Saprolite, physically intact but chemically weathered bedrock, sits as a boundary layer between the soil profile and unweathered bedrock. It weathers into soil. Saprolite has distinctive properties which would affect how a contaminant behaves in this zone compared to in the soil or bedrock. There is currently a gap in knowledge about the extent to which saprolite can act as a source or sink for different contaminants under different conditions. This is particularly timely in the context of more novel or persistent contaminants, including but not limited to: microplastics, pharmaceuticals, PFAS, bacteria, hydrocarbons and so on. The role of saprolite in the transport, storage and potential re-release of contaminants has implications for future soil health, as well as wider environmental and water quality.
This project will review the current evidence on the presence and behaviour of contaminants in saprolite and use this to inform digital mapping of saprolite and contamination risks, fieldwork sampling of saprolite contamination, mesocosm experiments and modelling. This will enable the identification and quantification of both natural processes and risks.