GROTON — Members of the Conservation Commission were prepared to close a long-running public hearing on the issue of using herbicides to clear Baddacook Pond of invasive plants when they were reminded that word from the town’s legal counsel on the question had not yet been received.

The delay in concluding the evidentiary portion of the hearing was the latest step in a process that has been bogged down by the Water Commission which has refused to accept any evidence to the contrary that use of a chemical called Sonar would be safe in Baddacook, which is part of aquifer that feeds a well supplying the town with some of its drinking water.

Sensitive about preserving the quality of their drinking water, commissioners have expressed skepticism over the use of Sonar at Baddacook citing studies that state the chemical could end up contaminating the water supply.

For that reason, the commission voted to deny its support of the Great Ponds Advisory Committee’s plan to use Sonar in Baddacook.

Stymied by the commission, residents and members of GPAC have been working to satisfy demands by commissioners that they provide more information about hiring an independent consultant and possible solutions to a question of liability should the well water become contaminated despite assurances of the safe use of chemicals in the pond.

But having found technical confirmation of the safety of Sonar, including testimony by former Littleton Electric and Water Department Manager Savas Danos, Advisory Committee members decided to approach the Board of Selectmen for support in their appeal to the ConsCom.

Finding that support, GPAC applied to the Conservation Commission for permission to use Sonar in Baddacook with formulation of a list of demands that the Water Commission would need in order to be satisfied with the safety of Sonar being one of the first things needing to be done.

A public hearing held Tuesday opened with a report by Planning Board member George Barringer on the safety of using chlorine in the town’s drinking water.

With Barringer’s presentation over, Commissioner Mary Metzger concluded that looking at the evidence, all the data pointed to the conclusion that Sonar was safe as well.

“If we go down the route of what more information we don’t have we would never decide,” said Metzger, calling the degree of verification demanded by the Water Department a recipe for paralysis in coming to any kind of definitive answer.

Alex Woodle, a supporter of the use of Sonar in Baddacook, reiterated the contention that the use of Sonar was safe and asked why EPA standards for the safe use of chlorine in the town’s drinking water was accepted by the Water Department and not the same agency’s findings for Sonar.

Woodle also accused local media of “fear mongering” in its reporting of the issue.

“We’re not here to poison anybody,” insisted Woodle, adding that the Advisory Committee had done all its homework and checked with every relevant government department and agency.

When a motion was made to close the public hearing, Water Commission Chairman Gary Hoglund offered a number of items to be included in any potential order of conditions that the ConsCom would draft should it approve the use of Sonar in Baddacook.

Among the suggested items were that the Water Department be indemnified against contamination of the well water if herbicides were used, that the well water be tested monthly by a neutral laboratory, and that the drift of herbicides be controlled so that it did not drift downstream to areas under the department’s protection.

Hoglund also demanded agreement that no herbicides would be used in Baddacook without written approval by the Water Department.

Hoglund also noted that the Water Commission was responsible to 1,700 customers while elimination of invasive plants in Baddacook only served a “small group” of landowners around the pond.

But when he was asked by a member of the ConsCom if the Water Commission would approve the use of Sonar if all the conditions were met, Hoglund demurred.

“There’s a lot of unanswered questions,” said Hoglund. “These things take a long time.”

The hearing was continued until May 12 when word from town counsel was expected.