Komaron: Fears that Hungary`s toxic spill could destroy the ecosystem of the Danube, Europe`s second longest river, eased Friday, as contamination levels appeared to fall, an expert told reporters.
Four days after toxic sludge from an alumina plant reservoir swept through nearby towns killing four and injuring 150, samples showed water quality was close to normal in the river.
At 08:30 am (0630 GMT), alkaline levels showed a reading of pH 8.4 at Komaron, around 80 kilometres (49 miles) west of Budapest, according to the expert for the state-run Environmental Protection Agency.
Samples have been taken regularly since the spill occurred on Monday.
The level is only a slightly higher than normal and is not harmful to the environment, the expert added.
Water alkalinity is a measure of river contamination and on a scale of 1-14, pH values of 1-6 are acid, between 6 and 8 are neutral, and readings of 8-14 are alkaline.
Further upstream at the confluence of the Raba and the Danube, which is closer to the site of the disaster, pH levels showed a reading of 9 and there were also still sporadic sightings of dead fish, officials said.
The pollution already wiped out all life in the smaller Marcal tributary.
It reached the main branch of the Danube on Thursday, sparking concerns that the accident would similarly destroy the ecosystem of one of Europe`s most important waterways as well.
The toxic spill poured from a reservoir at an alumina plant in Ajka, 160 kilometres (100 miles) west of Budapest, which burst Monday, sending 1.1 million cubic metres (38.8 million cubic feet) of red sludge into surrounding villages.
The death toll could still rise. Three people are still missing four days after the disaster and one of those injured suffered such severe burns that doctors describe his condition as life-threatening.
In the village of Kolontar, which was hardest hit by the accident and where all the victims died, the clean-up could be finished by next week, officials said.
Despite falling alkalinity levels, environmental groups have expressed alarm about the longer-term effects of the pollution and Greenpeace was scheduled to hold a news conference in Vienna on Friday to present the results of its first tests.
The wildlife protection group WWF warned of a "string of other disasters waiting to happen" all along the Danube basin.
Hungary alone has two other sludge ponds storing similarly toxic and highly alkaline red muds from bauxite processing, such as Almasfuzito 80 kilometres from Budapest, WWF said.
"A spill from Almasfuzito would seriously impact drinking water, drinking water supplies and the fragile ecosystems of the middle Danube," said Andreas Beckmann, head of WWF`s Danube-Carpathian programme.
"A spill from the Tulcea facility in Romania, which has already experienced some leaks in the past, would have a devastating impact on the Danube Delta, an area of global importance for flora and fauna."
Serbia, Croatia and Romania said they were stepping up monitoring of the river given the risk of drinking water contamination in towns along the river.
Adrian Draghici, head of the water management authority in Mehedinti county, 400 kilometres west of Bucharest, said the pollution could reach Romania Saturday.
But a Hungarian water official played down the long-term impact of the pollution, saying it would only affect a limited part of the Danube.