The Fort Madison, Iowa, wastewater treatment plant is poised to undergo an extensive renovation that will improve its overall reliability and efficiency, as well as help protect it from flooding. The renovation is currently under design by Stanley Consultants, a global consulting engineering firm headquartered in Muscatine, Iowa, with local offices in Cedar Rapids, Iowa City and Des Moines.
The city’s wastewater treatment plant, originally constructed in 1965, serves a population of 11,000 and can process 6.2 million gal of wastewater per day. At the request of the city of Fort Madison, Stanley Consultants assessed the condition of the aging facility and evaluated the plant’s processes in order to develop recommendations for improvement.
The renovation is designed to maintain the plant’s viability, improve energy efficiency, address nutrient reduction requirements and provide flood protection. The upgrade will include a complete overhaul of the influent pump station and extensive replacement of the facility’s treatment equipment, some of which is 50 years old. Process improvements include a higher performance grit removal system, a new aeration system, new rotary drum thickening of biosolids and biosolids storage tank that will improve the plant’s treatment processes and increase biosolids storage capacity. The addition of a dechlorination process will facilitate operation of the existing chlorination disinfection system.
In keeping with the Iowa’s nutrient reduction strategy, the upgrade will position the facility for future improvements to further reduce nutrients discharged into the environment. Initially, operational adjustments to the existing treatment processes will be utilized to optimize reduction of nitrogen and phosphorus minimizing initial capital expenditures.
The plant is located adjacent to the Mississippi River and regularly impacted by floodwaters. A critical part of the renovation includes a new flood protection system consisting of a combination flood wall, with demountable portions and a levee. As a critical facility and in consideration of climate change impacts, the chosen flood protection level is the 0.2% probability event.
Construction of the $14 million renovation is expected to begin with the initial phase starting in April 2015 and the second phase being completed by May 2017.
