For the February entry of Wright-Pierce’s 2026 Calendar Series (which highlights projects featured in our yearly calendar), we focus on the Polk County Wastewater Treatment Facility.
Project Background
The Northeast Regional Wastewater Treatment Facility (NERWWTF) in Polk County, Florida, was nearing its treatment capacity and was challenged by aging equipment and evolving regulatory expectations. To address these challenges, Wright-Pierce is providing engineering services for a range of significant improvements that began with the design and construction of two 100-foot clarifier additions, completed in 2022.
Since then, Polk County Utilities (PCU) selected Wright-Pierce to lead the design of an ongoing facility-wide expansion, which will increase the plant’s capacity from 6 mgd to 9 mgd. So far, Wright-Pierce has designed expansions and improvements of the facility’s chlorine contact chambers, filters, effluent pump station, and headworks, as well as upgrades to electrical, instrumentation, and controls systems.
Project Team Services
This project employs a collaborative team including Wright-Pierce, Wharton Smith, and Hazen, working in close coordination with PCU. Regularly scheduled workshops allowed for design input from the capital improvements, operations, maintenance, and construction stakeholders. To accommodate a sizable project, limited completion time, and regulatory requirements, Wright-Pierce assembled a multidisciplinary project team and developed a phased design and implementation approach, with an interim treatment capacity of 7 mgd, to meet PCU’s immediate needs.
The project includes major upgrades across the facility, such as a new headworks structure with advanced screening and grit removal, three new 5‑stage Bardenpho oxidation ditches to enhance nutrient removal, and a repurposing of the existing biological nutrient removal (BNR) treatment tank to a 3.0‑mg equalization tank. Additional improvements include a new 5.2‑mg reject storage tank, new blowers and mixing systems to improve aeration, and high-service reclaimed pump station.
The project simplifies critical plant communications and electrical systems for easier and safer plant operation by converting to Modbus protocols and installing new low‑voltage switchgear. The addition of new motor control centers (MCCs) and emergency generators will provide more reliability for the facility.
About The Photo
The ongoing expansion and modernization have provided substantial operational improvements, positioning the NERWWTF to support long-term community growth and environmental protection. The accompanying photo, taken by Discipline Technician, Andy Phaphilom, showcases the initial construction of the newly expanded chlorine contact chambers, which are part of Phase A. Katie Gierok, Operations Manager and NERWWTF Expansion Project Manager, reflected that “understanding the client’s needs, a collaborative project team, some out-of-the-box thinking, and a bit of hard work has made this project successful and rewarding.”
Project Impact
The upgrades and expansion to this facility improve operational efficiency, support regulatory compliance, and protect local water resources. Once completed, the expanded NERWWTF will provide Polk County with reliable, high‑quality reclaimed water to meet the needs of one of the fastest‑growing areas in Florida and the United States.
Contact us to learn more about the NERWWTF Expansion and how Wright-Pierce can support your community’s utility infrastructure needs.