A Little Guidance

Volunteer members and staffers from two trade associations have combined efforts to produce what they call “viable, in-use construction and demolition (C&D) wood fuel specifications.”

The Construction Materials Recycling Association (CMRA), Eola, Ill., and the National Solid Wastes Management Association (NSWMA), Washington, D.C., worked together to develop the specifications. In a news release announcing them, the two groups say the specifications “are based on industry experience, permit requirements for boilers using C&D wood as a fuel stock and regulatory requirements governing the use of this material.”

Dan Costello, chair of the CMRA’s Material Standards Committee and president of Middleboro, Mass.-based Costello Dismantling, says, “Wood is one of the primary materials generated at construction and demolition sites, coming from a wide variety of sources. In fact, we estimate that it can make up 30 percent of these materials. The specs will help standardize wood chips processed at C&D processing facilities and expand markets for this valuable biomass fuel.”
Costello and others involved in developing the specs are optimistic that they will be a valuable resource to the industry. “The specifications provide real-world guidance on what works in the marketplace for C&D wood fuel buyers (boiler owners and operators) and sellers (C&D wood processors),” says the news release issued by the two trade groups.

DEFINITION PLEASE
The new specifications begin with the basic exercise of defining C&D wood the following way: “C&D wood-derived product—a renewable, biomass product prepared from wood materials generated at construction and demolition sites that is processed to create a commodity that can be used as fuel for a boiler and/or other energy generation technology (e.g. gasification). This product can also include other biomass materials such as boxes, crates, pallets and other wood products from industrial and post-consumer sources.”
The next step, after defining C&D-derived wood fuel, is to offer some guidance on what it’s not. In a section labeled “Unwanted Materials,” several materials are identified as being unwelcome in the wood fuel stream.
“Certain substances should be discouraged from entering the C&D wood processing operation,” states the document. “Limiting these materials will improve the characteristics (e.g, fuel heat content) of the final product.”
The following materials are specifically mentioned:

• Scrap metal;
• PVC piping;
• Drywall;
• Non-combustibles such as rocks and aggregate (which can create operational problems with the C&D wood used as fuel);
• Lead-based painted wood and certain treated woods; and
• Asbestos-containing materials.

As with the long-time specifications for scrap metal and paper that are published and available from the Institute of Scrap Recycling Industries Inc., the authors of the wood fuel specifications note end consumers will not necessarily have identical restrictions or requirements.

“Fuel purchasers may have specific limits or prohibitions on particular substances and materials,” write the authors. “C&D wood suppliers may be required through contractual obligations to further prevent and restrict these or other materials from entering the processing system. The limitation may be specified through standards or specifications from common standardization entities such as the American Standards and Testing Methods (ASTM). This document does not address such levels of specific requirements between individual purchaser-supplier agreements.”

Beyond seeking what the consumer wants, the authors of the specifications remind recyclers of another important obligation: “The C&D wood supplier must comply with all federal, state and local regulations. This document does not address such regulations. Suppliers and/or purchasers may need to comply with additional state, federal and facility testing procedures and protocols and sizing procedures.”

GETTING DOWN TO TERMS
The “Construction & Demolition Wood-Derived Product Specifications” document issued by CMRA and NSWMA provides names to several classifications of wood fuel products, categorizing material by both purity and size.
In terms used by the document, “Grade defines the acceptable amount of undesirable materials [and] sizing defines the range of acceptable particle nominal sizing from processing (i.e., grinding) of materials.”
Furthermore, according to the document, “All grade and sizing fractions are based on weight,” or, if a grade calls for one size of material to comprise 90 percent or more of a total shipment, that means 90 percent or more of the total weight, not the volume.

The purity classifications list these materials as restricted: “lead-based painted wood, CCA-treated wood, plastic, plaster and all non-combustibles such as rocks, concrete and aggregate.” The size classifications note that some consumers place strict limits on the amounts of fines (pieces smaller than 0.25 inch in size) permitted.
Based on a combination of purity and size differences, the following classifications of materials have been created by the two trade groups:

• Size A—3 inches or less in any
• dimension.
• Size B—A minimum of 90 percent is 3 inches or less in any dimension. All material is 6 inches or less in any dimension. A minimum of 85 percent is greater than 0.25-inch in its smallest dimension.
• Size C—A minimum of 90 percent is between 3 inches and 6 inches in any dimension. All material is 10 inches or less in any dimension. A minimum of 85 percent is greater than 0.25 inch in any dimension.
• Size D—A minimum of 90 percent is 6 inches or greater in any dimension. All material is 10 inches or less in any dimension. A minimum of 85 percent is greater than 0.25 inch in any dimension.
• Grade 1—1 percent or less restricted materials.
• Grade 2—1 to 5 percent restricted materials.
• Grade 3—5 percent or more restricted materials.

A STARTING POINT
Within the “Construction & Demolition Wood-Derived Product Specifications” document, the authors indicate that their work represents a starting point for any given transaction as well as the first steps toward the evolution of additional terms.

“The [specifications] are intended to provide a guide [for] differing grades of C&D wood-derived (C&D wood) product,” note the authors in their introduction. “The specifications serve as a starting point in negotiations between purchasers and suppliers. C&D wood suppliers will need to work with purchasers to ensure that the C&D wood meets the purchaser’s specific needs.”

Simply having such a starting point, however, should prove helpful in the wood fuel marketplace.