HAMMOND, La. - At first, BP tried to stop the oil rushing into the Gulf of Mexico by flipping a blowout preventer switch. A week ago, they attempted to capture the leak with a 100-ton box. The latest experiment? Trying to guide a skinny, mile-long tube into the gusher.
BP PLC technicians were gingerly moving joysticks to guide deep-sea robots and thread the 6-inch tube with a rubber stopper into the 21-inch pipe spewing oil from the ocean floor. That work continued Saturday morning for a second day, BP said.
The company also received word that federal regulators had approved spraying chemical dispersants beneath the sea, a contentious development because it has never been done underwater.
Traditionally used on the ocean surface, chemical dispersants act like a detergent to break the oil into small globules, which allows it to disperse more quickly into the water or air before currents can wash it ashore. Louisiana officials claim BP and the Environmental Protection Agency ignored their concerns about how the chemicals may harm the sea floor.
More than three weeks after the oil rig explosion that killed 11 workers and set off the disastrous spill, President Barack Obama assailed oil drillers and his own administration Friday as he ordered extra scrutiny of drilling permits. He condemned a "ridiculous spectacle" of oil executives shifting blame in congressional hearings and denounced a "cozy relationship" between the companies and the federal government.
"I will not tolerate more finger-pointing or irresponsibility," Obama said in the White House Rose Garden, flanked by members of his Cabinet.
"The system failed, and it failed badly. And for that, there is enough responsibility to go around. And all parties should be willing to accept it," the president said.
BP's Chief Executive Tony Hayward acknowledged the disaster will change the rules for deepwater drilling in U.S. waters.
"You can't have an incident of this seriousness and not expect significant changes as a consequence," Hayward said in a BBC Radio interview broadcast Saturday.
Obama's tone was a marked departure from the deliberate approach and mild chiding that had characterized his response since the rig went up in flames April 20 and sank two days later. At least 210,000 gallons of oil has been leaking into the Gulf each day, and BP has sought to burn the crude off the surface of the water, as well as use the chemical dispersants.
U.S. Coast Guard Rear Adm. Mary Landry said Friday that three underwater tests conducted at the leak site proved helpful at keeping oil from reaching the surface. So far more than 517,000 gallons of dispersants, most of which is a product called Corexit 9500 previously approved by EPA for use on the sea surface only, have been dropped over the spill or shot undersea.
Corexit 9500 is identified as a "moderate" human health hazard that can cause eye, skin or respiratory irritation with prolonged exposure, according to safety data documents. Louisiana Health and Hospitals Secretary Alan Levine said federal regulators dismissed state worries about the chemicals.
"Our concerns about the use of these dispersants underwater is based on the fact that there is virtually no science that supports the use of those chemicals," Levine said. "We're trading off what we know is going to be environmental damage on the surface for environmental damage of a level we don't know that is going to be under the surface."
EPA Administrator Lisa Jackson has said she reserves the right to halt the use of chemical dispersants at any time if new data show more serious environmental harm is occurring.
The Obama administration insists its response has been aggressive ever since the spill started, and the president said he shared the anger and frustration of those affected. He announced that the Interior Department would review whether the Minerals Management Service is following all environmental laws before issuing permits for offshore oil and gas development.
BP's drilling operation at Deepwater Horizon received a "categorical exclusion," which allows for expedited oil and gas drilling without the detailed environmental review that normally is required.
"It seems as if permits were too often issued based on little more than assurances of safety from the oil companies," Obama said.
Echoing President Ronald Reagan's comment on nuclear arms agreements with Moscow, he said, "To borrow an old phrase, we will trust but we will verify."
Obama already had announced a 30-day review of safety procedures on oil rigs and at wells before any additional oil leases could be granted. And earlier in the week Interior Secretary Ken Salazar announced plans to split the much-criticized Minerals Management Service into two agencies, one that would be charged with inspecting oil rigs, investigating oil companies and enforcing safety regulations, while the other would oversee leases for drilling and collection of billions of dollars in royalties. Salazar has said the plan will ensure there is no conflict, "real or perceived," regarding the agency's functions.
Obama decried what he called "a cozy relationship between the oil companies and the federal agency that permits them to drill." But the president, who had earlier announced a limited expansion of offshore drilling that's now on hold, didn't back down from his support for domestic oil drilling.
This week executives from three oil companies - BP PLC, which was drilling the well, Transocean, which owned the rig, and Halliburton, which was doing cement work to cap the well - testified on Capitol Hill, each trying to blame the other for what may have caused the disaster.
"I did not appreciate what I considered to be a ridiculous spectacle during the congressional hearings into this matter. You had executives of BP and Transocean and Halliburton falling over each other to point the finger of blame at somebody else," the president said.
Associated Press writers Erica Werner, Matthew Daly and Frederic J. Frommer in Washington, Jason Dearen in New Orleans and Melinda Deslatte in Baton Rouge, La., contributed to this report.