Project Details

City of Birmingham Birmingham, MI Surveying

HRC provided tunnel surveying, design and construction observation for the Birmingham Combined Sewer Overflow (CSO) control facilities, constructed as part of an $82 million national demonstration project. The demonstration project is a three-phase project aimed at eliminating CSOs in the Rouge River watershed. The Birmingham Retention Treatment Basin (RTB) and Tunnel were constructed under the second phase of the project, which implemented CSO controls. Phase I included monitoring and optimizing existing combined sewer systems and planning for CSO controls. Phase III evaluates the results of Phase II CSO controls and initiates further controls (if necessary) to meet water quality standards.

HRC’s surveying responsibilities included the verification and propagation of the horizontal and vertical control for the entire project. The primary control was continued from a prior project located at the East Lansing Wastewater Treatment Plant and transferred to the site expansion and tunnel project start point. In addition, the control was promulgated for the length of the project which traveled 8,000 linear feet. The control network was verified and proven for integrity. The tunnel alignment was mathematically calculated to produce a coordinate alignment to be transferred to the subterranean work and the horizontal and vertical control was set in the tunnel by “dropping” lines into the initial shaft for control points. These points were used as the starting tangent for the boring operations. Concurrently with the boring operation, the above ground alignment was run, setting pilot alignment holes and subsequent shaft locations for quality control. HRC’s survey crew was constantly working in concert with the subsurface operation and was performing a record survey during the construction project. Upon receipt of the record data, the HRC survey office staff was processing and creating the record drawing in concert with the on-going project, assuring the tunnel was correctly aligned and within the set tolerances and spatial restrictions.