Digging for Demo Data

Demolition industry commissions study of C&D waste stream to help develop recycling policies.

At Last Check, Googling the phrase “construction and demolition recycling ordinances” generated approximately 353,000 hits. Granted, not all of the hits refer to specific city, county and state regulations, but the fact is that more and more governmental bodies are seeing the value of construction and demolition (C&D) recycling and are mandating its implementation.

For example, at the beginning of 2007, Chicago began requiring that at least 50 percent of C&D waste be reused or recycled. On C&D projects involving at least 10,000 square feet of space, contractors that fail to meet the requirements are fined $1,000 for each percentage point that they fall short, resulting in a sharp incentive to divert C&D waste from landfills. Meanwhile, some states, like California, are developing model C&D recycling ordinances that cities and counties can then tailor to meet specific needs.

To make sure that legislation is based on solid statistics, the Doylestown, Pa.-based National Demolition Association (NDA) has commissioned an evaluation of the C&D waste stream and is working with the U.S. Environmental Protection Agency's (EPA) Office of Solid Waste and the National Association of Home Builders (NAHB). The aim of the evaluation, along with the input of the NAHB, is to assist the EPA in developing a comprehensive, national policy on the recycling of both construction and demolition wastes.

Among the questions being asked: Of the more than 135 million tons of C&D waste that the EPA estimates is generated annually in the United States, how much is from the construction industry and how much is from the demolition industry? Is demolition debris more benign than construction debris? If so, should demolition debris be subject to less regulation? Both the government agencies setting these rules and the industries subject to them want answers to these questions.

NDA, which consists of more than 1,100 demolition contractors, recycling and landfill operators, general contractors and civil engineering firms, argues that demolition debris is more benign than construction waste. That's because hazardous materials in a building scheduled for demolition are removed and disposed of before the process begins. Substances such as asbestos, lead, PCBs, compressed gases and mercury contained in electronic devices are taken from the structure by an environmental remediation company, leaving behind material that presents little danger to the environment.

In addition, all remaining materials generated during a demolition project are very carefully separated out for recycling, whether it is metal, brick, wood or historic architectural details. Quite often, aggregate materials, brick and concrete are processed on site and used as fill material for future construction projects. There is a big financial incentive for demolition contractors to find as many sources of re-sale and reuse as possible and to avoid the use of landfills.

This is often in contrast to the treatment of waste on a construction site, which can be a combination of benign materials mixed with plastic and polystyrene foam packing materials, and containers that hold remnants of mastic, glue, tar, and other adhesive substances that require Materials Safety Data Sheets for their handling and disposal. Quite often, because of tight timetables, these materials are combined and disposed of in a single waste receptacle.

Gathering Facts

As part of the evaluation commissioned by NDA, Gershman, Brickner & Bratton Inc., a solid waste management consulting firm, surveyed approximately 50 percent of the association's membership about their recycling practices. The firm's findings indicated that demolition providers reuse or recycle approximately 75 percent of the more than 115 million tons of demolition materials annually. Given the number of current recycling incentives, many contractors routinely recycle more than 90 percent of their debris.

The key reasons surveyed demolition companies gave for achieving a high recycling rate are that C&D recycling is required by law; recycling is specifically required in many demolition contracts; and the increased number of readily available markets for the materials — such as steel and lumber — found within the demolition waste stream. Demolition professionals cite other motivations as well: the increasing costs of landfill use, tax credits that are awarded for landfill diversion primarily by states, on-site recycling technology and a growing awareness of environmental issues.

The evaluation also discovered that California recycles the highest percentage of demolition debris, followed by Florida and New Jersey. Other states reporting high demolition recycling are Texas, Minnesota, Washington and Illinois.

The most commonly recycled demolition materials are, in order: concrete, asphalt pavement, metals, bricks/blocks and wood. With concrete at the top of the list of recycled materials, there has been some focus on the safety of recycling the relatively small percentage of concrete that may contain lead-based paint. A study conducted under the direction of the U.S. Army Corps of Engineers found there is no environmental or health risk for workers involved in the crushing and recycling of concrete containing lead-based paint because they follow certain lead compliance work protocols. Since concrete recycling has become the norm for the demolition industry, with an estimated 100 million tons generated during projects each year, it was very important that the industry learn that working with crushed concrete does not present a safety hazard.

The NDA supports the move toward the recycling and reuse of as much demolition debris as is economically feasible. Finding profitable aftermarkets for recycled materials remains a prime concern. For example, while the recycling of sheetrock is becoming more common in Europe, in the United States, it is still difficult to find a viable, cost-effective aftermarket for the recycled material. Until financially feasible aftermarkets are found for all demolition debris, then, local, state and federal authorities should gain a full understanding of the economic realities of today's recycling industry before imposing regulations.

Michael R. Taylor is executive director of the Doylestown, Pa.-based National Demolition Association.