Taxiway ZS used approximately 7,100 tons of WMA and 7,000 square yards of PCC. Upon completion of the Runway 9C-27C Northeast project, the contractor will have used approximately 67,000 tons of WMA and 108,000 square yards of PCC.

The Chicago Department of Aviation has been and continues to be very committed to incorporating green best practices into all aspects of O’Hare International and to Chicago’s smaller but well utilized second airport, Midway International. This includes airport design, construction, operations, terminal maintenance, and day to day management.

The CDA developed a Sustainable Airport Manual (SAM) to establish guidelines and policy and procedure for airport operations including construction and is applying this to the OMP. The exploration and research that went into the decision of using WMA follows the sustainability practices. The incorporation of WMA as a component in O’Hare’s taxiway design and construction meets the “triple bottom line” so to speak.

WMA is proven to be a paving method that has less of an environmental impact than HMA for example. WMA also has the potential to save time and expenses. In relation to a project with the scope of the OMP the saving of time, labor and materials cost as well as the lesser environmental impact are significant.

The benefits of using WMA are related to sustainable development and improved working conditions. Included in this are environmental benefits from reduced fuel consumption, and reduced asphalt plant emissions. There are physical benefits that relate to the paving process such as increased workability for transporting and placing asphalt and potentially extending the length of the paving season. Using this innovative and more eco-friendly paving technology is one of the many industry leading sustainability initiatives that continue to be incorporated at Chicago’s airports.

Howard Ande can be reached at howardande@sbcglobal.net.