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REGULATORY PERSPECTIVE ON MANAGING RISKS AT WOOD TREATING SITES
Citation:
Grosse*, D W. REGULATORY PERSPECTIVE ON MANAGING RISKS AT WOOD TREATING SITES. The Second International Conference on Remediation of Chlorinated and Recalcitrant Compounds, Monterey, CA, May 22 - 25, 2000.
Impact/Purpose:
To inform the public.
Description:
Over 700 sites in the United States have been identified where wood preserving operations have been conducted. The most common types of wood preservatives found at these sites are creosote, pentachlorophenol (PCP), and copper chromated arsenate (CCA). When properly used and disposed of, these preservatives do not impose a significant health risk. However, due to operating procedures (many of which were accepted industry practices at the time), wood treating operations have contributed to soil and groundwater contamination. Primary sources of pollution at these sites are lagoons, waste ponds, drip raacki areas and chemical storage and treatment tanks. To better understand the risks associated with the use of wood preserving compounds, it is important to identify the constituents of concern. Creosote is produced as a distillate from coal tar and hence, is a variable mixture of hundreds of compounds, mostly semivolatile organics (SVOCs). Polynuclear Aromatic Hydrocarbons (PAHs) generally, account for up to 85%, by weight, of the chemical constituents found in undiluted creosote. Genetic toxicity if individual PAHs increase with m,olecular weight. USEPA has determined that 7 PAHs are probable human carcinogens and has set forth order-of-magnitue relative potency factors for these constituents, Pentachlorophenol (PCP0 is another preservative used in wood preserving processes and is prepared by dissolving technical grade PCP in oil to produce a solution that is 4-8% PCP. Technical grade PCP contains 85-90% PCP, 4-8% 2,3,4,6-tetrachlorophenol and approximately, 0.1% polychlorinated dibenzo-p-dioxins (PCDDs) and chlorinated dibenzofurans (CDFs). The PCDDs are, primarily. octa with traces of hexa and hepta chlorodibenzo-p-dioxins. Copper chromated aresenate (CCA) has the potential to adversely impact soil and groundwater by releasing the highly soluble and mobile hexavalent chrome. Once in the groundwater this potentialo carcinogen can spread very rapidly through subsurface systems.