The Environmental Protection Agency’s independent watchdog can’t keep up with all of Administrator Scott Pruitt’s scandals. In January, EPA Inspector General Arthur Elkins revealed that his office will limit its investigation of Pruitt’s controversial first-class travel to the previous calendar year. The Office of the Inspector General lacks the “people, time and funds” necessary to investigate the matter beyond 2017 while continuing its other investigations, Elkins wrote in a letter to House Democrats. “The fact is that the OIG has been funded at less than the levels we deem adequate to do all of the work that should be done, and we therefore have to make difficult decisions about whether to accept any given potential undertaking.”

That the OIG must cut short any investigation due to insufficient resources is troubling enough, but even more so given the revelations about Pruitt’s travel in a Washington Post report this month. The Post found that in June alone, Pruitt and his entourage racked up at least $90,000 in travel bills, mostly from exorbitantly-priced first-class flights and one $36,000 military jet from Cincinnati to New York. Under pressure to justify these costs, the EPA said Pruitt has a “blanket waiver” to fly first class wherever he goes, due to vague “security threats.”

How is it that EPA can afford such luxurious travel, but not enough money for its independent watchdog to investigate whether that travel was improper? The EPA and its OIG have separate budgets—and Trump wants to further tighten the OIG’s budget. If he gets his way, this wouldn’t only limit scrutiny of Pruitt, but of the programs that reflect the EPA’s core mission of protecting Americans from pollution.

Pruitt is the subject of at least four OIG investigations opened last year at the request of Democrats in Congress, including the travel audit (which was expanded twice). The OIG is looking into Pruitt’s four-day, $40,000 trip to Morocco to promote the use of American natural gas, which may be improper because the EPA has no role in natural gas exports; his purchase of a $25,000 soundproof security booth for his office, which may have run afoul of appropriations law; and his use of EPA enforcement agents to provide him with 24/7 security detail, which may be improperly pulling resources away from enforcement programs against polluters.

An OIG spokesperson declined to detail the cost of these investigations, citing their ongoing nature. The travel audit appears to be the most demanding. OIG investigators will have to obtain and audit of hundreds of receipts for Pruitt, his many aides, and his security detail. Staff must then determine whether EPA travel policies were followed for each individual on every trip. That’s a lot of work, said Peter Tyler, an investigator for the Project on Government Oversight. “This looks like a full-on audit to be written by the IG himself,” said Tyler, who used to work in the inspector general’s office of the Department of Health and Human Services. “It seems legitimate for them to say, I’m setting a priority, and only looking at 2017.”