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Friday, 06 August 2010 10:00

How Big Is the Gulf Oil Leak?

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Obama Administration officials have this week announced new estimates of total oil leaked from the BP offshore well, capped on July 15, fewer than three months after an explosion on the Deepwater Horizon rig claimed the lives of 11 employees.

The Deepwater Horizon Unified Command issued a report dated August 2 stating approximately 4.9 million barrels — or more than 205 million gallons — were released from the well during the 85-day leak. Estimates range from 62,000 barrels of oil per day when the leak began to 53,000 per day at the time the well was capped. These numbers rank Deepwater as the largest offshore oil leak in history, still outstripped by California's Lakeview gusher, which spewed 378 million gallons — or 9 million barrels — on dry land over the course of 18 months in 1910 and 1911.

To better put the leak into perspective, consider that according to the Department of Energy (DOE), U.S. production from both offshore and onshore drilling amounts to just under 5.4 million barrels per day. That means the Deepwater leak equals less than one day's average production. Moreover, the estimate's margin of error is plus or minus 10 percent. So even in a worst case scenario, the leak equates to 5.39 million barrels or almost exactly the same as a day's output.

Borrowing from an analogy made by regular TNA contributor Ed Hiserodt, we can calculate the proportional equivalent of the oil leak by comparing the Gulf of Mexico to an Olympic-sized swimming pool. The latter is one trillionth the size of the former, holding 660,000 gallons compared to the Gulf's 660 quadrillion gallons. One trillionth of the government's estimate is 0.0002058 gallons, or less than three-hundredths of an ounce of oil in an Olympic swimming pool.

In addition to estimates calculated by DOE and the U.S. Geological Survey, the Department of the Interior and the National Oceanic and Atmospheric Administration created an "Oil Budget Calculator" to ascertain the fate of the leaked oil. These agencies found that, of the total leak, BP captured 33 percent through processes such as burning, skimming, chemical dispersing and direct recovery. Twenty-five percent of the oil has already evaporated or dissolved, and another 16 percent is naturally dispersed, meaning it is in the process of rapid degradation deep below the surface of the ocean and close to currents which will further speed the process.

The government classifies the remaining 26 percent, fewer than 1.3 million barrels, as "residual." This includes oil on or near the surface of the water, oil washed ashore or collected from the shore, and oil buried in sand and sediments. The report explains, "This oil has also begun to degrade through natural processes," and states the residual amount is biodegrading quickly. "It is well known that bacteria that break down the dispersed and weathered surface oil are abundant in the Gulf of Mexico in large part because of the warm water, the favorable nutrient and oxygen levels, and the fact that oil regularly enters the Gulf of Mexico through natural seeps."

Despite these positive findings, the Deepwater Horizon Uniform Command closed its report with a wince-inducing announcement of intent to continue investigation and mitigation efforts because "federal scientists remain extremely concerned about the impact of the spill to the Gulf ecosystem." The above-named agencies along with EPA, NASA and others which make up the Unified Command warned their planned projects will "take time and continued monitoring and research." In other words, your tax dollars will, for many months to come, pay to tackle a problem Mother Nature is capable of handling quite well on her own. Unified Command projects include monitoring of air, water, and shore quality along with rates of impact on wildlife and natural resources. The agencies also intend to further refine estimates of the leak amount and will publish regular updates at and

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