Introduction to Contaminated Site Management - Dealing with Contaminated Sites: From Theory Towards Practical Application - page 76

conservatism/precaution, for example, protection of the average human being, or
protection of all human beings. Usually, the protection levels and the level of
desired conservatism need to be determined in agreement with other existing
laws. Although decision-makers play a crucial role in the definition of boundary
conditions and degree of desired conservatism, it is essential that they unbias-
edly commit themselves to the scientific part of the Risk Assessment and Risk
Management.
Except for following fixed protection levels, decision-makers have other options
for soil quality appraisal. These options are mainly implemented when defining
the end goal of Risk Management, for example, through remediation. First, they
can relate the acceptable soil quality to background concentrations, independent
of associated risks. From the point of view of efficiency, an elegant procedure is
to base the end goal on the ALARA ( As Low As Reasonably Achievable) princi-
ple ,using Best Available Technologies (BAT) . This means that risk reduction is
performed up to a concentration level, possibly with a maximum value that is
'good enough', for which the costs 'are reasonable'. Obviously, the determination
of 'reasonable costs' in relation to the improvement of soil quality is a subjec-
tive process. A special level of protection, not directly related to risks, is based
on the stand-still principle , generally applied to assess the appraisal of groundwa-
ter quality or soil material transposition. According to this principle the soil quality
may not deteriorate, in other words, contaminant inputs must equal contaminant
outputs.
An approach that decision-makers can choose to follow is the precautionary
principle (Raffensberger and Tickner 1999 ), especially in case of lack of scien-
tific consensus. This principle is morally and politically based, and states that if
an action or process has adversely impacted human health, the burden of solving
the problem falls on those who caused the problem. At the 1992 United Nations
Conference on Environment and Development (UNCED) in Rio de Janeiro (often
called the Earth Summit) (United Nations 1992 ), the precautionary principle was
advocated with regard to environmental protection. When applying the precaution-
ary principle to contaminated sites, decision-makers can decide, for example, in the
case of doubt about the risks involved, that the polluter is responsible for (financing
the) elimination of the contaminants.
Along with the definition of protection levels, the decision-makers also have the
duty to communicate them. It is often asserted that the political underpinning of
these protection levels is based on coincidental aspects and very often not made
transparent. In the most extreme case, protection levels that the scientists (arbi-
trarily) derive are implemented in soil quality assessment frameworks, since 'they
are the only levels available' in the view of the decision-maker. Moreover, there
is a risk that a specific degree of conservatism 'slips' into the Risk Assessment,
since the scientists use the parameters that are available, without initially focussing
on a specified degree of conservatism. It is important that all policy decisions
are clearly specified in reports underlying, for example, Soil Quality Standards,
Decision Support Systems, etc.