BP may be capturing more of the oil gushing into the Gulf of Mexico, but authorities say they do not know for sure how much is still leaking.
And the environmental damage is also still a big unknown.
Wildlife has been affected in Louisiana, Mississippi and Alabama, and tar balls have been found on beaches in Florida.
But the oil is not just on the surface, and underwater life is also threatened.
Thomas Shirley from the Harte Research Institute for Gulf of Mexico Studies at Texas A&M University said: “The volume of those deep plumes is equal to the volume of Lake Erie. So, they are massive things. The sperm whales are diving through these plumes to get their food which also might be contaminated by the oil – so there are lots of reasons to be concerned.”
A third of the federal waters in the Gulf remains closed to fishing and the number of dead and injured birds and marine life is climbing.
Several hearings on the issue in Congress are planned and BP’s share price closed down five percent.
This after the US President said he wanted to know whose “ass to kick”, to use his words.
Already facing criminal investigation and lawsuits, the company is promising to donate the revenue from recovered oil to restore wildlife habitats.