Determination of pollution and recovery time of karst springs, an example from a carbonate aquifer in Israel

► This work combines the monitoring of two incidents of spring water pollution, together with artificial tracer tests. ► A valuable information was gain regarding karst system connections and direct estimation of the groundwater velocities. ► The groundwater velocities in the conduits were found to be in a range of 2-3 km/d. ► A complex hydrological system of polluted springs coexist with ncontaminated groundwater from boreholes from the same aquifer.