Summary:

The aim of the study was to determine the volume of infiltration and inflow within a selected sanitary sewer system by using the moving minimum method. The examined sewer system is located in Kraków County, Lesser Poland Voivodeship. Parasite water inflow into the sewer system was studied in the multiannual period of 2008-2011. Based on the analysis of the research results, obtained using the moving minimum method, it was determined that the infiltration fraction in the annual inflow of contaminated water into the sewer system was from 19.0 to 20.7%, while the fraction of extraneous water - from 19.5 to 31.4%. The largest inflows of extraneous water in the analyzed multiannual period occurred in 2010 (30 210 m3). Due to high total annual precipitation this year was evaluated as very wet. The lowest inflows of extraneous water to the sewer system (15 053 m3) were observed in 2011 (extreme dry year). On the other hand, the largest inflow of infiltration water (20 675 m3) occurred in 2009 (dry year) and the lowest (14 805 m3) - in 2011. The performed research demonstrated a strong correlation between the annual amount of precipitation and the annual volume of parasite water flowing into sewer interceptors in the analyzed sewer system. The study showed that the moving minimum method can be successfully applied to determine the volume of infiltration and inflow within sanitary sewer systems.