during operations, and to secondary effects, like the emission of
greenhouse gases due to combustion of fossil fuels. These conse-
quences cannot be grasped
by neither the risk analysis, nor by the tra-
ditional financial assessment carried out before remediation. This cost
assessment usually does not include valuation of environmental
goods, and thus internalization of the values of environmental re-
sources.
The evaluation of clean-up operations
in terms of environmental
merit is based on an Environmental Merit Index (EMI). This index is
constructed by rating the performances of clean-up options against a
list of measurable aspects and by aggregating these performances with
a weighting scheme.
The environmental merit perspective aims at quantifying the per-
formances of candidate cleaning-up options
along these evaluation cri-
teria. These results of environmental performances are based on the
comparison of alternatives. Since these criteria largely represent inde-
pendent concerns for the cleaning-up operations, the approach through
additive value functions can be applied.
The overall environmental quality
of a remedial option is a
weighted combination of the different performances. Intuitively,
weights represent the relative importance of one attribute compared to
another. The higher the weight attached to an aspect, the more the as-
pect drives the evaluation. Weights are assessed through interviews.
Precise question answer protocols are used to ensure that the respon-
dent provides weights which are a true representation of his/her deci-
sion strategy.
There are fundamental questions raised by this approach to envi-
ronmental merit:
1.Does the current practice of soil remediation
lead to a positive
balance for the environment?
2. Who and how many experts should be interviewed?
3.Are the differences in option across experts significant for the
evaluation?
The use of an environmental merit index shows that the environ-
mental balance of soil cleaning-up cannot be assumed to be positive in
all cases. Instead, it should be considered as an objective of the clean-
ing-up operations to be achieved by carefully designing remedial ac-
tivities.
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