Millions of gallons of crude oil has spilled from a poorly maintained pipeline in the Russian Arctic, fouling rivers, polluting drinking water and endangering the region's fragile tundra.
The spill, believed to be one of Russia's worst, wraps over the tundra like a ribbon some 3 feet deep and 40 feet wide.
It is estimated to be 6 to 7 miles long.
The spill was variously described as nearly half the volume of the 1989 Exxon Valdez disaster in Alaska's Prince William Sound and as many times larger. Russian officials dismissed U.S. estimates of a spill of 2-million barrels _ 84-million gallons or about eight times the size of the Exxon catastrophe _ as a gross exaggeration. But official versions of the spill's magnitude conflict.
"If it's even half the size of the information we have, it's obviously an ecological disaster, for both aquatic and territorial ecosystems," said George Davis, a New York land-use specialist who has made 20 trips to Siberia and the Russian Arctic since 1989.
A Russian government statement said a reservoir of oil poured onto the tundra around Oct. 1, after a network of earthen dams built to contain it collapsed under heavy rains. The dams, some up to 25 feet high, had held the oil since late August, when at least 16 ruptures sent oil cascading out of a pipeline.
The 26-inch pipeline was fed by at least 643 oil wells. It runs along an area about 30 miles north of the city of Usinsk, in the remote Komi region of northern Russia.
The Arctic regions of Russia are a treasure house of minerals and resources, which the country is desperately trying to tap in its search for hard currency. But it is also one where ecosystems are incredibly fragile _ it can take 40 years for a birch tree to grow to a height of 10 feet. The technology being used to harvest the resources is primitive.
Davis said that such a spill could prove virtually impossible to remedy in the permafrost, even if Russia had such equipment readily available, which it does not.
"You've got probably an impossible cleanup job," said Davis. "You're in a permafrost, you've got hot oil cutting through the permafrost; that's going to stay in the vegetation for generations."
Officials of Komineft, the oil producer that owns the pipeline, acknowledged Tuesday there had been abundant warnings that the 18-year-old pipeline was deteriorating as long ago as 1988, when it first started springing leaks. There was serious leakage in February, requiring extensive repair work. But in the chaotic end of the Soviet era, maintenance was long neglected and work on a replacement pipeline was delayed for lack of financing, said Valery Ilyin, spokesman for Komineft.
There were also indications that Komineft continued to pump oil through the pipeline even after it started leaking this summer.
William White, U.S. deputy energy secretary, said Tuesday that he had heard from his "oil industry sources" that lakes of oil from the Russian spill were larger than those in Kuwait after the Iraqis destroyed Kuwaiti oil wells in the 1991 Persian Gulf war.
Some Komi officials put the spill's volume at 100,000 barrels of crude oil and other liquids. U.S. officials said they had heard estimates of up to 2-million barrels. The reasons for the discrepancy were not immediately apparent.
The Exxon Valdez spilled 260,000 barrels.
Russian officials agree the spill is the most serious ever recorded in the sparsely populated Komi region, a desolate area of tundra and forests 1,000 miles northeast of Moscow. Yet they insist the worst has been averted. While oil slicks up to 6 inches deep were reported in two small rivers north of Usinsk _ the Usa and the Kolva _ officials said only small amounts have reached a larger river, the Pechora, which empties into the Barents Sea.
"We managed to avoid a catastrophe," Col. Anatoly Nuikin, head of civil defense for the Komi regional government, said in the Oct.
18 issue of Red Banner, the region's official newspaper. "A real catastrophe would have been if the Pechora River had been contaminated."
It was difficult, however, to make an independent assessment of the full impact of the spill, as snows and freezing weather have already slowed cleanup efforts. A Moscow official of the environmental group Greenpeace said the ecology of an area as large as 27 square miles could be ravaged by the spill, with severe consequences for drinking water, fish and game.
The cleanup was expected to be particularly difficult. What grows in an Arctic environment grows slowly, and what is damaged heals even more slowly. An environmental official in Komi said fishermen already are complaining of oil in their nets.
Much of the area is muddy and not passable for most of the year. Winter freezing of the rivers is expected to slow the flow of oil underneath the ice. Officials said it is possible that when the spring thaw comes, oil would again begin to move into the Pechora River and out into the Barents Sea and the Arctic Ocean.
U.S. officials said they have offered technical cleanup assistance to Russia.
_ Information from the New York Times and Associated Press was used in this report.