City of Macomb Wastewater Treatment Plant Process Improvements

Project Summary

The city of Macomb chose Hanson to provide engineering services when it needed improvements to components at its wastewater treatment plant. Hanson provided upgrades, including replacement air-distribution piping from the blower buildings to the aeration basins and the headworks building, a replacement of motor control center in the north and south blower buildings, replacement of three blowers in the north blower building with two high-efficiency turbo blowers with variable-frequency drives, a refurbished automatic backwash filter, a new AquaDiamond cloth media filter, a new blower to run the plant’s airlift sludge return pumps, new electrical drives, panels and a supervisory control and data acquisition (SCADA) telemetry system for centralized control and data collection at the plant and a fiber-optic loop for SCADA communication that provides redundancy if there is a break in the line. The project was funded through an Illinois Environmental Protection Agency (EPA) State Revolving Fund loan, for which Hanson provided administrative services before and during construction.

Hanson’s services included a topographic survey of the plant area; calculations to size the new turbo blowers and blower for the air lift pump; design of the new air piping; meeting with the city’s programmable logic controller vendor and the city to scope out control, monitoring and data acquisition points for the proposed SCADA system; preparing permit applications for the Illinois EPA and Illinois Historic Preservation Agency; preparing design plans and specifications for construction of the improvements; and assisting the city with bidding and construction-related services.

Hanson also replaced one of two grit chambers with a new “vortex”-style grit removal structure, as well as a grit washer and dewatering system. The plant’s two aerated grit chambers, designed for removing grit from influent wastewater, were at the end of their useful lives and used old, inefficient technology prior to the upgrade. Equipment in the plant downstream of the grit chamber was being damaged by the amount of grit passing through. The new structure, which Hanson installed inside the footprint of the original basin, improves operating efficiency.