Summary:

The aim of the research was to evaluate the pollutants' concentration in the household sewage drained from the rural or rural-urban districts located in Lesser Poland Voivodeship. The research was based on the analysis of 140 raw sewage samples taken from 34 sewerage systems in the period of 2000-2009. Val-ues of five selected pollution indexes were analyzed: BOD5, COD, total suspended solids, general nitrogen and general phosphorus. The results were compared to the amounts presented in the common literature on the sewage treatment.
The research showed that the average values of the pollution indexes in the household sewage drained from the rural and urban-rural districts in Lesser Po-land Voivodeship differ from the values presented in the literature. The biggest difference was found in the case of the general nitrogen (value 48% higher) and COD (value 4,4% higher). However the average concentration of the general phosphorus, 11 mgP•dm-3, turned out to be 45,8% lower than the average value presented in the literature. The maximum values of BOD5, COD, total suspended solids and general nitrogen in the tested sewage were much higher than the maxi-mum values in the analyzed references.
On the basis of the relationships between the average values of the pollu-tion indexes COD:BOD5, BOD5:Ngen, BOD5:Pgen it was ascertained that the sew-age drained from the rural and urban-rural districts in Lesser Poland Voivodeship can be effectively treated by the advanced biological methods with removal of the biogenic compounds
The results of the carried out research show that while designing of the sewage treatment plant the general information from the literature about the pol-lution concentration needs to be treated very carefully.