Alternative freshwater sources within the saline coastal areas
Dow Terneuzen uses about 60,000 m³ of freshwater per day. As much as 75% of this is already obtained through the use and reuse of local water streams (see project Biox; waste water purification and reuse). Our goal is to no longer need the primary source for drinking water by 2025 by using local water streams only. To this end, Dow is collaborating in several research projects.
The purpose of the Interreg2Zeeën-program is to support and develop the 2 Seas region, where natural resources are protected. In this case, the FRESH4Cs-project focuses on the resource of freshwater.
In recent years, long droughts in summer are becoming more common. Despite the fact that we have a good water system, it could happen that we have water shortages in the future. These problems are cropping up more frequently not only at Dow, but also at surrounding farmers and other large water users. This while excess water that falls in winter drains into the sea. Summers are expected to become drier and winters wetter, so finding a solution for this will become even more important in the future. To find that solution, we have joined forces with farmers from the border areas.
Fresh water supply in these areas can be considered a seasonal issue. The main objective of the FRESH4Cs project is to develop a sustainable year-round freshwater supply. This should provide solutions for the various water users in coastal lowlands and provide an alternative to using overburdened deeper aquifers or long-distance water supply by pipelines.
This is how Fresh4Cs works
The solution may be found underground. There are fresh water bubbles in old creek ridges (this is a higher-lying zone in a former tidal area), where some farmers get their water. Niels Groot, Water Specialist at Dow: “Potentially, those bubbles can be supplemented with excess fresh surface water. In this way we ensure that it doesn't drain off to sea but stays nearby for drier times. We are looking for subsoils with those fresh water bubbles, which are suitable for expanding and the farmers are looking for ways and facilities to do this. With this we spread the risk and share the outcome if it turns out to be successful. If it succeeds, it creates a win-win situation.”
The project sets up five pilot sites in the Netherlands, Belgium and Great Britain to install and test alternative methods of fresh water supply. The various methods include controlled charge, storage, and redistribution of the aquifer. The pilot sites will benefit local water stakeholders. These include water managers (public or private), water companies and water users such as farmers, tourism, industry and drinking water production.
Carmen Huth, Projectleader FRESH4Cs at Dow: At Dow, there is interest within the current project in exploring underground fresh water storage options within the Braakman South region (cross-border Netherlands/Belgium). Excess rainfall in the winter months can be captured and temporarily stored for use by agriculture and industry during periods of shortage.”
The pilot started at the beginning of 2022. This in collaboration with several local partners like Evides, supplying water from their basins, a local farmer and HZ University of Applied Sciences. Niels: “Since last summer we installed a demonstration site at one of those farmers' premises. In the winter we are going to infiltrate water into the subsoil, in other words, we are going to let the freshwater bubble that is already there grow. Will there be a dry period in April, May or June, for example? Then we can draw water from it.” This demonstration will have to show if and how it works, so that it can later be deployed on a larger scale. “There are several farmers in the region interested to participate in this concept. In the future, there is potential to enter into a form of cooperation with at least ten to twelve farmers from the border region. The demonstration project ends in 2022, after that we can evaluate and see how to continue.” In parallel to the pilot a full scale feasibility study is executed, addressing both technical and socio-economic aspects.
On March 30th 2022 we organized a successful workshop, which will be followed by a farmer field day later in the year. Finally there will be a last workshop to present the demo results and preview into full scale implementation. The project team aims to inspire stakeholders in the region to participate and/or support this project. The FRESH4Cs-project will end by March 2023.