Abstract: An environment protecting dike assembly is disclosed comprising interlocking, plastic, wall shaped components which can be erected as a dike wall around storage tanks or other liquid containing vessels. The components of the assembly are of modular construction, permitting dikes of different configuration and size to be constructed. When erected on a liquid impermeable substratum such as earth covered with plastic sheeting, the assembly forms an effective liquid barrier, preventing liquids contained within the assembly from escaping, as, for example, in the event of a storage tank rupture.