Building Cincinnati's next generation of wastewater infrastructure

As part of a long-term plan to increase system resiliency and treatment capacity, the Metropolitan Sewer District of Greater Cincinnati (MSDGC) is upgrading the headworks of its Mill Creek Wastewater Treatment Plant. The roughly $350 million project adds a new system capable of screening and pumping up to 700 million gallons of wastewater per day, while routing flows into the existing plant and preserving the hydraulic capacity and connections needed for a future high-rate treatment facility.

Fitting that infrastructure into the operating Mill Creek treatment plant presents a significant engineering challenge. The new facilities must be constructed adjacent to an existing pump station that has been in continuous operation since the 1950s and must remain in service during construction. The project site is tight, bordered by the Mill Creek, roadways, and existing buildings, with utility tunnels and other critical infrastructure below grade. Excavation for the new system will extend more than 100 feet below ground.

That complexity is why the team leaned on model-based design from the outset. Rather than develop the design primarily in 2D and assemble a detailed 3D model later, MSDGC, Burgess & Niple, and Ulliman Schutte began building the project spatially from its earliest planning stages, then added detail as decisions were made.

That distinction mattered to Eric Meister, Vice President at Ulliman Schutte. On other projects, he says, a model often arrives late and looks impressive, but the important decisions have already been made. On this project at the Mill Creek, Burgess & Niple had planning-level 3D information in front of the team when the design was only 15% to 20% developed.

"Some other jobs I've been on, the model comes at the end and it's great, but you didn't make decisions on it," Meister says.

Progressive design-build meant the three organizations were already working together at that stage, giving them a common place to test layouts and program decisions before the design became too difficult or expensive to change.

Burgess & Niple also made an early technical decision: models and existing-condition data would be geolocated, so laser scans, drone imagery, GIS information, Civil 3D data, and Revit models all appeared in their correct position across the site. Autodesk Forma (formerly Autodesk Construction Cloud) gave the firms a shared environment to publish, access, and review current project information rather than work from separate copies.

That approach paid off almost immediately: the team scanned an existing underground utility tunnel alongside the proposed pump station structure and compared its position against MSDGC's record information and potholing survey data. The 3D laser scan data aligned to within an inch of existing conditions.

"That gave us a lot of confidence that, spatially, the Revit model of the existing underground utility tunnel was positioned correctly and that we could ultimately use that information to aid in design of the nearby deep foundations," says Paige Forney, Project Manager at Burgess & Niple.

The initial assumption had been that utilities within the existing tunnel would need to be relocated, a major, costly, disruptive undertaking, says Jeff Eilers, Principal in Charge at Burgess & Niple. With a more reliable picture of their actual location, the team instead designed the new pump station parallel to the existing tunnel, keeping those utilities in service, and routed new conveyance around the tunnel, existing outfalls, an old pump vault, and other below-grade infrastructure.

The clearest test of the model's value came when the team looked for ways to stay within budget, proposing to repurpose the below-grade structure of the existing North Pump Station as a future chlorine contact tank rather than building a new one.

The team had already taken the new-build option to around 30% design, so changing course meant proving that repurposing the existing pump station structure was a viable solution. The shared 3D model helped them develop the alternative solution and discuss it with the Ohio Environmental Protection Agency (Ohio EPA), whose approval was required.

Ryan Welsh, Deputy Director and project executive for MSDGC, estimates that reusing existing infrastructure saved the district more than $25 million.

For the team, that number illustrates a broader point: model-based design did not necessarily mean less design work. Sometimes it meant more, because constraints and alternatives surfaced early enough to work through before construction.

"But it's a better project," says Patty Scharf, Digital Engineering Director at Burgess & Niple.

This new approach also changed who could participate in design decisions.

Eilers has never used Revit, but the model viewer in Forma Data Management let him navigate the combined model directly, open it himself, inspect an area, and use it in project meetings instead of waiting on another plan, section, or PDF.

"I could pop in there at midnight and check something if I wanted to," Eilers says. "It's been a game changer for how we go about design and reviews."

The model quickly became part of the team's normal review process. MSDGC staff saw proposed changes in 3D during weekly workshops, gave feedback, and returned the next week to see how the design had developed. That mattered in a large owner organization where many stakeholders might struggle to visualize a complex facility from 2D drawings alone.

The team extended that involvement through several virtual reality reviews at the University of Dayton, standing together inside the model at full scale to see the facility from the perspective of the people who would eventually use it. Ohio EPA representatives joined one of the sessions.

After one six-to-eight-hour review session, Meister recalls the team leaving with over 100 comments, including one about a large gate valve: could an operator reach the actuator, maintain it safely, and remove it with the bridge crane if it needed replacing? Based on feedback from the facilities operations team during the VR review, the gate valve design was adjusted to improve serviceability.

"These are things you would normally only realize once you're in construction," Welsh says. Identifying them during design helps prevent issues that operators might otherwise have to live with for decades, or a costly change order to fix them.

Construction of the new pump station began in January 2026 and is expected to be completed in 2032. The shared model continues to connect everyone involved. Ulliman Schutte has passed model information to subcontractors, vendors, and process-equipment designers, and major manufacturers are returning their own equipment models for incorporation into the project.

"That model has become a tool that everybody's using during construction," Meister says.

Because major equipment vendors were selected early, Burgess & Niple could design around the actual pumps, screens, and motors going in, rather than placeholders, and manufacturers could use the same model to see the space their equipment had to fit.

The exchange continues even with suppliers overseas: the project's large pumps are being manufactured in Germany, and manufacturer models have helped the teams work through orientation, connections, access, walkways, and maintenance requirements in the same 3D context before installation.

For the team, collaboration is what made it work.