Ecological Risk Assessment of Diffuse and Local Soil Contamination Using Species Sensitivity Distributions - Dealing with Contaminated Sites: From Theory Towards Practical Application - page 647

development process of the contaminant does not bring profit to the producer,
and whether this is based on a right or wrong model, there are considerable costs
involved.
Remediation of contaminated sites may be very costly. If a policy framework
prescribes specific actions when certain triggers have been exceeded (e.g., an eco-
logically based trigger-concentration for remediation), a government wants to be
sure about the fact that (a) there is real hazard, and (b) there is sufficient budget, as
well as (c) that the budget is spent best, with maximum ecological improvements as
a result.
Instead of prescribing certain actions when soil quality standards are exceeded,
this topic advocates, in Chapter 1 and Fig. 14.1 , tiered Risk Assessment schemes.
We thus propose that, when a soil quality standard is exceeded, there is a second
option for practitioners, namely: conventional Risk Assessment of how serious the
exceedance is in terms of local or future soil use. Factors such as differences in
sorption or compound breakdown may be addressed in the higher-tier approach,
with SSD-modeling, or other (even higher-tier) models. Relatively labor-, time- and
budget-intensive methods such as tests of site media or from field impact studies are
not justified, unless lower tier studies demonstrate a need. Exploration of possible
impacts using SSD-models is cheap and quick, provided that the basic input data
are available.
(Cost) effectiveness is an important practical driver in the context of decision
making processes, and we present some examples (below) in which we illustrate
that SSD-based risk modeling of alternative management scenario's can be helpful.
The examples of SSD use are practical illustrations of potentially large differences
in cost effectiveness of alternative Risk Management scenarios.
14.8 Practical Basis of SSD Modeling
Now that it is clear what SSDs mean (and don't mean) we turn to the construction of
SSDs. Practical application not only depends on meaningful output and accounting
of extrapolation problems, but also on ease of use. For SSDs, the situation is simple.
SSDs can be easily made with only two ingredients:
1. input data, which are ecotoxicity test data for a particular contaminant and
various species or functional traits, and
2. an appropriate data handling approach.
14.8.1 Ingredient 1: The Input Data
14.8.1.1 Raw Input Data
The input data for an SSD can be collected by original research, from the literature
or from databases in which such data are stored.