R. Steven Biggs Regional Wastewater Pretreatment Facility


In support of the largest manufacturing investment in North Carolina history, a $40 million wastewater pretreatment facility in Johnston County promises to be a powerful economic driver for the region. The plant supports a $1.8 billion Novo Nordisk Diabetes Active Pharmaceutical Ingredient (DAPI) manufacturing facility expansion currently under construction. When the wastewater pretreatment plant was complete, the pharmaceutical manufacturer donated it to the Town of Clayton so it could also serve future industrial partners.

Designed to handle 450,000 gallons a day, the facility removes nitrogen and phosphorus from industrial wastewater before it enters the municipal sewer system. Gannett Fleming provided turnkey project delivery services for development of the 22-acre site. The team utilized a multiphased engineer-procure-construct (EPC) delivery approach to meet the 17-month schedule requirement in alignment with clinical trial runs at the Novo Nordisk facility.

What We Did

The pretreatment facility handles waste from yeast-based fermentation, recovery, and purification processes. The plant’s two 500,000-gallon equalization basins control flow rate and pH at the facility, enhancing operational efficiency. Two bioreactor trains use a four-stage Bardenpho process to remove nutrients without the use of chemicals, reducing operating costs. The plant features 100% equipment and power redundancy to protect against failure and ensure optimal treatment to meet stringent wastewater discharge limits required in North Carolina. Supplementary items such as multiple pH fine-tuning locations, additional zoning aeration capacity within bioreactor zones, and automated controls with wider ranges of adjustments address potential influent constituent concentration increases.

Close collaboration with the client, Johnston County, the Town of Clayton, and the North Carolina Department of Environmental Quality enabled timely project delivery in accordance with client specifications and local and state requirements. Extensive stakeholder involvement and collaboration were essential for the success of the public-private partnership (P3) that supported the project.

Key Features

  • Bardenpho process eliminates need for chemical nutrient removal, reducing operating and disposal costs.
  • Rotary drum thickener treats solids to achieve flocculation, creating operational cost efficiencies.
  • Two secondary clarifiers promote additional clarification.
  • Equipment redundancy enables continuing operations in the event of equipment or power failure.

Awards & Recognition

  • Best Water/Wastewater Facility, 2020, Design-Build Institute of America Southeast.
  • Cleantech Innovation Award, 2019, Research Triangle Cleantech Cluster.


  • Biopharma manufacturing wastewater pretreatment for 450,000 gallons per day.
  • Complete support for Diabetes Active Pharmaceutical Ingredient manufacturing.
  • Capacity available to attract additional industrial manufacturing operations.
  • Highlights successful public-private partnership arrangement.


Novo Nordisk and the Town of Clayton


Clayton, N.C.


Engineering, Procurement, and Construction Services

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