Since mid-February 2022, contaminated mine water has been flowing from the Nižná Slaná mine into the Slaná River, the largest river in eastern Slovakia. The mine water spilled from the former iron ore mine and has turned the river into a rusty color. Laboratory results of water samples taken by the authorities in February, show that the contamination has resulted in iron levels more than a thousand times higher than permitted. Arsenic, zinc, sulfur and manganese levels in the river are also above the limit. The level of toxic arsenic in the river is 187 times the limit value in Slovakia and 2 600 times the normal content in the river.
Although official investigations confirmed the disappearance of wildlife on a 20-kilometre stretch of the Slaná River, until July the Environment and Economy ministries have only pointed fingers at each other over responsibility, and Greenpeace Slovakia has only been active in indicating that they are following Greenpeace Hungary's work on the spill. Apart from that, no action has been taken on their side.
The 2.5 tonnes of pollution entering the Slaná River every day has already upset the ecological balance of the river. A study to assess the damage caused by the pollution has measured a 99% fish mortality rate in the 10 kilometers following the source of the pollution. It found 90-95% mortality in the following 10 kilometers and poor health of fish stocks in the 10 kilometers after that. Despite the official results, until 20th of July, the Slovak state has not officially declared any water pollution
In 2014, the Slovak government approved a national program to be implemented by 2020. The program reported 308 closed mines, of which 25 sites were classified as hazardous and 52 as potentially hazardous. The most dangerous mines were identified as Slovinky, Banská Štiavnica, Staré Hory - Špania Dolina, Liptovská Dúbrava, Rožňava and Nižná Slaná. In Nižná Slaná, apart from measuring the level of contamination, no solution has been found for the tailing pond. Who knows how long it will take to repair the ecological disaster caused by the inappropriate closure of the mine.
The Nižná Slaná mine and ore processing plant were operated by the state-owned company Železorudné bane during the communist era. From 1996, the company was privately owned by Siderit a.s., which went bankrupt and closed in 2008. After the closure of Siderit, ownership of the mine reverted to the state under the local mining law. The state-owned company Rudné Bane was therefore responsible for ensuring the reclamation of the closed mine. After the power supply was cut off in 2011, the pumps on the second level of the 13-level mine, which were used to drain the water, stopped working. Everyone knew the mine would fill up with water. Water levels were supposed to be checked every three months by the state-owned company.
River pollution is not the only problem with the Nižná Slaná mine. On the hillside next to the mine is the 20.6 hectares of land where waste containing heavy metals and arsenic was dumped after the extraction of iron ore. The tailing pond was covered with water while the mine was working, but now the dried-up, fine-grained, sandy waste is picked up by the slightest wind. Everything in the area is covered in fine dust, and in strong winds and storms, the slag covers the villages in the area.
”The Slana River problem is just a consequence of the real problem, namely arsenopyrite weathering in flooded mines. The disused mine was carelessly filled in some parts with rocks containing arsenopyrite and then flooded. Then it took 11 years (until now) for the consequences of this naturally occurring but highly dangerous bioleaching to become visible for the first time: namely in the form of the contamination of the Slaná River. Further problems, which we are all still unaware of, can follow from the flooded mine in the next years- as long as this actual problem is not eliminated as quickly and permanently as possible.”- says Ing. Darina Štyriakova.
Ján Korpa, a kean angler and one of the main activists in the fight for Slaná, is fly-fishing on the still clear stretch of the river. He is one of the people living along the Slaná River whose drinking water quality is affected by the river's pollution. In 80 percent of the wells tested near the polluted river, iron levels exceeded the limit, and manganese levels are worryingly high in some places.
The Sajó Band (Sajó means Slaná in Hungarian) sings the Hungarian folk song "Zavaros a Sajó vize" (The waters of the Slaná River are troubled) in protest against the Slovak government's inaction for months.
According to Ing. Jan Vieloha, who worked as a section manager at the mine for 30 years and was mayor of Nižná Slaná for 12 years, everyone knew the mine would fill up with water. In his opinion, the tailing pond is also extremely dangerous, as the bottom of the terraces has not been concreted out. If water were to accumulate at the top, the high pressure would tear the sides of the tailing pond.
The Mayor of Nižná Slaná, Tibor Jerga enters the mayor’s office. He and his colleagues have proposed several solutions to the problems of river pollution and dust from the reservoir. They feel that they are "in over their heads" when it comes to river issues and are constantly running into obstacles. Tibor Jerga would like President Zuzana Čaputová to come to the village to inspect the mine pollution. During his visit, Minister of Environment Ján Budaj promised an effective solution to be implemented in a short time, however, no significant progress has been recorded yet.
Ica Prónaiová is sitting on the balcony of her apartment in Nižnoslanská Baňa. She has been working with the iron ore, extracting slag from the five-meter wide blast furnace of the iron ore plant for 30 years. She lost her hearing and sight, she says, because of her job. Her husband, who used to work in the mine, has lung disease and her son's joints were damaged from working there.
Allotments next to residential buildings in Nižnoslanská Baňa. According to the 2020 study on soil and ambient air pollution in the Nižná Slaná mine area, the mine area, which includes residential and agricultural areas, is classified as a very high risk from a health and environmental point of view.
According to Dr. Ing. Darina Štyriakova what actually should happen to ensure and restore the health and living environment of all people living along the Slaná River in the long term is solving the real source of contamination. One option would be the backfilling of the flooded mine, using a final process in which the bioleaching taking place there is reversed at the same time. Then the dissolved pollutants (arsenic, iron, manganese, sulfur in particular) would crystallize again, and not be leached out again. Following on from this, all threats from this source of damage will disappear. Already polluted river sediment could be cleaned up by biological leaching to restore life to the river.
"…On the basis of the increased content of potentially toxic elements, which penetrate into soils, groundwater, the food chain and subsequently into human tissues, a correlation with the occurrence of the most serious chronic and carcinogenic diseases has been verified, especially in the historical mining areas of Slovakia,…"
Programme for the Prevention and Management of Risks Arising from Abandoned and Closed Mining Waste Disposal Sites (2014 - 2020) Ministry of the Environment of the Slovak Republic
Dr. Tibor Varga is trying to raise public awareness of the toxic levels of arsenic in the riverbed, which could in the future increase the number of cancer cases; naturally- occuring abortions and defectively-born children.