Fairfax County officials, fresh from a spat with District authorities over escapes from Lorton Reformatory, took aim yesterday at Virginia corrections officials after a man walked away from the state's Camp 30 correctional unit late Tuesday.

Brian L. Fox, a 23-year-old Loudoun County man who had served one year of his eight-year term for burglary and grand larceny, apparently walked away from groundskeeping duty in the front yard of Camp 30 between 5 and 6 p.m. Tuesday, state officials said. His absence was not discovered until about 9 p.m., they added.

Fairfax officials said state authorities at Camp 30 violated an agreement with the county by not sounding the prison's siren three times to alert local residents of the escape and by not notifying county police promptly. Fairfax police said they were notified of the escape at 10:40 p.m. -- an hour and 40 minutes after Fox was discovered missing.

County Board of Supervisors Chairman John F. Herrity said he would ask for a meeting with Camp 30 officials to discuss notification procedures after escapes.

The correctional unit, which houses about 150 minimum- and medium-security inmates, is off West Ox Road about three miles west of Fairfax City.

County officials compared the escape to one at Lorton on Jan. 3.

"This is just as serious as the Lorton situation," said Herrity. "I don't think we ought to tolerate any more from our own state government than we do from the District of Columbia."

Camp 30 Superintendent James E. Collins said the siren was not sounded Tuesday night because prison officials thought Fox was long gone by the time he was discovered missing. "What are you going to do if a guy's gone five hours?" Collins said.

Collins added that Fox, a minimum-security prisoner with no record of violence, remained at large late yesterday.

He said two other Camp 30 inmates have escaped in the last three years. Both were recaptured, he said.