After pumping a septic tank, in addition to checking the inlet and outlet baffles, the tank should be examined for any cracks or holes where water can infiltrate or leave the tank depending on soil conditions. Sometimes precast concrete tanks have holes in the bottom to allow water to drain out if they are sitting outside at the manufacturing plant.
There are two potential problems with holes like this: one is the infiltration that can add unwanted water to the system if the soil around the tank becomes saturated, and the other is that water can leave the tank so the
