The problem, the biggest ever inland spill in the USA, was first spotted on March 2 when a worker spotted oil leaking from a BP pipeline.

Although the pipe is fitted with a leak detection system BP is still unsure when the oil began to escape.

Estimates of how much oil has leaked from the fractured pipe have varied wildly, from somewhere in the region of 60,000 to more than 270,000 gallons.

Either way, it is a huge amount of oil, and the biggest inland spill ever to hit Alaska, but is dwarfed by the infamous Exxon Valdez catastrophe where some 11 million gallons leaked into the Prince William Sound when the ship ran aground.

While the spill will doubtless add weight to the argument of those calling for a halt on further oil extraction and exploration in Alaska, the spill is not in an area of pristine wilderness but in a semi-industrialised region.

It does however undermine the Bush administration’s argument that the gas and oil reserves in the Arctic National Wildlife Refuge can be tapped while causing little impact on regional ecology (see related story).

The cause of the leak remains unknown and is currently being investigated by BP and the Alaskan Department of Environmental Conservation.

Work recovering the spilled oil has been slow as temperatures have dipped to -70C including wind chill and workers can only manage brief shifts before having to returning to shelter to thaw out.

Nevertheless, BP believes it can recover at least 90% of the oil which will then be treated and sold.

The environmental impact of the spill is as yet unclear but the fact that it is on land rather than at sea is something of a silver lining, meaning the oil is less likely to travel and affect a large area.

A vacuum truck has been used to suck up the oil where it has pooled and fresh snow has been used to absorb oil elsewhere.

By Sam Bond

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