Lewiston Wastewater Treatment Plant Improvements

In May of 2018, Keller began working with the City of Lewiston to complete a Wastewater Treatment Plant Facility Planning Study. The WWTP Master Plan evaluated the condition of the WWTP equipment, capacity, redundancy, hydraulics, and treatment performance to determine deficiencies. In fact, several deficiencies were identified, including aging plant facilities—70% of which were over 30 years old with some major process over 60 years old and a lack of system redundancy—putting the City at risk, and insufficient capacity both for current and future growth.

Keller provided planning, design, and construction management services for the City’s $34.5 million WWTP upgrade project (5.59 MGD). Our team evaluated the redundancy, capacity, and performance of existing infrastructure and equipment. The project also addressed necessary process improvements for ammonia removal and future biological phosphorus treatment. The project improved the influent pump station, return activated sludge/waste activated sludge pump station, headworks, primary and secondary clarifiers, aeration basins, blowers, UV disinfection, solids thickening, digesters, and dewatering systems. Keller’s civil, process, structural, mechanical, electrical, and control disciplines each contributed to the design of this complex project.