Riverbank filtration in highly turbid rivers

Riverbank filtration (RBF) is a surface water filtration method for drinking water through the banks and bed of a river, using extraction wells located near the water body in order to ensure direct aquifer recharge. As the surface water travels through the sediments, contaminants, such as suspended and colloidal solids and pathogenic microorganisms, are removed. Apart from water quality improvement, RBF has the advantage of reducing peak concentrations which commonly pass through a river. RBF has been widely used in Europe, USA and, nowadays, in some Asian countries (e.g., South Korea, India, China). Latin-American and specifically Colombian river basins, have been suffering a continuous deterioration, leading to high suspended sediment loads being transported by the rivers. The RBF technology has not been proven yet in highly turbid waters, in which the excessive transport of suspended sediments threatens sustainable operation. Clogging of both the riverbed and deeper aquifer may increase flow resistance, reducing water revenues over the course of time. To assess the feasibility of RBF for highly turbid river waters in Colombia, a combination of field and laboratory research was conducted – both in the Netherlands and Colombia. In Colombia, the studies were done at the Cinara institute's Research and Technology Transfer (R&TT) Station for drinking water and at the Fluid Mechanics lab. The station is located at the Northeast of Cali, Colombia, and was built at the premises of the main water treatment plant of Cali, Puerto Mallarino. In the Netherlands, the laboratory work was done at the Delft University of Technology, running infiltration column experiments at the Sanitary Engineering lab and the flume experiments at the Fluid Mechanics lab..