This chapter helps readers to understand the chemical and physical properties associated with chemical destruction processes. It explains how to apply basic concepts of chemical kinetics, equilibrium, and mass transfer to the design of chemical destruction processes. The chapter also focuses on a general design approach for hydrolysis, dechlorination, and chemical oxidation. The hydrolysis process is typically an ex situ operation. Key factors involved in hydrolysis design include: type of contaminant, gradation of soil particles, and solvent solution. There are two principles that must be considered in the design of a hydrolysis unit operation: nucleophilic substitution and diffusion rate theory. Key factors involved in dechlorination design include: type of contaminant, gradation of soil, and reagent used. Dehydrohalogenation is the likely form of elimination in the dechlorination process. Key factors to consider in the design of a chemical oxidation unit are contaminant chemistry and gradation of soil.