Abstract: An above-ground secondary containment system for a primary tank holding liquids includes a dike surrounding the tank, a hood over the dike for preventing ambient precipitation and trash from entering the dike and preventing evaporation of liquids spilled or leaked from the primary tank and contained by the dike, and a closable tank port access means in the hood for permitting access to tank input or output ports when desired, but closable to maintain the hood's property of preventing ambient precipitation and trash from entering the dike at other times. In one embodiment, the dike is a right parallepiped having an open top and a floor and the hood includes a flat top surface and surfaces sloping downward, from the flat top surface to opposing sides of the right parellepiped. The sloping surfaces have inwardly turned flanges along their lower edges to return liquid condensate flowing down the inside of the sloping surfaces to the dike.

Abstract: An above-ground secondary containment system for a primary tank holding liquids includes a dike surrounding the tank, a hood over the dike for preventing ambient precipitation and trash from entering the dike and preventing evaporation of liquids spilled or leaked from the primary tank and contained by the dike, and a clossable tank port access means in the hood for permitting access to tank input or output ports when desired, but closable to maintain the hood's property of preventing ambient precipitation and trash from entering the dike at other times. In one embodiment, the dike is a right parallepiped having an open top and a floor and the hood includes a flat top surface and surfaces sloping downward from the flat top surface to opposing sides of the right parellepiped. The sloping surfaces have inwardly turned flanges along thier lower edges to return liquid condensate flowing down the inside of the sloping surfaces to the dike.