(CNN) -- BP is doing all it can to respond to the oil leak in the Gulf of Mexico, a top BP official said Monday, even as criticism of the company's handling of the crisis was growing.





"We are going to clear every drop of oil off the shore," Tony Hayward told reporters at Fourchon Beach, Louisiana, where cleanup efforts were under way. "We will remediate any environmental damage and we will put the Gulf Coast right and back to normality as fast as we can."





The company's next effort to plug the leak is to come at dawn Wednesday. BP plans to pump thick, viscous fluid twice the density of water into the site of the leak to stop the flow so the well can then be sealed with cement -- the "top kill" procedure.





Hayward, noting that the attempt will be carried out on the seafloor a mile below the sea surface, estimated the odds of success for the method at 60 percent to 70 percent.





Asked about the company's continued use of an oil dispersant in the face of an EPA request that it use a less toxic alternative, Hayward said, "Everything that we do with dispersants is with the explicit approval of the EPA."





But EPA Administrator Lisa Jackson said she was not pleased with BP's response to the government's request. "The answer we got back from BP, to me, seemed more like a defense of their current choice -- reminded me a little bit of that old commercial 'I'd rather fight than switch,'" she told reporters in Venice, Louisiana.





"We need to ask ourselves whether there's not a better product out there."





Federal officials told BP that "we expect to see a substantial reduction in the overall amount of dispersant used," from 50,000 gallons or more per day to less than 15,000 gallons per day, she said.





That can be accomplished by releasing the dispersant below the surface of the water, she said. She said tests showed that the dispersant, Corexit 9500, was more toxic to baby shrimp and baby silverfish than were any of five other dispersants.





Coast Guard Commandant Adm. Thad Allen, the Obama administration's point person in the Gulf, called the decision to use dispersants a tradeoff. "It means we're willing to accept the effect of the oil in the ocean rather than on land," he said.





Hayward acknowledged that BP's reputation has taken a beating, but said the company is being straightforward about its efforts. "We're trying to communicate openly and transparently about everything that we've done," he said.





As the environmental impact of the disaster was just beginning to unfold, he noted that BP will set aside a half billion dollars to open a research program to study the effects of the spill.





Hayward's comments came a day after Interior Secretary Ken Salazar expressed frustration with the delay in stopping the spill, asserting that BP has "from day one, frankly, not fulfilled the mission it was supposed to fulfill."





He said the company has missed "deadline after deadline" and that he was not confident that BP knew what it was doing.





"If we find that they're [BP] not doing what they're supposed to be doing, we'll push them out of the way," Salazar said.





BP Chief Operating Officer Doug Suttles acknowledged Monday that the federal government could take over the effort, but said the results would be no better.





"I don't think anyone else could do better than we are," he said.





If the "top kill" procedure does not work, he said, BP will try to fit a second, smaller containment dome over the ruptured pipe, Suttles said. A first containment dome failed to stop the leak.





If the second dome does not work, he said, the company would "still have plenty of other options."





The company could try a "junk shot," which would involve plugging the well with rubber and other substances, BP Managing Director Robert Dudley said Sunday
What does the U.S. declare in oily Gulf? when "Top kill," latest effort to plug the leak, set to start? where was the disaster How much is BP to set aside?
"We are going to clear every drop of oil off the shore," at dawn Wednesday. the Gulf of Mexico, half billion dollars
question: What does the U.S. declare in oily Gulf?, answer: "We are going to clear every drop of oil off the shore," | question: when "Top kill," latest effort to plug the leak, set to start?, answer: at dawn Wednesday. | question: where was the disaster, answer: the Gulf of Mexico, | question: How much is BP to set aside?, answer: half billion dollars