Medicines in rivers and lakes

Pollutant cocktail of medicines, pesticides and other chemicals pollutes the waters

21/09/2012

Residues of medicines and pesticides are increasingly polluting the lakes and rivers. The Baden-Württemberg Ministry of the Environment has for the first time submitted a report on the enrichment of so-called trace substances in the waters of the country.

The report captures the concentration of substances, „which we do not want to have even in the smallest amounts in our rivers and lakes as well as in our groundwater“, explained the Minister of Environment Baden-Württemberg, Franz Untersteller (Alliance 90 / The Greens). In that „Trace substance report Baden-Württemberg 2012“ Among other things, it describes the pollution of rivers and lakes with residues of medicines, pesticides and chemicals. The report is one „important situation analysis and good basis for one of the most important permanent tasks of the country: the permanent improvement of the quality of our waters“, said the Minister of the Environment.

Trace substances in waters of unknown environmental impact
The trace substances are usually detectable only in very low concentrations in the range of micro or nanograms per liter and registered by human activities, reports the State Environment Ministry of Baden-Württemberg. What effect they have on the human organism or the creatures in rivers and lakes, is so far unknown in many of the substances. They come, for example, from drugs, X-ray contrast agents, personal care products or cleaning products. „Take medicines that are unfortunately disposed of in many households via the toilet flush. These we find later as trace substances in the water again“, explains Franz Untersteller and added: „Old medicines belong in the residual waste - a simple, but effective way of water purification.“

Pilot project for trace substance concentration in the Schussen
According to the Ministry of the Environment, the trace substance report forms the basis for further water purification activities in Baden-Württemberg. In addition, Baden-Württemberg supports the project „Shot AktivPlus“, in which the occurrence of the trace substances and the entry paths are analyzed in the 62-kilometer inflow of Lake Constance. The investigations in the field of firing are part of a pilot project within the framework of the Federal Priority Program „Risk management of new pollutants and pathogens in the water cycle“. Under the leadership of biology professor Rita Triebskorn, from the University of Tübingen, a 50-member research team has been working on the trace substances in Schussen, one of the most heavily polluted rivers in the Lake Constance, since the beginning of the year. The sewage from several communities ends up in the river. Although the wastewater is purified by sewage treatment plants, some trace substances remain unaffected.

Cocktail of 150 pollutants in the river
The scientists discovered in the river a mix of about 150 trace substances, which apparently also affects the living creatures in the river unfolds. Thus, according to the study leader in the Schussen increased trout with crippled ovaries and testicles. Compared to the animals in the much cleaner neighboring river, the Argen, the proportion is increased by 30 to 40 percent. Although the fish are apparently still able to reproduce sufficiently, but the development is in the opinion of the expert extremely questionable. Especially as the Schussen as well „Early warning system for Lake Constance“ to evaluate. Regarding the origin of the pollutants, Prof. Rita Triebskorn explained that on the one hand, these are residues of pesticides and fertilizers, which enter the river in rainfall. On the other hand, according to the expert, increased loads are mainly caused by wastewater.

Water pollution from residues of medicines
The pollution of waste water with pharmaceuticals is a growing problem. Because the people „are getting older and take more medication“, explained the study director. The substances contained then often end up chemically almost unchanged in the wastewater. While reprocessing in the sewage treatment plant, while nitrogen and phosphorus compounds can be reliably filtered out of the water, other compounds can often not be eliminated in conventional plants. According to Prof. Triebskorn, residues of the medicinal products are still detectable in the water samples from the shots below the sewage treatment plants. The concentration after the inflow from the sewage treatment plants is often even higher, because the trace pollutants only get into the river through the insufficiently cleaned sewage.

Modernization of wastewater treatment plant is promoted
The state government of Baden-Württemberg has also recognized the need for action in sewage treatment plants and is therefore supporting it „including municipalities that want to upgrade their wastewater treatment plants with an activated carbon filtration system, the so-called fourth purification stage“, declared the country's environment minister. This would be preferred plants promoted, which are located on surface waters that are used for drinking water supply, such as Lake Constance. So also at the Schussen the sewage treatment plant Langwiese near Ravensburg is to be modernized for about nine million euros. The installation of a further clarification stage with activated carbon filters is expected to be completed in May 2013. Thereafter, the concentration of individual pollutants will be reduced by up to 90 percent, explained Ralph-Michael Jung, Technical Director of the Abwasser-Zweckverband Langwiese.

Drinking water supply over the Bodensee not impaired?
So far, the trace gas concentration in the bowl is indeed questionable and even in the mouth area of ​​the river in Lake Constance can be detected even higher levels of pollution, but the drinking water supply from Lake Constance is not at risk, reported the Zweckverband Bodensee-Wasserversorgung. In the middle of the sea, therefore, due to the mixing with the water from the clean alpine tributaries no increased pollution could be detected. „According to the current state of science, a risk to human health can be ruled out“, explained the Zweckverband Bodensee-Wasserversorgung in a recent communication. However, development must continue to be closely monitored, as around four million inhabitants of Baden-Wuerttemberg receive their drinking water from Lake Constance. Here it remains to be seen whether an improvement can be achieved by installing the activated carbon filter in the sewage treatment plant. (Fp)

Picture: Photo: NABU / Helge May