Dealing with construction and demolition waste is one of the most daunting challenges we face in the construction industry. Disposal costs are high, resources are being needlessly wasted, and we are running out of landfill space. The C&D waste problem provides an opportunity for builders and designers to really do something positive for the environment. This article provides a brief overview of the C&D waste problem and suggests measures we can take to solve it.
C&D Waste—an Overview?
C&D waste can be divided into a number of categories: waste left over from new construction (new material scraps, packaging, etc.), remodeling/demolition debris from older buildings (old wood, insulation, plaster, brick, fixtures, appliances, etc.), and debris from large civil works projects such as highways and bridges, which this article does not address.
With all the attention that has been given to the solid waste crisis over the past ten years, it is remarkable how little we really know about C&D waste. There are no reliable statistics on quantities of C&D waste generated nationally, and just a very few studies of the composition of this waste.
Traditionally, a lot of C&D waste has never left the job-site, being buried or burned instead. Burning is no longer an option in most communities. Even if permitted, it is a poor choice environmentally, both wasting resources and polluting the air. Burying certain types of C&D wastes (masonry rubble) when backfilling foundations or as aggregate under parking lots of driveways is an option, but only for limited materials. Even more disturbing than on-site burning is the illegal dumping that we have increasingly seen as landfill disposal costs have risen.
Much of our C&D waste goes into conventional landfills—particularly C&D waste from residential construction. The future of municipal landfills, as has been widely publicized, does not look good. More than half of present landfills are expected to reach capacity by the year 2000 and then be shut down. Already, many MSW landfills have stopped accepting bulky C&D waste, or they have greatly increased disposal cost (tipping fees) in an effort to keep it out. In some areas, mixed waste is now handled by material recovery facilities or transfer stations where they are sorted. Recoverable materials are separated out for recycling before the rest is landfilled.
In some states, most construction waste goes into specialized C&D landfills. Nick Artz of Franklin Associates believes that nationwide “at least half of C&D waste goes into separate sites, maybe more.” The conventional wisdom with C&D landfills has been that this kind of waste—mostly inert materials such as wood, concrete, cardboard packaging—doesn’t require as diligent environmental safeguards as standard solid waste. Increasingly, however, this argument is being challenged. Not only are many construction materials significant pollution sources (paints, solvents, and pressure-treated wood scraps, for example), but the more lax standards at C&D landfills have resulted in other, more hazardous, substances being dumped there illegally to avoid higher costs of hazardous waste landfills. As a result, C&D landfills may soon be required to have more stringent environmental safeguards, such as liners and leachate collection systems.
Incineration of C&D waste is another option, with or without using the resultant energy to produce electricity. With wood scraps, incineration is not necessarily a bad solution, as long as pollutants are adequately controlled and the heat is used for power production. The bigger problem is the fact that C&D waste includes a lot of stuff other than wood and paper—stuff that doesn’t burn or that leaves a lot of ash, which has to be disposed of.
The above is what happens to most C&D waste—but not all. Innovative builders, waste haulers, and entrepreneurs are coming up with better solutions all the time. Most of the motivation for finding alternatives is economic. Tipping fees are very high. In some cases, the old disposal option of simply landfilling unsorted C&D waste is no longer an option—at any cost—as municipalities change their landfill regulations in an effort to stretch the service life.
But there is another factor that’s playing a more and more important role: concern about the environment. An increasing number of builders are willing to spend a little extra time to reduce their waste and sort materials even if the savings in disposal costs do not fully offset the extra costs incurred in sorting and handling. A number of important strategies for dealing more responsibly with construction site waste are summarized in the table on the following pages.
To succeed with significant C&D waste recycling, your crews need to know where to take different materials. Builder John Abrams, of South Mountain Company on Martha's Vineyard in Massachusetts, has compiled information on all the disposal options right on his employee time sheets—which landfill accepts cardboard for recycling, where scrap metal can be taken, etc. In some parts of the country, municipal agencies have done this work for you (see side-bar). In many other areas, even though directories are not assembled, the municipal solid waste office will be glad to assist you in identifying your options.
To take advantage of most of these disposal possibilities, you will need to separate wastes on-site. This will require fairly significant changes for most construction businesses. As with any new technique, it may take you a job or two before you work out the bugs and come up with strategies you and your crew(s) are comfortable with. But with some practice, you should be able to deal more responsibly with much of your waste at little or no additional cost. To get started with these strategies, ease into it gradually. Start with wood scraps, for instance, on your next job. Then add other waste categories as your crew gets used to the idea.
Watch for problems that might come up—contamination of sorted waste by mixed refuse, for example, as crew members or passers-by throw trash into your bins. Clearly label the different storage bins. In some areas, you might actually have to lock the dumpsters after-hours—that's right, we’ve reached the age when we have to lock our trash containers to keep other people’s trash out! If crew members are included in the planning of such efforts, they are more likely to cooperate effectively—and come up with better, more efficient systems.
(1992, November 1). Dealing with Construction Waste: Innovative Solutions for a Tough Problem. Retrieved from https://www.buildinggreen.com/feature/dealing-construction-waste-innovative-solutions-tough-problem