Bank filtration is the infiltration of surface water, mostly from a river system, into a groundwater system induced by water abstraction close to the surface water e.g. a river bank. This water abstraction is commonly done by operating wells. As the water flows through the soil, it is filtered and the quality is improved. In the context of developing or newly-industrialised countries, BF may bring relief by replenishing stressed groundwater resources with surface water, which receives treatment while percolating through the soil and is mixed with the groundwater aquifer.