Literal question
[Questions 1-13 were asked in cases of a housing unit or a collective living quarter, except hotels or similar and institutions of "other type" -- that is occupied as a usual residence or for seasonal use, per questions A, B]
6. Sewage disposal system:
[] 2 Housing unit without sewage disposal system
[] Housing unit with sewage disposal system:
[] 4 Connected to a public sewage disposal plant
[] 6 Connected to a private sewage disposal plant (septic tank, etc.)
[] 8 Other sewage arrangements (open pit, ditches, brook, etc.)
Interviewer instructions
[Questions 1-13 were asked in cases of a housing unit or a collective living quarter, except hotels or similar and institutions of "other type," that is occupied as a usual residence or for seasonal use, per questions A, B]
Question 6 - Sewage disposal system
As for sewage disposal system we understand all permanent installations that allow the evacuation of residual waters of a dwelling through a determined way.
A septic tank is a special structure recipient that, making use of a particular piping, collects the waste of one or a few housing units, and requires particular procedures for its maintenance.