• Location: Lake County, OH

The Madison Wastewater Treatment Plant handles the majority of sanitary flows in the eastern portion of Lake County, Ohio. Built in 1974, the vintage plant was at its hydraulic capacity and in desperate need of improvements when an upgrade and expansion was recommended.

B&N led a multi-consultant project team for the $17 million plant expansion that switched plant operations from a conventional contact stabilization activated sludge process to a Biological Nutrient Removal Process (BNR). The project team reused existing structures while planning for future needs and regulatory changes, which was a key part of the project’s success.

Treatment capacity of the plant was expanded from 3 to 5 million gallons per day (MGD) and includes four trains of two-stage anaerobic-aerobic zones for an AO or Phoredox process. The upgrade also allowed the plant to double its peak hydraulic flow from 7.5 to 15 MGD.

Additional modifications to the process equipment resulted in a more cost-effective waste activated sludge thickening process, improved process aeration efficiency and control, and high efficiency mechanical mixing of the anaerobic treatment tanks associated with the BNR Process.