"The new information provided by Mr. Chmiewelski, if accurate, leaves us certain that your leadership at EPA has been fraught with numerous and repeated unethical and potentially illegal actions on a wide range of consequential matters that you and some members of your staff directed", the lawmakers wrote to Pruitt.
McCollum said the GAO report showed a culture of "corruption, cronyism, and incompetence that is pervasive" at the EPA under Pruitt.
"Can you confirm that the EPA does in fact search all your official email accounts when responding to [Freedom of Information Act] requests?"
EPA officials said the booth was needed so Pruitt could "make and receive calls to discuss sensitive information ..." Along with the $24,570 contract for the actual booth, that sum included $7,978 to remove closed-circuit television cameras, $3,470 for concrete floor leveling, $3,360.97 to install a drop ceiling, $3,350 for patchwork and painting, and $509.71 for cabling and wiring.
GAO stressed it was not ruling on whether Pruitt's phone booth itself broke the law, rather that EPA's failure to notify Congress about its spending above the $5,000 limit was the breach. Pruitt's office did not notify Congress about the excessive spending, the GAO contends, in violation of the Financial Services and General Government Appropriations Act.
The EPA said at the time that two of them are used by staff for scheduling and correspondence, one is used by Pruitt himself and one hasn't been used except for three test emails.
"Scott Pruitt likes to talk about returning the EPA to the rule of law, but it turns out he's better at breaking it than following it".
If the agency had informed the House and Senate Appropriations committees of the plans to spend that amount on the booth, investigators said, its installation would not have been illegal.
Statements from environmental groups also poured in, with several calling on Pruitt to leave the agency. He also asked the EPA head to provide a list of all of the email accounts that Pruitt uses. Donald Trump shouldn't wait to see what ethical norm or law Pruitt breaks next.
Republicans also expressed concerns in response to the GAO ruling released today.
GAO General Counsel Thomas Armstrong determined that EPA's purchase of the booth violated federal law prohibiting agencies from spending more than $5,000 for redecorating, furnishings or other improvements to the offices of presidential appointees without informing Congress.
"Salaries are based on work history; and, any increases are due to either new and additional responsibilities or promotions", EPA spokesman Jahan Wilcox said in reference to the OIG probe into the hiring and salary raises.
EPA in the past has run up against GAO legal opinions.