Danube blues as factory sludge seeps on

• Locals and rescue workers walk on a temporary bridge in Kolontar. Pic AFP/Getty

The European Union and environmental officials fear an environmental catastrophe affecting half a dozen nations if the red sludge, a waste product of making aluminium, contaminates the Danube, Europe's second-longest river.

Officials from Croatia, Serbia and Romania were taking river samples every few hours but hoping the Danube's huge volume would blunt the impact.

The Hungarian reservoir break on Monday disgorged a toxic torrent through three villages and streams that flow into waterways connected to the river.

The red sludge reached the western branch of the river early yesterday and its broad, main stretch by noon, Hungarian rescue agency spokesman Tibor Dobson said.

He said the spill had at first been highly alkali, with a pH of 13, but that had since dropped to below ten, with no dead fish being spotted in the main river.

A neutral pH level for water is seven, with normal readings ranging from 6.5 to 8.5. Each pH number is ten times the previous level, so a pH of 13 is 1,000 times more alkaline than a pH of ten.

The Hungarian Academy of Science said sludge samples taken two days ago showed that the muck's heavy metal concentrations do "not come close" to levels considered dangerous to the environment. But the academy said it still considered the sludge dangerous - apparently due to its caustic characteristics.

The sludge has devastated local waterways.

"Life in the Marcal river has been extinguished," Mr Dobson said, referring to the river's 25-mile stretch that carried the red waste from Kolontar into the Raba river and to the Danube.

He said emergency crews were pouring plaster and acetic acid - vinegar - into the Raba-Danube meeting point to lower the slurry's pH value.

"The main effort is now being concentrated on the Raba and the Danube," he said.

South of Hungary, the 1,775-mile long Danube flows through Croatia, Serbia, Romania, Bulgaria, Ukraine and Moldova before emptying into the Black Sea.

At the Croatian village of Batina, the first site after the Danube leaves Hungary, experts were taking water samples daily for the next week. In Romania, water levels were reported safe, with testing being carried out every three hours.

Hungarian Prime Minister Viktor Orban, stopping at dawn in Kolontar, described the reservoir break as an unprecedented disaster in Hungary.

"If this had happened at night then everyone here would have died," he told villagers."This is so irresponsible that it is impossible to find words!"

Soldiers, emergency workers and volunteers dressed in a range of mud-splattered protective gear kept shovelling out the muck, a process that one official said could take months.

It is still not known why part of the reservoir collapsed and allowed an estimated 35 million cubic feet of waste to sweep through the villages, killing at least four people and leaving three missing. Disaster officials said over 150 people had been treated at hospitals and 11 were still in serious condition.

Hungary's top investigative agency, the National Investigation Office, took over the probe into the spill and planned to look into whether negligence was a factor.

MAL Zrt, the company which owns the Ajkai Timfoldgyar plant where the spill occurred, insists the sludge is not considered hazardous waste according to EU standards.

The reservoir, more than 1,000ft long and 1,500ft wide, is no longer leaking and a triple-tiered protective wall is being built around its damaged section.

Kolontar mayor Karoly Tili noted the disaster occurred only a week after authorities declared the reservoir safe."People are scared," he said. "People no longer trust or believe what is said about the reservoir."