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Documents indicate heavy use of dispersants in gulf oil spill

BP, the government and an army of volunteers are fighting to contain and clean the millions of gallons of oil spewing from the site of the Deepwater Horizon explosion in the Gulf of Mexico.

Charles M. Pajor, a Nalco spokesman, said that the amount of dispersant the company recommends depends on the acreage sprayed and the amount of oil spilled, with variations for oil quality, degree of weathering, temperature and thickness. Typically, two to 10 gallons per acre are used or one gallon for every 10 to 50 gallons of oil, Pajor said.

Similar dispersants were used after the Exxon Valdez spill in Alaska in 1989, and afterward government officials vowed to study their environmental effects more carefully. But urgency faded, research dollars evaporated, and when this spill arrived, the questions were still unanswered.

Now, scientists say, it's difficult to tell what the added use of dispersants permitted by the Coast Guard meant for the gulf. The chemicals may have helped break up some oil before it reached sensitive marshes along the Louisiana coast. But it also may have poisoned ecosystems offshore, helped deplete underwater oxygen and sent oil swirling through the open-water habitats of fish and coral.

"It's still a trade-off. I mean, you're using dispersants to protect the shoreline, and you're going to be killing things in the water column," said Carys Mitchelmore, a professor at the University of Maryland. By using more dispersants, Mitchelmore said, "you're just going to be killing more things in the water column."

In May, under pressure from environmental groups, the EPA and the Coast Guard issued a directive to BP, ordering the company to "eliminate" the use of dispersants on the surface. The directive said BP could seek an exemption in rare cases when other cleanup methods were not feasible.

The government allowed BP to continue injecting dispersants below the surface, as oil leaked from the well on the gulf floor. Their logic was that the chemicals could be used more efficiently underwater, where the gushing of BP's well provided a turbulence that helped them work.

"Because so much is still unknown about the potential impact of dispersants, BP should use no more dispersant than is necessary," Jackson wrote in a letter to BP that day.

But, over the next nine days, BP made daily waiver requests for the use of surface dispersants. Every day the Coast Guard gave its approval. On May 28, for instance, BP sprayed 6,400 gallons of dispersant on the surface, saying it was needed to control dangerous fumes -- volatile organic compounds -- where rig and platform workers were trying to get the blowout under control.

In early June, federal documents show, an EPA official raised concerns about the ease with which BP was obtaining waivers.

"The approval process appears to be somewhat pro forma, and not as rigorous as EPA desires," the official wrote, according to a Coast Guard memo that quoted him. It said BP "must be put on notice that the request for exemptions cannot be presumed to be approved at the point they are submitted."

Two weeks later, on June 22, Jackson said that the Coast Guard had begun giving her agency a greater role in the approval of dispersant use. But federal documents show that the chemicals were still being used, sometimes more than 10,000 gallons a day. A federal official said the last surface dispersants were sprayed July 19.

Scott Dean, a BP spokesman, said that his company had been careful to obtain federal permission before using dispersants on the ocean's surface.

"Since the very beginning, BP has operated in a unified command and we have always worked hand in hand with the Coast Guard and EPA on dispersants," Dean said, "and we've complied with EPA requests regarding dispersants." He added that "dispersants are an EPA-approved and recognized tool in fighting oil spills."

Aaron Viles, at the Louisiana-based Gulf Restoration Network, said the Obama administration gave the impression of controlling the controversial dispersants while allowing their use to continue. The result, he said, was that more oil sank out of sight and out of reach of the cleanup operation.

"Clearly, you know, there was a bit of a show here," Viles said. "Whether EPA wasn't serious, or the Coast Guard didn't care, they kept cranking, and kept exposing the Gulf of Mexico to this giant science experiment."

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