2000 Baia Mare cyanide spill

The 2000 Baia Mare cyanide spill was a leak of cyanide near Baia Mare, Romania, into the Someş River by the gold mining company Aurul, a joint-venture of the Australian company Esmeralda Exploration and the Romanian government.

The polluted waters eventually reached the Tisza and then the Danube, killing large numbers of fish in Hungary and Yugoslavia. The spill has been called the worst environmental disaster in Europe since the Chernobyl disaster.

Aurul, the mine operator, is a joint venture company formed by the Australian company Esmeralda Exploration and the Romanian government. The company claimed it had the ability to clean up a by-product of gold mining, the toxic tailings, which began to be spread as toxic dust by the wind. Promising to deal with them and to extract remaining gold from them via gold cyanidation, the company shipped its waste product to a dam near Bozinta Mare, Maramureş County.

On the night of January 30, 2000, a dam holding contaminated waters burst and 100,000 cubic metres (3,500,000 cu ft) of cyanide-contaminated water (containing an estimated 100 tonnes of cyanide) spilled over some farmland and then into the Someș river.

Esmeralda Exploration blamed excessive snowfall for the dam failure.

After the spill, the Someș had cyanide concentrations of over 700 times the permitted levels. The Someș flows into the Tisza, Hungary's second largest river, which then flows into the Danube. The spill contaminated the drinking supplies of over 2.5 million Hungarians. In addition to cyanide, heavy metals were also washed into the river and had a long-lasting negative impact on the environment.

Wildlife was particularly affected on the Tisza: on a stretch, virtually all living things were killed, and further south, in the Serbian section, 80% of the aquatic life was killed. 200 tons of it was the fish in these rivers.

Large quantities of fish died due to the toxicity of cyanide in the waters of the rivers, affecting 62 species of fish, of which 20 are protected species. The Romanian government claimed that the fish had died of cold, and they were not at fault. In Hungary, volunteers participated in removing the dead fish to prevent the disaster from spreading across the food chain, as other animals, such as foxes, otters and ospreys have died after eating contaminated fish.

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Wikipedia