AUGUSTA — An environmental group has asked the federal government to investigate whether Gov. Paul LePage violated federal law when he appointed Darryl Brown to head the Maine Department of Environmental Protection.

The Androscoggin River Alliance alleges that the appointment violates a provision of the federal Clean Water Act that prohibits people from directing such an agency if they have received more than 10 percent of their annual income over the previous two years from water pollution permit holders.

Brown owns Main-Land Development Consultants, an engineering and land-planning firm that helps developers obtain permits from state and local governments.

One of the firm’s current clients, Black Bear Entertainment, will be seeking state permits to build a casino in Oxford.

That type of “direct and substantial” conflict of interest is generally illegal under the Clean Water Act, said Neil Ward, program director for Androscoggin River Alliance, a citizens group based in Lewiston.

Brown has told lawmakers that he plans to sell his company and that in the meantime he will recuse himself from any decisions that might affect his company or its clients.

Brown was sworn into office last Tuesday. He has resigned as president and has established a governing board to run the firm. The board last week selected Robert Berry, an engineer and project manager at the firm, to serve as president.

LePage spokesman Dan Demeritt said that Brown has gone to great lengths to shield himself from conflict of interest.

He noted that the Androscoggin River Alliance did not attend Brown’s confirmation hearing, which was held two weeks ago.

“The fact that they are raising these concerns just a week after Commissioner Brown has taken office should make it clear to everyone that this is a stunt,” he said.