Turf battles between the Loudoun Board of Supervisors and the county school board are nothing new, but now the boards are tussling over the turf itself, as they debate whether artificial and natural turf athletic fields at high schools should be tested for potentially harmful chemicals.

The supervisors have expressed interest in testing three synthetic turf fields, but the school board has insisted that an equal number of natural turf fields also be examined so as to make a comparison. Supervisors have responded that testing the natural fields is unnecessary and that the additional requirement was concocted by the school board to kill the initiative altogether.

The issue remained unresolved last week, when the school board declined to vote on a compromise proposal that would have allowed testing of three artificial turf fields and at least one natural grass field.

At the center of the dispute is the question of whether carcinogens or other potentially harmful chemicals are present in “crumb rubber” and other materials used in synthetic fields. Responding to community concerns, the supervisors in May asked the school board for permission to test three synthetic fields for chemicals that might pose health risks for children.

In June, the school board countered by approving the request under the condition that an equal number of natural turf fields also be sampled for the presence of herbicides, pesticides and other potentially dangerous chemicals.

The squabble between the boards heated up Sept. 6, when supervisors balked at the additional requirement, which county staff members estimated would increase the cost of testing the fields by about $40,000.

Board of Supervisors Vice Chairman Ralph M. Buona (R-Ashburn) called the requirement to test natural grass fields a “poison pill.”

“They didn’t want us doing this,” Buona said. “They don’t want us on their fields, and so this was their way of giving us a way out.”

Supervisor Suzanne M. Volpe (R-Algonkian) said that it would be “ludicrous” to test natural grass fields.

“We’re going to test something that probably covers half of the county?” Volpe said.

Board Chair Phyllis J. Randall (D-At Large) scolded the school board members.

“You ought to be ashamed of yourselves, because there may or may not be something there in the turf fields, the artificial turf,” Randall said. “We don’t know. But we know that we’ve been playing on grass for centuries.”

On Tuesday, it was the school board’s turn. Member Jill Turgeon (Blue Ridge) floated a proposal that would have allowed the county to have three synthetic fields tested, while the school board would cover the costs of testing one or more natural turf fields.

Turgeon said she was “very troubled” by the supervisors’ charges, and that the school board’s intentions had been misunderstood. The purpose of testing the natural fields, she said, was so “we have some sort of baseline to go on, so we can hopefully make a more informed decision as to whether or not we need to take any action on the crumb rubber.”

“My intention in wanting additional information is so that we don’t unnecessarily remove crumb rubber for a certain chemical or a certain concern that we found was also present in our natural turf,” Turgeon said.

Debbie Rose (Algonkian) opposed the proposal, saying that identifying a list of chemicals present in the fields would not establish a conclusive link between the chemicals and potential health problems.

School board member Beth Huck (At Large) said the Environmental Protection Agency and the Consumer Product Safety Commission are jointly doing extensive studies on the issue, expected to be completed this year.

Turgeon said that although she was willing to wait for the test results from the federal studies, “we need to be vigilant on this.”

“I don’t think it’s something that we need to just shove aside and make go away,” Turgeon said. “I think it’s really important.”

County spokesman Glen Barbour said in an email Wednesday that there had been no indication that any members of the Board of Supervisors want to consider the issue again.