Environmental Protection Agency administrator Scott Pruitt said Tuesday the days of "political science" are over at the agency, announcing a new conflict of interest policy that prevents individuals sitting on EPA scientific boards from receiving grants from the agency.

Under the last three years of the Obama administration, members sitting on just three of the agency's scientific advisory boards received $77 million in EPA grants. Pruitt said individuals advising in policy and regulatory matters should be completely independent of the EPA.

"These federal advisory committees are very, very important to agencies and how they conduct their business in the rulemaking process," Pruitt said.

"The EPA grants, we control that and we think it sends important things to the American people that we're not going to have $77 million in grants going to a certain number of advisers at the same time they are advising about the efficacy of the rules that we're adopting across the whole spectrum of the agency," he said.

"Whatever science that we're involved in at the EPA should not be political science," Pruitt said.

The directive will go into effect immediately.

The EPA is finalizing appointments to three of its scientific advisory boards: Board of Scientific Counselors (BOSC), the Clean Air Scientific Advisory Committee (CASAC), and the Science Advisory Board.

Earlier this year the agency broadened its application process, soliciting applications from underrepresented states.

Pruitt said large geographic areas like the Midwest have not been represented on the advisory boards. For instance, no members were from West Virginia, Montana, Kentucky, Louisiana, Oklahoma, Kansas, North Dakota, Nebraska, and other states.

The new pool of appointments, which will be announced in the coming week, will include members from EPA regions 6, 7, and 8. Those regions, which cover Dallas, Kansas City, and Denver, previously did not include a single representative on CASAC.

Pruitt said current members who are asked to continue their service and have received EPA grants would have to forgo grant funding if they stay on the board.

"You can choose service on the committee or choose the grant, you can't do both," Pruitt said. "And that's the fair thing to the American people."

The EPA will continue its ethics review for all members appointed to advisory boards, which addresses conflict of interest on whether applicants have received funding from third parties or industry.