Screening of risk management options for abandoned wood-preserving plant sites in Alberta, Canada

Abstract

Several abandoned wood-preserving sites have been identified in Alberta, Canada, which pose a potential threat to human health and the environment. The physiochemical, environmental, and toxicological properties of wood preservatives are discussed together with the predominant human exposure pathways for these chemicals in the environment. A Level II soil fugacity model is used to illustrate the comparative environmental fate of individual organic wood treatment chemicals following release to the soil environment. An evaluation of risk management options at five priority sites is used to illustrate problems associated with the treatment and disposal of mixed organic and inorganic contaminated soils, soil property limitations, and the predominance of organic contaminants within the residual oil phase. The latter reality dominates options for exposure reduction and risk management. Key words: contaminated soils, wood-preserving sites, remediation options, screening, fugacity model.

Effects of Copper, Lead, and Cadmium on the Sorption of 2,4,6-Trichlorophenol Onto and Desorption from Wheat Ash and Two Commercial Humic Acids

“…In this work we selected Cu 2+ , Pb 2+ and Cd 2+ , as three examples of toxic metals that commonly exist at elevated levels in the contaminated soil environment and TCP as a typical example of an organic contaminant listed as a priority pollutant by the U. S. Environmental Protection Agency. Copper, Pb 2+ , Cd 2+ , and TCP may occur together in contaminated soils, particularly in proximity to wood preservation facilities, where TCP was used as biocides . While extensive individual studies on the sorption of either organic contaminants or metals to humic substances have previously been conducted, there is limited information on the mutual effects these two types of contaminants have on sorption ,, or the mechanisms involved.…”

Evaluating fugacity models for trace components in landfill gas

“…Among its uses from global-scale to in vivo modelling, its application to waste problems is increasing, albeit with an attending need to address the gross heterogeneity and multiphase character of wastes. Applications include its use for directing site remediation decisions (Pollard et al, 1993;She et al, 1995), in quantifying vapour emissions at contaminated sites (Mills et al, 2004) and in assessing the environmental fate of hydrophobic compounds in landfills (Kjeldsen and Christensen, 2001).…”

“…Due to these difficulties, a scalable initial value of 10 mg kg -1 for all of the chemicals was initially selected (Pollard et al, 1993). This represented a load to the cell of 160 kg.…”

“…Level I modelling (Figure 3) illustrates the role of organic matter (f oc ) in determining the partitioning of trace components in the landfill system. Organic carbon can be represented by conventional soil organic (humic) matter or by the presence of a free organic phase common to many hazardous waste systems (Pollard et al, 1993;Kjeldsen and Christensen, 2001).…”