As more and more municipalities look to preserve landfill airspace, reduce disposal costs and work toward a "zero-waste" approach, diversion of construction and demolition (C&D) debris has become a key consideration. In many regions within the United States, C&D debris can make up 20 to 30 percent of waste disposed in landfills, and therefore may have a significant impact on the rate at which landfills reach capacity. Sustainable building programs set performance standards for waste diversion and materials management at construction, renovation and demolition sites, and can influence the extent of the recovery of C&D material.
Leadership in Energy and Environmental Design (LEED), developed by the U.S. Green Building Council (USGBC), is a nationally recognized sustainable design program. USGBC established multiple LEED rating systems to address various types of commercial construction and renovation activities. USGBC later expanded the rating systems to include residential construction and neighborhood development.
Construction sites earn points for various activities, such as diverting materials from landfills, and at least 40 points are needed for LEED certification.
Many local governments are beginning to incorporate green building into their strategies for increasing diversion from landfills and reducing greenhouse gas emissions. A few policy approaches that state and local governments have implemented include:
- Requirements for new buildings to be LEED certified;
- Mandatory diversion from new construction and demolition projects; and
- A streamlined permitting process (or reduced fees) for projects with construction waste management plans.
The following summary provides four examples of how some local and state governments have approached implementing green building and waste diversion into their respective communities.
The State of California recently adopted a new green building code known as CALGreen, which is voluntary until the end of 2010, but is scheduled to become mandatory on Jan. 1, 2011. CALGreen is intended to incorporate green building concepts into all newly constructed buildings or structures. Specifically, Section 5.408.3 of the code requires that a minimum of 50 percent of construction waste be recycled or salvaged for reuse, or that local C&D waste management ordinances be met, whichever is more stringent. Material may be counted by weight or volume, but not both.
A property can be labeled as CALGreen compliant upon passing an inspection process.
King County, Wash.
King County enacted a Green Building and Sustainable Development Ordinance in July 2008. The ordinance pertains to all projects owned by or financed by the county. This program requires all eligible new construction and major remodeling and renovation projects to achieve the LEED Gold certification (at least 60 points), but it also is an effort to apply sustainable design to smaller projects where the pursuit of LEED certification is not feasible. (Read about King County's Shoreline Recycling and Transfer Station, which was recently credited with being the first transfer station to achieve Platinum LEED certification.)
If a King County project is ineligible to obtain a LEED rating, the project must follow the county's Green Building and Sustainable Development Ordinance Guidelines. Projects not eligible for LEED certification are rated on a percentage of points achieved rather than the total points applicable to that specific project.
These guidelines contain construction best-management categories for both diversion and reuse of diverted C&D materials. The diversion credit has a value of up to three points, one each for reaching diversion goals of 50, 75 and 95 percent. Through this ordinance, waste diversion is occurring not only at large capital improvement projects, but also at smaller projects.
The city of Plano specifies that all residential and commercial C&D projects requiring a building permit shall provide a deposit to the Building Inspections Department. Deposits are calculated based on project square footage. Upon completion of the C&D project, the developer must submit the signed C&D Deposit Refund Request Form, in addition to any other necessary documentation, demonstrating compliance with C&D diversion practices. Deposits are fully refundable when a 60 percent diversion goal is achieved and are prorated for lower diversion percentages.
In 2005, the city of Chicago passed an amendment to its Construction or Demolition Site Waste Recycling Ordinance in an effort to increase the amount of debris being recycled. Chicago took a staged approach to the requirement with an initial diversion requirement of 25 percent of C&D material generated at the site. On Jan. 1, 2007, the requirement increased, requiring contractors to divert 50 percent of the material generated at designated sites.
By implementing sustainable building programs and waste diversion requirements, state and local governments are developing a more reliable supply of diverted materials for the marketplace, and educating owners and contractors about the benefits of diversion strategies, which can be applied to other projects. These results work together to help create and enhance a sustainable C&D waste diversion system.
Of course, it is not practical for all regions to adopt a waste diversion program. Program feasibility is impacted by population, population density, availability of local recyclers, landfills, material resources and many other variables. When implementing requirements to divert significant amounts of C&D, it is important for state and local governments to consider the infrastructure that needs to be in place to process mixed C&D debris from project sites. Moreover, there also must be a consistent material supply and end users for the various materials targeted for recovery.
Seth Cunningham, P.E., is a project manager and financial consultant for the solid waste practice of R. W. Beck, an SAIC company. Ian Sutton, P.E., is a senior associate with R. W. Beck. Both are LEED accredited professionals.