Many of Europe’s rivers contain mixtures of chemicals that are harmful to algae and aquatic life. Although the concentrations of some pollutants are monitored in the EU’s water bodies, there are doubts as to whether monitoring focuses on the right substances and what role is played by transformation products and combinations of substances. In the European project SOLUTIONS, a team of researchers led by the UFZ has developed tools, methods and practical solutions for identifying substances that require priority treatment, assessing the risk posed by chemical mixtures, and minimising the pollution burden. At the final conference in Leipzig, project members from 39 institutions in 14 European countries as well as China, Brazil and Australia met to discuss their results with stakeholders and end users from government and public authorities.
The EU project SOLUTIONS was launched in 2013 with the ambitious goal of identifying ways of monitoring and managing the many substances that occur in complex mixtures in our surface waters and that jeopardise both ecosystems and human health. More than 100 scientists have developed and tested new methods and models to enhance the monitoring of water quality. They have identified relevant substances and drafted recommendations to improve the European Water Framework Directive (WFD). They have also conducted large-scale case studies to test the efficacy of the methods, models and tools developed in the project. According to project coordinator Dr. Werner Brack from the Helmholtz Centre for Environmental Research (UFZ), this means that all the key project objectives were achieved.
Improving monitoring, assessment and management
The EU’s Water Framework Directive currently lists 45 pollutants which are referred to as priority substances. To have good water quality, a body of water is only allowed to contain small amounts of these substances. However, there are also more than 100,000 different chemical substances which we use every day and which end up in our environment and our water. So most substances are not included in the assessment of water quality under the current Water Framework Directive.
In 2013, thousands of samples were taken as part of the Joint Danube Survey 3. In the on-board lab below deck, the first in-situ analyses were carried out and samples were processed and preserved. Photo: UFZ / André Künzelmann
“The current monitoring framework is expensive, ignores the majority of substances and fails to address the actual problems. Most of the priority substances were replaced by the market with other chemical substances with very similar effects. Adding new substances to the list is a cumbersome political process.” says Werner Brack. Furthermore, the WFD has so far been limited to the testing of individual substances. However, pollutants do not affect the environment individually but in combination, and as a result may reciprocally intensify one another. “It is not the presence of a polluting substance that is crucial, but its effect in a body of water.” explains Brack.
The SOLUTIONS researchers therefore recommend that the monitoring of water quality should be switched from the chemical analysis of individual substances to effect-based methods such as biological effect tests. This would mean that all substances with the same effect would be recorded, including mixed substances. Expensive chemical analysis would only be necessary where certain effect thresholds were exceeded. For their proposal, the researchers investigated existing biological test techniques and used them as a basis to develop a set of organismic and highly specific cell-based test systems. These tests can detect both acute toxic effects on aquatic organisms and long-term impacts, for example on reproduction. Limit values were also defined to distinguish between problematic and non-problematic levels. As Brack explains, one of the key confirmations that this effect-based approach works, and identifies not just substances but also their sources, came from numerous case studies carried out on European rivers such as the Danube and the Rhine, which formed an important part of the five-year project.
One of the things researchers are interested in is the aquatic biology, which provides indicators of the water quality. Photo: UFZ / André Künzelmann
The SOLUTIONS scientists also developed and refined numerous models that make it possible to estimate the distribution, transport and degradation of substances and their risk, and thus support environmental monitoring. To predict the concentrations of thousands of substances in European river areas, they linked up these models like carriages in a train. “The modelled values correlate astonishingly well with the measurements, which confirmed we were on the right track.” says Brack. “However, this shouldn’t distract us from the fact that there are still plenty of uncertainties.” These include, for example, the lack of data on production quantities and the use of many substances, which meant that in many cases the researchers could only insert estimates into their models. However, they already show that, after nutrients, chemicals are an important factor in the poor ecological status of many of Europe’s rivers. The models can help to separate out substances that in all probability do not pose a problem to our water resources.
Simply measuring and assessing water quality is, however, not enough to improve the status of a body of water – monitoring must be followed up with appropriate measures. “That is why we provide recommendations for a more solution-focused approach to water management in which monitoring, assessment and potential measures should be much more closely linked from the outset than is currently the case.” says Brack. For example, research carried out on the Upper Rhine clearly demonstrated the impact of adding a fourth cleaning level to wastewater treatment plants in Switzerland. A noticeable improvement in water quality was recorded in terms of the concentration of pesticides, pharmaceuticals and cosmetic ingredients as well as of impacts on the ecosystem.
“Even though SOLUTIONS is now complete, there is still a lot of work to do.” says Brack. For the purposes of effect-based monitoring it is important to have specific tools for each mechanism by which pollutants work. “Unfortunately we have not progressed to that stage yet.” he adds. During the project, the team were also able to identify the significance of the chemical and toxicological fingerprints of different pollution sources. However, a specific investigation of this was not part of the SOLUTIONS research programme. “So we have just started a study to record the effluents from wastewater treatment plants and inputs from agriculture. This data can be directly linked to SOLUTIONS. There is also plenty of work to be done on abatement measures, especially in terms of the evidence-based definition of priorities and monitoring of effectiveness.”
Top Picture – The Danube is Europes second largest river and is used intensively by people. It is one of six rivers that formed the focus of the EU project SOLUTIONS. Photo: UFZ / André Künzelmann