Some of the pilings in docks and piers, especially on the East Coast, are 100 years old. Jim Graham, professional engineer with the National Timber Pilings Coun-cil (NTPC) in Rye, N.Y., echoes most others in the industry when he says that the first choice for handling old wood is to reuse it in some manner. "TCLP testing of penta and creosote treated wood has conclusively demonstrated that treated wood products are not a ‘hazardous waste,’" according to Wilbur. Some preservatives do not contain any TCLP constituents. The materials in a wood sample depend on the type of preservative used. If, after applying the TCLP test to a particular set of timbers, the extract contains concentrations of chemical constituents above any of the 39 chemical-specific regulatory levels, the waste is classified as hazardous. "The number one consideration usually is toxicity," Wilbur says.ĮPA’s Toxicity Characteristics Leaching Procedure establishes the thresholds for 39 different chemicals. Toxicity, ignitability, corrosiveness, and reactiveness are the major concerns. Environmental Protection Agency regulates treated materials under the Resource Conservation and Recovery Act. According to Allan Wilbur, director of public affairs for the American Wood Preservers Institute, Vienna, Va., the U.S. However, several common-sense handling precautions do apply. In general, treated materials are safe to handle and safe to reuse and recycle. But the options for disposing of it are limited. A number of manufacturers guarantee treated wood to resist decay and termite attack for 40 years or more. For one, the quality of the wood may be better. Pressure treated materials are a whole different ball game than the typical C&D timbers from a normal knock-down job. In most cases, the chemical preservative, regardless of type, has been forced deep into the cellular structure of the wood in a closed cylinder under pressure. Water-borne treatments include chromated copper arsenate, ammoniacal copper quat, and ammoniacal copper zinc arsenate. In addition to the typical sources of treated wood like railroad ties and utility poles, treated C&D materials are found in warehouse floors, boat docks, outdoor decking around hotels and homes, and other buildings where weather-resistance is important.Ĭreosote, pentachlorophenol and water-borne timber treatments are the most common for recyc-lers to encounter. However, many kinds of treated timbers are not appropriate for grinding into wood mulch. Some states have specific rules for handling treated timbers, although most treated wood is not considered a hazardous waste. When the call comes in to clean up a construction or demolition project that involves pressure-treated timbers, the rules can be quite different than those for the average project.
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