Dr. Bailus Walker, who was director of the D.C. Environmental Health Administration in the 1970s, has emerged as the leading candidate to head the city's Department of Human Services, informed sources said yesterday.

The current DHS Director, James A. Buford, has said he is leaving at the end of this month and plans to become a consultant.

Annette Samuels, press secretary to Mayor Marion Barry, said yesterday she had no information on the decision but that an announcement might be made by the end of this week on the mayor's choice of Buford's replacement.

But sources said they expect Walker to be named and that he is scheduled to meet with DHS employes soon. The nomination would have to be confirmed by the D.C. City Council.

Neither Walker nor Buford could be reached yesterday.

Walker, 50, became Michigan state health director in 1981 after two years with the U.S. Occupational Safety and Health Administration as director of health standards. He left the Michigan health department at the end of February.

Walker currently is a consultant to DHS and a professor of graduate studies in occupational and environmental health sciences at Howard University.

As director of environmental health from 1972 to 1979, Walker was best known for his aggressive enforcement of city health regulations in restaurants and food stores, including closing down nine of 12 fresh seafood stands along Maine Avenue because of unsanitary conditions in 1975.

He caught grocery stores selling hamburger with too much fat and restaurants serving turkey salad as chicken salad or frozen food as fresh.

In 1977, he prepared a study that showed staggering levels of lead poisoning in children living in affluent Northwest neighborhoods.

That same year, he inspected the city's health clinics and found almost all of them with major deficiencies, including substandard sanitation, plumbing and lighting.

"He was responsible for shaping the city's environmental health standards," said one person familiar with his work. "He has a very good national reputation in his field."

Others say they would expect Walker to have a higher profile as DHS director than the quiet Buford and to be a more aggressive advocate of programs. "Buford turned the place around . . . . There are tremendous things that he was responsible for," said a City Council source. "But he has a quiet, serious, competent management style. He is not an advocate."

Buford was named DHS director in 1980 at a time when the department was under heavy criticism for mismanagement and poor handling of welfare and health problems, and he was the first head of the agency to be appointed by Barry.