District officials plan to erect a 100-bed prison quickly at the Lorton Reformatory and to increase substantially the city's halfway house capacity for Lorton inmates, according to documents filed by the District in federal court yesterday.

But officials are rejecting a recommendation to consider moving as many as 600 mentally ill inmates to a hospital to reduce prison overcrowding.

The District's notice of its plans came in response to a court-ordered report on prison crowding released Monday 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 Department of Corrections.

Fauntleroy's report and a District response were ordered by Green before a July 1 deadline for the city to meet population limits at its Occoquan facilities, which comprise three of the nine Lorton prisons. According to D.C. government statistics, 1,958 prisoners were in the Occoquan facilities as of May 31 -- 667 more than the number that will be permitted under Green's order.

District officials have attributed the increase in prisoners in the Occoquan facilities to the population limits on other Lorton facilities, drug arrests associated with Operation Clean Sweep, court sentencing practices and Board of Parole revocation actions.

Fairfax County officials have criticized the Fauntleroy report recommendations, calling them "disastrous," and they have referred to the proposal for adding prison space at Lorton as an attempt to turn the county into a "concentration camp."

But the report drew praise from attorneys for inmates suing the city, who cited the recommendations as "a major accomplishment."

The District's response to the court said that mentally ill prisoners could be placed in a "noncorrectional setting" only if new facilities for treatment of the mentally ill were "created" by the D.C. Department of Corrections.

Fauntleroy's report recommended that the court consider confining mentally ill inmates, which it estimated at 10 percent of the total, in a nontraditional prison environment at St. Elizabeths Hospital or another hospital facility.

The report 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.

In response, the District emphasized that Green did not need to issue an order for the modular facility because the city is "currently planning the expeditious erection" of the prison.

Also, Fauntleroy recommended that Green consider directing the District to devise a plan within 90 days to rebuild obsolete Lorton dormitories.

In response, the District argued that such a plan could not be formulated in 90 days.

A contract to perform the study, which the city estimates will take at least 10 months and cost about $800,000, is being negotiated with a Washington firm, District officials said.

The District agreed to "substantially increase" facilities for minimum-security prisoners, as recommended by Fauntleroy. His report said the corrections agency has found a site that could accommodate 350 to 500 inmates in a halfway house or minimum-security prison.

The location could not be learned.

The District's response to the Fauntleroy report follows legislation enacted by the D.C. Council and signed Monday by Mayor Marion Barry 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. @Caption: john d. fauntleroy sr.