A green experiment: Sandia National Laboratories, New Mexico, puts construction materials recycling to the test

Construction & Demolition Recycling, Nov-Dec, 2006 by Kelly Ingalls

The benefits of this program include increased solid waste recycling rates for SNL/NM, recycling business development within the local community, increased recycling awareness of construction contractors and accurate reporting. The significance of this program is that large construction projects previously had not been recycling any material, but now can divert more than 80 percent.

SMALLER SCALE

Each small construction project generates relatively small quantities of recyclable materials. These small quantities represent a unique challenge to implementing recycling. Without a common staging area to collect small quantities of construction materials the debris needs to be removed in a short timeframe. It is cost prohibitive to make individual trips to recycling facilities for small quantities. Although each project generates small quantities, it is estimated that 15,000 cubic yards of scrap materials from small construction projects were disposed of in the KAFB Landfill in 2003.

The SNL/NM P2 staff determined the most effective way to capture and manage recyclable materials generated from small construction projects was to develop a single collection area. A construction debris recycling center has now been built at the SNL/NM Solid Waste Transfer Facility. This new feature will provide collection and storage capabilities for recycling small quantities of construction debris.

This new recycling program will be implemented first by providing training to the SNL/NM facilities staff responsible for small construction projects and the pre-qualified contractors. The training will be conducted at the Solid Waste Transfer Facility to allow individuals to observe the location of storage areas and will provide clear criteria for acceptable materials. All individuals who generate scrap from small construction projects will be required to take their materials to the transfer facility and to segregate recyclables from materials for disposal.

In addition to construction debris, SNL/NM has building demolition debris and routinly works to process solid waste such as white paper or cardboard. A recycling opportunity assessment was completed to determine the feasibility and priority of including several additional materials for recycling. Materials were evaluated by identifying the current disposal practice, quantity generated, availability of recycling resources/options and potential for recycling implementation.

Several materials present in the solid waste stream that are known to be recyclable were evaluated. The items from routine work processes include alkaline batteries, electronic media, glass, mixed paper including strip-shredded and pulverized paper, plastic, Styrofoam, transparencies, Tyvek and yard debris. Construction materials were evaluated and have been implemented as described previously. Concrete from demolition was evaluated separately from construction concrete because it is heavily reinforced.

Heavily reinforced concrete and mixed paper were identified as the highest priority items for immediately developing implementation strategies. In past years concrete from demolition activities was accepted for erosion control purposes and was not disposed of in the landfill. However, reinforced concrete was determined to be unacceptable for this purpose. Because demolition concrete is now being disposed of in the landfill, SNL/NM recycle quantities by weight reported to Waste Wise decreased from 2002 to 2003. Concrete from demolition is being evaluated to determine whether it is feasible and cost effective to establish a staging area to collect concrete for eventual crushing into recycled aggregate base course.