Disclosed is a system and method for sealing containment sumps used in connection with underground storage tanks. A resilient member is configured to move the valve member to separate the valve member from the engaging part when the push lever moves from the lower dead center to the upper dead center. 001 to 25 part by weight of metal salts consisting of alkali metal cation, and anion which is counter-ion of super strong acid and has perfluoro alkyl group, and prevent whitening of appearance under high temperature and humidity condition as well as static electricity without change of the durability, transparency, and adhesion.