Removal requirement and purification treatment effort for the Dutch Rhine water from 2000-2018

The Water Framework Directive (2000/60/EC) (WFD) is the most comprehensive instrument of European Union water policy. The objective of the WFD is to protect and improve freshwater bodies with the aim of achieving good status in European waters.

WFD Article 7.3 states: “Member States shall ensure the necessary protection for the bodies of water identified with the aim of avoiding deterioration in their quality in order to reduce the level of purification treatment required in the production of drinking water.”

Looking back over the years since the introduction of the WFD, the question arises to what extent the WFD was able to prevent deterioration of water quality and reduce the level of purification treatment required in the production of drinking water.

For this purpose, to evaluate the required level of purification treatment, we developed a simple, easy to understand index that links source water quality data of the Rhine to the Dutch drinking water target values. In addition, our method takes into account that water quality is not static, referring to the new emerging substance which contribute to the purification treatment level.

Our calculations show that the measures taken to achieve the objectives of the WFD have not led to an improvement of the water quality of the Rhine with regard to the purpose of drinking water production. Apparently, additional effort is needed in the field of emission reduction, with a focus on new and emerging substances, in order to reduce the purification treatment level required for the preparation of drinking water.