Gevolgen van de Europese Kaderrichtlijn Water (KRW) voor de communale waterzuivering in Nederland

The introduction of the European Water Framework Directive (WFD) influences the organisa-tion of the Dutch communal water purification. The research’s main goal was to investigate in which way future demands are aimed and how knowledge concerning this subject is trans-ferred. Therefore a literature study was performed concerning the current situation with regard to this subject and interviews were held at eight different water boards, STOWA and several engineering companies. These interviews focus on the technical developments, the status of the implementation of the Framework, and problems and chances concerning this subject.According to the research the water boards are developing a new strategy concerning surface water quality, in which the wastewater plants (WWP’s) occupy a central position when their contribution to surface water quality is significant.Because of the implementation of the WFD individual WWP’s have to accomplish an effluent quality, which depends on the desired quality of the receiving surface water. Rising costs are therefore very likely. Depending on the situation investments will be made in newer and bet-ter purification techniques. STOWA already researched on a number of possible techniques. A number of water boards use new techniques in their installations, but in general they have less operational experience. It is often unknown what the efficiency of the measures will be.Some conventional WWP’s wimpy fully with the current demands. If demands are getting stricter it is not always necessary to invest in new techniques. Several different water boards are active in the Dutch river basins. They have in depth knowl-edge of water purification techniques. However, commercial parties still have an important contribution in both advisory and engineering. Many of them develop their own new unique system for excessive water purification and there is no standard by which the water boards choose one system or another. Some water boards are using membrane bioreactors, while other have chosen sand filtration or conventional active-sludge installations. The question rises if water boards choose best means or best solutions.Within the timescale required for the implementation of the WFD a plan has to be made by the Ministry of Transport, Public Works and Water Management. Therefore they have to develop so-called river basin management plans, in cooperation with provinces, municipali-ties and water boards. The measures in these plans have to be carried out in 2012. The targets as set in these plans have to be established in 2015. Due to gaps concerning knowledge and the slowness by which the values of the Framework are formulated it is possible that wrong or costly choices are made.