The disposal of wastes generated from construction and demolition (C&D) activities represent a significant portion of operating expenses in addition to consuming valuable landfill space. C&D waste represents a significant part of the solid waste steam, with current estimates at 28 percent of the total tonnage. Its reduction also will help meet the state mandated diversion goal of 50 percent by 2000.
Separation of materials on a job site provides a specific, clean waste stream that can be processed into products made from materials that would otherwise be discarded. This end result can be achieved if the material is commingled, but separating the useful material afterwards at a material recovery facility adds cost, contamination, and decreases the likelihood of high order uses of construction and demolition wastes.
A contractor or builder would want to practice source separation at a job site to save on disposal costs and potentially generate income through the sale of salvaged material. To maximize the disposal cost savings, the additional labor requirements must be minimized by planning a source separation strategy and locating local processors that will meet your needs.
The scraps and wastes generated at construction sites are more likely than demolition wastes to be recycled due to the relative ease in separating the materials which, in turn, lowers the degree of contamination. Most construction occurs in phases which increases the potential of separating and compiling similar materials.
Studies conducted by the Solid Waste Department of Portland, Oregon (Metro), estimated that approximately 4 lbs. of waste is generated for every square foot of new residential construction.
Metro studies concluded that the recyclables in waste from new residential construction were primarily wood and drywall, while residential renovation activities generated wood, drywall and rubble as its primary components of the waste stream.
A case study of Cornerstone Material Recovery in McHenry, Illinois highlighted one method that may make site separation more likely. In lieu of large drop boxes used for disposal at a development of single family homes, Cornerstone used small temporary bins made of plywood or plastic fencing in front of each home. Each site was serviced at least once a week. As a result, the workers did not have to transport the waste to a centralized drop box and illegal dumping by the public was limited as there were no familiar roll-off boxes. The frequent service and small containers resulted in almost “automatic” site separation due to the inherent stages of construction.
The materials most often separated and recovered from general construction and renovation activities include wood waste, drywall, metal, paper, and cardboard. The economic practicality of on-site separation and recovery would of course depend on local markets and processors of the materials.
At the beginning of each job, bins or other means of containment should be set up to hold separated scraps and the contractor should identify processors in the area that are interested in the materials. The paper, cardboard, and metal packaging that the building materials and major appliances come in should also be separated and stored. There are well established markets for these materials that could both generate income and reduce disposal costs. Recyclers for these materials can be found in the telephone directory Yellow Pages under “recycling centers” or “scrap metal.” Lists of manufacturers, processors, and receivers of construction and demolition materials are referenced in the publications section at the end of this fact sheet.
As indicated above, source separating materials at a demolition operation site is more difficult than construction sites due to commingling of materials. However, disposal costs represent a far larger part of operating costs of demolition activities. Metro estimated that over 70 lbs. of waste are generated for every square foot of residential demolition. As a result, waste reduction measures during demolition could represent significant savings and be a great incentive to recycle.
Architectural items should be removed and salvaged where practical. Larger urban centers generally have businesses that purchase windows, doors, mirrors and the like for resale. Many of these items can also be donated to local organizations. At the beginning of the job, local dealers and processors of the materials and items resulting from demolition should be contacted. Some of these businesses can be located in the lists referenced in this fact sheet, in local material exchanges, or in the telephone directory yellow pages under “salvage,” “demolition contractors,” or “building materials-used” or under material types such as flooring, windows, wood, or glass. It is worth the time to check it out, as significant savings could result.
Hand demolition or deconstruction should also be considered. As documented in the Whole House Recycling Project, a hand demolition project was cost competitive in Portland, Oregon. It documented a hand demolition base bid of $5,400 while mechanical demolition bids ranged between $8000 and $10,000. The savings were seen in resale of the material as well as avoiding the difficulties, and resulting costs, of bringing large equipment into urban sites. The savings more than offset the additional labor cost.
According to the Solid Waste Association of North America (SWANA), there are three general categories of construction and demolition waste that are potentially marketable. They include inert granule products such as asphalt and concrete, wood waste products, and ferrous metals. These categories comprise more than 90 percent of the total C&D waste stream. As the metals markets are fairly well established, it would benefit a contractor to concentrate on the wood and aggregate portions of the waste stream to realize the greatest returns.
Publications & Resources
- Recycled-Content Construction Products database.
- CalMAX: California Materials Exchange online listings and other information.
- C&D Recycling Publications section of CalRecycle’s online publications catalog.
- Recycled Aggregate fact sheet (pub #431-95-052)
- Drywall Recycling fact sheet (pub #431-95-069)
To download or order publications, and to see a complete publications list, go to CalRecycle Online Publications Catalog.
The Waste Papers: Analysis and Discussion of the Potential for Salvage and Re-use of Construction Materials from Residential Demolition.
Metro Regional Environmental Management (Portland, OR) Contract # 902816
Requests for this publication or information regarding other publications produced by Metro–please FAX a request to Karen Green at (503) 797-1795.
Construction and Demolition Waste: Generation, Regulation, Practices, Processes and Policies
Cosper, S.D., Hallenback, W.H., and Brenniman. G.R.(1993)
Office of Solid Waste Management, Univ of Illinois–Chicago
Construction Site Recycling: National Association of Home Builders’ Handbook on Recycling Building Materials for Home Builders, Developers, and Contractors
1201 15th St., NW
Washington, D.C. 20005-2800
(202) 822-0200 ext. 463