Deepwater Horizon Trial

Government experts estimated that the Deepwater Horizon disaster, which killed 11 workers, caused 176 million gallons of oil to spill into the Gulf. BP attorneys have urged U.S. District Judge Barbier to set the figure at nearly 103 million gallons.

The final number will determine how much BP pays for the cleanup. Using government figures, a maximum penalty if the company is found grossly negligent could total $18 billion. The company's figures would result in a $10.5 billion fine.

[...]

In the first eight months of 2013, some 3.01 million pounds of "oily material" were cleaned up on Louisiana's coast, up from 119,894 pounds in the same period last year, according to the state's Department of Natural Resources.

While the state did not reveal why there was a more than 20-fold increase in the amount collected this year, some believe Tropical Storm Karen, which occurred earlier in October, may have washed away sand and exposed more oil.

  al Jazeera

And, would it be possible that the toxic chemicals BP used to “disperse” the oil are breaking down?  They didn't eat the oil.  It's still somewhere.

Danny Wallace, a BP incident commander, said the rise in recoveries this year stemmed from where BP was focusing its efforts after Hurricane Isaac rearranged sands in August, 2012.

"In 2013 most cleanup activities have focused on the barrier islands where Hurricane Isaac uncovered heavily-weathered residual oil that had been buried when tropical storms deposited deep layers of sand along the shoreline in 2010 and 2011," Wallace said.

OK, I can buy that...they're just now cleaning up areas where perhaps a majority of the oil settled.

But the bottom line is, don’t let BP settle and call it quits. The penalty figure should simply be that: a penalty. The actual (and opportunity) costs for businesses and clean-up should still be paid by BP, no matter how long it continues.

...but hey, do what you want...you will anyway.