household or family

A "household" may contain more than one family (depending on the definitions of family and household that you use), so I don't think the terms are necessarily interchangeable, depending on the level of accuracy you are trying to achieve. In non-clinical communication the terms might be interchangeable.

If the sentence was in relation to a scientific study, then "household" would probably be the more accurate term if the study dealt with dwellings instead of familial relationships.

The original context is global water by domestic use, but domestic doesn't have a noun form, so I change it to households, and I also wonder families.

"home"