Sump plumbed to water drain

[fkshiu]

Could open up a can of worms plumbing directly into your home drainage system. As untamed mentioned there's the possibility of backflow from the rest of the house as well as sewer gases if the proper trap isn't installed.

A properly designed sump should be able to handle any expected overflow from the main tank. Having a tiled floor and a floor drain next to the tank would be the ultimate safety mechanism even if your whole tank suddenly decided to explode on you.