Tuesday, August 17, 2010

Day 118 BP Oil Spill: 75% Gone; 79% Left; Confused?

Aug 16: A report released on August 16, by the Georgia Sea Grant and the University of Georgia concludes that up to 79 percent of the oil released into the Gulf of Mexico from the Deepwater Horizon well has not been recovered and remains a threat to the ecosystem. Perhaps that sounds confusing because on August 4, the Federal government issued a report indicating that the vast majority of the oil from the BP oil spill (i.e. approximately 75 percent) had either evaporated or been burned, skimmed, recovered from the wellhead or dispersed -- much of which is in the process of being degraded [See WIMS 8/4/10]. At the time the government report was release officials said a significant amount of the removal was "the direct result of the robust federal response efforts." 

    The differences are significant because the percentages must be applied to the latest government estimate released by the Flow Rate Technical Group (FRTG) on August 2, indicating that 4.9 million barrels -- nearly 206 million gallons -- of oil were released into the Gulf by the BP leak. The University of Georgia report also corrects that figure and says that it uses a figure of 4.1 million barrels since .8 million barrels were piped directly from the well to surface ships and, therefore, never entered Gulf waters.

    The University of Georgia report, authored by five prominent marine scientists, strongly contradicts media reports that suggest that only 25 percent of the oil from the Deepwater Horizon oil spill remains. Charles Hopkinson, director of Georgia Sea Grant and professor of marine sciences in the University of Georgia Franklin College of Arts and Sciences said, "One major misconception is that oil that has dissolved into water is gone and, therefore, harmless. The oil is still out there, and it will likely take years to completely degrade. We are still far from a complete understanding of what its impacts are."

    Co-authors on the paper include Jay Brandes, associate professor, Skidaway Institute of Oceanography; Samantha Joye, professor of marine sciences, UGA; Richard Lee, professor emeritus, Skidaway; and Ming-yi Sun, professor of marine sciences UGA. The group analyzed data from the August 2, National Incident Command Report, which calculated an "oil budget" that was widely interpreted to suggest that only 25 percent of the oil from the spill remained.

    Hopkinson notes that the reports arrive at different conclusions largely because the Sea Grant and UGA scientists estimate that the vast majority of the oil classified as dispersed, dissolved or residual is still present, whereas the NIC report has been interpreted to suggest that only the "residual" form of oil is still present. Hopkinson said that his group also estimated how much of the oil could have evaporated, degraded or weathered as of the date of the report. Using a range of reasonable evaporation and degradation estimates, the group calculated that 70-79 percent of oil spilled into the Gulf still remains. The group showed that "it was impossible for all the dissolved oil to have evaporated because only oil at the surface of the ocean can evaporate into the atmosphere and large plumes of oil are trapped in deep water."

    On a positive note, the group said that natural processes continue to transform, dilute, degrade and evaporate the oil. They add that circular current known as the Franklin Eddy is preventing the Loop Current from bringing oil-contaminated water from the Gulf to the Atlantic, which bodes well for the East Coast. Professor Joye said that both the NIC report and the Sea Grant report are best estimates and emphasizes the need for a sustained and coordinated research effort to better understand the impacts of what has become the world's worst maritime oil spill. She warned that neither report accounted for hydrocarbon gasses such as methane in their oil budgets. She said, "That's a gaping hole because hydrocarbon gasses are a huge portion of what was ejected from the well."

    Marine scientist Professor Joye and other faculty members directly involved in assessing the impacts of the Gulf of Mexico oil spill have been holding regular briefings for media since June 22. Joye continues to provide regular updates on her research findings through her widely read blog (see contact below). Joye is an expert in the cycling of nutrients, metals, and organic materials between the living and non-living components of the ecosystem (a field known as biogeochemistry) as well as microbial ecology, metabolism and physiology. She has conducted research in the Gulf of Mexico for about 15 years. When the Deepwater Horizon oil rig exploded on April 20, she was coordinating a research mission aboard a NOAA-funded research vessel that was just 8 miles from the disaster site.

    At an August 16, press briefing Thad Allen, National Incident Commander (NIC) explained in some details the current status of the BP attempt to intercept the well and conduct the so-called "bottom kill." He explained that BP engineers and the government's science team are working to look at test results and do investigations to define the best way to mitigate any risk of intercepting the annulus and increasing the pressure in the annulus. He said, "We want to make sure before I give the order and direct BP to do that, that we know the implications of that pressure, and how we will deal with it. There're basically two courses of action that are being looked at right now and at the same time we are continuing to do what we call a near ambient pressure test on the blow out preventer." The science team was scheduled to meet late yesterday and then would brief Secretary Chu and Secretary Salazar.  And the science team and Secretary Chu will make a recommendation on how to proceed. 

    Access a release from University of Georgia (click here). Access the complete Georgia Sea Grant/University of Georgia Oil Spill report (click here). Access figures from the report (click here). Access the Gulf Oil Blog by Professor Joye (click here). Access the latest NIC press briefing transcript with details on the intercept options (click here). Access more information on BP activities from the BP response website (click here). Access the Restore the Gulf website for more information (click here).