Sewer Emergencies

In the event of a sewer emergency after 3:30 pm Monday through Friday or during weekends, please call 319.530.6224.

Plant Staffing

The Coralville Wastewater Treatment Plant has five staff members. The staff is responsible for the operation and maintenance of the wastewater plant, laboratory analysis, sanitary sewer system, storm water pump stations and sanitary sewer lift stations located throughout the City.

Plant Information


The City of Coralville’s Wastewater Treatment Plant was built in 1969, and the City’s sewer system dates back to the late 1940s. Prior to 1969, the sewage was pumped to the City of Iowa City for treatment through a series of lift stations. In 1975, 1984, 1993, and 2002, there were significant plant upgrades due to increasing flows and changing Department of Natural Resources regulations.


The growth of Coralville has made it necessary to upgrade the current wastewater treatment plant. The project to upgrade and expand the current wastewater plant includes:
  • Expansion of the equalization basin
  • New headworks building including pumps, grit removal, and screening
  • New aeration basin
  • New clarifiers
  • Replacement of the UV disinfection system 
These upgrades are planned to accommodate City growth to 2030. The project is expected to be completed and online by 2020. Learn about the improvements


The Plant consists of various screening operations and grit removal. The biological removal is accomplished by a four-basin Sequencing Batch Reactor (SBR) process. The final effluent is treated by ultraviolet (UV) light; the UV light doesn’t kill the microorganisms, but alters the DNA of any remaining bacteria, thus rendering the organism unable to reproduce. The effluent is then pumped to the Iowa River.

In 2010 an ISAMS-SAMS system (Integrated Surge Anoxic Mix System - Surge Anoxic Mix System) was added for additional bio-solids processing. The bio-solids are pumped to ISAMS-SAMS, aerobic digesters then to a gravity belt thickener for volume reduction then stored in an enclosed area until land application. The bio-solids are beneficial for agricultural purposes as a soil amendment and for its fertilizer and nutrient value. 


The average daily flow into the Wastewater Plant for 2016 was 2.86 million gallons per day (MGD). The 1993 designed average dry weather flow is 2.2 MGD. The average wet weather flow is 3.9 MGD.

Annual Reports