Eutrophication of fresh water in the Netherlands, 1999
Policy
The government wishes to combat the overfertilisation (eutrophication) of surface water. Numerous measures, such as phosphate removal, are already in place in wastewater treatment plants (UWWTPs). Phosphates have also been banned in laundry detergents.
Maximum acceptable concentrations (MACs) for the nutrients nitrogen (N) and phosphorus (P) have been adopted for "eutrophication-sensitive, stagnant waters", in other words for waters with little or no current. For other waters, these values are "guidelines". These general values, however, do not do justice to the differences between regions and types of water. The Fourth Water Management Policy Document (V&W, 1999) and the Third National Environmental Policy Plan (VROM, 3) therefore allow for a system of differentiated standards. Proposals have recently been made in this respect (Van Liere en Jonkers, 2002).
Relevance
The map shows where limit values for nitrogen or phosphate are exceeded in, for example, eutrophication-sensitive lakes in the Netherlands (waters with little or no current). The exceedance of MACs for nitrogen and phosphorus can result in undesirable effects on ecosystems such as excessive algae growth.
