Reducing River Pollution and Runoff While Limiting Combined-Sewer Overflows

The Ohio River is home to more than 150 species of fish and 40% of North America’s freshwater mussel species. Further, the river supports nearly 27 million people with drinking water, jobs and recreational opportunities. However, the Ohio River is consistently ranked as one of the most polluted waterways in the United States.

The $37 million Rowan Deep Tunnel Submersible Pump Station — and associated tunnel — is the Louisville-Jefferson County Metropolitan Sewer District’s response to a consent decree limiting the quantity of combined-sewer overflows. The station is the only visible portion of the massive Waterway Protection Tunnel, a 4-mile underground tunnel that will ultimately collect 25 CSOs and divert approximately 439 million gallons of rainwater and wastewater from overflowing and polluting the Ohio River. The tunnel will store the sewage and rainwater mixture until capacity is available in the sewer and treatment systems. 

The Rowan Pump Station is the deepest submersible pump station in Kentucky and one of a very few that are operational around the country. The 220-foot-deep shaft houses 10 large pumps, each capable of moving 5 million gallons per day — enough capacity to empty the tunnel in just over a day. Above ground, the pump station doubles as a stunning architectural feature that enhances the planned expansion of Waterfront Park Phase IV. With back-lit corrugated aluminum panels and weathering steel, the facility performs practical functions within it while enhancing the environment around it. Phase IV includes westward expansion of open space along the downtown banks of the Ohio River, connecting the downtown core with West Louisville and promoting social and economic development. The building provides a “living” feature within the park space using a light-emitting diode system that creates a dynamic attraction for the community.

In offering MSD an effective and sustainable design, the team overcame a complete transition in project scope and design at the 30% mark to move from a storage tank design to the tunnel. During construction, the team blasted through considerable limestone bedrock on a site shared by contractors for the pump station and tunnel projects. Completed within budget, the project’s success is expected to provide a pathway for other engineers and agencies to consider the cost savings and operational simplicity of deep submersible stations.