Until further notice, swimming is not recommended at the Bilja dam.

Workers from the National Water Management Office (NLZOH) in Nova Gorica collected water samples from the Vipava River on Tuesday, July 14, 2026, at predetermined locations to conduct microbiological and chemical analysis aimed at determining the river’s suitability for swimming in the area of the municipality of Miren-Kostanjevica. The results showed that microbial analysis revealed a exceedance of the limit value for the bacterium Escherichia coli (E. coli) at the location of the dam in Bilje. At other sampling points, Šelo, Mlin, and Grabec, the samples were well below the limit and the river was deemed suitable for swimming. As a result, swimming has been temporarily suspended at the Bilje dam site until further notice. The presence of E. coli serves as a primary indicator of the presence of harmful gastrointestinal pathogens and viruses in water. Strict regulations apply to both artificial and natural swimming waters. Contact with such water poses a risk of illness, including gastroenteritis, stomach cramps, heat-related illnesses, or inflammation, according to the National Institute of Public Health (NIJZ). Escherichia coli, commonly known as E. coli, is a type of bacteria that naturally resides in the intestines of humans and warm-blooded animals. Most strains of this bacteria are harmless and even beneficial, aiding in digestion and vitamin K production. However, certain pathogenic strains can cause severe intestinal infections if ingested through contaminated water or food. E. coli is used as a fecal indicator in water quality testing because it originates exclusively from human and animal waste. Its presence in rivers or lakes reliably indicates contamination by feces, which suggests that other more dangerous pathogens, such as Salmonella, Shigella, or various viruses transmitted via the fecal-oral route, might also be present in the water. The decision to suspend swimming at the Bilje dam follows routine monitoring procedures conducted by the NLZOH. These tests are part of regular efforts to ensure public health and safety in recreational water bodies. The affected area will remain closed to swimmers until additional analyses confirm that the bacterial levels have returned to acceptable limits. Local authorities have advised residents and visitors to avoid contact with the water in the Bilje dam area until further notice. They emphasized that while the rest of the river remains safe for swimming, the specific location near the dam requires caution due to the elevated E. coli levels detected. This precautionary measure aligns with standard protocols for managing waterborne health risks. Environmental agencies continue to monitor the situation closely. Additional samples will be taken and analyzed to determine whether the conditions have improved. If the bacterial levels remain above the permissible threshold, the closure could be extended. In the meantime, local officials are urging the public to stay informed and follow official guidelines regarding water safety.