Backward erosion piping is a type of internal erosion process in which pipes are created in the sandy aquifer underlying a water retaining structure, such as a dam or a river embankment, as a result of the removal and transport of soil particles by seepage pressures. The onset and progression of the phenomenon is typically revealed by the occurrence on the ground surface of the so-called sand boils, hence the acronym of the project. In a sand boil, local soil fluidization occurs and, due to high seepage pressures, particles are ejected on the ground surface and deposited in a ring forming a sand volcano. If the progression of the erosion towards the riverside is not stopped, failure of the river embankment may occur. Sand boils are often observed in many river systems worldwide. In Italy, over the last years a total of 130 sand boils have been catalogued along the river Po. Most of them have been mapped in the main course of the river and suffer from recurrent reactivations during high water events, whereas those located in the delta area reactivate also at relatively moderate water levels. A large number of sand boils have been also observed along the Danube river and many other major watercourses worldwide. The mitigation of this phenomenon is therefore a priority to assure stability of many water embankment systems and safety of the surrounding territory.