Interpolation values to judge the water quality of estuarine and coastal waters : method and application to the Dutch Delta

The purpose of this report is to present a method on which water quality references can be developed for the zone between rivers and the sea when the fresh water standards and the future standards for marinewaters differ from one another. To develop the interpolation values and test the method, the following compounds were chosen: copper, cadmium, nitrogen and phosphate, PCBs and PAHs. The interpolation values have been compared with water quality data collected in existing monitoring programs in the Dutch Delta Region