When the Trump administration last fall unveiled its cornerstone policy for carrying out the Clean Water Act—new language spelling out the reach of the Environmental Protection Agency’s authority—it said one of its goals was to return power to states and tribes.

“This proposal recognizes that states and tribes know their local land and water resources best,” the EPA said in a news release announcing its revised definition for “waters of the United States.” That plan is still in the works and on Friday the agency said it would be seeking public comment on a number of regulatory alternatives.

But the EPA is moving forward with revisions to a separate set of Clean Water Act regulations that would limit state and tribal authority over waterways—especially when it comes to weighing in on major energy projects like oil and gas pipelines, export terminals and hydropower dams.

At issue is Section 401 of the Clean Water Act, which requires that any such projects that could result in pollution to a navigable waterway get a water-quality certification from the states or tribal lands where the pollution would originate before they can obtain their federal permits.

The Trump administration maintains that state and federal cooperation—what it calls “cooperative federalism”—is a key pillar of EPA Administrator Lee Zeldin’s policy framework. But the EPA says this requires clear rules, including that states cannot improperly use Section 401 to veto projects for reasons other than specific aspects of water quality.