Cut-off walls built using self-hardening slurries are an important tool for modern engineering pursuing Sustainable Development Goals. Much like cement concrete, this material is affected by the challenges posed by the increasing human pressure on the environment, although it is used significantly less widely than concrete; for this reason, relatively little comprehensive literature data is available describing the interaction of self-hardening slurries with the environment. This article provides a review that complements the current state of knowledge on self-hardening slurries in this area, with a particular focus on the durability of the material and its pollutant immobilization capabilities. To provide context, the material’s operating conditions, properties and components are briefly characterized. The resistance of self-hardening slurries to environmental aggression is described extensively, as it is a key factor in ensuring the durability of the material. A sample analysis of the material’s carbon footprint in several representative composition variants is presented. The subject of pollutant immobilization by self-hardening slurries is outlined. Lines of further research are proposed to fill gaps in the available knowledge.