Mike Utsler, president of BP's Gulf Coast Restoration Organization, said finding oil onshore from the failed Macondo well in the Gulf of Mexico wasn't a surprise.
Oil, he said, was discovered in "isolated stretches" of beach the company was cleaning before the storm hit. Hurricane Isaac made landfall in Louisiana in late August.
"In July 2010, early in the cleanup, Tropical Storm Bonnie pushed tons of sand toward the shore, burying some of the oil we were working to clean up," he said in a statement.
"Now, two years later, Hurricane Isaac has moved sand again and uncovered some buried tar mats."
BP said it was proposing operations in parts of Louisiana to clean sandy areas beyond 18 inches deep.
The Louisiana Environmental Action Network said incidents of post-hurricane industrial pollution weren't isolated to BP. The organization said industry leaders aren't willing to take the appropriate steps to prevent hurricane-related environmental damage.
Hurricanes, LEAN said, "consistently" leave oil spills in their wake.
The 2010 spill in the Gulf of Mexico was the worst accidental offshore release in history.