McAlpine Creek Wastewater Management Facility Reliability and Process Improvements

Built in the 1960s, the McAlpine Creek Wastewater Management Facility is the largest of five wastewater treatment facilities operated by Charlotte Water, with a maximum monthly treatment capacity of 64 million gallons per day (MGD). The aging infrastructure was reaching the end of its lifespan and needed to be refurbished in order to continue providing water to the surrounding community. 

Garney and design engineer Brown & Caldwell were selected as the progressive design-build team to bring this rehabilitation to fruition, which will ultimately extend the facility’s lifespan by 30 years. This project includes the rehabilitation of 16 secondary clarifiers, 28 aeration basins, and the replacement of the plant’s two blower buildings. The project also consisted of the installation and operation of a return activated sludge (RAS) fermentation pilot study, along with data evaluation and implementation of a full-scale RAS fermentation system. 

The design-build team worked with the owner to determine a cost-effective solution to rehabilitate the secondary clarifiers and aeration basins for long-term asset protection via epoxy coatings. When tested against three other coatings products in a pilot study, Warren Environmental’s (Warren) epoxy system was deemed the best value solution. A&W Coatings applied Warren’s 301-14 high-performance epoxy to the clarifiers and aeration basins in a single coat, structurally enhancing their existing condition and extending their service life. The single coat application and the epoxy’s quick cure time resulted in schedule savings and associated overhead costs.

By further prioritizing the plant’s needs versus wants, Garney was able to optimize capital spending, resulting in significant savings of over $60 million from the initial cost estimate. Garney continued to bring value to the client by evaluating the design and conducting constructability reviews that resulted in further value engineering (VE) resulting in an additional $4 million in savings throughout the duration of the project.

The rehabilitation of the McAlpine Creek Wastewater Management Treatment Facility is expected to reach completion in 2024 and treat wastewater from the McAlpine Creek Basin, Sugar Wastewater Treatment Plant, and the Irwin Creek Wastewater Treatment Plant.