GRAND ISLE, LA - JUNE 14: A clean-up worker walks along a stretch of oil-contaminated beach June 14, 2010 in Grand Isle, Louisiana. The BP spill has been called the largest environmental disaster in American history. U.S. government scientists have estimated that the flow rate of oil gushing out of a ruptured Gulf of Mexico oil well may be as high 40,000 barrels per day. President Obama will make his fourth trip to the Gulf on Monday. (Photo by Spencer Platt/Getty Images)