Abstract: A modular overflow spout that covers a tank outlet comprising an overflow cover removably attached to a curb assembly. The overflow cover includes a canopy and a cover plate. The curb assembly comprises an outer curb having a lower curb flange that can be incorporated into the tank outlet and an upper curb flange that is positioned above the tank outlet. An inner curb is attached to the outer curb and can be incorporated into the tank outlet with the inner curb. The modularity allows the outer curb to be adjustable within the outlet so that the angle of the upper curb flange is conducive for attachment of the cover plate on the overflow cover after the curb assembly is incorporated into the tank roof.