Septic tanks are supposed to be pumped out every 3 to 5 years. Sounds to me like she was just uncovering the lid so that the pump truck could have access. There is also a dam at the outflow of the first tank before it goes into the second tank.... those dams are notorious for breaking and it's a good idea to make sure that something is there to keep the raw sewage from the first tank from going straight into the second tank which is more for 'refinement' before it discharges into the weeping tiles....
I wouldn't consider uncovering the lid as maintenance in the tank. Bad she fell in, but that reason would be less dramatic than what the article implies, that she was on a DIY mission to work on her tank.
"There was a tractor in the area and a hole had been dug exposing the tank..."
Looks a tad more involved than merely digging a hole to expose the lid for the pumping truck.
In any case, Manuel OKelley wins the thread pun at post #25. That's what is truly important here! :)