Lysimeter tests were carried out on water-soluble wood preservatives and on wood preservative components leached out of impregnated wood. The purpose of these tests was to determine the extent to which the migration behaviour of environmentally relevant ions in the soil is influenced under comparable conditions. The results clearly show that the groundwater is especially at risk when wood preservatives are allowed to penetrate the soil unhindered (worst case). Anions, such as chromates for example, are a particular risk as they are scarcely adsorbed by the ground matrix and can therefore enter the groundwater supply very quickly. On the other hand, copper, for example, is adsorbed so firmly by the soil that only negligible concentrations are found in the eluate. Its risk to the groundwater can therefore be ruled out. The lysimeters were filled with leachates containing preservatives from treated wood. The copper, zinc, chromium and fluorine ions were mainly analysed in the top layers of soil, thus indicating that in practice "only" regional soil contamination is to be expected. On the other hand, the concentrations of these ions found in the eluate are of the size if those which occur naturally, as was expected. The following ranging can be concluded for the tested water-soluble wood preservatives and their leachates containing preservatives from treated wood with regard to a possible risk to soil water or groundwater: wood preservative >> impregnated wood (wood preservative not yet fixed) > impregnated wood (wood preservative fixed).

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