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Today most of our building waste ends up in landfills, increasing the burden on landfill loading and operation. The practice of minimizing and diverting construction waste, demolition debris, and land-clearing debris from disposal and redirecting recyclable resources back into the construction process is commonly referred to as construction waste management (CWM).
Waste management affects carbon reduction efforts by impacting one or more of the following:
- Energy consumption (specifically, combustion of fossil fuels) associated with manufacturing, transporting, using, and disposing the product or material that becomes a waste.
- Non-energy-related manufacturing emissions, such as the carbon dioxide released when limestone is converted to lime (which is needed for aluminum and steel manufacturing.)
- Methane emissions from landfills where the waste is disposed.
It is estimated that anywhere from 25–40 percent of the national solid waste stream is building-related waste and only 20 percent of construction waste or demolition debris (C&D) is actually recycled. In 2004 estimates, landfill tipping fees ranged from $24 in south central United States to more than $70 in the Northeast. In 1998, the U.S. Environmental Protection Agency estimated that 136 million tons of building-related waste is generated in the United States annually. A 2003 update shows an increase to 164,000 million tons annually, of which 9 percent is construction waste, 38 percent is renovation waste, and 53 percent is demolition debris. Employing CWM into the construction process not only is beneficial for the environment, it is beneficial to the bottom line. The architect can influence successful waste management by developing a construction waste management plan, which is incorporated in the specifications.
Incorporating practices that reduce the production of waste at a project site through reusing, salvaging, and recycling ensures that the project’s environmental goals can be met.
Comingled Construction Debris
| A comprehensive CWM plan should include:
- A list of materials that are targeted for reuse, salvage, or recycling
- Landfill information (including tipping fees)
- Description of the proposed means of sorting and transporting the recyclable materials
- An estimate of the packaging materials generated, noting whether the supplier can eliminate or recycle packaging)
- A provision for addressing noncompliance of the CWM, including a stop-work order or provisions to rectify noncompliant conditions
- Recycling facility information (including how materials will be recycled and tipping fees)
- Other project specific information relevant to the scope and intent of the project
Making up to 95 percent of the building, some of the more common C&D wastes are lumber, drywall, metals, masonry (brick, concrete), carpet, plastic, pipe, rocks, dirt, paper, cardboard, or green waste related to land development. Of these, metals are the most commonly recycled material while lumber makes up the majority of debris that still goes to a landfill. Diverting 90 percent of construction job site waste and more than 80 percent of demolition debris from landfill disposal is not uncommon.
Wastes can be prevented from ever entering the waste stream by:
- Reducing packaging wastes; purchase available items in bulk
- Reusing/recycling nonreturnable packaging and containers on site
- Purchasing materials in returnable packaging/containers
- Donating nonreturnable/recyclable packaging/containers to local organizations
- Building material-efficient buildings
- Examining demolition and creative salvage techniques
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A successful CWM plan involves all the principal parties of a project-owner, architect, engineer, contractor, and subcontractors. Involving each of the vested parties early on in the design process makes accomplishing the established goals more easily obtainable. The CWM plan should include requiring the contractor to minimize waste, developing ways to reuse existing materials, which may be included in the new design or elsewhere. The architect will also need to be familiar with the regional waste management infrastructure and establish a waste management goal for the contractor. Due to the recent interest in CWM, companies are emerging that provide the necessary services of sorting, removal, and recycling. The Construction Waste Management Database contains information on companies that haul, collect, and process recyclable debris from construction projects. Created in 2002 by the U.S. General Services Administration’s Environmental Strategies and Safety Division to promote responsible waste disposal, the database is a free online service for those seeking companies that recycle construction debris in their area.
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Within the conventional delivery methods (design/bid/build) the architect must be very careful to include the CWM plan in the construction documents.
Steel
Steel has been sorted, reused, recycled, and reclaimed for many years. Steel continues to be recycled at a volume higher than all other recyclables combined. In the past 50 years approximately 50 percent of all steel produced in this country has been recycled through the steelmaking process. In 2006 the construction structural recycling rate was 97.5 percent and has been since 2005.
Modular Buildings
Buildings that are prefabricated and assembled on site decrease the amount of waste generated from off-cuts (by-product) and on-site damage. The mass production allows for buying in bulk and using or recycling the majority of the materials at the manufacturing site.
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