ADVOCATES AND AGGREGATES: WASHINGTON STATE INCLUDES NEW PARTNERS IN RECYCLING

In 1991 the Washington State legislature required the Washington State Department of Transportation (WSDOT) to study the use of recycled materials for road construction in concert with the Clean Washington Center, a department of the Washington State Department of Trade and Economic Development that promotes the development of markets for certain recycled materials. Through a series of meetings involving members of the recycling community, the Clean Washington Center, and representatives of the WSDOT, the recycling community gradually came to recognize the problems that the use of recycled materials in transportation could raise, and the department came to understand the urgency of testing and evaluating these waste and recycled materials as promptly as possible. The Clean Washington Center, which represented the middle ground in this debate, frequently defended the stance of the WSDOT, and was especially supportive of the department's caution regarding materials such as crumb rubber and glass in asphalt pavements. WSDOT has been testing, evaluating, and using recycled materials in roadway construction and other highway-related applications for more than 25 years. For the past 10 years WSDOT has also used a New Products Evaluation Committee to oversee the evaluation of new products. This article reviews the experience of WSDOT with recycled asphalt pavement, crumb rubber, scrap tires, wood fiber, glass, fly ash, compost, reclaimed portland cement concrete, plastics, and aluminum sign stock. In conclusion, it is pointed out that WSDOT's recycling program reflects longstanding efforts to save money, ensure performance, and use waste and recycled materials sensibly; that the Clean Washington Center is an ally in these efforts; and that the New Products Evaluation Committee is examining private sector innovations in the use of waste and recycled materials.