The Chicago Center for Green Technology (CCGT) is a significant step toward Mayor Richard M. Daley’s vision to make Chicago the greenest city in America. The previous owner of the CCGT’s current site violated the city’s environmental laws and filed for bankruptcy in 1997. The ChicagoDepartment of Environment then took control of the 17-acre (6.9 ha) property. The brownfield site was littered with more than 600,000 yd3 (460 000 m3) of construction and demolition debris,including a pile of rubble so dense it sank 15 ft (4.5 m) into the ground. Clean up took 18 months and 45,000 truck loads, with some of the clean stone and concrete recycled into public infrastructure projects throughout the city.