Precious water resources

Water plays a crucial role in our production process and good quality freshwater is becoming increasingly scarce, making it important that we handle it as carefully as possible. In our Path2Zero roadmap, making our water consumption more sustainable is an important part. What we must do to use water sustainably is now also laid down in the water permit, which was granted by Rijkswaterstaat Zee en Delta on June 1, 2023. Our colleagues Niek van Belzen (Senior Environmental Analytical Manager) and Melanie Bos Bouwhuizen (Environmental Improvement Specialist) explain exactly what this new permit entails.

Old permit needed to be renewed
Every company needs permission from the government to be able to produce. This is the so-called License to Operate. The water permit is part of this. The old permit was 20 years old and due for renewal. Melanie explains why: “The old permit mainly consisted of outlines. For example, it included the requirements that the wastewater discharged by the bioorganic waste water purification plant (BIOX) had to meet. But only limited information was given about which components and what quantities may be present in the wastewater. And what the process looks like up to the discharge of the waste water. This is discussed in more detail in the new permit.” Niek adds: “A permit is in principle valid for an indefinite period. But a lot has changed in recent years in the field of legislation and regulations. The list of substances of very high concern (see explanation at the bottom of the page) has been expanded and more clarity has become known about the effect of various substances. None of this was included in the old permit. An extra reason to renew the permit.”

Adjust to new standards
Drawing up a new permit takes a lot of time. This was granted by Rijkswaterstaat Zee en Delta on June 1, 2023. Melanie explains how this went and what the water permit looks like. “We started applying for the water permit in 2015. For example, where previously emphasis was placed on how carbon and nitrogen were removed by the BIOX, more requirements are now being imposed on what the wastewater must meet. This concerns the possible presence of specific contaminants that can influence the water quality in the Western Scheldt. To keep an eye on this, we need to do more research and also examine the internal water flows even more closely.”

Niek explains how this is tackled: “All factories on the Dow Terneuzen site must indicate which substances they work with, what exactly is made and which substances end up in the wastewater. By knowing which substances are used, we can determine in advance whether they pose a potential problem if they are discharged and which analysis techniques we need to use to detect them in the wastewater flows. This gives us the opportunity to proactively advise in advance on the use of alternative substances that may have no or less impact on water quality.” Melanie adds: “The European guidelines are becoming increasingly strict and we are continuing to adopt this in the Netherlands. We must meet these requirements in order to be granted a permit. The RIVM's list of substances of very high concern is updated every six months. We naturally follow this at Dow and adapt our policy accordingly. If a substance is added that was not of high concern before, we will look at it and work on adapting our processes and implementing policy. This may take longer, because not much is known about it yet. But we always approach it with the knowledge and possibilities that are available.”

Analyzing wastewater
The stricter laws and regulations have resulted in many changes in a short period of time and more companies are being asked to obtain a permit. Melanie explains what else is happening. “One of the obligations is that we must map out which components are in the wastewater and where they come from. We do this when introducing substances, when we use them for the first time, but also by analyzing the wastewater.” Niek adds: “A number of years ago we saw these demands coming our way and therefore started investing in new analysis techniques in a timely manner. This allows us to measure lower concentrations and we can also measure the different components more and more specifically. We are looking at micrograms per liter. For comparison: we are looking at a teaspoon of a substance in an Olympic swimming pool full of water. We are now busy further developing these analysis methods. Although you are not there yet with the right analysis methods. We also want to understand how changes in raw materials and changes in processes can impact the components found in wastewater. To achieve this, we must continue the monitoring program for a longer period of time.”

Bioorganic waste water purification plant (BIOX)
Our own bioorganic waste water purification plant (BIOX) plays an important role in purifying wastewater. Niek explains why: “Long ago we started projects on how to reduce the amount of wastewater from the factories, so-called 'reduction at source'. In 1995, the bioorganic waste water purification plant (BIOX) was built to minimize the discharge of residual contaminants. Until now, we mainly looked at general parameters such as carbon and nitrogen and a number of harmful substances for which discharge limits were imposed. Now we see that we have to specifically look for all substances that can enter the water from the processes and then we also have to look at how these are converted and removed in the BIOX. We are working to make the BIOX increasingly effective and are looking for opportunities for improvement.”

Water is vital, but also scarce. So we have to handle it sparingly. When new substances are introduced by factories, the effect on the waste water is already examined and we analyze the water before it is discharged. But we are also looking at how we can use water better in other areas. Niek says: “What we have been working on for years is the reuse of waste water. Once the water has been purified, it is not discharged, but returns to the process. We do this with our own waste water, but also with the waste water from the municipality of Terneuzen.”

Separating water flows
Another project, aimed at our water management, is a research project on the separation of rainwater and wastewater. Niek explains: “At a number of places on our site, rainwater and wastewater are already separated. This means that the rainwater does not become contaminated and can be discharged. Part of the rainwater is still mixed with the wastewater that goes to the BIOX. If we can collect and dispose of this clean water separately, we do not have to treat it as wastewater and we can make it more easily suitable for reuse. In addition, we will also reuse even more of our treated wastewater in the future."

Niek concludes: “As part of the Dow sustainability objectives, we have been working for several decades to reduce our water footprint and our impact on the environment. We now see that the government is also imposing obligations on industry through regulations in the water permit in order to improve the quality of surface water and bring it in line with European standards. We are on the right track, but we will have to continue to work hard to achieve the targets and use the water we use in a sustainable way.”