In addition, Mr. Pruitt faced irritation from the White House after The Atlantic magazine reported that Mr. Pruitt’s office gave raises to two aides, even though the White House had declined to approve the raises.
The E.P.A. has denied any wrongdoing on Mr. Pruitt’s behalf.
As the scandals mounted through the spring, Mr. Pruitt was called to testify before several House and Senate committees. Although they were routine budget hearings, they ended up serving as forums for lawmakers to interrogate Mr. Pruitt about his management practices. Mr. Pruitt, who is deeply religious, spent considerable time in the days before the hearings in prayer, according to a person close to him.
He got through the hearings battered but intact, after deflecting blame for numerous issues onto his staff, particularly his chief of staff, Mr. Jackson, whom he blamed for making controversial decisions such as the illegal purchase of the $43,000 secure telephone booth.
But the tactic of blaming his employees cost him loyalty.
In recent months, nearly a dozen political appointees have quit or been fired from the E.P.A. More recently, many of those staffers have been called to testify to investigators on the House Oversight Committee, which had launched a probe into Mr. Pruitt’s expenditures. The results of that investigation were expected to be the subject of a Senate hearing next month.
Inside the E.P.A. on Thursday, as news of Mr. Pruitt’s departure spread, some career employees said that the mood was jubilant but quiet given that many people were out of the office around the July 4 holiday. Some employees met for early drinks at Mackey’s Public House, a bar near the E.P.A.
It remains unclear how well some aspects of Mr. Pruitt’s regulatory rollback agenda, and his effort to undo the environmental work of his predecessors, will stand the test of time. In his haste to cripple government regulation and publicize his success, Mr. Pruitt and his officials have failed to follow important procedures, and courts have already struck down at least six of his rollback efforts.