U.S. District Judge Richard L. Williams declined yesterday to dismiss a lawsuit contesting the Prince William County School Board's decision to bus students from the eastern portion of the county to a high school about 18 miles from their homes.

The judge did dismiss a claim by the five families from the Montclair section that the busing decision would deny their children their right to a full education and destroy the values of their homes. Williams said he wanted to receive more information about two other claims the families made -- that the county School Board denied them a full hearing on the issue and unfairly singled out their neighborhood for the busing. The county has denied both the allegations.

Five Montclair families sued the county in Alexandria federal court last month in an effort to block the plan which the county said is needed to balance enrollments at two of its six high schools.

The board decided in December that children from the Montclair area in the county's rapidly growing I-95 corridor would have to enroll their children in Osbourn Park Senior High, located just outside Manassas, about 18 miles away. The students previously had been assigned to the nearby Potomac High School.

Potomac had 1,838 students last fall, well above its 1,650 capacity. Osbourn, with a capacity for 2,183 students, had an enrollment of 1,578. The busing plan, scheduled to go into effect next month, would bring enrollment at Osbourn to 1,160 and at Potomac to 1,816.

Attorney David Fudala, representing the five families, told Williams that the students wouldn't be able to participate in extracurricular activities at Osbourn because of transportation problems. The suit claimed that families would not get a good price for their homes because few people would be willing to buy a home where they had to bus their children that far.

Attorney Joseph Dyer, representing the school system, said students can participate in after-school activities and catch a special late bus that will take them home.