Pressing ahead after another setback, British energy giant BP said it hoped to complete its latest effort to contain the huge Gulf of Mexico oil spill late on Saturday, while the company's chief executive appeared to dismiss the disaster as "tiny."
The accident at the offshore oil rig is threatening an environmental and economic calamity along the U.S. Gulf Coast.
While London-based BP moved forward with its tricky undersea efforts to redirect the flow of oil, the Obama administration demanded "immediate public clarification" from BP Chief Executive Tony Hayward over the company's intentions on paying costs tied to the accident.
With crude oil gushing unchecked from its blown-out offshore well a mile deep on the floor of the Gulf, BP was attempting to guide undersea robots to insert a small tube into a 21-inch pipe, known as a riser, to funnel the oil to a ship at the surface.
BP's initial attempt to insert the tube into the riser ran into trouble when the metal frame that supports the siphon shifted, BP Chief Operating Officer Doug Suttles told reporters in Robert, La., on Saturday.
Suttles said BP hopes to get the siphoning tube inserted late on Saturday night and operational overnight.
"We did have to pull it back to surface [Friday] to make some adjustments so that we could connect it properly to the pipework," Suttles said. "We expect to begin operation of that equipment overnight tonight."
The company's previous attempt to contain the oil using a giant containment dome failed last week.
BP: A "tiny" amount of oil in "a very big ocean"
In an interview published in a British newspaper on Friday, Hayward appeared to play down what threatens to become the worst environmental disaster in U.S. history.
"The Gulf of Mexico is a very big ocean. The amount of volume of oil and dispersant that we are putting into it is tiny in relation to the total volume of water," Hayward was quoted as saying in Britain's Guardian newspaper.
Hayward also acknowledged his job was on the line and that he would be judged by the company's response to the disaster. BP's shares have tumbled and wiped out $30 billion of market value since the disaster began last month.
The spill began after an April 20 explosion on the Deepwater Horizon rig, which killed 11 workers. It threatens to eclipse the 1989 Exxon Valdez spill off Alaska as the worst U.S. ecological disaster ever.
Officials said on Saturday that so far the spill has had minimal impact on the shoreline and wildlife.
There have been questions about the implications of current U.S. law that limits energy companies' liability for lost business and local tax revenues from oil spills to $75 million.
In a letter to Hayward, Interior Secretary Ken Salazar and Homeland Security Secretary Janet Napolitano cited statements by BP executives that the company was taking responsibility for the spill and would cover spill-related costs.
"Based on these statements, we understand that BP will not in any way seek to rely on the potential $75 million statutory cap to refuse to provide compensation to any individuals or others harmed by the oil spill, even if more than $75 million is required to provide full compensation to all claimants," Salazar and Napolitano wrote.
Earlier, BP spokesman Mark Proegler said oil washed up in Mississippi for the first time in the state on Saturday, when tar balls were discovered at Long Beach. Oil has now contaminated eight beaches in three states after it was also located at Whiskey Island, Louisiana, and several in Alabama.
Seeking to curb the volume of oil reaching the surface, the U.S. Coast Guard and Environmental Protection Agency said they have authorized more undersea use of chemical dispersants at the source of the leak. Dispersants are designed to break the oil into small droplets more likely to sink to the sea floor.
Some environmental groups and the Gulf's shrimping industry have raised concerns about the effect of the chemicals, saying the oil might not sink all the way, but become suspended in the water column and ingested by fish and other wildlife.
A statement by the EPA and Coast Guard sought to allay those fears, saying dispersants are "generally less harmful than highly toxic oil" and biodegrade more quickly.
Cleanup crews continue attacking the oil slick using surface dispersants, skimming and controlled burns.
Inland, BP contractors assisted by flotillas of hired shrimp boats continued to string containment booms around sensitive coastal areas, while National Guard teams with bulldozers and helicopters press on to plug gaps in booms protecting Louisiana's storm-battered shoreline to prevent oil from reaching the fragile marshlands behind them.
Scientists and shrimpers alike have said that contamination of marshes, the foundation for the region's economy and way of life, would be devastating.
The vast but dwindling marshes are the nurseries for shrimp, oysters, crabs, and fish that make Louisiana the leading producer of commercial seafood in the continental United States and a top destination for recreational anglers.
U.S. President Barack Obama on Friday gave a tongue-lashing to all the companies involved in the spill--BP, Halliburton and Transocean--and said he would not rest until the leak was stopped at its source.
Estimates of the rate of escaping oil range widely from the official BP figure of 5,000 barrels per day, adopted by the government, to 100,000 barrels per day.