We are confronted more and more with increasing drought damage in agriculture and nature. There is growing pressure on our supply of water for high-quality uses, such as drinking water production. The year 2018 offered a good example in this regard. To manage these risks, strategies are being developed, including within the Delta Programme Freshwater Plan, to safeguard the long-term provision of freshwater.
One of the pillars of these strategies involves increasing the role of regional freshwater self-provision in meeting demand, so that the available water sources can be used more efficiently. Work is being done through the European Commission on a directive concerning the regulation of water reuse, with the aim of further stimulating the reuse of residual water in agriculture. Treated residual water is therefore increasingly being seen internationally as an alternative source of freshwater.
Similarly, in a variety of applications and pilots in the Netherlands and Flanders, the reuse of industrial and municipal effluent is taking place (at a local scale), consciously and unconsciously. For example, the use of residual water in industry and agriculture can enhance the availability of freshwater for other sectors, such as nature and drinking water production. However, the spread of effluent, and of the pathogens and anthropogenic substances it might contain, remains an important issue of concern.
It is therefore important to anticipate these developments in a timely manner by (1) developing a clear overview of current developments and future scenarios regarding the reuse of residual water, (2) examining the water streams and sectors in the water system as a whole, and (3) identifying the opportunities, risks and knowledge gaps.
Integrated aspects of water reuse
The reuse of residual water for freshwater provision purposes is a subject that requires the involvement of experts from many different fields, so that the opportunities, risks and future projections can be examined from the various required perspectives (Figure 1). This should involve thinking about the technical aspects, such as water storage and treatment, but also giving consideration to the chemical and microbial risks, the social and economic aspects, and regulation. These different expertises are being brought together in this project to quantify the opportunities and risks of the increased reuse of effluent, using projections of different realistic developments in both policy and technology.
Water reuse in the water system
There are many forms of water reuse in different places in the water system, including agriculture, industry and the urban environment. See, for example, the initiatives at Bavaria, Haaksbergen, Suiker Unie, and CoreWater.
By considering the water system as a whole, one can identify the existing potential opportunities and risks, and how water reuse can contribute to the development of a robust water system in the Netherlands and Flanders.
This project is identifying and exploring current developments and future scenarios – in the EU, and in the Netherlands and Flanders – regarding the further use of treated industrial and municipal residual water as a freshwater source. The effects of water reuse – in terms of opportunities and risks, today and over the coming decades – on the freshwater system are being systematically quantified via an integrated framework.