I’m an avid recycler and have lived in several major cities that take part in recycling programs. In Chicago, we recycle everything—glass, paper, aluminum, plastic—together. You don’t have to sort, all you have to do is dump it in one of the blue carts, and the rest is recycled history. Or is it? Any insights as to what happens at Chicago recycling centers?—Jenny Dalton, North Center
Chicago is part of the growing trend of cities favoring single-stream recycling programs. Letting people throw glass, metal and paper all in the same blue cart is easier (and cheaper) than separating recyclables, which multistream collection demands. The easier it is to recycle, the more people do it. In Chicago, recycling trucks empty the blue carts’ contents and crush everything together. At a privately run processing plant, the unsorted heaps are loaded onto conveyor belts to be manually and mechanically separated. Workers in face masks and goggles pick through the moving stream of debris, but machines are more efficient: Magnets get steel; eddy currents nab nonferrous metals; and blowers, screens and optical scanners separate paper, glass and plastic. The materials are then shipped off to manufacturers to be reprocessed. The downside to single stream? With all the items crushed together, some become contaminated and unusable for manufacturers. Studies have found that typically about 15 percent of recyclables in single-stream systems end up in a landfill; in multistream systems, only 1 percent to around 6 percent of recyclables are wasted.