Isotopic tracing and quantitative assessment of rainwater in a separate sewer system in Tiszavasvári, Hungary

The hydrological processes that commonly occur within the sewer system i.e., rainwater percolation or groundwater infiltration, can be easily described applying water isotopes. This study investigates potential of tritium and stable isotope composition (δ 2 H δ 18 O) for tracing entering urban estimating amount. work consists collecting analyzing wastewater samples over a six-day-long period including 30-min-long rainfall event, then isotopic results to determine mixing ratios in pipes sensitivity applied methods. Results reveal reacts inflowing sensitively: detectable flow rate increase resulting from is 0.62 m 3 h -1 tritium, 2.49 O 1.25 H. While variation discharge, these values are 12.15 18.91 daytime nighttime, respectively. Due more positive precipitation summer half-year, difference (being less enriched) notable, subsequently, traceable amount parasitic case examined area lower than winter half-year. In recharged under cold climate conditions sampling should carried out night hours, after an at least three-day-long dry period. Though, all three tracers this proved suitable detect small precipitation, came as most sensitive one. • Isotopic detecting system. Tritium, followed change rate. data verified binary rainwater. Tritium method trace extraneous water. Quantitative contribution was also evaluated.