In the case that there exist more than one origin, for example: underground well and stream and tank and stream, etc., you should mark only one of them.

You should choose as origin the water that is used for drinking and cooking.

You are enumerating a dwelling in which you see a waterwheel for the extraction of water. However when you ask the occupants about the origin of the water, they tell you that in the dwelling they have service or running water provided by O.S.E. [Obras Sanitarias del Estado] and that the water from the well is for cleaning and irrigation.

Mark the corresponding box in the Census document.

[Below the text are two charts, one of them with the box "Public service" marked]