Manitowoc Public Utilities is wrapping up a project fixing two of its clarifiers.
A clarifier separates solids and liquids in wastewater by slowing the flow, allowing suspended solids to settle out by gravity.
In this case, MPU uses rock or stack filters to help clean the water before it is returned to Lake Michigan.
The sludge and scum are later placed into digesters for treatment.
Clarifiers #2 and #3 were recently put back online after being rebuilt.
The West Stack Filter also underwent a complete upgrade and was put back online over the summer.
MPU explains that while construction is ending for the year, the East Stack Filter and final clarifiers #1 and #4 will be upgraded and rebuilt in 2026.
The upgrades are part of an MPU Wastewater Treatment Facility Master Plan study conducted in 2022, which identified a critical need for maintenance of the nearly 50-year-old stack filters.
The city received about $15 million in state funding to help complete the project.
