COUNTY PROPERTY TAXES pay for most of the school budget, and Fairfax officials are increasingly worried that too much revenue comes from property owners. In 2001, about 50.7 percent of the county's total revenue came from real estate taxes. This year, the figure will be 59.1 percent. The problem? State lawmakers won't allow Fairfax to diversify its tax base by charging new levies. If they did, county residents would pay lower property taxes, according to school officials.

THE COUNTY'S POPULATION is projected to be 1,015,600 people this year, reflecting the addition of about 14,000 residents a year. That creates a demand for more schools and more money in the budget. Four elementary schools will open this fall, in Centreville, Lorton, Vienna and Kingstowne. All will include school-age child care, a growing cost in the budget. To pay for this increase in students, the schools are asking for $23.6 million more this year, along with 351 jobs.

EVEN WITH AN INCREASE of 6 percent in school spending over last year, the county will fall $3.15 million short of giving the school district what it wants. County and school officials will be deciding over the next few weeks how to make up that difference.

COUNTY SCHOOLS SPEND about $5 million a year to handle crowding. About 13,800 of the district's 166,601 students attend classes in trailers. Just five years ago, Fairfax had 15,000 fewer students. The county is the 12th largest school system in the nation.

IN ADDITION TO THE MONEY the county gives schools for operating and debt service costs, it spends $27.4 million on the school-age child care and Head Start programs, $8.5 million for school nurses, $6.8 million for crossing guards and security officers, $6.2 million in ballfield maintenance and recreation, and $1.3 million in human services and Fairfax-Falls Church Community Services Board programs.

Source: Fairfax County Public Schools, proposed 2004 budget

Four elementary schools will open in the county this fall -- including one, above, in Centreville -- to accommodate a growing population. Right, trailers are necessary at nearby Greenbriar West Elementary School to handle crowding. About 13,800 of the district's 166,601 students use trailers.The reason a new elementary school is needed in Centreville is evident: new houses. With an estimated population of more than 1 million this year, the county adds about 14,000 residents annually.