The Hungarian town of Kolontar near the toxic red sludge reservoir that flooded the area and killed at least seven people was evacuated on Saturday over fears of a new leak of the dangerous heavy metal waste, officials said.
Experts fear the walls of the reservoir may weaken further, disaster management spokesman Tibor Dobson told The Associated Press.
No new waste, however, has escaped from the huge container so far, Dobson said. The evacuation of the town of several hundred people began before dawn.
In addition to the fatalities, more than 120 were injured when the walls of a reservoir at an alumina plant gave way on Monday and up to 700,000 cubic meters of toxic waste flooded several towns in western Hungary. The amount was not much less in a few hours than the 757 million litres, the blown-out BP oil well gushed into the Gulf of Mexico over several months.
But the concentration of toxic heavy metals where Hungary's red sludge spill entered the Danube has dropped to the level allowed in drinking water, authorities said, easing fears that Europe's second longest river would be significantly polluted.
The red sludge devastated creeks and rivers near the spill site and entered the Danube on Thursday, moving downstream toward Croatia, Serbia and Romania. Monitors were taking samples every few hours on Friday to measure damage from the spill but the sheer volume of water in the mighty Danube appeared to be blunting the red sludge's immediate impact.
Test results released by Hungary's disaster agency show the pH level of the water where the slurry entered the Danube was under 9, well below the 13.5 measured earlier in local waterways near the site of the catastrophe.
That is diluted enough to prevent any biological damage, Interior Minister Sandor Pinter said.