THE FIERY explosion of the Deepwater Horizon oil rig that killed 11 men on April 20th was followed by images of stricken wildlife, acrimonious hearings on Capitol Hill and revelations that BP failed to take the most elementary safety precautions. For example, it shut off the rig’s fire alarm so workers’ sleep would not be interrupted.
Just a day after Tony Hayward – BP’s gaffe-prone, scapegoat chief executive – stepped down, the company could take comfort in a story with a different twist: that of the incredible shrinking oil spill.
The company fitted a temporary but tight-fitting cap on the well on July 15th and, since then, little oil has escaped.
As the New York Times reported on its front page yesterday, vast oil slicks covering thousands of square kilometres have all but disappeared, though tar balls and emulsified oil continue to be found.
Furthermore, toxicity levels on the ocean floor appear to be low.
One hundred days after the disaster began, BP and the US government are wondering how quickly they can wind down the massive and costly response to the worst environmental disaster in US history.
So was the ill-fated Mr Hayward right when he predicted that the environmental impact of the spill would be “very, very modest”?
Retired coast guard admiral Thad Allen urged caution. “In the history of this country, we’ve never put this much oil into the water. And we need to take this very seriously,” he said.
“Less oil on the surface does not mean that there isn’t oil beneath the surface, however, or that our beaches and marshes are not still at risk,” Dr Jane Lubchenco, an administrator at the National Oceanic and Atmospheric Administration, said at a briefing this week.
Government scientists have determined that the oil is mainly in the water column, not sitting on the bottom of the ocean, Dr Lubchenco said.
One-third of the gulf’s fishing industry has been shut down, and fishermen remain concerned about the effect of oil and chemical dispersants on the larvae that replenish their stocks.
There are at least four explanations for the rapid disappearance of oil slicks in the Gulf of Mexico.
Even in normal times, oil from beneath the ocean bed seeps into the Gulf, though nowhere near the quantities spilled between April 20th and July 15th. According to the New York Times, “the Gulf is swarming with bacteria that can eat oil”.
Tropical storms Alex and Bonnie were deplored for pushing oil into Louisiana’s marshes, and for slowing work to definitively close the well. But the storms are now credited with helping to disperse the oil.
The joint clean-up effort by the government and BP has also helped. As Mr Hayward said on Tuesday: “We mounted the largest response to an environmental incident and industrial accident the world has ever seen. There are 45,000 people involved in that response, thousands of ships and unprecedented sub-sea intervention.” Finally, up to 40 per cent of the petrol is believed to have evaporated.
Until the well is “killed”, there’s a risk of further leakage. Anxious residents of Grand Isle, Louisiana, have asked the coast guard to maintain clean-up equipment in situ for at least six more weeks.