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Whether it is a greater focus on conserving municipal landfill space, urban redevelopment, requirements for certifying “green” building construction, or serving “new” material reuse markets, waste processing facilities play an increasingly important function. By Bruce Clark, Michelle Leonard, Robert Gardner, and Richard Ludt Waste processing facilities continue to evolve in order to serve a changing marketplace. New facilities also continue to come online in areas where local landfill disposal space and cost is at a premium. This article will highlight some of the key processing features of new facilities that are being driven by the current marketplace that are emerging new markets for processed materials. Emphasis will be on facilities specifically developed for the processing of construction and demolition debris (C&D) and other components of the waste stream that are typically not part of a municipal recycling program. Processing Facilities and Techniques These systems include conveyors, trommels, primary and secondary screens, manual picking stations, and even magnets and balers, aggregated to meet the customer’s layout requirements. Some larger systems can handle a wide variety of materials at capacities exceeding 700 cubic yards per hour. A dual line system (two separate conveyors) can divide the material into two size ranges that makes the downstream separation process more effective. Although the capital cost of such systems can top more than $1 million, they can achieve separation efficiencies ranging from 75% to 90% depending on the types of materials handled. They can be configured to separate metals, fibers (carpet, cardboard, etc.), plastic, inserts (glass and ceramic), and wood (lumber and pallets), and to filter out rocks and chunks of concrete into multiple size ranges. Sun and Marpan have actually found uses for a material created in the separation process called recovered screen material (RSM). Finding the right site for a processing facility can have a significant bearing on its success. If it is too far away from its material sources or a good transportation system, it will not be competitive. Finding a good site requires that a balance be struck between easy access to highways and major roads and proximity to the source of materials, as well as location relative to residential neighborhoods and other sensitive areas. Truck traffic, elevated noise, and odor from certain outdoor processing activities can be problematic if the facility is located too close to a neighborhood. Sometimes the sensitive areas cannot be entirely avoided. Some companies have decided that in order to reduce the potential for creating a nuisance or hazard with onsite activities, they have placed most or all of the entire processing operation inside an enclosed building. Although the mechanized processing equipment is the backbone of the operations, it is the employees that are the heartbeat of the operations. Being able to turn out a quality product on a consistent basis and developing and growing end-user markets requires dedication, smarts, and the ability to treat people right. Deconstruction Techniques Commercial interior projects can benefit from some deconstruction, but the steel studs in these projects are difficult to save and much of the carpet and other fixtures in these types of spaces are not salvageable due to the way they were installed. Carpet that has been glued to concrete often needs to be cut into small strips to make it possible to pull it up, and much of the millwork is custom-built for the space, making it harder to reuse it in other applications. Added to this is the fact that most commercial interiors are fairly new and generic. While attractive in their own right, the finishes used seldom stand the test of time and often look out of place in other settings. The better candidates for deconstruction are older wood framed or brick buildings that offer a variety of reusable materials. Old barns and farm houses offer wood that is prized by builders due to the character it has gained in aging, and used brick has a much more pleasing look to it than many new products. Old doors and fixtures are in high demand as more and more people are looking to design houses that take them back to their roots, and others are refurbishing their houses to look the way they did when they were built. Hinges, doors, doorknobs, and windows from older dwellings are in great demand if you can find the right place to bring them to. Look for architectural salvage stores in your area and have them walk the space before you start demolition and/or deconstruction. This way you can salvage the items that you know can be reused and you do not have to spend the money to carefully remove items that are not going to have buyers. New Emerging Markets and Materials Reuses Some institutions, including Florida State University, are requiring building renovation projects that are attempting to achieve the Leadership in Energy and Environmental Design (LEED) certification. The LEED Green Building Rating System for New Construction and Major Renovations, Version 2.2 provides two point-scoring options for participation in material diversion activities. When 50% of construction waste is diverted from the landfill, 1 point is earned, when 75% is diverted, 2 points are earned. The intent of this credit is to divert construction, demolition, and land clearing debris from landfill disposal, and to redirect recyclable recovered resources back to the manufacturing process. By diverting these waste materials, reusable materials can be redirected to appropriate sites. Included as acceptable strategies are donation of material to charitable organizations and salvaging of material for reuse in the project. Diversion Planning and Specifications
In order to meet such a requirement, some advance planning is necessary by the construction team to develop an overall plan for integrating C&D material recovery efficiently and effectively into the overall construction project. Many examples of good planning documents that could be used as a reference exist in the industry. For example, the California Integrated Waste Management Board (CIWMB) developed a model ordinance to discourage landfilling of C&D wastes and encourage recovery and recycling of C&D materials from a construction, renovation, or demolition project. Cities in California can voluntarily adopt and implement the ordinance. In addition, the Construction Materials Recycling Association has developed master specifications for construction and demolition recycling. They are to be used in construction documents for new construction, building demolition, or site clearance. The ordinance or specification language indicates a minimum diversion goal and requires a waste management plan be prepared for certain projects meeting a threshold construction value and size. The