The estimation of infiltration and inflow in a sewage network by combining continuous monitoring of hydrological parameters, flow and temperature with stable isotopes of oxygen and hydrogen.

The failure of sewage network systems can lead to the introduction of external water, impacting the capacity, performance, and environmental sustainability of urban infrastructures. This study examined methods for identifying and quantifying external water in a sewage system in cold climate conditions through the analysis of stable isotope of oxygen (δO) and hydrogen (δH) from samples, and continuous temperature monitoring, followed by the simulation of the network's hydraulics and temperature profile. The assessment was conducted during periods of low and high groundwater levels, specifically during dry weather flow.