$50M Iowa City Wastewater Treatment Plant Expansion

In 2008 a flood inundated the City of Iowa City's North Wastewater Treatment Plant (WWTP), temporarily shutting the plant down and causing untreated sewage to flow into the Iowa River. The flooding accelerated the schedule for the City's planned shutdown and decommissioning of the North WWTP requiring a major expansion of the City's South WWTP. Decommissioning of the North WWTP eliminated treatment flooding problems of an aging and obsolete treatment facility.

Accurate assessment and routing of wastewater flows through the existing collection system to the South WWTP was a necessary part of the upgrade planning process. The City last performed flow monitoring in its collection system more than a decade ago.  In addition, the City also desired development of a 30-year sewer master plan to guide City sewer infrastructure investment.

Stanley Consultants constructed and analyzed a hydraulic model of the City's wastewater trunk sewer system to use in developing a 30-year sanitary sewer master plan. The flow metering program was developed with City staff to obtain flows at critical locations in the collection system. Stanley Consultants procured a combination of both permanent and temporary flow meters to install at 12 locations in the collection system.