Integrated and efficient assessment of contaminated sites

摘要

Under the auspices of the MOKKA project, current contaminated-site management practice was examined, including standardized and not yet standardized site assessment strategies and methods. Current practice was critically evaluated, and the bottlenecks - the barriers to more efficient site assessment and risk assessment - identified. One of the problems identified in the case of contaminated sites is that the site characterization is a separate activity from the remediation-specific assessment of the same site, and often these activities are also widely separated from each other in time. By applying a more dynamic site-assessment tool, we can get an answer not only about the current state of, and risk posed by, the site, but also about the site's own potential to mitigate it. The soil samples taken for contaminant analysis also allow natural biodegradation to be measured or proved.rnAnother barrier to proper decision making is the time required for sampling, analysis and evaluation of the results. The longer this takes, the poorer the decision. The assessment tool and its time requirement should be optimized in every case, for example by the combination of in situ and laboratory assessment tools.rnThe most typical bottleneck in obtaining good-quality results and a real picture of a contaminated site, is that the proper assessment tools are not selected. They are not suited to the site, to the contaminants or to the most important dynamic factors, such as the interactions between soil matrix, contaminants, soil ecosystem, environmental parameters, etc. Most of the assessors are satisfied with the existing and standardized methods. The standardization of a method does not mean that it is suitable in a particular case. The assessment tool-box should be constructed taking into account the problem, the site and the target.rnTo create the optimal tool-box, we have to understand not only the available tools and their applicability, but also the problem and the site. But, because the problem and the site are not known at the beginning of the process, we have to apply a dynamic and iterative concept, which results in a step-wise, cost- and time-effective site-assessment tool, able to integrate all the risk-management tasks: site assessment; risk assessment; and selection of the cost-, time- and eco-efficient risk-reduction tools.rnThis paper provides help in the creation of the optimal assessment tool-box for the management of contaminated sites by means of an effective grouping of the assessment tools and by emphasizing that the tools are only models of the real environment, which are at a certain distance from reality -in our case from the actual contaminated site. When we can clarify the nature and potential of the assessment tools, it makes our decision on the selection of the assessment tool-box easier.