Urban Wood Waste

Introduction

Urban wood waste is the portion of the wood waste stream that can include sawn lumber, pruned branches, stumps, and whole trees from street and park maintenance. The primary constituents of urban wood waste are used lumber, trim, shipping pallets, trees, branches, and other wood debris from construction and demolition clearing and grubbing activities.

The disposal of wastes generated from construction and demolition (C&D) activities represents a significant portion of operating expenses in addition to consuming valuable landfill space. C&D waste represents a significant part of the solid waste steam, with current estimates at 28 percent of the total tonnage. Its reduction will help meet the State-mandated diversion goal of 50 percent by 2000.

Wood waste is, by far, the largest portion of the waste stream generated from construction and demolition activities. As such, this fact sheet is geared toward contractors and local governments considering alternatives to disposal. These alternative uses represent a significant potential savings in disposal costs.

Quantities

The quantities of urban wood waste documented in California vary depending on the study and the source. Based on information compiled from local waste generation studies (1990), the California Integrated Waste Management Board, now CalRecycle, estimates that approximately 3.8 million tons of wood waste, not including yard waste, are generated throughout the state and enter the municipal waste stream in California every year. Of the 3.8 million tons generated, approximately 3.35 million tons are disposed of in permitted disposal facilities and the remaining 450,000 tons are diverted from landfilling.

A considerable amount of wood waste is also consumed by the biomass industry for boiler fuel to produce electricity, and steam in some cases. Based on figures supplied by the biomass industry, it currently consumes approximately 1.3 million tons of urban wood waste. This is above and beyond the 3.8 million tons quantified in the previous paragraph. The biomass industry’s fuel consumption is decreasing due to closures and curtailment of operations of private and public plants contracted to sell power to utilities in the state.

Treated Wood Waste

Wood treated with chemicals for preservation against insects, microbes, etc. may need to be managed using alternative methods. The Department of Toxic Substance Control (DTSC) is developing regulations for the handling of treated wood and has developed information on treated wood. CalRecycle also provided guidance to LEAs on treated wood waste handling.

Markets

The markets for wood waste include use as feedstock for engineered woods, landscape mulch, soil conditioner, animal bedding, compost additive, sewage sludge bulking medium, and boiler fuel. All these end uses have similar processing requirements in that the wood waste has to be separated from other wastes, cleaned by removing contaminants and fasteners, and processed through grinding or chipping. The final use of the wood waste often determines how clean and consistent the feedstock must be.

The most desirable option for wood waste management would be to reuse the structural elements or reuse of architectural elements which include casings, banisters, and mouldings. Large timbers from older or unique structures can be salvaged and reused as structural elements in new buildings. However, if lumber is to be reused as a structural element, it would need to be recertified by a lumber inspector first. One option that may be potentially cost effective is the employment of firms that offer certified lumber inspectors that can grade lumber for use on site. If you are considering hiring this type of service, verify that it is approved by American Lumber Standards (ALS). ALS is the licensing body for lumber graders. Refer to our fact sheet Lumber Waste for a listing of inspection and grading services.

The next most desirable option for wood waste is as a feedstock for engineered woods. Engineered wood is the term given to material derived from smaller pieces of wood that are bound together through a variety of glues, resins, and other chemicals to make a wood-like product. These include particle boards, laminated woods, and plywoods.

Because of the limited options available to reuse wood waste as building materials or feedstock for engineered woods, the largest markets for urban wood waste are as a feedstock for biomass fuel, mulch, and compost. The processing requirements for all three products are similar and recyclers of wood waste for this type of end use are more plentiful throughout the state.

The end uses of wood recovered from construction and demolition activities are sometimes limited because the wood is commingled with other materials and contaminants or is in such poor condition that the cost of processing and cleaning limits the economic viability of processing and reusing the material.

Wood waste generated at residential and commercial wood frame construction sites offers a greater potential for reuse due to the ease of separating the wood during the various stages of construction. Cut-offs and scraps generated during the framing and trimming stages constitute a relatively clean and homogeneous waste steam that can make an excellent feedstock for engineered wood production. This type of wood waste represents a highly desirable form of wood waste that processors are eager to obtain. To minimize disposal costs and potentially generate income, contractors should contact local wood waste processors and inquire about setting up drop boxes on site for wood waste scraps. Contractors should also consider collecting pallets and crates that building materials and equipment are shipped in. There are usually several businesses listed in the phone directories, under “pallets” or “skids,” that collect and remanufacture pallets.

Demolition operations usually generate a far less desirable form of wood waste due to the non-uniform nature of the wood waste compounded by the commingling of the wood with other materials. The wood can still be reused, but generally has a lower value and is destined for uses such as boiler fuel or mulch feedstock. Wood waste processors may still be interested in this material for processing. Since demolition activities generate far more waste per square foot than construction activities, disposal costs represent a much greater portion of operating expenses. It is therefore worth the time to contact local processors to determine if a savings in disposal costs can be realized.

Processing

The wood waste processors vary in what they require for a feedstock. Some request only clean wood that is untreated or unpainted while others will take a mixture of waste woods. Disposal fees vary with each facility and some facilities may pick up loads and supply drop-off boxes. It is therefore important to contact the wood waste processors in the area to determine the most cost effective option for each situation.

Publications and Resources

Publications

To download or order publications, and to see a complete publications list, go to the CalRecycle Online Publications Catalog.

Videos

  • Wood and Organic Waste: YouTube (00:04:12)| Transcript: Chapter 9 from the 12-chapter Best Practices in Waste Reduction video. All 12 chapters are available to watch on YouTube or on our .Reducing waste can save you money, conserve energy and resources, and reduce air, soil, and water pollution. The Best Practices in Waste Reduction video shows you real options for recycling, reducing, or reusing solid waste products. Helping promote California’s development of markets for recyclable materials is part of our mission. We can help you with technical, financial, and permitting assistance. Please feel free to contact CalRecycle’s Office of Public Affairs for more information.

Related CalRecycle Web Pages

Additional Resources

For more information contact: C&D Program Staff, cdrecycling@calrecycle.ca.gov