waste management plan includes specific information on the materials that will be recycled, who will transport them, and where they will be processed for eventual reuse. They also require preparation of a report following project completion that includes completed forms on actual waste tonnage data, receipts, weight tags, and other documentation on the actual C&D material management process. The Triangle J Council of Governments has produced a planning document called WasteSpec that provides model specifications addressing waste reduction, reuse, and recycling before and during construction and demolition. Power Plant Fuel One company, Marpan Recycling in northern Florida is working on contracts to supply wood biomass to four power plants. The biomass will be produced as pellets and chips in accordance with the user’s specifications. To do this, Marpan has purchased a Morbark Inc. primary shredder, a trommel screen, and a Morbark Inc. vertical mill to create the clean biomass fuel in an energy-efficient process. Marpan also is working on an arrangement with a regional landfill where it will supply RSM for use as alternative daily cover (ADC) on the landfill and potentially backhaul wood waste removed from the landfill’s incoming waste stream to its processing plant. Furnishings and Fixtures The secret is to find these items before they are run over by the excavator or plowed under by the loader at the processing facility. It takes very little room to store these items, and many municipalities have Web sites dedicated to reuse activities. Look into what your area has to offer and make the best use of these opportunities. The tonnage diverted from landfills can be significant, and the value to the community can be measured not just in tonnage diverted, but in goodwill and local pride. Resource recovery parks is a new term coined for some facilities that have been around for almost two decades, like the Urban Ore in Berkeley, CA. They and others like it have become a hub for the movement of these materials from demolition sites to direct reuse without heavy-duty processing. An interesting summary of the Urban Ore facility and operations can be found on the California Integrated Waste Management Board (CIWMB) Web site. “Soil-Like” Fill Substitute One company, after an exhaustive state-mandated laboratory-testing program to demonstrate that the material could meet the state’s “clean soil standards,” was granted unlimited distribution of the material for use in residential and commercial projects within the county administering the permit. RSM in that situation has been permitted for use as a substitute for natural soil fill in residential developments and golf course construction. It is not approved for placement in groundwater or surface waters. A lower quality of RSM also has found use as alternate daily cover at landfills throughout Florida. Soil Conditioner/Livestock Bedding Gypsum drywall (sheetrock) residual from new construction is finding a reuse niche rather than being dumped in a landfill. A Georgia Pacific plant in New Hampshire takes in excess, new construction drywall and uses the calcium sulfate in it as an ingredient in fertilizer. New Hanover County, NC, uses drywall extracted from its wastestream as a soil amendment at the landfill to buffer salts that accumulate in the cover soil at their treated leachate spray sites. The gypsum in the drywall is believed to produce this beneficial effect. The paper covering on the drywall sheet can be reused in some areas. It is stripped off the sheet at the processor and sent out for use as livestock bedding. The Future Of these materials, most traditional processing facilities would only recover and track the metals. While this has been the norm since the inception of processing facilities, those that track the points in the LEED program are becoming increasingly less inclined to accept the facility average for diversion when the facility does not include a breakdown of materials that are recovered during processing. This is going to eventually lead to facilities having to track these materials as the LEED program gains ground in the construction arena. Some have the opinion that we will eventually have to have two separate processing facilities, one that processes and tracks the traditional construction-and-demolition (C&D) wastestream of concrete, asphalt, dirt, metals, wood, and old cardboard containers (OCC), and another that tracks the materials found in commercial interior demolition. Those materials again being the gypsum wallboard, carpet, ceiling tiles, particleboard, and plastic laminate cabinetry that are now not being addressed. Another approach suggested by some C&D recyclers is to reclassify C&D as something other than a “solid waste.” This approach is being suggested because there are many local communities that have adopted ordinances that constrain the collection and recycling of C&D. Many of these ordinances were enacted decades ago when recycling and other reuse initiatives were not in play. One approach being proposed in Florida is to potentially reclassify C&D that is destined for a recycling facility as an “Industrial Byproduct,” which is a specific regulatory definition under the Florida Statutes. The State Legislature recognized that improvements in technology over time would increase the recycling ability beyond the statutorily itemized “recovered materials” and provided for that evolution by the classification of “Industrial Byproducts,” to which they granted an exemption from regulations, so that implementation to accommodate such evolution would be unfettered. The state of Florida has historically recognized that certain types of solid waste should be managed and regulated differently due to their unique characteristics or recycling potential. For example, the state has established different requirements for Class I, Class III, and C&D landfills. Class I wastes are solid waste that must be disposed in a lined facility pursuant to certain requirements. The state has concluded that the environmental and heath risks posed by Class III and C&D wastes are materially different than Class I landfills, and require less stringent design and environmental controls. Design, construction, operation, monitoring, closure, and post-closure requirements have been established for these different wastestreams. Section 403.7045, Florida Statues (commonly referred to as the Solid Waste Act), lists the following wastes or activities that are not regulated pursuant to this act:
Michelle Leonard is vice president of SCS Engineers in the company’s Long Beach, CA, office. Bruce Clark is project director of SCS Engineers in the company’s Tampa, FL office. Richard Ludt is the waste management administrator with IRS Demolition. Bob Gardner, P.E., is senior vice president of SCS Engineers in Virginia Beach, VA. MSW - Elements 2009
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