Attenuation of groundwater pollution by bank filtration

Bank filtration, either natural or induced through the river bed by pumping from a system of connected lateral or vertical wells, provides a means of obtaining public water supplies. The success of such schemes is dependent on the microbial activity and chemical transformations that are commonly enhanced in the colmation layer within the river bed compared to those that take place in surface or ground waters. The actual biogeochemical interactions that sustain the quality of the pumped bank filtrate depend on numerous factors including aquifer mineralogy, shape of the aquifer, oxygen and nitrate concentrations in the surface water, types of organic matter in the surface and ground water environments, and land use in the local catchment area. This paper provides an introduction to a series of nine papers contained in this Special Issue that highlight these factors and finishes with a list of recommendations for co-ordinated research into attenuation of groundwater pollution by bank filtration.