Unique Wastewater Treatment Plant Earns National Excellence in Construction Pyramid Award

The ambitious Clean Water Nashville Overflow Abatement Program in Nashville, Tennessee, was created to ensure the environmental health of the Cumberland River and its tributaries. The expansion of the Central Wastewater Treatment Plant (WWTP), Nashville’s largest treatment plant, was a major part of this initiative.

Baker was contracted by Garney Construction in 2020 to expand the 65-year-old plant’s headworks. Among wastewater treatment plants, Central WWTP stands out for its unique architectural elements. To blend with the surrounding historic Germantown community, the design incorporated concrete corbels, architectural brick that required special ledges, and special foundations for arches to receive decorative glazing.

The structural design was also extremely complex. Approximately 70% of the structure is water retaining, requiring many custom waterstop designs and fabrications. Varying elevation changes within water-containing concrete had to be placed monolithically. In addition, the project had a two-inch expansion joint across the entire structure in two places within the water-retaining portion of the cast-in-place concrete.

The Baker team also needed to work through the challenge of an extremely tight and active jobsite. A 500 series tower crane with 262 feet of jib length enabled the team to minimize its footprint yet still access every portion of the project. The use of building information modeling technology also proved vital to project coordination and quality.

The focus on preplanning, coordination, collaboration, and safety resulted in a smoothly run schedule. The efficiency paid off after two unusual snow events shut down the project for a week on two separate occasions. The team had accrued enough float in the schedule to quickly make up for lost time.

The project expanded Central WWTP’s capacity from 300 million gallons per day (MGD) to 440 MGD – making a significant contribution toward the abatement program’s goals. It also earned Baker’s Southeast Region two Associated Builders and Contractors (ABC) awards: an Eagle Award from ABC — Greater Tennessee and an Excellence in Construction Pyramid Award from the national organization. The team is proud to have made a lasting impact on the environmental health of Nashville’s Metro Water System.