An apparatus for repairing an existing spill containment manhole operably associated with an underground fuel storage tank. The apparatus includes a containment vessel for containing fuel spilled during filling of the underground fuel storage tank. A major portion of the containment vessel is adapted to be inserted into an existing spill containment manhole. The containment vessel includes at least one wall that surrounds an existing pipe section operably associated with the underground fuel storage tank when the containment vessel is installed. The at least one wall has an inner surface and an outer surface. Preferably, the containment vessel includes an upper annular flange that extends over and surrounds a portion of an existing cover rim of an existing spill containment manhole thereby isolating an upper portion of the containment vessel from an upper portion on the existing spill containment manhole when the containment vessel is installed. Optionally, a replacement cover is provided to replace an existing cover of the existing spill containment manhole. The replacement cover may include at least one sealing member that engages the inner surface of the at least one wall of the containment vessel when installed. The containment vessel may also include a drain assembly for selectively draining fuel collected in the containment vessel back into the underground fuel storage tank. Preferably, the containment vessel includes a compact seal assembly for providing a fluid tight seal around an existing fill port.