Impacts of runoff from sulfuric soils on sediment chemistry in an estuarine lake.

The impact of runoff from sulfuric soils in the heavily drained Cudgen Lake floodplain, eastern Australia on water quality and downstream coastal lake sediments has been examined. The oxidation of sulfidic soils and the transformation into sulfuric soils leads to changes not only in the upper soil profile but also affects drainage water quality and the chemistry of bottom sediments in receiving waters. Oxidation transforms the soil from a sink for sulfur and metals to a significant source for downstream environments.