The Baia Mare spill

On January 30, 2000 there was a break in the dam encircling a tailing pond at a facility operated by the Aurul SA Company in Baia Mare, Romania.

The result was a spill of about 100,000 cubic meters of liquid and suspended waste containing about 50 to 100 tonnes of cyanide, as well as copper and other heavy metals.

The break was probably caused by a combination of design defects in the facilities set up by Aural, unexpected operating conditions and bad weather.

The contaminated spill travelled into the Sasar, Lapus, Somes, Tisza and Danube rivers before reaching the Black Sea about four weeks later. Some 2,000 kilometres of the Danube's water catchment area were affected by the spill.

In Romania the spill caused interruptions to the water supply of 24 municipalities, and costs to sanitation plants and industries because of interruptions in their production processes.

Romania reported that the amount of dead fish was small. Hungary, however, estimated its amount of dead fish at 1,240 tonnes. Yugoslavian authorities reported large amounts of dead fish in the Yugoslavian branch of the Tisza River and no major fish kills in the Danube River.

The assessments made afterwards showed that the concentrations of cyanides and heavy metals decreased rapidly with increasing distance from the spill. Regarding cyanide, acute effects occurred along stretches of the river system down to where the Tisza and Danube meet. Water plankton were completely killed when the cyanide plume passed and fish were killed in the wave or immediately after.