After a Greenpeace report on excessive salt discharges into the Oder, one of the accused Polish mining companies rejected the allegations. The company Jastrzebska Spolka Weglowa (JSW) announced on Friday on request that all provisions and regulations of the Water Act were observed. The salinity in the Oder is constantly monitored at Krzyzanowice. JSW is majority state owned.

The company admitted that salty mine water was collected via the so-called "Olza collector" and then fed into the Oder in a controlled manner via nozzles on the river bed. In addition, mine water is also introduced into the Oder tributary Bierawka, among other things. This is done in an environmentally safe manner, it said.

In its report, the environmental organization Greenpeace accused JSW and another coal and mining company of having caused the mass death of fish in the Oder last summer. A team took and analyzed 57 water samples from three tributaries to the Oder and six tributaries to the Vistula, the organization said. After the investigation, she assumes that wastewater from the mining industry was the cause of the fish kill in the border river.

Experts assume that salt discharges were a major reason for the Oder fish die-off, combined with low water, high temperatures and a toxic species of algae. It is estimated that at least 360 tons of fish died on the Polish and German sides in August.

The environmental organization WWF called for "complete transparency of data on industrial discharges" on Friday. There is still a problem with the exchange of information between Poland and Germany. "All the facts about the harmful environmental inputs into the Oder and its tributaries must finally be put on the table," demanded Finn Viehberg, head of WWF Germany's Baltic Sea Office. This is the only way to remedy the causes of the poor water quality.