The Prince George's County government rather than the Washington Suburban Sanitary Commission supervised construction of a sewer line to the Bowie ambulatory care clinic that was 30 feet off its proper course. The supervising agency was incorrectly identified in a story in Tuesday's editions.

Fifteen minutes after the press releases had been distributed announcing Earl C. Mechtensimer's selection as Prince George's County's new hospital director, County Executive Lawrence J. Hogan walked into his first formal press conference yesterday and withdrew Mechtensimer's nomination.

"It's just a logistical problem -- I haven't had a chance to check with the County Council on this," Hogan said. "I'm embarrassed."

Then Hogan smiled weakly. "Anyway, all the other announcements in the press release" -- naming the members of two health task forces -- "are still operational, as they used to say."

Yesterday's confusion only contributed to a series of blunders and stumbles that have dominated Hogan's week-old administration, which itself even now is only partly operational.

In the past six days Hogan or his aides have been forced to clarify or retract announcements of programs or appointments three times, and several of Hogan's plans or statements have been openly challenged by veteran county officials as impractical or inaccurate.

The last time something like this happened was late last week, when Hogan's chief aide, Robert T. Ennis, had told a reporter -- accurately -- that Hogan planned to create a new post of county director of public safety.

The following day, a second aide characterized Ennis' report as a "misstatement" and Hogan called a 10 a.m. press conference to clear the air. No reporters arrived. Hogan's aides had been unable to locate reporters to inform them of the meeting.

"We're off to an awkward start," Hogan conceded, but added, "we'll get better as we get older."

Hogan's most apparent problem has been his obligation to act immediately on appointments and budget policies, even though he is still struggling to fill out his own personal staff and acquaint himself with a vast and, to a former congressman, largely unfamiliar local government bureaucracy.

Last week, attempting to fulfill a campaign promise to voters, Hogan announced a series of measures that he said would cut the costs of the executive's office and the personnel department.

Before the day was over, however, high ranking county officials were already saying that his plan to personally review all overtime requests was impractical and his strict rules for use of county cars were already in force.

Yesterday, Hogan's embarrassment was caused by his ignorance of the county council's schedule. "I was hoping to talk to some of them this morning [about Mechtensimer's appointment]," Hogan said, "but they are meeting on zoning. I should have known that."

Council Chairman William B. Amonett said yesterday that he was not acquainted with Mechtensimer, who is a deputy director of Baltimore City hospitals, but did not think that the council would object to the appointment.

Amonett, however, was taken aback by another of Hoganhs announcements. Told that he had been named to a new mental health task force, Amonett said, "What? I didn't know that."

Council administrator Kenneth V. Duncan, who was appointed yesterday to Hogan's second task force, on health services, said he was told of his new job late Sunday night.

"All I know about it is that Hogan talked about [the task force] in his inauguration speech," Duncan said. "I don't even know who else is on it."

In announcing the two task forces, Hogan spoke at length on the county's health and hospital problems, calling for both the end of waste in services and for the addition of two news services -- a dental clinic and mobile health units for senior citizens.

He charged, in part, that the school boards' health services for students were "inadequate" and that the new Bowie ambulatory clinic was struggling with the Washington Suburban Sanitary Commission, which, Hogan said, had mislaid a sewer line to the hospital. "That little mistake will cost $300,000," Hogan said.

A WSSC spokesman said yesterday that the pipeline had indeed been mislaid but that the cost to fix it would probably be about $60,000, and Louise Blavelt the supervisor of county school health services, said, "We have staffing probems. But our services are not inadequate. I haven't talked to Mr. Hogan and I don't know where he's getting his data from."