Also, pumps must always be located at the bottom to pull liquid uphill by more than ~30'. Storing large tanks of diesel fuel on the 17th floor (or higher), is a heavy and perhaps dangerous situation.

An always-submerged in-tank pump, not unlike that of a water well, powered via a sealed line from the generators above could, in principle, avoid this problem.

I hope the generators are able to power some sort of mechanical lifting arrangement. Manually hauling the drums is mighty hard.