School builders expect to get approval soon from Loudoun County officials to scrap plans for a 150-foot-long shrubbery-filled pit in front of the new Belmont Station Elementary School, quieting a simmering controversy among parents.

The bioretention pond, filled with marshy plants and bushes, was supposed to act as a natural filtration system to pull pollutants out of draining rainwater. But parents at the Ashburn school complained that the "rain garden" could attract snapping turtles and snakes.

Some parents also feared children could trip in the foot-deep pond and even drown -- though construction officials said that was unlikely. Although the garden would fill with water in heavy rain, it was designed to drain quickly, said Tom Sullivan, construction director for the Loudoun public school system.

County officials said during the school's design phase that the pond was necessary to comply with Loudoun's Comprehensive Plan, which spells out what can be built in the county and how.

The potential elimination of the pond highlights the debate about how closely public buildings should be required to follow environmental regulations in the plan. Several members of the Republican-majority Board of Supervisors elected in November have said the regulations enacted by the previous board went too far.

School officials said they felt confident county government officials would give approval soon to a redesign eliminating the pond.

"It's the way the new board is interpreting the rules," said schools Planning Director Sam Adamo. "They're looking at some of the green infrastructure [pieces of the Comprehensive Plan] as guidelines rather than hard-and-fast rules like the previous board."

Parents have traded e-mails since spring about the pond, enlisting local School Board member Bob J. Ohneiser (Broad Run) to lobby against it. Sullivan said parents may have become wary of the pond during construction, as they watched a deep hole dug in front of the school. He said plans always called for the ditch to be filled in significantly before the school opened in September.

"I can only speculate people saw that and said, 'This is what we're going to end up with, and that's not acceptable,' " he said. Sullivan said a similar bioretention garden behind Hamilton Elementary School has never caused trouble.

Assuming approval from the county, school officials will convert the pond into a grassy swale, a gently sloping ditch that channels rainwater. That will provide some filtration, said Randy Vlad, the school system's civil engineer, who said water runoff at the school already exceeds standard industry best-management practices.

"We were doing something above and beyond what was required," he said.

The action speaks to the impact parent activism can have in a county where petition-drives and public speaking on school issues are a routine part of school life for many.

Stacy Chapman, a parent who closely followed the school's planning process and lobbied against the pond, said the swale option would satisfy her concerns. She said she appreciated the county's attempt to preserve the site's "natural integrity" by calling for the natural-looking water filtration pond. But, she said, she worried about the aesthetics of marshy vegetation wedged between the school's front door and the street. "It shouldn't have been something forced on us," Chapman said.

Ohneiser said he planned to carefully inspect school plans in the future to avoid similar problems.

"Not only should [the pond] never have been in front of this school, but we need to make sure these types of esoteric contributions should never be forced on a school again," he said.

The pond in front of Belmont Station Elementary could be converted into a sloping ditch.