Launch Slideshow

Error: less than 300px wide output not yet supported

Managing C&D debris

Managing C&D debris

  • Image

    http://www.pwmag.com/Images/tmp473%2Etmp_tcm111-1334505.jpg?width=150

    true

    Image

    150

    Metal pipes and related components removed during construction, like the cast iron water main and valve shown above, can be taken to salvage yards and recycled. Photos: Pam Broviak

  • Image

    http://www.pwmag.com/Images/tmp474%2Etmp_tcm111-1334506.jpg?width=150

    true

    Image

    150

    The National Association of Home Builders Research Center estimates that construction of a typical 2000-square-foot single-family home creates 8000 pounds of waste. This consists of wood, gypsum, metal, siding, cardboard, plastic, asphalt roofing, and miscellaneous materials.

  • Image

    http://www.pwmag.com/Images/tmp475%2Etmp_tcm111-1334507.jpg?width=150

    true

    Image

    150

    Black coal tar residue from an old gasification plant was discovered in excavations for this pipeline job. Surprises like this can be avoided by conducting environmental assessments during the planning phase of infrastructure projects.

With landfill space decreasing and environmental concerns and regulations increasing, public works officials are sifting through the waste stream for new ways to manage waste disposal. One portion of the waste stream that they have identified as lacking comprehensive and standardized management guidelines is construction and demolition (C&D) debris.

Estimated to make up 10% to 30% of total waste in the United States, C&D waste management is now gaining momentum as a necessary tool for effectively reducing a city's contribution to the local landfill. Effective management of C&D waste from a public works perspective requires that it be further divided into two components: debris generated from building sites and waste generated from infrastructure-related projects.

Most managers of municipal landfills already have C&D waste policies in place for pickup and disposal. Some cities, though, are now developing regulations and ordinances addressing management of C&D waste on public and private building sites. California in particular has led this effort by passing a 1989 state-mandated 50% waste diversion for all governmental jurisdictions. Because C&D waste is a large part of total waste, diversion of this component has been crucial to achieving this waste reduction goal. One effective management approach is in San Jose, Calif. To meet their diversion goal, officials there use financial incentives to encourage builders to rethink their waste strategy. In order to obtain a building permit in San Jose, a builder must pay, along with the permit fee, a deposit—the amount of which is determined by the square footage of the building. To get this deposit refunded, a builder must show how much C&D debris they were able to divert from the landfill. The refund received corresponds to the percentage of debris diverted.

Specifying A Waste Management Plan

Some cities across the nation have chosen to include a construction waste management specification in public building contracts. This specification typically establishes percentages by weight of C&D waste generated by the project that must be diverted from the landfill through salvage, reuse, and recycling efforts. Materials approved for diversion also are established by the specification and typically consist of asphalt, wood, drywall, carpet, metals, and cardboard.

A key component of this specification is the submittal and approval of a waste management plan prior to starting construction. This plan must include an estimate of construction waste quantities, methods of waste reduction to be used, recycling and reuse facilities involved, and specific transport and handling procedures including roads to be used by trucks hauling wastes.

To ensure compliance with the waste management plan, at the end of the job the contractor must submit a report that documents the amount by weight of each type of material salvaged, reused, or recycled and the amount disposed of in the landfill. Other requirements of this type of spec can include appointment of someone as the waste management lead for the project, site requirements involving dumpster use, burn bans or restrictions, and subcontractor agreements for waste management.

Policies regulating disposal of C&D waste can affect not only how a city handles C&D debris on its own building projects, but can extend to every building site in the community. For example, the town of Chapel Hill in Orange County, N.C., requires an approved solid waste management plan before issuing a zoning compliance permit for a development site.

Successful Implementation

In order to successfully introduce a reuse and recycling program, officials must impress upon builders and citizens the need to conserve landfill space and building resources. Unique aspects of a community and region also can influence regulations and policies.

The availability of local recyclers often determines the percentage of material that can realistically be diverted. If there are few local recyclers, public works officials can join forces with local builders to encourage the development of recycling or reuse facilities.

Some areas in Oregon, for example, have established depots where builders can drop off C&D debris for purchase or reuse by the public. Other communities encourage contractors to have yard sales or to stack materials and offer them free to the public.