As landfill space becomes scarcer, states and municipalities are thinking creatively about disposal alternatives, especially for one of the largest sources of solid waste: construction and demolition (C&D) debris.
More than 130 million tons of C&D debris are discarded each year, according to the U.S. Environmental Protection Agency. A surprising amount of that material is reusable. For example, a manufacturer may mistakenly make a window or woodwork order to the wrong specifications. No one benefits when materials like these are reduced to trash.
In July 2006, the Massachusetts Department of Environmental Protection banned asphalt pavement, brick, concrete, metal and wood from disposal in state landfills. A San Francisco law took effect around the same time, mandating that construction waste be sent to recycling facilities. The trend toward “greener” design and construction includes minimizing waste and creating a waste management plan for each job, including recycling and reuse.
Contractors can choose source separation, which involves placing materials in separate containers at the job site, or commingled recycling, placing all recyclables in a single container. Source separation means lower tipping fees, but involves more containers, signage and communication with crew members.
“It's one thing to ban, but it's just as important to also mandate the use of building materials with recycled content,” says William Turley of the Construction Materials Recycling Association (CMRA), a industry group based in Eola, Ill. “That way the market is working in favor of recycling.”
Examples of such materials include landscaping material made from crushed and tumbled porcelain, retaining wall blocks that include recycled plastic aggregate and siding made with recovered wood fiber. Building projects that have made use of recycled-content materials include the restored Cambridge, Mass., City Hall Annex (steel framing, carpet, ceilings); The Crossings conference center in Austin, Texas (concrete containing fly ash, wood/plastic decking); Rinker Hall at the University of Florida (steel components, cellulose wall insulation, ceilings) and two McDonald's restaurants in Kent and Lynden, Wash. (copper roofing, aluminum windows).
Finding a market for “fines” (small pieces of waste material) has proven challenging to Massachusetts waste processors. Mixed-debris processors use screening systems to pull out fines, but need markets for them. “Commodities extracted from the waste stream must offset the cost it takes to separate and process the material so that recyclers can compete with local landfills, incinerators or exportation out of state,” notes Greg Wirsen of Green Seal Environmental in Sandwich, Mass., director of CMRA's New England chapter.
Potential uses for fines include as aggregate for the base of a road or building, or shaping and grading. The bottom line, Turley says, is that an “economically viable home” is needed for all types of C&D waste.
Happily, removing some materials from the waste stream also give low-income homeowners an affordable way to repair their homes. Architectural materials in excellent condition can be donated to a reuse center. At the Building Materials Resource Center in Boston, more than 1,200 customers each year purchase materials to improve their homes and communities.
As recycling moves beyond the blue bins in homes to the materials used to construct homes, waste disposal can no longer be an afterthought. All aspects of the recycling loop will come into play as the trend toward C&D recycling takes hold.
Deb Beatty Mel is assistant director of the Building Materials Resource Center, a nonprofit organization in Boston that accepts donations of high-quality reusable materials and makes them available at deep discounts to income-eligible homeowners.