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Goal, Scope and Background. Canadian LCA practitioners currently use European or American methodologies when conducting comprehensive impact assessments, despite the fact that these methods may not be appropriate for Canadian conditions. Due to the lack of suitable models that are currently available, work has been undertaken to develop an LCTA method by adapting existing LCIA models to the Canadian context. This new method allows the characterization of 10 impact categories. Methods. This project is strongly based on preliminary outcomes from SETAC recommendations for the best available practices in LCIA. Models from 3 recent LCIA site-dependent methods, EDIP2003, IMPACT2002+ and TRACT, were used in this midpoint Canadian-specific method. Characterization models were chosen based on their level of comprehensiveness, scientific sophistication and the possibility of integrating site-specific values in the models. Results and Discussion. All regional and local impact categories in the method are site-differentiated. For aquatic eutrophication, (eco)toxicity and land-use impact categories, regionally-differentiated models taking into account fate and effect were already available: the parameters of these models were modified for the Canadian context. For acidification, aquatic and terrestrial eutrophication, existing models were spatially differentiated for fate: regionalization of the effect factor was also included, based on the level of sensitivity of each ecozone assessed with vulnerability factors. The default spatial resolution selected for this method was Canadian ecozones, which define spaces in an ecologically meaningful way where organisms and their physical environment evolve as a system. For each ecozone, 2334 site-dependent characterization factors have been calculated. Conclusion. This LCIA methodology proposes an attractive and useful set of site-dependent characterization factors for the 15 Canadian terrestrial ecozones. Recommendation and Outlook. Efforts are being carried Out to extend the specificity of some factors used in eutrophication modelization. The transparency of the methodology will allow to recalculate site-dependent characterization factors for different regions and for additional substances. [ABSTRACT FROM AUTHOR]

Abstract: A new method is proposed for the identification of environmental impact category weights using a panel approach and a MultiCriteria Decision Aid (MCDA) for use within the weighting step in Life Cycle Impact Assessment (LCIA). Seven environmental criteria were assessed by panellists and weights were obtained. The weighting factors of 10 impact categories were calculated according to a four-step procedure: (1) criteria definition; (2) scoring of each impact category (scale of 1–100, 100 causing the most damage) according to seven environmental criteria (human health, ecosystem health, resource consumption as well as scale, duration, reversibility and “distance-to-target”) by a panel of Canadian citizens; (3) assessment of each criterion''s importance using a “resistance to change” approach; and (4) criteria aggregation (through MCDA) which allowed the calculation of a final weighting score for each impact category. The greatest advantage of this procedure is the ease with which it can be implemented in a Life Cycle Assessment (LCA) study whatever the LCIA method is used. Integrating weighting factors specific to the Canadian environmental context into a site-dependant LCIA method will contribute to the progress of LCA in Canada. [Copyright &y& Elsevier]

Goal and Scope. Primary and secondary environmental impacts associated with bioremediation of diesel-contaminated sites were assessed using a retrospective life cycle assessment (LCA) as a function of the duration of treatment and the achievement of regulatory criteria. The case study consisted of the remediation of diesel-contaminated soil using biopiles of 8,000 m³ of sub-surface soil impacted with an average of 6,145 mg of diesel fuel/kg soil over a two-year period. Methods. Two scenarios were compared; the construction of a single-use treatment facility on site or the use of a permanent treatment center that can accept 25,000 m³ soil/year. Moreover, since bioremediation is never 100% efficient, different efficiency scenarios, including the transportation of partially treated soil to landfill were analyzed. The primary impact of residual soil contamination was determined by developing a specific characterization factor (ecotoxicity and human toxicity categories in the EDIP method) based on the toxic components of diesel. Secondary impacts were assessed with an LCA software. Results and Discussion. One major observation was the fact that the soil itself is responsible for an important fraction of the system's total impact, suggesting that it is beneficial to reach the highest level of remediation. The reutilization of the treatment facility is also an important issue in the overall environmental performance of the system. In the case of a single-use treatment center, the analysis showed that site preparation and site closure were the major contributing stages to the overall impact, mainly due to the asphalt paving and landfilling processes. Results indicated that off-site transport and the biotreatment process did not contribute notably to the level of environmental impact. The use of a permanent treatment center is preferred since it allows a significant decrease of the secondary impact. However, when soil had to be transported for a distance greater than 200 km from the site, global impacts increased significantly. Conclusion. Results from this study allowed identifying several process optimizations in order to improve the environmental performance of the biopile technology including: the achievement of low level of residual contaminants, the minimization of asphalt or the use of a permanent treatment center. Recommendation and Outlook. LCA was found to be an efficient tool to manage contaminated soil in a sustainable way. However, because of the major contribution of residual soil contamination, additional spatial and temporal data should be collected and integrated in the substance characterization models. [ABSTRACT FROM AUTHOR]