Natural colloids are, in principle, present in every natural groundwater. CRR concentrated on the investigation of the potential formation of bentonite colloids at the bentonite/host rock interface. Colloids were formed in the laboratory under dynamic and quasi-stagnant groundwater conditions, implying that colloids may be produced even in the absence of strong erosional forces. The concentration of colloidal material generated at the interface was observed to increase with increasing water flow.

Scanning electron microscope images of FEBEX bentonite colloids