Abstract: A compact, efficient, easy-to-maintain enclosable cabinet for sanitizing a liquid flowing along a cascade within a cabinet body, having a cabinet body, a plurality of troughs directing the liquid along a predetermined path including a cascade within the cabinet body and one or more sanitizing radiation sources for subjecting the liquid to a sanitizing radiation for a predetermined time while flowing along the predetermined path, whereby the liquid is subject to sufficient sanitizing radiation for a predetermined level of sanitization. The sanitizing radiation sources are assemblies having a UV light source, a UV light shield located between the UV light source and the liquid and a rigid internal reflector shield located between the UV light source and the UV light shield.