The Decatur MBR Expansion Project was an SBR to MBR retrofit via the Progressive Design-Build delivery method. This project included an influent pump station renovation, existing wet well expansion, process piping, construction of a new electrical building, and equipment for fine screening, sludge dewatering, ultraviolet disinfection, aeration, chemical injection, and biological treatment. The Design-Build Team was able to provide cost-saving and constructability ideas throughout the entirety of the project, which provided the City a better end product. Their innovative approaches included the following:
- Placement of MBR tanks on top of the existing SBR Equalization structure, allowing for siphoning of permeate water, reducing energy consumption and minimizing plant shutdowns
- Incorporation of VFD’s on existing equipment
- Implementing SCADA in order to automate the new to existing plant
- Conducting clean water testing before the train shutdown to make the startup more efficient and effective
The successful completion of the project in February 2019 made the Decatur Wastewater Treatment Plant the first MBR plant in the State of Arkansas, and it also became the first Progressive Design-Build project in the State. The project now enables the City of Decatur to be in compliance with the ADEQ under a re-permitting of the plant effluent requirements to stricter and more technologically advanced permit, with the ability to treat up to 4.6 MGD (a 109% increase from the initial capacity) for roughly $4.08/gallon of treatment capacity.