Race is on to build emergency dam

Workers raced to build an emergency dam in western Hungary yesterday as cracks in a reservoir widened, threatening to unleash a second torrent of toxic sludge on the village of Kolontar and nearby rivers.

About one million cubic metres of the waste material leaked out of the aluminium oxide reservoir into villages and waterways last week, killing seven people, injuring 123 and fouling rivers. Kolontar was evacuated on Saturday after cracks appeared in the northern wall of the reservoir, threatening a second spill of the toxic red sludge.

A by-product of the production of aluminium, the thick, highly alkaline substance has a caustic effect on the skin. The Environment Secretary Zoltan Illes said yesterday that a 25-metre-long crack in the weakened wall had widened slightly and the wall of the damaged reservoir now looked beyond repair. Mr Illes said the northern wall of the reservoir could collapse "within one day or a week" and crews at the scene were scrambling to complete a new dam to protect Kolontar and the nearby town of Devecser.

Mr Illes said authorities had amassed plaster and various types of acids to neutralise the high alkaline content of any new spill before it reaches the Danube, a major European waterway. The Interior Ministry said samples showed alkaline levels in rivers affected by last Monday's spill had now returned to normal.