The South Milwaukee Water Plant had been operating with two in-ground clearwells connected to a high service pump station that provided finished water to the distribution system. The WDNR determined that these clearwells were not compliant with current code.

Donohue led the engineering and successfully addressed these challenges by developing a robust, cost-effective, and neighbor-friendly solution. The South Milwaukee Water Utility was actively involved in every step of this project and became a true partner with Donohue.

The work included modifications to increase the speed of existing membrane feed pumps, demolition of flocculation/sedimentation basins currently used as raw water storage, construction of two new pre-stressed concrete clearwells and a 6-million-gallon-per-day high service pump station. The project also included reusing the existing high service pump station structure for new electrical facilities, repurposing of the existing north and south clearwells for intake flushing/raw water storage and upgrading the plant’s control system network.  Taking advantage of existing structures and developing a hydraulic design that allowed the reuse of existing membrane feed pumps, membranes, and membrane building without modifications saved over $10 million.

Maintaining continuous water operations during construction was critical. Two major construction sequencing challenges were identified. The project team developed a sequence of construction to successfully overcome these challenges.