Avoid swimming in the river located in Baden-Württemberg, as it is contaminated with wastewater from sewage treatment facilities.
The Neckar River, a significant waterway in Germany, is home to a diverse ecosystem, but it also faces challenges due to wastewater contamination. The Waterways and Shipping Administration (WSA) tolerates swimming in the Neckar, but with restrictions in many areas, owing to safety concerns and health risks.
The river's water flow, which averages 57.8 cubic meters per second in summer, is influenced significantly by municipal wastewater. Approximately half of this water flow comes from wastewater treatment plants in the catchment area, which clean not only household and industrial wastewater but also stormwater and foreign water.
However, despite wastewater treatment, some residual pollution, including pathogens and medicinal residues, still enters the Neckar. This contamination can lead to the presence of harmful bacteria, viruses, parasites, and fungi, posing potential health risks.
The main health risks associated with wastewater contamination in rivers like the Neckar stem from pathogens, chemical pollutants, and nutrient imbalances. Pathogens, such as bacteria, viruses, and parasites, can cause illnesses like gastroenteritis, E. coli infections, and skin or ear infections upon contact or accidental ingestion.
Chemical pollutants, often found in industrial and residential wastewater, can introduce harmful chemicals, including nitrogen compounds that alter the river's nutrient balance. This imbalance can indirectly affect human health through toxins or algal blooms.
Elevated nitrogen and phosphorus levels from wastewater can also cause eutrophication, promoting harmful algal blooms that produce toxins dangerous to swimmers. Cyanobacteria growth in the Neckar river is a concern due to its potential health risks.
Recent research by Kumar et al. (2023-2024) highlights that human-induced nutrient imbalances, especially in nitrogen forms, heavily affect river water quality and ecological health, which directly impacts recreational water safety.
While no direct studies focus specifically on swimming in the Neckar under current contamination levels, the broader evidence indicates increased health risks from wastewater in rivers due to microbial and chemical contamination leading to infections and toxic exposure.
Swimming in the Neckar River during or after significant wastewater discharges should be approached with caution due to these potential health hazards linked to waterborne pathogens and chemical pollutants. The Neckar river is not safe for swimming in many areas, including 100 meters above and below bridges, near weirs, harbors, locks, or floating devices like cranes.
The Rhine-Neckar district warns that germs in the Neckar river can cause diarrhea, eye, and ear infections. The presence of pollutants and the risk of infections make swimming in the Neckar a risky activity, and it is advisable to avoid it unless the water quality is tested and deemed safe.
[1] Kumar, A., et al. (2023-2024). Human-induced nutrient imbalances in rivers: Impact on water quality, ecological health, and recreational water safety. Environmental Science & Technology.
