Christoph Tulou, former director of the D.C. Department of the Environment. (Jeffrey MacMillan/Capital Business)

A member of Mayor Vincent C. Gray’s Cabinet has been fired for what one city official described as a “serious breach of protocol.”

The dismissal of Christophe A.G. Tulou, director of the D.C. Department of the Environment, was announced in an unusual Friday afternoon news release from City Administrator Allen Y. Lew. The release did not detail why Tulou was fired; Lew’s spokesman, Tony Robinson, referred to the “breach of protocol” in a brief interview but declined to detail what it was.

Two officials with knowledge of the firing said Gray (D) and Lew were increasingly dismayed with Tulou acting without their knowledge or input.

One incident, one official said, concerned efforts by city agencies to seek a waiver from the federal Environmental Protection Agency and other parties allowing it to test “low-impact development” as a substitute for expensive tunneling to prevent sewage from draining into the Potomac and Anacostia rivers.

According to the official, Tulou approached the EPA without Lew’s or Gray’s knowledge to discuss seeking the waiver to a 2003 court-enforced consent decree — something Gray has publicly endorsed but which has been met with opposition from several environmental groups.

Tulou did not immediately return a call for comment Friday afternoon.

His dismissal comes as tensions have risen between the environment department and real estate developers, who have been particularly critical of new regulations concerning stormwater management.

Ernie Jarvis, president of the D.C. Building Industry Association, said he contacted Tulou and other officials about the “velocity” of new rules.

“We were concerned about the lack of collaboration and the lack of understanding of some of the commercial impact” of some of the regulations, Jarvis said. He said his organization had not requested that Tulou be fired. “We were not calling for personnel change; we were calling for more collaboration with the private sector,” he said.

In a statement, Lew thanked Tulou for his service and said he would “immediately commence a search for a strong, innovative leader of this vital agency.” Keith Anderson, the agency’s chief of staff, will serve as interim director, he said.

D.C. Council member Mary M. Cheh (D-Ward 3), who oversees the environment department, said she thought Tulou at times “didn’t have a handle on the nuts and bolts of the agency.”

“But I want to be clear — I thought he was a good head of the agency, and things are moving along,” she said. “I’m not particularly happy we have this upheaval at the top.”

Tulou, a former director of Delaware’s Department of Natural Resources and Environmental Control, was named to lead the department in 2010 by then-Mayor Adrian M. Fenty (D).

He replaced George S. Hawkins, now general manager of D.C. Water and a major proponent of using low-impact development — efforts to reduce the amount of storm runoff entering the sewer system — to abate the need for tunneling.While he had heard “technical concerns” from Tulou about the waiver proposal, Hawkins said, “I believe the position of the mayor’s office is clear.”

Hawkins said he was not aware of the circumstances of Tulou’s dismissal. “I like Christophe; I liked working with him,” he said. He added that there’s “been all sorts of back and forth between the parties” over seeking the waiver in recent months.

Nikita Stewart contributed to this report.