Study into the consequences of fertiliser on drinking water extraction

The fertiliser problem for the drinking water companies in the south and east of the Netherlands is always a topical issue, despite a considerable reduction in the use of nitrogen in the agricultural sector since the 1990s. This is the conclusion of a study that was conducted by KWR and RIVM on behalf of Vewin.

The study concerns the effects of fertiliser on the quality of the groundwater that is extracted by drinking water companies. The study provides an up-to-date overview of the nature and the extent of the problems that drinking water companies face due to the use of fertilisers. For example, the drinking water companies in the Eastern and Southern Netherlands are still faced with levels of nitrate, hardness, sulphate and nickel that exceed the limits. The fertiliser problem therefore requires continuous efforts and resources in order to manage the problems.

Evaluation of the Fertilisers Act

The Ministry of Economic Affairs is currently conducting an evaluation of the Fertilisers Act. The negotiations about the Sixth Nitrates Directive Action Programme between the Cabinet and the European Commission will be conducted on the basis of this evaluation. Drinking water companies are experiencing the consequences of the use of fertilisers. According to Vewin, it is therefore important for the Sixth Action Programme that measures take into account meeting the targets of the Water Framework Directive and specifically those for sources of drinking water. Potential measures are a tightening of the nitrogen standards in recharge areas and targeted enforcement. Continuation or expansion of the existing nitrate-reduction measures in recharge areas of vulnerable extractions is necessary. This can be achieved, for example, by using national policy to scale up collaboration projects between drinking water companies and farmers which have already proven successful in the past. This also concerns measures to ensure healthy soil.

Delta Approach to Water Quality and Fresh Water

Clean sources, both groundwater and surface water, are vital for drinking water companies. The impact of fertilisers on groundwater quality is immense. Good drinking water quality is essential for a reliable supply of drinking water. Dozens of drinking water extraction sites exceed the permitted levels for nitrate and the same applies to other related values such as those for hardness, sulphate and nickel. This leads to undesirable situations whereby drinking water companies have to undertake extra purification or even have to shut down or relocate extraction sites. The excessive use of fertilisers is still a topical issue and is a major problem for the drinking water companies. On the basis of a motion in the Lower House of Parliament, Minister Schultz van Haegen from the Ministry of Infrastructure and the Environment (IenM) has launched the Delta Approach to Water Quality and Fresh Water in order to analyse additional measures required to improve the water quality and to be able to achieve the KRW targets. All public and private stakeholders are involved in this, including the Ministry of Economic Affairs. Fertiliser has been mentioned in this as one of the priorities. The fertiliser policy for the period 2018-2021, the period of the Sixth Nitrates Directive Action Programme, must establish a link with the statements made in the Delta Approach to Water Quality and Fresh Water.