Sens. Tom Carper, D-Delaware, and Tom Udall, D-New Mexico, released, on April 30, a letter from the Environmental Protection Agency Office of Inspector General to Office of Management and Budget Director Mick Mulvaney outlining OMB’s lack of cooperation in a probe examining a number of troubling irregularities in the crafting of a November 2017 proposal to repeal air emission standards for heavy-polluting “glider trucks.”

The letter provides a timeline that details a consistent pattern over several months to ignore and sidestep basic requests from the IG’s office.

“I do not accept today's response from OMB that, while ‘very supportive of EPA OIG's work,’ it declines to support our work due to the supposed deliberative character of the sought information,” wrote EPA Acting IG Charles Sheehan. “...Such protracted delay constitutes a clear impediment to our audit. It undermines our ability to fully answer the congressional request that led to our audit. Accordingly, and as required by the IG Act in the event of information being requested by an inspector general and being unreasonably refused or not provided, ‘the inspector general shall report the circumstances to the head of the establishment involved without delay.’ Please consider this letter my report to you of such circumstances.”

Carper and Udall released a joint statement reacting to this letter.

“We are deeply troubled to learn that, for several months, top leadership at the Office of Management and Budget has been evading the EPA Office of Inspector General’s entirely reasonable investigatory requests,” according to the statement. “Director Mulvaney’s refusal to cooperate with the EPA OIG investigation we requested it undertake only leads to more questions about this administration’s blatant disregard for transparency and the rule of law — if there is nothing to hide, why is this administration shielding EPA? We call on OMB to fully cooperate with this investigation so that both Congress and the American people have a clear and complete understanding of EPA’s decision-making on a matter that will lead to more polluting trucks on the road.”

A PDF of the letter from the EPA OIG can be found at