Students at the University of Virginia, already the subject of a federal grand jury investigation into drug dealing, must be told that illegal drugs will not be tolerated but that help is available to abusers, the school's president told a task force today.

The 11-member group, appointed Monday by President Robert M. O'Neil, is to investigate the extent of drug use at the school, review drug and alcohol policies, and recommend changes by April.

Sitting beneath a portrait of founder Thomas Jefferson in the university's historic Rotunda, O'Neil said that drug use is so pervasive in society that there is no way to create an "island of abstention" at the school.

However, he said, "I would not accept as our goal a 'tolerable' level of drug or alcohol abuse."

One of the task force's first jobs will be to help O'Neil prepare antidrug materials for new students this fall and to draft a letter to parents about the university's drug policies.

U.S. Education Secretary William Bennett recently urged college presidents to take a hard line against drug use by writing students a letter this summer that reads: "Welcome back to your studies in September, but no drugs on campus. None. Period."

Most task force members rejected that message as simplistic. "Not that we're going to have the Gestapo in the dormitories . . . . I'm not sure that is the message we want to communicate," said Dr. Randolph J. Canterbury, medical director of a university hospital drug treatment facility.

The proper message, he said, is to "set some limits" but show "we are concerned about caring" for people.

"The message to convey is a little more complex than Secretary Bennett said," according to O'Neil.

The task force's 90-minute introductory meeting was short on specifics, but members agreed to consider expanding drug counseling programs currently offered university employes so that students could benefit.

Next week, a federal grand jury that has been investigating drug dealing here since last fall is expected to return indictments against students and local residents. A former university football player and a law student have pleaded guilty to drug charges and are awaiting sentencing July 28.

The grand jury investigation has set the school on edge, but O'Neil said his concern about campus drug use dates to his arrival at the school last year.

Task force members said they did not think Virginia has heavier drug use than other schools. If anything, Virginia usually lags two years behind trendy areas like California, said Dr. John Buckman, a psychiatrist who is a member of the Governor's Advisory Council on Drug Abuse.

The latest national survey of college student drug use, released this month, found that one in three students tries cocaine, but that use of marijuana and other illicit drugs is dropping.

Some task force members said they are realistic about the lure of experimenting with drugs, but hope to reduce the amount of serious side effects that might result.

The dean of students' office is compiling the results of a survey of drug use among 700 randomly selected students, of whom 357 responded. Some results may be released next week.

The task force, whose members include students, professors of medicine, law and education, a social worker and administrators, includes no representatives of the athletics department. That was deliberate, said Chairman John A. Owen Jr., a medical professor, because "we don't see the need to treat them any differently" from other students.