The Oakland-Macomb Interceptor Drain (OMID) is a 50-year-old concrete system bordering Oakland and Macomb Counties in southeast Michigan. Authorities targeted more than seven miles of this large diameter interceptor sewer – 40 feet below a busy county road (M 59) – as a priority for evaluation and repair to avoid catastrophic failure. This project is part of a $160 million effort that has been under construction since 2009. Given the unique opportunity the project afforded to have access to this critical trunk sewer, the owner’s objective was to perform as many repairs possible.
Lanzo Trenchless Technologies was selected to provide multiple rehabilitation services, including high volume sewage control management, cementitious grout in place liners, fully deteriorated model CIPP, large bore spot repairs, cementitious grouting of voids, access manhole restoration, localized crack/failure repairs using chemical grout and CCTV. Challenges included working in and around flow that could not be disrupted during the construction process. Work was difficult and dangerous, and required extreme care in safety consideration, monitoring and management.
One of the first tasks of the project was to tunnel a shaft down to the 96-inch diameter sewer crown, create access and build a platform for staging of both the chemical and cementitious grouting activities within the pipeline. Lanzo retained the services of G2 Consulting Group to design two 16-foot diameter corrugated steel liner shafts to gain access to the existing sanitary interceptor approximately 20 to 25 feet below ground surface. To meet project requirements, G2 designed a shaft system that is uncommon for this part of Michigan.