Grand River Avenue and Jo Road Sanitary Sewer Repairs

Spalding DeDecker (SD) has held an as-needed engineering services contract with the City of Novi since 2005. Under this contract, SD provided design engineering and construction engineering for two sanitary sewer repairs. The first project was a sanitary sewer that failed at the intersection of Grand River Avenue and Meadowbrook Road in front of a Cadillac Dealership. The second project was a sanitary manhole repair on Jo Road.

The Grand River sanitary sewer was 15 feet underground and was leaking raw sewage into the ground. The 10-inch PVC pipe was 20 to 30 years old and failed due to resting on soft peat soil. If left undisturbed, the failure would have resulted in a sinkhole. The Jo Road manhole had also been separated from the sanitary sewer due to settling on poor soils.

Spalding DeDecker’s team provided design engineering services, construction engineering, and traffic maintenance for both projects.

Due to the limited space of the project located between a busy intersection and a business, SD’s engineers determined the best option was to perform a jack and bore horizontal boring repair with grout soil stabilization injections

The SD team recommended stabilizing the peat soils by injecting grout into the ground, then utilizing clay pipes to jack and bore the new sanitary sewer into place. A long semi-rigid hose was inserted into the ground until it hit solid soils, then grout was injected at various intervals as they pulled the hose out. The jack and bore pipe installation method used a drill to generate a pipe-sized gap underground horizontally between two points without disturbing the surface.

Our team was able to replace the failed pipe to prevent any future sinkholes. We were able to complete the project without disturbing the dealership or the adjacent roadway. With the fix complete, any health risks to the public from the raw sewage were eliminated.