Construction and demolition (C&D) debris used to be a waste stream that was almost hidden from public view. While the general public focused on municipal solid waste (MSW) and the recycling of the cans, bottles and paper, not much attention was given to the much larger stream (by weight) that includes concrete, asphalt, wood, metals, drywall, asphalt shingles, old corrugated containers (OCC) and plastics from C&D activity at both buildings and road and bridge projects.
That has changed in recent years, as all levels of government have looked to recycle as much as possible from every waste stream, and as the economics of recycling C&D debris have become more attractive. Furthermore, the push to undertake environmentally friendly, or “green,” building projects has placed the material closer to the recycling spotlight.
And, why not? There is certainly a lot of material available. According to the Eola, Ill.-based Construction Materials Recycling Association (CMRA), about 350 million tons of C&D debris is generated every year in the United States, and that is a conservative estimate. The U.S. Environmental Protection Agency (EPA) has tried to get a handle on how much C&D debris is out there. In 1997, the agency estimated that 136 million tons of the material is generated annually. Currently, EPA is trying to update that number, but is finding it a slippery fact to nail down.
The growing C&D recycling industry faces a number of issues. First, numerous jurisdictions in recent years have passed laws mandating the recycling of C&D debris, requiring builders and recyclers to navigate a broad range of regulations. In addition, the industry is fighting rail-waste transfer stations that handle building materials without government oversight and is lobbying for tax credits to spur markets for recycled C&D debris.
Whatever the amount of C&D debris generated, there definitely has been a rise in the number of regulations and legislation related to the material. For example, Chicago now mandates that construction and demolition sites recycle at least 50 percent of the debris they generate. Local governments in California — such as San Diego, Palo Alto, Woodward, Contra Costa County and Tulare County — have passed similar ordinances.
California's well-known AB 939 law, which requires local governments to recycle at least 50 percent of the waste they generate, has sparked interest in C&D recycling as a way of reaching the targeted rate. In its last session, the California Legislature passed the CMRA-backed SB 420, which directs the state to use recycled aggregates in its highway projects unless doing so is economically unfeasible.
California legislators are expected to push for additional pro-C&D recycling steps, such as requiring local governments to mandate the use of recycled aggregates in their roadway project bids and adding C&D material to the list of recycled products that governmental agencies must mandate in their requests for proposals.
One of the most famous examples of C&D legislation is the Massachusetts Department of Environmental Protection's (DEP) ban on the landfill disposal of concrete, asphalt, brick, metals, OCC and wood. Those materials are to be diverted to a recycling center instead.
DEP determined there were markets for those materials, and, to a degree, the department is correct. But the state highway department, MassHighway, does not use recycled aggregates in its projects, and DEP has placed stringent regulations on the use of C&D fines in the state.
About 30 percent of what a C&D recycling center takes in are pieces of material that are less than 1 or 2 inches in length. These small pieces are created by the demolition or construction process or by the act of hauling the material to the center. Much of this material is dirt, concrete dust, small pieces of wood and other debris, and gypsum drywall. The fines can, under certain conditions, create hydrogen sulfide gas, which has a rotten egg smell.
During discussions with the recyclers before the ban was implemented, the DEP was told that if there was a ban, the recyclers needed a steady output for the fines product as either an alternative daily cover (ADC) in landfills, or as a shaping and grading material for the state's old landfills to bring them up to modern standards. The material had been used in this way for years with little problem.
But after the ban took effect on July 1, 2006, some landfill operators and others used the fines in such a way that hydrogen sulfide gas was created at a level high enough to nauseate people nearby. And therein lies the key to the problem: the ADC product must be used properly at the site by the landfill operator. If it isn't, the odor can be created.
DEP's response was to require financial assurance mechanisms at any site using the fines, effectively making it economically unfeasible to use them. This makes C&D recycling a money-losing proposition for most recyclers and has created a negative perception of the ban among C&D recyclers. CMRA, along with several of the stakeholders, is working with the DEP to find ways to use the fines and to pinpoint more markets for them.
Overall, innumerable legislative and regulatory actions that have the intention of promoting C&D recycling have been passed across the country. Many of those regulations mandate that a certain amount of a site's C&D debris be diverted from landfill disposal. Many in the C&D recycling industry believe it would do more good to have government support for recycled products instead of disposal bans.
Rail Yard Concerns
The C&D recycling industry joins with the entire solid waste industry in its opposition to rail-yard transfer stations, which have sprung up in recent years primarily in the Northeast.
These facilities mostly handle C&D debris. And as rail operations, they can operate under a special federal exemption for railroads that shields such companies from state and local permitting and oversight. CMRA, the National Solid Wastes Management Association, the Solid Waste Association of North America, and several recycling and waste hauling companies are members of a coalition that is fighting these rail facilities. As Chaz Miller pointed out in the January 2007 issue of Waste Age (“Fearless Forecasts, p. 16), if the Surface Transportation Board, the federal entity in charge of railroads that permits the railroad exemption, does not fix this problem, then expect federal legislators to move to eliminate the exemption.
Another issue facing the C&D recycling industry is tax credits. While a movement exists to create tax credits for firms that purchase equipment to recycle MSW, C&D recyclers would like to see credits for the entity buying the recycled C&D products, especially in the non-aggregate arena. This will help to develop the market for these products.
So, in the final analysis, how does the future look for C&D recycling? CMRA estimates that C&D recycling of all types of material has been growing by at least 10 percent, by weight, each year for the past 10 years. From road contractors buying a crusher to process what they generate, to large waste companies buying out strategically placed mixed C&D recyclers, all types of businesses are entering the market.
Pressure for more C&D recycling is also being applied by the green building movement, which emphasizes both the recycling of C&D waste and the use of recycled products in new construction. Couple this with government emphasis on the diversion of C&D debris from landfills, and the C&D recycling industry can expect to enjoy double-digit growth for the foreseeable future.
William Turley is the executive director of the Construction Materials Recycling Association, which promotes the recycling of construction and demolition materials.