ABSTRACT
This paper presents the results of a seven-year deep-well recharge experiment in the Amsterdam Dune Area along the North Sea coast of the Netherlands. This extended pilot study with four injection wells is a precursor to a possible artificial recharge system comprising seventy wells, with a total capacity of 13 million m3/year. Pre-treated water is used from the 55 km distant river Rhine. Within the dunes, the water flows through a 4 km long open supply channel to the injection site. There, a 300 m long slow sand filter embedded in the bottom of the water supply channel feeds the four injection wells. Since the start of this recharge experiment in June 1994, more than 6.2 million m3 water have been injected, i.e. 6.7 L/s/well. Although the average injection rate is still above the planned recharge capacity of 5.6 L/s per injection well, the total recharge capacity of the system declines gradually over time. Without further conditioning, the average artificial recharge rate will decrease to below the proposed recharge capacity in 2005, after which cleaning will be necessary.
