But McSlarrow, in remarks made before the first Senate hearing into the Aug. 14 blackout, urged lawmakers not to wait for the investigation to be completed before passing this fall a comprehensive energy bill, which he said would go a long way toward preventing another outage.
McSlarrow didn't pinpoint the cause of the blackout, which also hit parts of Canada, affected 50 million people and shut down more than 100 power plants. The U.S.-Canada task force investigation is still in the beginning stage of its inquiry.
"You believe the provisions in the energy bill right now will get the job done?" asked Sen. George Voinovich, chairman of a Senate Governmental Affairs' oversight panel.
"It will get most of the job done," McSlarrow said, adding that if there are additional legislative recommendations that come out of the investigation, the administration would present them to Congress at a later time.
McSlarrow emphasized the administration's support for mandatory reliability rules for transmission lines and added that it supports additional federal oversight on where to put new lines. He shied away from adding support for mandatory regional transmission monitors but said the administration supports the concept.
"We think they actually require some encouragement, but the issue as to whether to make them mandatory, we haven't taken a position," McSlarrow said.
Congress is under pressure from state and federal regulators to mandate that utilities join the groups, which would enforce quality standards and monitor electric transmission lines.
"Such entities would improve reliability because they have a broader perspective on electrical operations than individual utilities," said Pat Wood, chairman of the Federal Energy Regulatory Commission.
Officials from two regional transmission monitors, the Midwest Independent System Operator and PJM Interconnection, told congressional investigators that agreements to share data, such as one they reached just before the blackout, would improve reliability.
"All the regional entities involved have an appreciation today that communication between reliability coordinators and other entities has to be raised to a higher level than has been required or practiced in the past," James Torgerson, president of Midwest ISO, said in prepared remarks.
Craig Glazer, vice president of PJM, and William Museler, president of New York ISO, were to testify in favor of having all utilities join regional transmission monitoring groups such as theirs. Currently, the decision to create such regional groups to monitor the grid is voluntary and rests with state utility commissions.
Alan Schriber, who is chairman of the Public Utility Commission of Ohio, was to testify in favor of the plan while James Kerr, commissioner of the North Carolina Utilities Commission, planned to tell lawmakers that such regional groups "are certainly not the answer."
Opponents say the formation of such groups won't add additional transmission capacity but will cost millions to implement. Kerr has said such monitors aren't needed in the south, which escaped the recent blackout and enjoys rates that are among the lowest in the country.
Voinovich, the subcommittee chairman, hasn't said what provisions he wants to modernize the transmission system, but says changes should be included in a comprehensive energy bill now before Congress to make sure the light goes on when people flip their switches.
Sen. Carl Levin, D-Mich., argued that Congress should move separately to enact the new rules because the issue is too important to be tied up in legislation that includes controversial measures such as drilling in Alaska.
President Bush has sought approval for such drilling for years, saying it is necessary to explore Alaska's Arctic National Wildlife Refuge for oil because the region might supply enough crude to allow greater U.S. energy independence.
But Democrats and environmentalists have opposed the move, arguing it would spoil the pristine landscape.
The nation's worst blackout started in Ohio and Michigan before sweeping through transmission lines running into Canada and down through New York state. Investigators have focused on failures of a power plant and lines owned by FirstEnergy Corp. of Akron, Ohio, although the probe is also concerned with how the blackout rippled through the national grid.
First Energy has denied being at fault.