Much like every other sector of the North American waste stream, construction and demolition (C&D) recycling has been hurt by the U.S. economic slowdown. For both landfills and recycling centers, incoming C&D material is down as much as 40 percent from a year ago.

But that figure doesn't tell the whole story. There still is demand for many of the products made from C&D material, a byproduct of many years of recyclers working to expand their markets. For example, power plants still like C&D wood as a fuel, and the United States is turning more and more toward green, renewable energy fuels such as C&D biomass. But that demand also means that some recyclers are scrambling to get infeed to keep those markets satisfied.

Some other products made from C&D materials are not so lucky. Recycled concrete, asphalt and asphalt shingles are most often used in highway construction. The biggest customers for those products are governments at all levels. But many state and local governments are hurting financially, especially some big states like California and Illinois. They have no money to do the needed infrastructure work. As a result, their roads, bridges and water systems are crumbling.

Yet these states need to get this work done, and if those projects get going they will stimulate the use of concrete, asphalt and asphalt shingles. The big question is how much federal stimulus money will be used on infrastructure jobs like these.

Indeed, the use of recycled materials in highway projects will provide more bang for the taxpayer buck. For example, in California, natural aggregate is scarce and has to be shipped in from Mexico or Canada. Recycled aggregates, which provide the same or better engineering characteristics compared to virgin aggregates, usually cost about $4 to $6 a ton less than virgin materials. It may not sound like much, but on a common 40,000-ton road project, that $5 average multiplied by 40,000 tons results in a $200,000 savings, which would be far more appreciated in the local school system than buried in the nearby road.

But the big driver in the C&D recycling industry is the green building movement. The U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) program rewards owners and developers for the recycling and reuse of C&D material.