Posted for Mark Schrope
Since soon after the tragic Deepwater Horizon oil spill began, the official government oil flow estimate has remained at 5,000 barrels per day, or 795,000 litres. Numerous researchers have questioned the methods used and some have roughly estimated the spill could be 20 times larger or more. Nonetheless, for weeks BP and the Obama administration said the estimate was good enough and that having a better number would not change the response.
“We’re not going to take any extra efforts now to calculate flow there at this point,” BP spokesman Tom Mueller told the New York Times, “It’s not relevant to the response effort, and it might even detract from the response effort.”
Researchers have given numerous reasons why such reasoning is suspect. Jeffrey Short, an environmental chemist with the Washington, DC-based advocacy group Oceana who worked for NOAA for over 30 years and was a leader in the effort to assess damages from the Exxon Valdez spill, has questioned how BP can effectively plan its efforts to stop the flow if they don’t know how much they are dealing with.
How the ultimate impacts of the spill can ever be gauged without knowing its size is another open question. Short points out that the liability legally established for a spill is typically tied to the size of the spill.
More recently, Obama administration officials have finally admitted that a better estimate is needed. Earlier this week they announced that a multi-agency effort was being launched to establish a better number.
But while acknowledging the number’s importance is a positive step, all agree that actually establishing a solid estimate will be extremely challenging. This point has become all the more clear with the report that substantial quantities of oil may be lingering in the deep sea, beyond the reach of normal monitoring techniques.
Scientists inside and outside the government agencies are currently brainstorming ideas about the best ways to make effective estimates. In this week’s issue of Nature, David Valentine at the University of California, Santa Barbara, suggests a novel method. He wants to use measurements of methane, which is being released in large quantities from the well along with oil, as a spill estimation tool. He reasons that most of the released gas will end up dissolved in the water. And he’s calculated what the methane levels should be in seawater if in fact the spill rate is 5,000 barrels per day (795,000 litres), so if methane levels are higher he’ll be able to scale up the size estimate.
As with any method there will be substantial uncertainties involved, but Valentine also suggests additional work that will minimize error. He’s currently talking to government agencies to see if he can muster the needed funding and resources. Valentine says, “We’ll see if the idea falls on deaf ears, gets taken up, or end up somewhere in the middle.”