Long past bedtime for a stay-at-home mom with three kids, Allison D. Broadbent was huddled over her computer last month, typing away. Her printer spit out the news that would soon reach 154 homes in and around Fultonham Circle: The School Board wants to send our kids to a new school outside the neighborhood.

The next day the phone lines lit up in and around the Ashburn Village cul-de-sac, and a swiftly organized phone tree targeted School Board members. Board member Edward J. Kiley (Mercer) got seven calls. Chairman Joseph W. Vogric (Dulles) got 20, including the guy who called at 10:30 at night when Vogric was at a board meeting and left four messages on his answering machine before he was through stating his case.

"There are over 5,000 homes in the village," said Broadbent, who moved here from Centreville four years ago. "Why would they want to take our 154 homes out of the boundary?"

At the next board meeting, 70 residents showed up. There was no yelling and no name-calling. But the message was clear: Do not move our children from Dominion Trail Elementary School--their local campus--to Mill River Elementary, which is now under construction.

"The importance of the sense of community will be torn apart as our children are dispersed," said Ed Trexler, a Dominion Trail parent whose daughter has attended three elementary schools in four years.

On Tuesday, school officials will recommend boundary lines for the new school, and Fultonham Circle won't be part of it, said Sam Adamo, director of planning and legislative services for the district. Instead, he said he will recommend moving students from other elementary schools, including Sanders Corners and Hillside, which are facing a more immediate space crunch.

Although Broadbent and her neighbors can relax, their organized campaign demonstrates how the threat of a boundary change can mobilize a community.

Redistricting students is an annual event in Loudoun, where three or four new schools are scheduled to open every year. To ease crowding at existing campuses and to fill up space in a new school's gleaming classrooms, officials redraw boundary lines to decide which students will attend what schools.

But emotions are at full throttle when PTAs and Boy Scout troops are scattered among campuses, when children can no longer walk to schools and when child care and after-school routines are disrupted.

More than that, a school takes on a greater identity in a field of winding subdivisions with no true community center.

"If they went to this other school, then we'd really lose that whole feeling of being in this community," Broadbent said in an interview last week, "and you don't find that much in this day and age."

School Board members said that drawing boundary lines is one of the worst tasks they face in their elected post. "No matter what you decide," Kiley said, "someone's going to lose. Someone's going to be unhappy."

Vogric said his philosophy is to "move the least amount of kids the least number of times."

The process works this way: Adamo's staff suggests four scenarios of how boundary lines should be drawn. After several public hearings, Adamo recommends one of the four suggestions to the School Board, which makes the final decision. Another hearing is held before board members decide. They can accept Adamo's recommendation, tweak it or come up with different boundary lines.

The board will vote Dec. 14 on Mill Run boundaries. The new school will open in August 2000 in the Broadlands area.

School Board members say the boundary process is much more fair than it was just two years ago. Then, deliberations would begin after the staff brought a recommendation to the board. That left the public little time to influence where the lines were drawn.

"Things were much more rancorous than they are now," Kiley said.

Maria Madigan, who did not want her two children switched from Dominion Trail to Mill Run, said she was impressed that Adamo agreed to meet with the neighbors late last week--and that he hung around for nearly two hours answering their questions.

"They were really very open and very gracious about listening to us," she said.

Adamo said he is well aware of the emotions that boundary changes evoke: "You're dealing with somebody's most important possession--their child."