If municipal solid waste (MSW) is the vivacious youngest child in our garbage family, construction and demolition (C&D) waste is the neurotic, disciplined oldest sibling who hides some serious turmoil beneath her unassuming exterior. Of course, hazardous waste would be the toxic middle child, nursing maniacal plans of world domination.
Let us then turn our eyes away from the young starlet as well as the toxic megalomaniac and study this oldest member of the garbage family. C&D waste is all the rubble produced in building, renovating, or demolishing a structure: concrete, wood, asphalt, gypsum, bricks, metal, glass, plastics, wiring, paints, insulation, carpeting, appliances and fixtures, as well as many other things.
More than 270,000 homes and 44,000 commercial structures are demolished each year in the US. This means each year we demolish about 1 billion square feet of building space. Estimates of how much waste this amounts to vary wildly: a 1998 EPA study suggests that C&D waste amounted to 136 million tons. However, a 2003 EPA study found C&D waste to be 170 million tons, or 3.2 lbs per capita day (pcd). The Institute for Local Self-Reliance says annual C&D waste is almost 230 million tons. A study published in C&D World Magazine came up with a much higher number, 680 million tons to 860 million tons.
I’m throwing all these numbers at you to demonstrate that this is hardly an accurately measured segment of the waste stream. However much C&D waste we produce, the vast majority of it is landfilled, usually in special C&D landfills. The EPA says there were at least 1,900 C&D landfills in the US in 1994, largely regulated by local and state governments. Often, these landfills are not held to the same standard as MSW landfills, ostensibly because C&D wastes are mostly inert (e.g. concrete and bricks).
There seem to be two major issues with how we handle C&D waste in the US. First, many, many of the materials we landfill or burn are still useful and even valuable. It makes no sense that we demolish and landfill a structure, wasting good wood, wiring, and other materials. Second, demolition is hardly a fine-tuned process. People leave large appliances, possessions, and household chemicals behind. When you’re tool is the bucket of an excavator, you don’t have a very discriminating touch: what could be useful is destroyed and made useless. Demolition, like any other industry, is driven by profit and crews are hardly going to take the time to empty cupboards or remove appliances if there’s no profit in it. In addition, as more and more composite materials are utilized in construction, the percentage of C&D waste that is inert is going to fall.
There is an interesting new trend. As virgin materials become more expensive and transportation costs also increase, salvaging materials from C&D waste is becoming a good-looking alternative. Organizations like the RE Store in Bellingham, Washington, Urban Miners in Connecticut and Habitat ReStores all over the country, are creating an industry called deconstruction.