Milwaukee MSD Wet Weather Project Receives 2006 Engineering Excellence Honor Award

The Milwaukee Metropolitan Sewerage District and Donohue & Associates were selected for a 2006 Best of State award from ACEC of Wisconsin in its Engineering Excellence Awards competition. The project was also a national finalist. The award recognizes wet weather capacity improvements to the District's Jones Island Wastewater Treatment Plant.

Prior to this project, the Jones Island Wastewater Treatment Plant's peak treatment capacity often fell 50 to 100 million gallons per day (mgd) below its theoretical design capacity of 330 mgd due to limitations in their secondary treatment process. The Donohue team designed low-cost modifications to overcome these limitations and restore this lost capacity, thereby reducing blending of partially treated effluent and combined sewer overflows.

The project applied several innovative engineering concepts to increase capacity. One such innovative concept was the conversion of six of the plant's 32 aeration basins into dual purpose units. When the plant receives high flows, the basins automatically switch over to serve as offline biosolids storage basins. As flow subsides, the basins revert back to the original configuration. Improvements were also made to the secondary clarifiers.

Of particular note is that this is the largest purely plug flow facility in the country to incorporate off-line storage of active biosolids, accomplished without adding new facilities or changing the plant's process flow configuration.

"The improvements provide significant benefits to the District, the community, and the environment by reducing the number and volume of wet weather overflows, including blending, at a low cost," stated Kevin Shafer, PE, Executive Director of the Milwaukee Metropolitan Sewerage District.

The Milwaukee Metropolitan Sewerage District is a state-chartered, government agency providing wastewater services for 28 Milwaukee area municipalities.