Tests suggest oil dispersant washing up on Alabama beaches
Published: Tuesday, August 03, 2010, 5:00 AM Updated: Tuesday, August 03, 2010, 6:16 AM
Ben Raines, Press-Register
Follow
Share this story
Story tools
View full size(AP Photo/Patrick Semansky)In this Tuesday, April 27, 2010 file photo, a dispersant plane passes over an oil skimmer as it cleans oil in the Gulf of Mexico near the coast of Louisiana. A preliminary test suggests that oil dispersant is washing up on Alabama beaches.
50
1
940Share
The stained, brown water seen washing up in pockets along Alabama beaches for the last two weeks appears to contain the dispersant widely used on oil from the Deepwater Horizon spill, according to a preliminary analysis.
The Press-Register collected samples from multiple locations along the Fort Morgan peninsula during the last several weeks and provided them to Ed Overton, a Louisiana State University chemist.
While heavy oil sheen was visible in the areas where the material was collected, little if any oil was found to be present in the samples, said Overton, who is analyzing oil samples for the federal government.
"We didn't see oil in the analysis we do, but I passed some of these water samples to a colleague who does fluorescence analysis," Overton said. "We saw some preliminary indications that there was a dispersant signal in the sample."
Fluorescence analysis provides ultra-fine detail and can measure chemicals to the parts per billion level or better. Overton said it was too soon to say definitively that the material in the samples was the Corexit dispersant, but the signal was similar to a Corexit sample.
Overton asked the Press-Register to take some of his researchers back to the sites this week to collect more samples for further study.
"I'm very interested in it. We need to find out what it is," Overton said. "If dispersants are getting onshore, that's news. We need to know that."
Over the last several weeks, Harriet Perry, a scientist at the Gulf Coast Research Lab in Ocean Springs, has collected larval crabs, finding blobs of oil beneath their shells. Further testing has suggested that there may be dispersant present in the crab bodies as well, she said.
"They looked specifically for the Corexit. It looks like they found it," Perry said of work by research colleagues at Tulane University.
"These (oil) droplets in the crabs, they are pinhead-sized. For a droplet to be that small, it has to be dispersed oil," Perry said. "It's supposed to biodegrade rapidly. It's supposed to disappear in days, not weeks, but that may not be happening."
In fighting the spill, BP applied dispersants to oil on the surface and at the wellhead. Press-Register calculations suggest about 1,500 gallons of oil was flowing from the well per minute. Into that stream, BP injected between 10 and 20 gallons of dispersant per minute, or about 12,000 to 20,000 gallons a day.
The material collected by the Press-Register was found in water between two sandbars that lie about 50 yards and 100 yards off the beach, respectively. A heavy, metallic sheen was floating on the water between the bars and stretched for miles to the east and west.
Gulf water in the areas sampled by the newspaper was a muddy brown. The discoloration began just inside of the outer bar.
Seen in a jar, the Gulf water was turbid with tiny flecks of a dark, reddish brown material.
At some locations, the brown material was present from the surface to the sea floor. At other locations, the brown material was in a layer in the bottom 5 feet of the water column. At those sites, another material -- stringy, milky yellow filaments the thickness of a human hair -- formed a layer above the brown material.
Overton said the filaments appeared biological in nature and might be the remnants of bacteria that consumed oil.
Monday, the U.S. Environmental Protection Agency released a new round of test results on dispersants. The testing concluded that oil mixed with dispersants was no more toxic than oil alone. In a previous round of testing, the agency determined that dispersants were "generally less toxic than oil."
