Gulf Spill Dispersants Surprisingly Long-lasting
Dispersant impacts on environment a major concern, expert says.
In an unprecedented tactic, U.S. authorities pumped some 800,000 gallons (3,028,000 liters) of dispersants directly into the flow of oil at the Deepwater Horizon wellhead, at about 4,000 and 5,000 feet (1,200 and 1,500 meters) deep. Most of the dispersant was applied in May and June, and the wellhead was capped in July.
No one knew how effectively the dispersants would work. But a new analysis shows the dispersants lingered for months pretty much right where they were put—trapped in subsurface plumes of oil and gas.
(See "Why the Gulf Oil Spill Isn't Going Away.")
"The dispersants got stuck in deep water layers around 3,000 feet [915 meters] and below," said study leader David Valentine, a microbial geochemist at the University