MOUTH OF THE MISSISSIPPI RIVER
As the worst U.S. oil spill in decades began endangering the shoreline habitat along the Gulf Coast, documents emerged showing that British Petroleum downplayed the possibility of a catastrophic accident at the offshore rig that exploded.
In its 2009 exploration plan and environmental impact analysis for the well, BP suggested it was unlikely, or virtually impossible, for an accident to occur that would lead to a giant crude oil spill and serious damage to beaches, fish and mammals.
At least 1.6 million gallons (6 million liters) of oil have spilled so far since the April 20 explosion that killed 11 workers, according to Coast Guard estimates. One expert said Friday that the volume of oil leaking from the well nearly 5,000 feet (1,500 meters) below the surface could actually be much higher, and that even more may escape if the drilling equipment continues to erode.
"The sort of occurrence that we've seen on the Deepwater Horizon is clearly unprecedented," BP spokesman David Nicholas told The Associated Press on Friday. "It's something that we have not experienced before ... a blowout at this depth."
Amid increased fingerpointing Friday, efforts sputtered to hold back the giant oil spill seeping into Louisiana's rich fishing grounds and nesting areas, while the government desperately cast about for new ideas for dealing with the growing environmental crisis. President Barack Obama halted any new offshore drilling projects unless rigs have new safeguards to prevent another disaster.
Jane Lubchenco, head of the National Oceanic and Atmospheric Administration, met with fishermen and others Friday night in Louisiana. Lubchenco said she had participated in conference call earlier with governors from the gulf states. BP was part of the conference, she said.
"I think they heard an earful about how unhappy everyone is," she said.
Stemming the flow of oil is the top priority, she said.
"There is very deep concern about what is happening," she told the group. "We are very concerned about you and your livelihoods."
However, the seas were too rough and the winds too strong to burn off the oil, suck it up effectively with skimmer vessels, or hold it in check with the miles of orange and yellow inflatable booms strung along the coast.
The floating barriers broke loose in the choppy water, and waves sent oily water lapping over them.
The spill -- a slick more than 130 miles (200 kilometers) long and 70 miles (110 kilometers) wide -- threatens hundreds of species of wildlife, including birds, dolphins and the fish, shrimp, oysters and crabs that make the Gulf Coast one of the nation's most abundant sources of seafood. Louisiana closed some fishing grounds and oyster beds because of the risk of oil contamination.
BP's 52-page exploration plan for the Deepwater Horizon well, filed with the federal Minerals Management Service, says repeatedly that it was "unlikely that an accidental surface or subsurface oil spill would occur from the proposed activities."
And while the company conceded that a spill would impact beaches, wildlife refuges and wilderness areas, it argued that "due to the distance to shore (48 miles) and the response capabilities that would be implemented, no significant adverse impacts are expected."
Robert Wiygul, a Mississippi-based environmental lawyer and board member for the Gulf Restoration Network, said he doesn't see anything in the document that suggests BP addressed the kind of technology needed to control a spill at that depth of water.
"The point is, if you're going to be drilling in 5,000 feet (1,500 meters) of water for oil, you should have the ability to control what you're doing," he said.
Although the cause of the explosion was under investigation, many of the more than two dozen lawsuits filed in the wake of the explosion claim it was caused when workers for oil services contractor Halliburton Inc. improperly capped the well -- a process known as cementing. Halliburton denied it.
According to a 2007 study by the federal Minerals Management Service, which examined the 39 rig blowouts in the Gulf of Mexico between 1992 and 2006, cementing was a contributing factor in 18 of the incidents. In all the cases, gas seepage occurred during or after cementing of the well casing, the MMS said.
While the amount of oil in the gulf already threatened to make it the worst U.S. oil disaster since the Exxon Valdez spill in Alaska in 1989, one expert emphasized that it was impossible to know just how much oil had already escaped and that it could be much more than what BP and the Coast Guard have said.
Even at current estimates, the spill could surpass that of the Valdez -- which leaked 11 million gallons (40 million liters) -- in just two months.
Ian R. MacDonald, an oceanography professor at Florida State University, said estimates from both Coast Guard charts and satellite images indicate that 8 million gallons to 9 million gallons (30 million to 34 million liters) had spilled by April 28.
Coast Guard Admiral Mary Landry brushed off such estimates that suggested the rate of the leak was five times larger than official estimates.
Doug Suttles, BP's chief operating officer for exploration and production, said it's impossible to measure the flow. But he said remote cameras show the rate doesn't appear to have changed since the leak was discovered.
As of Friday, only a sheen of oil from the edges of the slick was washing up at Venice, Louisiana, and other extreme southeastern portions of Louisiana. But several miles out, the normally blue-green gulf waters were dotted with sticky, pea- to quarter-sized brown beads with the consistency of tar.
High seas were in the forecast through Sunday and could push oil deep into the inlets, ponds, creeks and lakes that line the boot of southeastern Louisiana. With the wind blowing from the south, the mess could reach the Mississippi, Alabama and Florida coasts by Monday.
In Louisiana, officials opened gates in the Mississippi River hoping a flood of fresh water would drive oil away from the coast. But winds thwarted that plan, too.
For days, crews have struggled without success to activate the well's underwater shutoff valve using remotely operated vehicles. They are also drilling a relief well in hopes of injecting mud and concrete to seal off the leak, but that could take three months.
U.S. Interior Secretary Ken Salazar said he has pressed BP to work more efficiently to clean the spill and has pledged that "those responsible will be held accountable." President Barack Obama has ordered Salazar to report to him within 30 days on what new technology is needed to tighten safeguards against deepwater drilling spills.
With the government and BP running out of options, Salazar has invited other companies to bring their expertise to the table.
BP likewise sought ideas from some of its rivals and was using at least one of them Friday -- applying chemicals underwater to break up the oil before it reaches the surface. That has never been attempted at such depths.
Animal rescue operations have ramped up. A rescue crew had its first patient Friday, a bird covered in thick, black oil. The bird, a young northern gannet found offshore, is normally white with a yellow head.