Dam Breach at Coal Mine Wastewater Pond in Southern Poland

A dam at a wastewater settling pond in an abandoned coal mine in the Silesian Coalfield in southern Poland breached, causing a massive spill of highly acidic mine wastewater containing heavy metals such as iron and manganese. The wastewater flowed through channels into the Przemša River, a tributary of the Vistula River. The pH level of the contaminated river section dropped significantly, resulting in a strongly acidic reaction. Concentrations of heavy metals such as iron and manganese far exceeded environmental standards; the river water took on an abnormal color, the bottom sediment became contaminated, and fish, benthic organisms, and the aquatic ecosystem suffered severe damage.