The Worst Spill in U.S. History

Operations continue to mitigate the effects of the Deepwater Horizon/BP oil spill May 23, 2010, including controlled burns, surface skimming and flaring.

Image: U.S. Coast Guard photo by Lt. Cmdr. Rob Wyman.

The gusher in the Gulf of Mexico is by far the worst oil spill in U.S. history, surpassing the Exxon Valdez, according to the latest estimates. But a last-ditch effort to plug the well in the Gulf appears to be working.

Even if the so-called top kill operation under way to stop the flow of oil and gas from the Deepwater Horizon site 5,000 feet under the Gulf and 40 miles south of Venice, Louisiana, works, those cleaning up the mess may have the biggest oil cleanup job in U.S. history on their hands.

A group of scientists tells the Associated Press that the gusher has spewed two to five times as much oil into the Gulf as BP, the company responsible for the well, had previously estimated. Even using the most conservative estimates that means the spill, which has lasted more than a month, has spewed more than 19 million gallons of oil into the Gulf. The highest estimate for the BP disaster is nearly 39 million gallons. The Exxon Valdez disaster off the coast of Alaska resulted in a spill of about 11 million gallons.

But there is at least some preliminary good news. Officials and engineers say the effort to pump heavy drilling fluid into the well, then seal it with concrete, appeared to be slowing the flow of oil today. If it works, the top kill operation could finally stop the flow of oil.

Plenty of damage has already been done, both to the delicate ecosystem of the Louisiana Gulf Coast and those who rely on it to make their living.

Oil has washed ashore on the barrier islands of Louisiana, and has infiltrated the fertile marshes that are the incubators for the nation’s second largest fishery. Much of the Gulf around the Mississippi Delta has been placed off-limits to fishing.

And the economic damage has spread beyond the Louisiana coast to neighboring states that have not seen any effects from the spill itself.

In the Florida panhandle town of Destin, business people report that their bookings dropped off a cliff with the reports of the spill. As far away as Key West, the Ripley’s Believe it or Not museum has sued BP, Halliburton and Transocean—all companies with some degree of responsibility for the spill, over lost business.

And the damage to plans for further oil exploration off the U.S. coast has also been done. President Barack Obama is scheduled to discuss new and tougher restrictions for offshore drilling at a press conference this afternoon.