Skip to main content

Burlington Mississippi River Interceptor Replacement Project

Client:

City of Burlington

Location:

Burlington, IA

Project Type:

Engineering & Design

Market Type:

Water & Wastewater

Key Takeaways

Best-Value Solution Identified Through Comprehensive Analysis

Conventional, hybrid and full tunnel-boring alternatives were evaluated using a 40-year life cycle cost analysis and a decision matrix, providing the lowest long-term cost while meeting all CSO consent order requirements.

Strategic Routing Through Challenging Urban Conditions

Detailed hydraulic and route evaluations identified a feasible interceptor replacement solution that overcame significant elevation changes, historic infrastructure conflicts and constrained utility corridors.

Real-World Data to Inform Critical Design Decisions

Stanley Consultants deployed 10 flow meters and rain gauges across the study area to collect six months of continuous data, producing a calibrated hydraulic model that directly sized the interceptor, lift station and equalization infrastructure.

About the Project

Developing a Long-Term Solution for Aging Sewer Infrastructure along Burlington's Historic Riverfront Corridor

Facing aging sewer infrastructure and regulatory requirements tied to combined and sanitary sewer overflows, the City of Burlington, Iowa, needed a comprehensive strategy to relocate its Mississippi River Interceptor and improve system reliability. The decision was made to replace the existing gravity-driven pressure sewer system with a modern, reliable system capable of serving the community for decades to come.  

Stanley Consultants led the evaluation of wet and dry weather flows to determine the correct methodology, route and profile for replacing the river interceptor. The project’s design was complicated by significant topographic and infrastructure constraints, including conveying wastewater upstream from Cascade Valley to the wastewater treatment plant across a limestone river bluff, coordinating around the 109-year-old Bonn’s Hollow arch beneath Main Street and addressing a 50-foot vertical storm sewer drop.  

To evaluate replacement alternatives and develop a reliable long-term solution, the team deployed 10 flow meters and rain gauges across the study area and collected six months of continuous data. This monitoring captured 10-year, 25-year and 50-year storm events during the study period, providing the foundation for a calibrated hydraulic model that guided the sizing and routing of key system improvements. 

The project was designed as a single, integrated package to address multiple city priorities including sewer separation to reduce combined and sanitary sewer overflows and a sustainable replacement route for the Mississippi River Interceptor. The recommended solution also supported future community improvements by coordinating with a proposed recreational trail along the city's Main Street and an upcoming bridge replacement. The approach preserved eligibility for EPA funding and provided the flexibility to phase construction through 2031.

By The Numbers

  • 10

    Flow Meters and Rain Gauges Collecting Six Months of Continuous Data

  • 6 MGD

    Primary Lift Station Capacity

  • 1.3

    Million-Gallon Equalization Tank

Solutions

Engineering & Design

Engineering and design services at Stanley Consultants combine our robust technical skills with forward-thinking innovation to deliver the highest-quality results.

Environmental & Regulatory

At Stanley Consultants, we help clients navigate the complex world of environmental regulations and the challenges of a changing climate through proactive and sustainable environmental engineering solutions. Our team of engineering consultants provides comprehensive support services and innovative solutions to stay compliant and protect the environment. As a leading environmental engineering firm, we're dedicated to guiding your projects toward a sustainable and resilient future.

More Projects

Related Projects