A bucket-shaped fitting placed around the product-delivery opening of an underground tank, and designed to capture incidental spills that might occur when the delivery hose is disconnected.
A few such manholes are capable of holding up to 25 gallons of liquid, although the five gallon capacity is most common. If product remains in the hose after delivery is completed, the product might be spilled onto the ground, causing contamination. But with the manhole in place, the product, instead of being spilled, can be contained.
Typically, spill containment manholes are equipped with a drainage port that leads into the storage tank below. If spilled product collects in the manhole, the port can be opened to allow the product to drain into the tank.