TODAY STUDENTS will begin filling up the classrooms as well as various makeshift spillover facilities in Prince George's County, just as they have been doing in increasing numbers in recent years. During their summer break, county and school officials were supposed to be putting an end to a sorry flap over how to address swelling enrollments that are expected to add as many as 10,000 students by 2006 to the approximately 137,000 on the rolls now. But as reported by The Post's Nancy Trejos and Ovetta Wiggins, the rift between the County Council and schools chief Andre J. Hornsby remains as wide as it was three months ago, when the parties were exchanging more insults than ideas. At issue was -- and still is -- whether to concentrate on expanding existing facilities, which the School Board favors, or on building new schools. Absent is any great sense of urgency.

When we last left this turf tussle, the council and school board had agreed to build one additional high school. The council voted against the board's plan to expand existing schools and formed a -- you guessed it -- task force to come up with a recommendation by the end of September. Now task force members report that the school district is not cooperating with the consulting firm that they hired to analyze school population. School officials say they have provided all the necessary data; the task force says it needs more and may have to delay its report.

The quest for more data on future school enrollments is a constant pursuit, but it ought not paralyze the county. Some existing schools can and should be expanded; others may need replacement, and additional schools must be built as well. The capital region has been growing by 60,000 to 80,000 people a year since the 1950s and is looking at perhaps 1.5 million more by 2020 on top of the 5.7 million people here now. Nearly half of the recent population growth was foreign-born. Regional economic analyst Stephen Fuller of George Mason University says that this area accounted for one out of every five jobs created in the United States in the last year.

Where these new residents wind up within the region is difficult to predict. "There's a churn going on that nobody knows much about," says Mr. Fuller, with people whose children are grown selling older homes, renters buying homes and jurisdictions looking at changing their ratios of jobs to housing units. Still, the job growth rate means a regionwide surge in demand for classrooms that will continue to put pressure on Prince George's, where a growing number of people are moving from outside the region. County officials can let the enrollment studies continue, but their sparring must give way to an agreement to join forces and get moving.