Containment barrier systems are among the most widely used technologies for remediating contaminated sites. Various structures have been engineered to address site-specific needs, while barrier selection depends largely on whether regulatory requirements are prescriptive, or performance based. This publication provides an introduction to the design and construction of different containment barriers for low-level radioactive waste generated from remediation activities: basal (bottom) liners, final covers, in situ vertical barriers and in situ permeable reactive barriers. Practical aspects of each structure are discussed in theoretical case studies, which allow remediation project designers, implementers and regulators to make more informed decisions about the use of these barriers.