In 2020, V&K worked with the City of Coralville to make improvements to their wastewater treatment plant. And, the site project presented some unique challenges. Located in the center of town and bordered by commercial areas, floodplains, and wetlands, there was very little space for additions. Due to the site’s limitations, construction phasing while maintaining plant operations was of utmost importance.
The improvements to the plant involved converting the existing SBR system to a continuous flow activated sludge treatment plant with nutrient reduction, which could handle flows up to 8 millions gallons per day (MGD), with peak hour wet weather flows of 30 MGD.
Improvements included a 16 million gallon equalization basin, screening and grit removal, aeration basins, two 90-diameter clarifiers, sludge pumping, and ultraviolet disinfection. A new Headworks Building was constructed to house the two 32 MGD coarse screens, five 100-HP vertical turbine pumps, two vortex grit removal units, and two rotary drum fine screen units. The building also contained a new electrical feed to power the entire plant site as well as connection to switchgear and new 1,500 KW diesel generator with sound attenuated enclosure.