What is the slope of the topping line inside an all-weather tank and where does it terminate?

The correct option outlines that the slope of the topping line inside an all-weather tank is 6 inches per 10 feet and that this line terminates 4 inches from the sump bottom. This specification is important because it helps ensure effective drainage and proper functioning of the tank. A slope indicates that as you move away from the sump, the line rises to promote drainage and minimize the risk of water pooling or stagnation.

The specified distance from the sump bottom is crucial because it establishes a height that balances operational efficiency with safety measures. Terminating the line 4 inches from the sump bottom helps prevent sediment build-up and ensures that the tank can adequately manage not only the liquid it holds but also the residuals that may settle at the bottom. This design consideration ultimately contributes to the longevity and performance of the tank system.