Triggered by a reservoir collapse Monday at the Ajkai Timfoldgyar alumina plant in the town of Ajka (map), a toxic-sludge flood has devastated seven towns, which now face contaminated water, fouled fields, and wrecked ecosystems, according to the Associated Press. Alumina, or synthetic aluminum oxide, is used in the smelting of aluminum.
Hungarian authorities report at least four people have been killed and several others are missing in the wake of Monday's fast-moving, 35-million-cubic-foot (1-million-cubic-meter) flood. Hundreds more have been injured or forced to evacuate.
Authorities are fighting a feverish battle to close the burst reservoir and contain the sludge spill before it enters the Danube River and spreads downstream beyond the country's borders—potentially as far as the Black Sea.
Teams are dumping tons of plaster into the Marcal River in an attempt to stop the sludge from reaching the Danube, Kendall said. But the spill’s own velocity and the region's persistent rains make the prospect of containment uncertain.
"It’s a major ecological issue right now," Kendall said, "and the chances of it reaching the Danube are quite high."
On Tuesday a resident of Kolontar, Hungary, takes stock of his yard, flooded with the caustic alkaline substance produced when bauxite is refined into alumina.
Such toxic waste is typically stored in open reservoirs until evaporation leaves a claylike material behind. But after the retaining walls of an enormous reservoir burst Monday, the watery sludge surged through neighboring towns in a wave six feet (two meters) tall, according to the Associated Press.
Photograph by Bela Szandelszky, AP
Toxic Sludge Hits Home in Hungary
With rubber boots to shield against the harmful sludge, a man surveys his home in Devecser, Hungary, on Tuesday.
Toxicologist Ronald Kendall said local authorities are using acidic substances to ease the burning effect of the alkaline sludge on skin. But that the process creates other, less obvious problems.
"It's a double-edged sword," Kendall explained, "because you're also enhancing the release of toxic heavy metals bound in that sludge."
The heavy metals in the sludge—byproducts of alumina production—can wreak havoc on the food chain from the base up by altering plant growth as well as egg and larvae development. They also can cause serious neurological damage in living animals, Kendall said.
Seen Tuesday, a crimson waterline in Devecser, Hungary, shows just how deep Monday's toxic-sludge flood was.
Ultimately, remediation efforts may be extensive, expensive, and time-consuming, Kendall said. Layers of topsoil may require removal in agricultural areas, and river bottoms may have to be dredged where heavy metals have settled out.
"This is huge," Kendall added. "Some volume estimates are approaching the size of the BP oil spill. Even if this was clean water, it would be a big problem in terms of flooding—and this stuff is highly toxic."