Groundwater and surface water contain too much nitrogen and phosphorus in many places. As a result, the Netherlands does not meet the goals of the European Nitrates Directive. Due to excessive nitrogen and phosphorus, the biological water quality is insufficient in many waters in the Netherlands, and the quality of drinking water in some parts of the Netherlands is under pressure. Especially in areas with sandy and loess subsoils, it is important to improve the quality of groundwater. This is evident from the report Agricultural practice and water quality in the Netherlands 2020-2023.
The substances nitrogen and phosphorus cause crops to grow better. When farms use manure, excess nitrogen and phosphorus wash away into groundwater and surface water, polluting it. Nitrate is the most common form of nitrogen in the soil and water. This report describes the development of nitrate concentrations in groundwater and surface water and total concentrations of nitrogen and phosphorus in surface waters.
Groundwater Results
This report illustrates the effects of policy measures (up to 2022) on water quality. Water quality has not structurally improved since 2012. Between 2020-2023, nitrate concentrations in groundwater under agricultural enterprises increased compared to 2016-2019. At more than half of the agricultural enterprises in areas with sandy or loess subsoils, the nitrate concentration is often still too high according to European standards. This is partly due to the dry summers from 2018 to 2020. Crops absorb less nitrogen during drought, leaving more in the soil. Since 2021, nitrate concentrations have been declining, but they are still higher in these areas than before 2018.
Surface Water Results
Due to excessive nitrogen and phosphorus in surface water, the biological water quality is insufficient in many waters in the Netherlands. For example, there are too few different species of plants and animals living there. In 44 percent of the waters in the Netherlands, the biology is not in order, partly as a result of fertilizers. In 11 percent of the waters, there are still enough plants and animals, but the concentrations of nitrogen and phosphorus are too high.
Drinking Water Quality Under Pressure
Clean groundwater and surface water are important for producing drinking water. Therefore, it is essential to improve water quality. Especially on sandy soils, nitrate poses a problem for drinking water sources. Groundwater containing more than 50 milligrams of nitrate per liter is less suitable for drinking water preparation. Currently, problems already exist in about 20 percent of groundwater extractions, or could arise in the near future.
European Nitrates Directive
The goal of the Nitrates Directive is to protect drinking water sources and to prevent pollution of surface water from agricultural sources. The RIVM reports together with RWS Rijkswaterstaat (Rijkswaterstaat), Deltares, CBS Centraal Bureau voor de Statistiek (Centraal Bureau voor de Statistiek), WEcR, and RVO Rijksdienst voor Ondernemend Nederland (Rijksdienst voor Ondernemend Nederland) every four years on the use of fertilizers in agriculture and its effects on the quality of groundwater and surface water. With this report, the Netherlands reports to the European Commission on the progress in improving water quality.