A $46 million renovation of the wastewater treatment plant on Olentangy River Road is complete, giving Delaware County the infrastructure capacity to keep pace with rapid growth along the Sawmill Parkway corridor and US Route 23.

The Delaware County Regional Sewer District held a ribbon-cutting Aug. 10, at the Olentangy Environmental Control Center at 10333 Olentangy River Road in Powell. The facility broke ground in September 2022 and wrapped up a roughly four-year construction timeline.

"The OECC serves what we have identified as key growth corridors along Sawmill Parkway and US Route 23," Delaware County Board of Commissioners President Jeff Benton said at the ceremony. He called the project an investment in managing the county's growth strategically.

The project stands out for more than its price tag. It was one of the first public-sector projects in Ohio to use a contracting method called Progressive Design Build, in which design work happens collaboratively with engineering and construction firms rather than bidding out construction after design is finished. The county estimates the approach saved $12 million compared to traditional procurement.

The Ohio Department of Development provided a grant to help fund the project, though the county's announcement did not specify the grant amount.

Arcadis U.S., Inc., working from its Columbus office, handled design engineering. Peterson Construction Company of Wapakoneta built the facility. Chad Dunn, the Arcadis project manager, said the Progressive Design Build method kept the project on budget and on time despite supply-chain disruptions during the four-year construction period.

Delaware County Regional Sewer District Director Tiffany Maag credited her staff for maintaining EPA-compliant operations throughout construction with limited equipment available at times, calling the finished product "state-of-the-art technology and processes."

The district serves more than 129,000 people across 550 miles of sewer lines.

That service area is growing fast. Delaware County added 5,169 residents in 2025 alone, reaching 242,032, according to census estimates reported by Cleveland.com. The county ranks second in Ohio for percentage growth since 2020 at nearly 15%. Powell itself grew 28.1% since 2020, reaching 18,269 residents in 2025, according to WorldAtlas population data.

The OECC was Delaware County's first large-scale wastewater treatment facility when it opened in 1979. A second facility replaced it at the same site in 1994. The renovated plant now serves the corridor where much of the county's commercial and residential development is concentrated.