Abstract: A locking sterile water valve system releasably couples a sterile water valve to a cage. The water valve is releasably coupled to an outside water supply while maintaining a barrier condition. A locking member is attached to the animal cage. A raised portion of the locking member is received in a recessed portion of the sterile water valve assembly. The water valve can be rotated for snapping the water valve into locking engagement with the locking member connecting the water valve assembly to the cage. An internal cup can be used with the water valve for collecting water leaking from the valve to prevent water from leaking into the cage and jeopardizing the animals and maintaining barrier condition.