The District should erect a 100-bed prison at the Lorton Reformatory, transfer up to 500 Lorton inmates to a halfway house or minimum-security prison outside the Fairfax County complex and move as many as 600 mentally ill inmates to a hospital, a court-ordered report on prison crowding recommended.

The recommendations to reduce crowding were among several listed in a report by former D.C. Superior Court judge John D. Fauntleroy Sr., who was appointed last month by U.S. District Judge June L. Green to oversee planning for the city's Corrections Department.

The 10-page report, which was released Friday, was ordered by Green before a July 1 deadline for the city to meet population limits at its three Occoquan prisons at Lorton. According to D.C. government statistics, 1,953 prisoners are currently in the three Occoquan facilities -- 672 more than the number permitted under Green's order.

Fairfax County officials criticized the report yesterday, but it drew praise from attorneys for inmates suing the city.

John F. Herrity, chairman of the Fairfax County Board of Supervisors, called the recommendations "disastrous" and vowed to "oppose them vigorously through legal and political action."

"Fauntleroy is trying to turn Fairfax County into a concentration camp," said Herrity, referring to the proposal for added prison space at Lorton. "The District is trying to dump every prisoner that they possibly can into Fairfax county. It's becoming increasingly dangerous."

Attorney Peter Nickles, who represents jail inmates, cited the report as "a major accomplishment" in the battle to reduce crowding.

"Instead of continuing to stuff people in these old facilities and have a lot of guards around," Nickles said, "I hope the District will take the study to heart . . . . "

Corrections Director Hallem H. Williams Jr. had no comment.

In the report, Fauntleroy recommended that Green direct the District to submit a timetable for the immediate erection of a 100-bed modular facility that the city recently bought from Prince George's County for $1. He also recommended that Green consider directing the District to devise a plan within 90 days to rebuild obsolete Lorton dormitories.

Fauntleroy urged the District to "substantially increase" facilities for minimum-security prisoners. The report said the corrections department has found a site that could accommodate from 350 to 500 inmates in a halfway house or minimum-security prison. The location could not be learned.

The report recommends that the court consider confining mentally ill inmates, which it estimates represent at least 10 percent of the total, in a nontraditional prison environment at St. Elizabeths Hospital or another hospital facility.

The report follows legislation enacted by the D.C. Council last Tuesday that allows the city to make some prisoners eligible for early parole whenever the prison system's overall population exceeds its official capacity for 30 consecutive days. D.C. Mayor Marion Barry said the law would allow for the release of up to 252 inmates in 180 days.