Watchdog group questions whether Pruitt is using private email to conduct business The Sierra Club wants the EPA to see whether Pruitt used personal email

A watchdog group that requested access to all of Environmental Protection Agency Administrator Scott Pruitt’s email communications was provided with only a single email addressed to anyone outside of the EPA.

Officials with The Sierra Club, the environmental group that sought Pruitt’s emails as part of a Freedom of Information Act request, said they believe the lack of external communication raises concerns that Pruitt could be using a private communication method in his official capacity.

The disclosure was not reviewed by ABC News.

“The idea that Scott Pruitt sent a single work-related external email during nearly a year leading EPA is absurd on its face," said Justine Thompson Cowan, the lawyer leading Sierra Club's case. "That’s why the Sierra Club is demanding that EPA search Pruitt’s personal email accounts for work-related communications, or certify definitively that he does not use personal email or secretive messaging applications like WhatsApp and Signal to circumvent records retention laws."

The Sierra Club requested records of all of the administrator’s emails and communications with individuals outside of the executive branch, but according to a new release, only received one single email sent to an outside source during a 10-month-window. In the same time span, Pruitt received tens of thousands of emails and other communications from top aides.

The group is now demanding that the EPA search Pruitt’s private emails to ensure he was not using personal forms of communication for official business.

The EPA said the request did not reveal many emails because the administrator prefers to communicate in person. It’s unclear if Pruitt used a member of his staff to communicate over email on his behalf.

“Administrator Pruitt works mostly in person through conversations,” a spokesman for the EPA said Friday morning.

Pruitt has been the subject of a host of ethics investigations looking into his spending on things like security details, office furniture and private planes. Two of his top aides recently resigned amid ongoing turmoil in the department.