One of the basic problems in sewerage system constructing is proper determination of domestic sewage volume. It is an essential parameter, which if properly assumed later affects the investment and operational costs of the whole system and influences the efficiency of sewage treatment. It is usually assumed that the volume of domestic sewage produced by households equals the volume of used water. However, in small settlements and in the areas where housing is scattered volume of consumed water and the way in which it is utilised are highly diversified. Both national and foreign directives state unitary sewage volume us equal to 150 dm3•Mk-1•d-1. The investigations conducted at Mszana Górna village demonstrated considerable divergence between the actual amount of water consumption and assumed in the projects, which also involves the volume of domestic sewage discharged to the sewerage system. The observed water consumption per one inhabitant on an average reached c.a. 61 dm3•Mk-1•d-1 , which was only 40 % of the assumed value. The difference resulted among others from so called sewage-free water consumption, which may be determined using the structure of water use. In the studied households water used for animal keeping had the main share in this type of use, but it might also be water used for crop watering, car and farm machinery washing and for diluting chemicals used for plant protection.