Abstract: A seal and extender assembly which prevents surface water and other environmental liquids from inadvertently entering a sump, such as one used in a gasoline service station. The seal assembly includes an extender and a cover. The extender defines a channel and has a first end and a second end, the first end has a larger diameter than the diameter of the second end, the first end is secured to the sump adjacent the access port. The cover has a top surface and a perimeter surface, the top surface covers the access port and the perimeter surface secures to the second end of the extender.