On January 30th, 2000 a dam of a tailing lagoon at a gold mine near Baia Mare, north-western Romania broke and washed 100.000 m3 stored waste water down the Szamos (Somesul) river. The waste water, highly contaminated with cyanides and heavy metals, arrived at the Hungarian border on February 2nd. The concentration of the cyanide at the border was 32 mg/l, and decreased very slowly while moving down the rivers. Practically all aquatic life has been killed in the Szamos River and in the upper Tisza River. The long-term effects on the ecological system can not be estimated so far, but experts fear that it will take years until the rivers will be back to the pre-disaster stage, and some of the effects may be non-reversible.
The plume moved down the Tisza and is now at the city of Szolnok, which relies exclusively on the river for its drinking water supply. Until now, more than 300 km of the river has been affected in Hungary. According to Hungarian scientists, the concentration of cyanide will not be higher than 0.1 mg/l (which is exactly the health limit) when the Tisza river enters Yugoslavia.
On February 7th Romanian authorities alerted the Hungarian public by reporting a second spill of cyanide. It happened in a location not very far from the first one. Fortunately, it was much less serious than the previous event, although in some places the concentration still exceeded the health limit 60 times.
According to the first news received from Romania, the company causing the first disaster was fined for an equivalent of 166 USD. Between Romania and Hungary there is a bilateral agreement on trans-boundary water courses, but it is not specific enough on liability. More concrete provisions and enforcement of the international treaties are needed to avoid similar environmental disasters.