Four senior aides to embattled Environmental Protection Agency (EPA) Administrator Scott Pruitt have resigned from the agency in the past week, according to reports.

John Konkus, deputy associate administrator within the EPA's Office of Public Affairs, reportedly resigned on Friday (May 4) to accept a position with the Small Business Administration. One day earlier, Konkus' boss, Liz Bowman, also reportedly left the agency to become a spokeswoman for Republican Sen. Joni Ernst of Iowa.

Two other senior advisers to Pruitt, Albert Kelly and Pasquale Perrotta, left earlier in the week, according to reports. Kelly formerly managed the EPA's Superfund cleanup program, while Perrotta was in charge of Pruitt's security detail.

The departures came one week after Pruitt testified before two House panels. The EPA administrator defended his performance and spending at the agency to lawmakers on the House Subcommittee on Environment, and the House Subcommittee on Interior, Environmental and Related Agencies.

Last month the Government Accountability Office said the EPA violated federal law when it installed a soundproof privacy booth in Pruitt's office, a luxury that cost taxpayers more than $43,000. A growing number of lawmakers, including Republicans, have called for Pruitt to be fired or resign.