GROTON -- Members of the Great Ponds Advisory Committee had reason to hope that their counterparts on the Water Commission might have a change of mind about a decision they took against the proposed use of weed-killing herbicides in Baddacook Pond.

"Baddacook was discussed at the GPAC meeting held Feb. 19," reported committee Chairman James Luening. "I received an update that the Water Commission will be reviewing their position based on new information provided by the Massachusetts Department of Environmental Protection (DEP) and the United States' Environmental Protection Administration (EPA).

"This doesn't indicate that they have changed their viewpoint," Luening hastened to add. "Just that there is a lot of community pressure to review the new information.

"This information very strongly supports the fact that Sonar doesn't migrate to adjacent wells," continued Luening of the prime chemical under consideration for use at Baddacook. "It is safe and has been stringently tested. It also points out that the town of Natick, which the Water Commission pointed to as an example of opposing chemical treatment, has started to use herbicides."

With the areas of open water on Baddacook Pond shrinking every year, the Great Ponds Advisory Committee decided that it was time to do something about such invasive weeds as milfoil and cabomba that are choking the life out of it.

Plant stems can grow as long as 15 feet and their remains at the bottom of the pond, called "biomass," have piled up 10 feet deep in places.

After successfully seeking and winning support last year to treat Lost Pond with weed-killing chemicals that have gone a long way to rectifying the situation there, the committee decided that the same could be done for Baddacook.

But the committee's nascent plans were nipped in the bud by the Water Commissioners, who voted to nix the idea. Fearful that the chemicals would endanger the groundwater that feeds their Baddacook Pond well site, members of the commission decided to err on the side of caution.

Firm in the belief that not only were chemicals the only practical solution to the weed problem at Baddacook but that they posed no danger to the well site, committee members met in joint session with Water Commissioners and the Board of Selectmen on Feb. 10 to see if the commission's vote could be revisited.

At that meeting, Luening argued in favor of the chemical-treatment plan, bringing up a similar case in Natick that at first was resisted by local officials but later lauded for its success in eliminating the weeds without causing harm to anything else.

Luening also arrived at the joint meeting armed with responses from the EPA refuting the Water Commission's arguments against use of herbicides.

Recommended by the state agency as well as the Federal Forestry Service was the use of Sonar, a nontoxic weed-killing chemical that has been used in reservoirs and potable water supplies without migration to nearby well sites.

Sonar has been used successfully in Lost Pond.

One hundred years ago, in 1913, Baddacook Pond had 103 acres of open water, today it has less than 76 acres.

"Regarding alternatives to Sonar treatment, we have not found an effective alternative due to the massive size of the infestation, 35 acres," said Luening. "We have been using a harvester for years as an alternative but have lost the battle."

Although no members of the Water Commission were in attendance at the committee's meeting of Feb. 19, members felt that some forward progress on the issue of using herbicides to cure Baddacook's ills can yet be made.

"We continue to hope that we can work together with the Water Commission to solve these community wide issues and that they will consider attending our meetings in the future," said Luening.

Those interested in seeing the problems faced by the committee at Baddacook more or less first hand can check out a YouTube video of the pond at youtube.com/watch?v=tJ4DId8bl8g.