The pest control seal for a recreational vehicle comprises a relatively soft and resilient foam material, which is compressed into the annular opening between the conduit and a passage through the wall or panel of the service compartment of the RV, and a relatively thin, hard retainer, which is attached to the rim or flange of the hose or conduit opening or passage. The first and second surfaces are inclined to the axis of symmetry of the tank and the minimum distance between the first and second surfaces and the axis of symmetry is near the bottom of the tank. The memory array separates the columns with deep trenches 46 that may also be formed into charge pump capacitors.