Quality and mutagenicity of water and sediment of the streams impacted by the former uranium mine area Olší–Drahonín (Czech Republic)

The water quality research performed in the years 2003–2010 demonstrated an impact of the mine water pumped from the closed Olší uranium mine and discharged from the mine water treatment plant (MWTP) and groundwater from springs in the area on the water quality of the Hadůvka stream. The water ecosystems of the lower part of the Hadůvka stream are impacted mainly by water originated from the springs located in the stream valley and drained syenit subsoil, naturally rich in uranium. Those inflows caused a very high concentration of uranium measured in the water of the stream, which exceeds the given limit value. No negative impact on the water ecosystems of the receiving Bobrůvka River was found. This reduction of impact is caused by five times higher average daily flow rate of the Bobrůvka River in comparison with the Hadůvka stream, which results in a sufficient dilution of pollution from the Hadůvka.

► No significant impact of former uranium mining in the Olší mine area on the water ecosystems.
► The water ecosystems impacted mainly by natural sources of uranium.
► The occurrence of mutagenic compounds in the surface water was found using Ames fluctuated test.
► The mutagenicity was repeatedly detected in sediments.
► None of the samples showed cytotoxic effects in tests with S. typhimurium or P. phosphoreum organisms.