Updated

WASHINGTON  -- The Environmental Protection Agency chief on the job during the Exxon Valdez oil spill in Alaska in 1989 and a former Florida senator will lead the presidential commission investigating the Gulf of Mexico disaster.

President Barack Obama on Saturday announced the appointments of William K. Reilly, EPA administrator under Republican President George H.W. Bush, and Bob Graham, a Democrat who also was Florida governor, as the panel's heads.

Obama intends to name five others to the commission, which will examine issues such as what caused the spill, the safety of offshore drilling and operations at the Minerals Management Service, the federal agency that grants drilling rights. A report is due in six months.

"I can't think of two people who will bring greater experience or better judgment to the task at hand," Obama said in his weekly radio and Internet address.

The Gulf oil spill began April 20 when BP's Deepwater Horizon drilling rig exploded off the Louisiana coast, killing 11 workers and rupturing an underwater pipe. Since then, at least 210,000 gallons of oil a day have been spewing into the Gulf, threatening beaches, marshes, fisheries and wildlife along the coast.

A month after the explosion, residents, elected officials and environmental groups are becoming frustrated with BP PLC's failure to cap the well. They have called for the government to take charge. BP was leasing the rig and is responsible for the cleanup. The government is signing off on the company's efforts to cap the pipe, but one Republican senator said more needs to be done.

Sen. David Vitter, R-La., said many Louisianians are frustrated that Democrats who run Congress have been holding hearings while the uncapped well continues to sully Gulf Coast waters.

"The time for committee hearings is for after the well has been capped, not before," Vitter said in the weekly Republican message.

Vitter said the focus should be on stopping the oil flow and protecting the coastline. He said coastal communities also are in desperate need of more containment booms, the barriers designed to stop oil from reaching the coast.

Vitter also promoted a bill that would raise the limit on a company's liability for an oil spill and direct work on technologies that can be used to cap similar oil leaks deep underwater.