Mayor Marion Barry suggested yesterday that an effort to find an alternative site on which to build a new prison in the District will fail because the other locations are proving unacceptable.

Barry, in wide-ranging remarks at a luncheon for reporters and editors, said a proposed site at Bolling Air Force Base -- which previously was opposed by the Department of Defense -- likely would be rejected as an alternative to a site next to the D.C. Jail because it is only a few hundred yards from a hangar used by crews that fly the president's helicopters.

The District, after years of controversy and prodding by Congress, decided last year on the D.C. Jail site in Southeast, but early phases of the $50 million construction were stopped in September by the Senate appropriations subcommittee on the District.

Sen. Tom Harkin (D-Iowa), chairman of the subcommittee that oversees D.C. government spending, cited complaints from neighborhood residents and the discovery of historical Indian and Civil War artifacts. Harkin and city officials are awaiting a review of three other sites by the General Accounting Office and Federal Bureau of Prisons. A report is due Feb. 1.

Another potential site, an old brick yard along New York Avenue NE, is owned by the Department of the Interior, which has refused to release the land. It also lies in a flood plain that would pose dangers to the building, Barry said.

The mayor did not mention the third site -- vacant land near Fort Lincoln in far Northeast, which city officials have said is unacceptable because it has been used as a dump for potentially hazardous electrical equipment.

On other issues, Barry said:In response to a question, that he had "never knowingly" used marijuana. In a reference to published admissions by Supreme Court nominee Douglas H. Ginsburg and other public officials that they had used the drug, Barry said intense media scrutiny has "swung the pendulum too far" and that good candidates for public office or civil service may simply say "to hell with it." He expects no further major indictments arising from federal investigations into the use of his ceremonial fund and city government contracting. Barry said he has not been subpoenaed by any grand jury and doesn't expect to be. The city's drug problems are worse than an epidemic. "We've gone beyond epidemic . . . . I don't know if there is a word for it . . . but we've gone beyond that." Barry has said he will propose new antidrug initiatives next month. The District has one of the most liberal Freedom of Information acts in the country, and that news organizations have cost the city about $2 million in recent years in staff work. Barry did not suggest changes in the law, but said he would consider charging more of the cost to news organizations.

He has no specific answers to the dispute between Metro officials and Mitch Snyder, an advocate of the homeless, who began a hunger strike this week to try to persuade Metro to remove a fence barring homeless people from using the Farragut West station at night. He said some advocates see the fence as a "symbolic locking of the homeless out," and added that suburban representatives on the regional Metro board "don't feel as sympathetic to the homeless as we do."