The inspector general of the Environmental Protection Agency will inspect EPA Administrator Scott Pruitt’s construction of a $24,570 “privacy booth” in his office, the IG said in a letter published Tuesday.

Rep. Frank Pallone (D-NJ), the ranking member of the House Committee on Energy and Commerce, published a letter from EPA Inspector General Arthur Elkins Tuesday, in which Elkins said a probe of Pruitt’s construction of a “secure, soundproof communications booth” in his office is “within the authority of the IG to review, and we will do so.”

In a hearing last week, Pruitt confirmed that he’d constructed a SCIF — short for Sensitive Compartmented Information Facility — in his office for conversations of classified information and for “secure conversations that need to take place,” including with the White House. He didn’t put a number on what percentage of his time he spent in the SCIF.

“The use of a secure phone line is strongly preferred for cabinet-level officials, especially when discussing sensitive matters,” EPA spokesman Jahan Wilcox told ABC News in a report published Wednesday.

Elkins noted in his letter to Pallone that “[a]s you know, we have numerous pending matters, and are not sure when we can begin with this engagement” and that his office “has been funded at less than the levels we deem adequate to do all of the work that should be done, and therefore we have to make difficult decisions about whether to accept any given potential undertaking.”

It’s true: the EPA’s self-investigating body is swamped. The office is already probing investigating Pruitt’s use of charter and military flights at taxpayers’ expense, including on trips home to Oklahoma.

And in a letter to Pallone dated four days prior to his message about Pruitt’s secure phone booth, Elkins confirmed that his office would look into a meeting between Pruitt and the National Mining Association in April 2017, to establish whether Pruitt or his staff may have violated lobbying laws by communicating their opposition to the Paris climate accord.