The patented T-HEX™ Cover System provides more efficient production and management of municipal and industrial wastewater lagoons. Molded from HDPE, T-HEX™, hexagon modules are placed on the surface of a lagoon, a self-filling ballast maintaining the stability of each module independently. The interlock design of the modules provides a self-arranging shield against UV, heat, and evaporation, while maintaining odor and algae control. The T-HEX™ Cover System is ideal for small lagoons, ponds or tanks where permanent covers are too costly or impractical, and may be installed or removed by workers on site.