'Natural' recharge of groundwater: bank infiltration in the Netherlands

In the Netherlands 5% of the drinking water is produced from bank infiltrated surface water. The catchment with this recharge method amounted in 1999 to 62.4 million m(3) This is performed by. 17 catchment areas. The median travel time during the aquifer passage varies between 3.8 and 250 years. The contribution of surface water in the abstracted bank infiltrated water varies between 20 and 100%, and the quality of the abstracted water is strongly influenced by this aquifer passage. Nowadays, three important challenges for the production of drinking water from bank infiltrated surface water are (polar) organic micropollutants, hardness and chloride. in the Netherlands 13 treatment plants have been installed. Since 1985 several additional treatment steps have been implemented to cope with this challenges. Treatment with anaerobic nanofiltration is very promising to cover all three challenges.