Use of LCA as decision support for the selection of remedial strategies for remediation of contaminated soil and groundwater

Groundwater is the dominant source of drinking water in Denmark and the general policy is to maintain the groundwater as a clean source of drinking water. The risk of groundwater contamination is therefore often the prime reason for remediating a contaminated site. Chlorinated solvents are among the contaminants most frequently found to be threatening the groundwater quality in Denmark and worldwide. Life cycle assessment has recently been applied as part of decision support for contaminated site management and subsurface remediation techniques. Impacts in the groundwater compartment have only gained little attention in established life cycle impact assessment methodologies. Often groundwater is included in a general freshwater compartment, is simply disregarded, or is only functioning as a sink for contaminant emissions. When applying LCA for decision support for contaminated site remediation, there is a trade-off between obtaining local beneficial effects from the remediation and generating environmental impacts on the regional and global scale due to the remedial actions. Therefore there is a need for including the impact of soil contaminants that will potentially leach to the groundwater, e.g. chlorinated solvents, in the LCA. The poster discusses possible ways to assess the risk for contaminating the groundwater with chlorinated solvents within the LCA framework. This can be used to assess the potential groundwater impact of residual contamination when remediation techniques with different remedial efficiencies are compared or when a no-action scenario is compared to a remedial action scenario. The groundwater impact is evaluated for a case study comparing a number of remedial scenarios to a no-action scenario.