This overview provides the background information for the Netherlands Member State report, 'Nitrate Directive, status and trends of aquatic environment and agricultural practice' to be submitted to the European Commission mid-2004. It documents current agricultural practice, and groundwater and surface-water quality, in the Netherlands, outlines the trends in these waters (especially the 1992-2002 period) and assesses the time scale for change in water quality as a consequence of changes in farm practice.
The report deals with the evaluation of the implementation and impact of the measures in the Action Programmes on water body quality. The Netherlands has, since 1987, reversed the increase of nitrogen and phosphorus surpluses in Dutch agriculture to a decrease. After the implementation of a mineral accounting system (MINAS) in 1998, the nitrogen surplus, which had been stable for about seven years, decreased again. In the reporting period (1992-2002) water quality, both with respect to nitrate concentration and eutrophication, improved due to measures taken since 1987. Nitrate concentrations in deep groundwater (> 30 m depth) still increase as a consequence of increasing nitrogen loads in the period before 1987. Water quality is expected to continue to improve in the next reporting period (2003-2006) as a result of measures taken during the second Action Programme (1999-2003). With respect to nitrate concentration in deep groundwater, reversal of the increasing trend is estimated to take several decades.