There is no question that a waste bin from a construction site is a treasure trove of recyclable commodities. And, unlike a load of regular solid waste, construction and demolition (C&D) materials are highly recyclable and, due to the nature of the material, tend to be heavy and bulky. While curbside collection of recyclables and green waste will get you close to your diversion requirements, construction and demolition waste materials are where the heavy tonnage exists.
According to recent surveys, C&D makes up approximately 35 percent to 45 percent of the waste stream and, of that, approximately 25 percent is recycled. Studies done by the EPA estimate that in 2004, 156 million tons of building related C&D debris were generated. Of this, 63 million tons were generated from residential sources and 93 million tons were generated from non-residential sources.
Wood waste from framing is the largest commodity generated at construction and renovation sites. Concrete is the largest material generated at demolition sites and include concrete slabs and foundations. Other materials found in quantities at either demolition or construction sites include asphalt from parking or road reconstruction, gypsum or wallboard from finish construction and asphalt shingles from roofing.
C&D material, much like curbside recyclables, has generated great discussion over the effectiveness of single-stream versus source-separated material. While some projects separate material on the job site, the trend has become to load all the material into one bin and sort it offsite at a C&D processing facility.
This “all-in-one” disposal method of C&D material makes sense for contractors at job sites as training onsite to explain the process for separating the material and then moving the material to multiple locations on a site for recycling adds time and cost to a project.
Due to this and the amount of material that can be diverted from landfilling for reuse, the solid waste and recycling industry is responding to develop C&D processing facilities that can handle the volume of materials while dealing with the dust, noise and processing issues associated with the material stream.
The Otay Landfill in South San Diego County will have a C&D processing facility operational in the spring of 2008 with another facility planned for the Sycamore Landfill in the city of San Diego. These two C&D processing sites along with a third open in Lemon Grove will help the cities in San Diego meet and exceed the recycling mandates set forth by the state of California.
Green waste and traditional recycling programs using the curbside blue container are working to achieve a 50 percent diversion requirement, but the ability to keep C&D material out of the landfill will ensure this level of diversion is accomplished while helping maintain valuable landfill capacity for future generations.