PARENT SESSION

6A - LCIA - Toxicity/RA
Poster Hall
8:30 AM - Wednesday, 30 April 2003
Chair: Jolliet, O.¹, ¹
Co-chair: McKone, T.², ²

(WEP/232) Using Life Cycle Assessment to Support a Contaminated Site Management Decision.

Godin, Julie^{1, 2}, Ménard, Jean-François^{1, 2}, Hains, Sylvain³, Samson, Réjean^{1, 2}, Deschênes, Louise^{1, 2}, ¹ NSERC Industrial Chair in Site Remediation and Management, Montréal, Québec, Canada² CIRAIG - Interuniversity Reference Center for the LCA, Interpretation and Management of Products, Processes and Services, Montréal, Québec, Canada³ Hydrogéo Plus, Montréal, Québec, Canada

ABSTRACT- In order to increase the relevance of LCA as a tool for managing contaminated sites, an LCA study was conducted integrating two types of impact: those generated by remediation activities (secondary impacts) and (eco)toxic impacts resulting from the presence of the toxic substances in the soil (primary impacts). Since primary impacts are generally treated by Risk Assessment (RA), the conducted LCA integrated some aspects of RA. The proposed approach was used in an LCA comparing five management options for an existing contaminated aluminum processing waste landfill site. Four of the studied management options were active remediation methods (requiring excavation of the source) while one consisted in a passive remediation method (leaving the source in place). For a reliable assessment of primary impacts, site-specific data from the physico-chemical characterization was used (e.g. hydrogeological, geochemical, and microbiological properties) to build a three-dimensional numerical model in order to simulate fate and transport processes affecting contaminant migration in the groundwater. According to a previous study which identified an ecotoxic risk to the marine environment, the numerical model was used to simulate the evolution of contaminant concentrations with time, under the five compared management scenarios for the marine environment. The resulting concentrations were introduced in the comparative LCA. For the Life Cycle Impact Assessment (LCIA), the characterization factors used were based on Persistence, Bioaccumulation and Toxicity (PBT) model. The results of the comparative LCA revealed a large dominance of primary impacts and also that consideration of contaminant bioavailability was necessary. In order to adequately integrate the risk assessment approach in LCIA, site-specific information is currently being integrated not only in LCI data, but also in characterization factors. This integration is currently being conducted using a multi-media model.

Key words: contaminated sites, comparative Life Cycle Assessment, risk assessment, site-specific approach