GZA GeoEnvironmental, Inc.

Scope Of Work

Huff & Huff, a subsidiary of GZA, based in Oak Brook, Illinois, was part of the team that recently completed this award-winning, sustainable, first of its kind interchange project for The Illinois Tollway.

The Project Team was tasked with the unique challenge of developing a “green” interchange so that a variety of sustainable concepts could be evaluated for incorporation into future designs. 

The Illinois Tollway has incorporated some sustainable practices in current designs; however, certain technologies have never been implemented, as there was no assurance that those concepts would be feasible for small-scale or large-scale projects.  In a sense, the Illinois Route 47 Interchange was a “prototype” project, allowing the environmental benefits, economic benefits, and longer-term costs to be evaluated for these sustainable concepts.  The process of selecting sustainable concepts included screening a variety of design features, developing life cycle assessments (LCA) and assessing their feasibility.

Designing this interchange was an opportunity to apply a diverse array of sustainable concepts, and beyond that, the ongoing evaluation process gathered data on the benefits and challenges of maintaining such systems.  Monitoring of energy usage and water quality in the storm water discharges provide data for performance evaluation and allow adaptive management of the sustainable practices. The practicability of green infrastructure, from concept to design to operation, is important so that designs can continue to be adapted and improved.  Data from this site will be used to enhance future design elements of the Illinois Tollway’s ongoing infrastructure improvement program. 

The sustainable features installed resulted in a savings of 34,000 pounds of carbon dioxide (greenhouse gases) per year at this interchange, and monitoring of storm events has shown a significant reduction in suspended solids and heavy metals concentrations and corresponding improvement to water quality. This project provides the Tollway both a qualitative and quantitative assessment that demonstrates the implemented concepts achieve the desired goal of creating a “green” and sustainable interchange that will be a useful model to the Tollway for future projects.

Huff & Huff was awarded ACEC Illinois’ Engineering Excellence Honor Award (highest level) for  work on this project.  From an article in the Chicago Tribune:  “The first "environmentally friendly" interchange on the Tollway system, it features a geothermal water piping system to heat and cool nearby plaza buildings and permeable asphalt paving to allow water to seep through and reduce storm water runoff, officials said.