Vienna, 28-11-2024) A current research project by the Inter-University Cooperation Centre Water and Health of MedUni Vienna, TU Vienna and Karl Landsteiner University Krems is the first in the world to provide precise evidence of small-scale wastewater and faecal discharges into watercourses caused by inland waterway vessels. A new integrative method was developed for this purpose. The first practical application on a 230-kilometre stretch of the Danube demonstrated the high input potential of inland navigation in the event of improper wastewater disposal, but also indicated that proper disposal took place during the period under investigation. The methodology, which has received much attention from experts, has now been published internationally with all its details. This allows it to be used in other navigable waters around the world.
In recent years, highly emotional accusations have repeatedly emerged that river cruise, liner and cargo ships could lead to localised and heavy faecal discharge into the Danube. A team led by Andreas Farnleitner (KL Krems and TU Vienna) and Alexander Kirschner (MedUni Vienna) therefore set about scientifically calculating the potential input from this source for the first time and at the same time developing a method to determine the true extent precisely and with high spatial resolution. As a result, a globally unique method for estimating and recording wastewater discharges from inland navigation has now been presented. This has already been applied in practice to a 230 kilometre section of the river, covering both the Wachau and Vienna.
Three-stage process
The ICC Water & Health, led by Regina Sommer and Andreas Farnleitner and consisting of research groups from TU Wien, MedUni Vienna and Karl Landsteiner Private University Krems, brings together the scientific expertise in health-related water quality analysis in Austria. In this study, ICC Water & Heath worked closely with the Water Management Department of the Lower Austrian Provincial Government. ‘Our newly developed method,’ explains Alexander Kirschner (Institute of Hygiene and Applied Immunology at MedUni Vienna), ’is based on a three-stage process that integrates theoretical predictions of pollution potential, precise field detection methods and complex statistical calculations.’
In a first step, the method involves calculating the possible inputs of faecal indicator bacteria (E. coli) within a specific river section (known as ‘pollution source profiling’). The theoretically possible inputs from municipal sewage treatment plants and from inland navigation are calculated separately. These calculations are based on known orders of magnitude for the number of relevant faecal indicator bacteria that people excrete per day (determined from population, tourist, passenger and crew figures). Data on the treatment performance of existing plants is also included in the calculations. ‘Then,’ says Farnleitner, ’we calculated two scenarios. One in which we assume proper wastewater management on board the inland vessels - i.e. proper disposal or reduction of microbiological faecal contamination - and a second in which we assume the opposite. This means, for example, that the wastewater on cruise ships is not treated and therefore the input is maximised.’
Satellite data is also included
The second step of the new method involves extensive field measurements to record the actual contamination with faecal indicator bacteria. The team used both the traditional standardised cultivation method and state-of-the-art molecular genetic methods, which Farnleitner's team has played a key role in developing in recent years. In addition, numerous chemical and physical values of the respective water samples were determined. A complex statistical analysis then forms the final step of the new method. This analysis incorporates satellite data (Automated Identification System, AIS) on ship movements in the analysed river section.
Publikationen:
Water Research
Assessing the impact of inland navigation on the faecal pollution status of large rivers: A novel integrated field approach. S. D. Steinbacher, A. Ameen, K. Demeter, D. Lun, J. Derx, G. Lindner, R. Sommer. R. B. Linke, C. Kolm, K. Zuser, M. Heckel, A. Perschl, G. Blöschl, A. P. Blaschke, A. K. T. Kirschner, A. H. Farnleitner, Water Research 261 (2024).
https://www.sciencedirect.com/science/article/pii/S0043135424009291
Environmental Science and Pollution Research
Long‑term impact of basin‑wide wastewater management on faecal pollution levels along the entire Danube River. A. K. T. Kirschner, I. Schachner‑Groehs, G. Kavka, E. Hoedl, A. Kovacs, A. H. Farnleitner. Environmental Science and Pollution Research (2024) 31:45697–45710.
https://link.springer.com/article/10.1007/s11356-024-34190-0