Villa Julie College's expansion plans suffered a setback this week when a Baltimore County Circuit Court judge ruled that the Board of Appeals should have allowed opponents to introduce evidence about the impact of the school's proposed wastewater treatment plant.

Judge Barbara Kerr Howe ordered the board to set a new hearing on the issue of the treatment plant.

Last July the board upheld an zoning exception allowing the Greenspring Valley school to expand. However, it also affirmed the zoning commissioner's limitations on expansion, which would allow a maximum of 2,500 students over a five-year period, as well as his decision to limit wastewater discharges from the new plant to 50,000 gallons a day.

During its hearing, the board granted a motion by the college to exclude testimony about the environmental impact of the treatment plant's discharge into a stream that cuts across adjoining property. Opponents, including nearby property owners, said the evidence should be allowed.

Villa Julie College, a 46-year-old private institution with 1,700 students, wants to add 98,000 square feet of classrooms, laboratories and study areas. The treatment plant is vital to Villa Julie's expansion plans because the college's septic system has been failing.

The County Council has included the wastewater treatment plant in its master water and sewer plan, and the state approved a permit to allow the plant to discharge up to 60,000 gallons a day.

But Judge Howe ruled that the zoning commissioner and the appeals board still must determine whether the plant requires its own special zoning exception.

"Our point from the beginning is that a wastewater treatment plant is not permitted in a RC-2 zone because of its impact, but the board wouldn't let us argue that point," said J. Carroll Holzer, one of the attorneys represeting the opponents.

Benjamin Bronstein, Villa Julie's attorney, could not be reached for comment.