In 1981 the Waste Water Treatment Plant (WWTP) was built at its current location of 595 Water St. At first it was a pond and lagoon system and consisted of a primary, secondary, and finishing ponds. Dewatering consisted of four large seepage cells where the cleaned water is reintroduced to the soil and the sludge is eventually hauled away. This system remained in effect until 2010 when the new plant was upgraded.
The WWTP is an activated sludge system with a head works building, a vertical loop reactor (VLR), two final clarifiers, two digesters, and the primary pond was converted to a drying bed, where the final product is dried, stored, and then eventually hauled away. Currently, the Evansville WWTP processes approximately 350,000 – 425,000 gallons of waste water every day. In 2017 the WWTP will be upgrading the sludge de-watering system from drying beds to a de-watering screw press. This will decrease the odor coming from the sludge, and disposal of the final processed sludge will be more convenient and cost effective. This process will also expand the processing ability of the WWTP allowing for future growth and large industry.
There is approximately 27 miles of sanitary sewer pipe in the city. We clean the sewer pipes with a high pressure water truck called a jetter. We perform this routine maintenance to avoid roots, rags, grease, and oils from building up in the pipes and clogging them. The old sanitary sewer pipe is clay and/or concrete. Newer construction, from the 90's to present day, is a more durable PVC.
There are eight lift station in the city. They are checked daily and routinely cleaned to avoid buildup of FOG (fats, oils, and grease). The lift station locations are on: CTH M, Union Street, Cherry Street, Lincoln Street, S. 6th Street, N. Water Street, N. Madison Street. The main lift station located on Water Street near S. Union Street which pumps all the sewage collected from the city to the waste water treatment plant.