In the weeks since the broken wellhead was capped, the growing debate is now, how much BP oil lurks beneath the surface.
Thursday, the Mississippi Department of Environmental Quality launched a program which they hope will provide answers.
The DEQ is pulling samples of water from the Mississippi Sound every four miles, from the Louisiana border to the Alabama border to get an accurate picture of what's in their water.
"We want to know what's in our waters," said Nick Gatlan, an Environmental Administrator at the Mississippi Department of Environmental Quality South Region Office in Biloxi. "We want to know where it is, how much is it, what it's doing to our environment."
According to the DEQ, operators of Vessels of Opportunity expressed enough concern about submersed oil, they decided to investigate themselves.
Oil is still washing on-shore across the state.
"We're still getting tarballs coming up on our beaches," Gatian said, "some areas are a little heavier than others. It obviously has reduced considerably from the peak time."
The DEQ hopes to have answers in a week or two.
"So far, all of our samples have indicated that there's not a lot out there," Gatian added. "We're not seeing measurable quantities. So, if we find something, we expect it to be in very low concentrations, but that's why we're looking, because we don't really know what's there."
26 Vessels of Opportunity and six state-owned skimmers are being used in the search.
