ON JUNE 15, the old D.C. jail is scheduled to be closed.The approximately 450 inmates usually held in the jail will be sent either to the city's new jail or to Lorton, the city's prison. If the jail were to close today, more than 200 inmates would have nowhere to go. The overflow of 200 inmates could not be legally held in the new jail for more than 24 hours because orders now mandate more space per person for every inmate in the jail.

Theoretically, the overload could be eased by sending the excess inmates to Lorton. But Lorton is already overcrowded. And although there is no court order requiring that Lorton keeps its population below its official capacity (about 1,600), corrections officials cannot send most of the inmates now in the old jail to Lorton. That is because the vast majority of the old-jail population is being held for misdemeanor crimes or as pre-trial detainees. Lorton, a prison, is for convicted felons, and people awaiting trial or convicted of misdemeanors are not to be mixed with convicted felons without their legal consent. Corrections officials say most of those being held at the old jail do not want to go to Lorton, a prison especially feared for its population of tough criminals.

"I have no problem closing the old jail," Dalbert Jackson, director of the Department of Corrections has said. "The mayor wants it . . . but I can't turn loose 200 people committed to the jail by the court without the court's consent. If we close the jail, we've got to have a place to put them. I won't do it otherwise." Despite Mr. Jackson's protests, Mayor Barry would like to see the old jail closed and demolished. Ivanhoe Donaldson, the mayor's general assistant, feels the city government should be urging the courts to put more people awaiting trial or convicted of misdemeanors into community halfway houses and to stop sending so many people to jail. "There are too many people in this town in jail for parking tickets, little things that the jail should never have to handle," he says.

Certainly the old jail should be closed. It is a hulking, badly designed structure that takes too large and costly a staff to operate. Most of its inmates are held in large open floors with barracks-like accommodations: rows of metal beds crammed next to each other. The few cells in the jail are kept for the older inmates as a privilege because these shelter them from the huge rooms that hold all the tension, assaults and trouble that you would anticipate if you were crowding jailed younger men together in one room. Some juveniles are held in a separate wing of the jail. When that wing is overpopulated, the extra young men are temporarily placed in the "penthouse," the former death row, next to an electric chair in which 44 people were electrocuted.

But despite all this, there is currently no other place to hold people who are awaiting trial or who have been convicted of misdemeanors. If community halfway houses for detainees are used to hold some people now in the old jail, then the halfway houses will become overpopulated too. And an overload at the halfway houses could drive up the size of an already too-large prison population at Lorton because there would be no space to accommodate prisoners who earn release to a halfway house. One solution would be to build a new jail. But that would take too much money out of an already city budget.And short of that, the city's top option is to make the best possible use of all jail space as well as community halfway houses and other facilities of non-violent criminals.