Project, worth $23.5 million, will help city deal with heavy rain and reduce CSOs
In a first for the State of Indiana, Mayor Jonathan Weinzapfel recently dedicated the new biological aerated filter (BAF) project at the West Side Wastewater Treatment Plant (WWTP) in Evansville. The BAF operates at a higher removal rate than the traditional process. It also takes up less area and treats more water.
"This technology is going to greatly benefit the residents of Evansville. The increased capacity means we will be able to more effectively deal with heavy rains and reduce the number of combined sewer overflows," Weinzapfel said. "We will also be protecting our environment because we will be able to treat more wastewater instead of having the overflow go into the Ohio River during large storm events."
The West Side WWTP's capacity had been 20.6 million gal per day (mgd). Using an innovative secondary treatment process, the BAF will allow for the treatment of 30 mgd. During peak storm events, like the September 2006 floods, the plant's capacity will double to 40 mgd. The use of the BAF is a significant step toward addressing combined sewer overflows (CSOs) and alleviating flooding. Sewers north and west of Pigeon Creek, including the Highway 41 corridor, flow into the west side plant.
The cost to treat wastewater using the BAF is less than $1.20 per gallon; that is one-quarter of the cost it would take to use a more traditional treatment method. The total project cost is $23.5 million, which is being funded as a direct result of Weinzapfel’s decision to cancel plans for a $63 million treatment plant on the north side. That plant would have had very little impact on CSOs or flooding. Future capacity needs will be met by the West Side WWTP expansion.
The BAF project is part of the $120 million the Weinzapfel administration has spent or committed to fix flooding and sewer issues in the city over the past five years.