Gina McCarthy testifies before a Senate Environment and Public Works Committee hearing on her nomination to be administrator of the Environmental Protection Agency on Capitol Hill in Washington, in this April 11, 2013 file photo. (Joshua Roberts/Reuters)

President Obama’s nominee to head the Environmental Protection Agency was quickly approved by a Senate committee Thursday when Republicans abandoned their boycott of a vote on the career environmental administrator, after what Sen. David Vitter (R-La.) described as “significant steps forward” on transparency issues important to the GOP.

The Committee on Environment and Public Works voted 10 to 8 along party lines in favor of Gina McCarthy, the EPA’s assistant administrator in charge of air and radiation. The vote sends McCarthy’s nomination to the Senate floor. However, Sen. Roy Blunt (R-Mo.) still has a hold on her nomination that will have to be withdrawn before a floor vote can occur.

The Democrats in favor of McCarthy included Sen. Frank R. Lautenberg (N.J.), 89, who has been ill and traveled from his home state in case his vote was needed to break a logjam. Shortly after the hearing began, Lautenberg was brought into the hearing room in a wheelchair and took his spot next to Sen. Benjamin L. Cardin (D-Md.).

Under Senate rules, a committee can vote on a nominee if 10 members, a majority, are present and vote in the affirmative. Democrats hold a 10-to-8 majority on the panel.

On May 9, all eight Republican members of the committee skipped a scheduled vote on McCarthy, postponing it. The move caught Democrats, who were notified a half-hour before the meeting, by surprise.

But Vitter, the committee’s top Republican, said at the beginning of Thursday’s session that meetings with McCarthy, acting EPA Administrator Bob Perciasepe and others had produced progress on Republicans’ complaints about EPA practices.

The EPA agreed to require retraining of its workforce on employee use of personal e-mail accounts; establish an expert advisory panel on economic modeling; and work to obtain underlying research on some EPA decisions requested by Republicans, according to a letter to McCarthy and Perciasepe released by Vitter.

Vitter also listed additional demands in each of five categories and promised that if “major additional progress” is made on all of them in the next two weeks, he would support a Senate vote on McCarthy without a filibuster. If all the requests are granted, he wrote, he would vote for McCarthy.

Asked in an interview after the vote what would constitute “major additional progress,” he said, “We’ll know it when we see it.”