This report describes field trials and testing of the commercially available Geodur solidification/stabilization system for processing contaminated soils and other industrial residues. It is one of a series of reports resulting from CIRIA's programme of case study demonstrations of remediation of contaminated land. The treatment system, which uses proprietary additives to enhance performance, is based on cement stabilization. The main trials involved two contaminated materials; additional trials were made on four different types of material imported from other sites. The mixed materials were transported to a nearby site and compacted as ground slabs. The report describes the field and laboratory work and presents the results of observations and tests on samples of the original and processed materials. The testing included determinations of compressive strengths of cube samples and specimens cored from the cast slabs at different ages and of chemical analyzes and leaching. The report includes some of the findings of a subsequent project which examined the performance of the cast slabs over four years later. All had gained in strength below some surficial damage.Water entering subsurface and surface drains as leachate and as runoff appeared not to have been affected by the stabilized material.