ACEC-NC Honors Morganton Treatment Project Team

Charles Archer, Jake Lantz, Robert Vinay and Bryan Jann

Congratulations to the project team for the Morganton Wastewater Treatment Plant Conversion and Expansion, which received an Engineering Excellence Honor Award last month from the American Council of Engineering Companies of North Carolina (ACEC-NC).

Our team designed process conversion improvements and provided construction management for the 8 MGD Catawba River Water Pollution Control Facility, which serves over 16,000 people.

In August 2014, when Freese and Nichols treatment personnel visited the plant, its pure oxygen system was near the end of its useful life. Our team helped the City develop a conceptual plan for a gradual conversion from pure oxygen to a contemporary diffused-air configuration.

Then the system failed.

The orderly progression, planned to take five or six years, was stopped mid-design for emergency modifications. Migrating from one type of system to another is already a complex process; in this case, the urgency of the situation increased the complexity. The failure of the pure oxygen generation capability necessitated an interim system to support continued operations while the new system was designed and constructed. Our team created an interim design that could keep the system running as the conversion was still being designed.

Now, just five years after the initial meeting, the conversion and expansion project is complete. The improvements included conversion of the secondary treatment process from pressure-swing absorption pure-oxygen to more conventional diffused aeration, and conversion of the disinfection process from chlorine gas to liquid sodium hypochlorite. Major components included two new 225-by-45-foot aeration basins; flow splitter boxes for aeration basins and secondary clarifiers; a new building to house the aeration blowers; electrical gear and chemical storage facilities; and improvements to the RAS/WAS pumping systems, peak flow diversion and SCADA. The new aeration basins are equipped with a high-efficiency oxygen delivery system incorporating fine-pore diffusers and high-speed turbo blowers.

This project demonstrates the importance of engineers’ ability to listen to their clients and understand their needs. Additionally, the project demonstrates the benefits of providing a flexible design that will easily allow for expansion and necessary modifications. By planning for the future, the facilities can then be repurposed and utilized to meet potential regulations and new facilities can be constructed as needed without major site modifications.

This project team met more than the client’s needs; they elevated the client’s expectations for performance in design, execution and responsiveness. The City of Morganton’s wastewater treatment plant continued to operate during the design, emergency modifications as well as the conversion and expansion of the plant, benefiting the residents and business operators of the City, neighbors of the Catawba River and visitors to the lakes downstream from the plant.