A sharply divided Prince William County School Board adopted the superintendent's recommendation last night for a high school boundary change that has plunged the county into one of its most acrimonious periods in a decade.

The board also approved a $193 million capital improvements plan to be implemented over six years and an instructional blueprint -- a six-year plan -- that would add a seventh period to the high school day starting in September.

The boundary change, recommended this month, pitted board member against board member, neighborhood against neighborhood and prompted allegations of meddling in School Board affairs by members of the Board of County Supervisors.

Under the new boundaries, which will affect ninth graders next September in the school system of 39,000 students, the "Old Woodbridge" neighborhoods along U.S. Rte. 1 will remain in the Woodbridge High School district, while children in neighborhoods west and south of Lake Ridge will attend Gar-Field High. A new grade will be affected by the new boundaries with each successive year.

The adopted boundary plan, which was supported by board Chairman Gerard P. Cleary (Woodbridge), Vice Chairman Maureen Caddigan (Dumfries), George P. Mullen (Brentsville) and Donald A. Chendorain (Neabsco), has been bitterly opposed by residents of the areas to be transferred from Osbourn Park and Woodbridge districts to the Gar-Field district. Some of the areas are closer to Woodbridge than to the school children in those areas will attend. Scores of those residents, from the Coles and Occoquan districts, attended last night's meeting.

"I'm outraged and insulted," said Springwoods resident Bob Harrington after the meeting. Harrington's neighborhood will be in the Gar-Field district.

Behind-the-scenes jockeying for support of the adopted plan and another favored by Ilona Salmon (Occoquan) and Odis Price (Coles), which would have kept their areas at Woodbridge and removed the Marumsco area to Gar-Field, has often been bitter, according to several board members.

Cleary and Caddigan said this week that threats have been made that they will not be reappointed to the board when their terms end. Caddigan's term is up at the end of March. Cleary and all other members of the board are up for reappointment July 1.

Each county supervisor appoints a school board member from his or her district. The entire board votes on the appointment.

Debate on the boundary issue last night was punctuated with applause and jeers from the predominantly Occoquan-Coles area audience, and with one unsuccessful attempt at compromise by board member Patricia L. Cusey (Gainesville).

The eastern end of Prince William has been plunged into controversy since early January, when Superintendent Edward L. Kelly offered four options for new high school boundaries.

Kelly has acknowledged that the capital improvements plan, which now goes to the Board of County Supervisors, is ambitious, but he stressed it is "only a planning document."