Evansville Water Department
The City of Evansville’s Water Department extracts water from the Ohio River to meet demands in and around the City. To ensure drinking water quality, the Water Department monitors for nearly 100 contaminants, including bacteria, metals, and pesticides at its water filtration plant. At the plant, water is treated with several chemicals, including aluminum sulfate, caustic, fluoride, carbon, chlorine dioxide, and ammonia, to remove contaminants and improve the water quality. The method that applies chlorine dioxide for treatment of drinking water was invented at the Evansville Filtration Plant in 1989.
In total, the Evansville Water Department has 8 storage tanks and 1,000 miles of water mains in the system. The Department treats, on overage, about 25 million gallons of water per day. Evansville’s drinking water meets or exceeds all state and federal regulations so that it can be drunk without any home filters.
Evansville Sewer Department
The Evansville Sewer Department manages the sewage system in the area that consists of a 504 miles of sanitary sewer system (for human waste) and a 318 miles of combined sewer system (for human waste and storm sewer). The sewage system begins with connecting pipes from residential and commercial buildings to larger underground trunk mains, which convey wastewater to two wastewater treatment facilities—the West Wastewater Treatment Plant and East Wastewater Treatment Plant. The West Wastewater Treatment Plant has capacity to treat 30.6 million gallons of wastewater from the western basins of Evansville per day, while the East Wastewater Treatment Plant has capacity to treat 22.5 million gallons of wastewater from the eastern basins.
Reduction of Combined Sewer Overflows
Combined sewer overflow (CSO) occurs when the volume of precipitation exceeds the capacity of waste water treatment plants and some untreated sewage / stormwater is discharged without treatment. To reduce the frequency of CSOs, the Evansville Sewer Department conducted a pilot project and created “green” infrastructure below eight city blocks of sidewalks that captures, stores, and infiltrates* stormwater in the downtown Evansville area. The pilot project that cost $235,000 has the potential to remove over 1.2 million gallons of stormwater from the Evansville’s combined sewer system annually.
*Infiltration systems allow runoff water to percolate into the subsoil, which reduces stormwater runoff
(Photo: Open graded stone being installed around Old Courthouse)