Road. Here, MSA led the design of 1,961 linear feet of new 8-inch gravity main, with six corresponding manholes and necessary appurtenances. Challenges to this portion of the project involved topography and bedrock; the MSA team worked to find solutions that would adequately position the gravity main at a proper depth and provided four alternate layouts to best solve the bedrock conflicts. This project was also horizontally directional drilled and saddle manholes were implemented instead of regular manholes to accommodate the depths greater than 25 feet. The resulting successful sanitary sewer extension positions the City of Hiawatha to continue to grow, increase their tax revenue, and welcome new residents and businesses to the community.