Site-specific risk assessment and management of point and diffuse sources - Environmental Deterioration and Contamination: Problems and their Management - page 361

Figure 10.12 Calculation of the risk reduction and retention rate and the site-specific target value at
watershed scale.
on the groundwater/surface water in the compliance points is adaptable to both local
and watershed scale, so that it can be used for both point and nonpoint sources.
The procedure may involve numerous simplifications and generalizations of com-
plex and diverse physico-chemical, geochemical, biological processes. This is justified
by the need to have an operational and relatively simple system. Attainment of the
target concentration values by the selected remediation technology can be verified by
microcosm models and field experiments.
The likelihood of achieving the site-specific target values—estimated by the inverse
modeling of contaminant transport from the compliance point back to the source—can
be predicted based on the experiments testing the selected risk reduction measure or
remedial technology. The risk reduction rate resulted from the risk reduction measure
or technology simulating micro- and mesocosms can be validated with the results of
field experiments (see the Gyöngyösoroszi, North Hungary, case study in Volume 5).
Results of the field experiments in subareas—assuming they represent the whole—
should be compared with the site-specific target values estimated by transport and fate
modeling. The validated source criteria (target concentration or target emission values)
will be transformed into site-specific quality criteria for the remediation goals of the
respective site.