Soil remediation: a systems approach.

Soil remediation has only a short history, but the problem addressed is a significant one. When solving soil remediation problems we have to deal with a large number of scientific disciplines, however solutions are often presented from the viewpoint of just one discipline. In order to benefit from the combined disciplinary knowledge and experience it is necessary to describe the interrelations between these disciplines. This has been realised by developing an adequate model of the desired process, which enables to consider and evaluate the essential factors as interdependent components.Three main phases in the soil remediation process are distinguished: problem identification, development of problem solving alternatives and selection of the best alternative.In the identification phase several sampling strategies may have to be compared. In this thesis probabilistic decision trees are used for the comparison. In the case studies we found that the value of surveys depends not only on the costs of the survey itself, but equally on the ratio of expected failure or success and the related costs of the actions based on the survey. Once a sampling strategy is chosen and data is collected, the results can be used to estimate the amount of polluted soil material. Probability kriging is a non-linear geostatistical estimation technique suitable for the estimation of the amount of polluted soil material.In the development phase work is aimed at generating problem solving alternatives. This thesis presents expert support models recombining knowledge and experiences obtained during ex and in situ soil remediations. The aim of the models is to optimise knowledge transfer among the various parties involved in contaminated site management. Structured Knowledge Engineering (SKE) has been used as a framework for model development. The model was applied several polluted sites. The structured approach requires scrutinising all relevant data in order to answer the questions related to ex and in situ soil remediations. Moreover, it clarifies the roles of the different disciplines involved in the process.After deciding whether or not a soil cleanup operation is necessary, the question remains which remedial strategy and technique should be applied. The triple-perspective REC framework simultaneously takes into account risk reduction, environmental performance and costs, and aims at increasing the effectiveness and efficiency of cleanup operations