Stabilization and solidification were some of the earliest techniques used to treat soils and sludges impacted with metals and/or non-volatile organics. The techniques consist of mixing an amendment with soil or sludge to reduce the liquid content thereby encapsulating the contaminant within the solid matrix of the end product. However, certain metals do not remain within the encapsulated matrix with the typical stabilization and solidification amendments. Chemical fixation of problematic metals can be achieved with specialty reagents to keep them from leaching in the future.