Journal of environmental monitoring vol:9 issue:4 pages:319-328
Alluvial soils may represent important sinks of contaminants as a result of the deposition of
contaminated sediments along the river by overbank flooding or after dredging. Because of the
erosion of alluvial deposits or the release of contaminants from sediments, alluvial soils can also
be a source of contamination. In this paper, a risk assessment for contaminated (alluvial) soils is
presented. The approach, mainly based on physico-chemical soil characteristics, single extractions
and leaching tests, is illustrated by means of a case study from four Belgian catchments. The
extractions and leaching tests that were used have been validated by European testing programs
and can provide valuable information for classifying the potential environmental risks of soils.
Irrespective of the location, pH, organic carbon content and ‘mobilisable’ metal concentrations
were the most important factors explaining ‘mobile’ metal concentrations in the alluvial soils.
Additionally, the data of the physico-chemical soil characterization, extractions and leaching tests
were combined with local and regional factors to classify the alluvial soils in different categories
according to their actual and potential risk for the environment.