The Solidification/Stabilisation method utilises chemically reactive formulations that form stable solids that are non-hazardous or less-hazardous than the original materials.

Solidification refers to the physical changes in the contaminated material when a certain binding agent is added. These changes include an increase in compressive strength, a decrease in permeability, and condensing of hazardous materials.

Stabilisation refers to the chemical changes between the stabilising agent (binding agent) and the hazardous constituent.

These changes should include a less soluble, less toxic constituent with hindered mobility. Common bonding agents include, but are not limited to, portland cement, lime, limestone, fly ash, slag, clay, and gypsum.

Because of the vast types of hazardous materials, each agent should be tested on the site before a full-scale project is put under way. Most binding agents used are a blend of various single binding agents, depending on the hazardous material it will be used on. Portland cement has been used to treat more contaminated material than any other S/S binding agent because of its ability to bind free liquids, reduce permeability, encapsulate hazardous materials, and reduce the toxicity of certain contaminants. Lime can be used to adjust the pH of the substance of drive off water by using high heats of hydration. Limestone can also be used to adjust pH levels. Slag is often used for economical purposes because of its low cost.