The process of stabilisation solidification is a physical treatment process which prevents the leaching of contaminants from soils over a period of time. The process is two-fold and encompasses the stabilisation element which is a chemical process which induces a chemical reaction between the stabilising agent and the contaminants contained within the soils matrix to render the material suitable for reuse. The second process of solidification endeavours to change and ultimately improve the physical stability of the material and prevent ingress of external influences (rainfall etc.) which could compromise the integrity and performance of the end product. This process is particularly successful when dealing with heavy Total Petroleum Hydrocarbon (TPH) and heavy metal contamination.

Stabilisation/Solidification can enable projects to be completed much more sustainably and can assist in the ultimate reduction of hazardous waste to landfill.