At its Tuesday meeting, the Conservation Commission voted 4-3 against allowing the use of chemical herbicides to Lake Maspenock this year to combat invasive weed growth.

Following a recommendation from a Citizens Input Group appointed by the Select Board, and after the town was unable to perform a lake drawdown due to the negative effect it could have on a resident’s well, Department of Public Works director John Westerling submitted a request for the herbicide application.

The plan was a one-time application in late spring/early summer, with the possibility of later spot treatments to areas missed in the first application. It likely would have required a two-day shutdown of the lake, certified lake manager Dave Mitchell told the commission.

Residents for and against the proposal spoke during Tuesday’s meeting. Some people initially were opposed to herbicides but came around to believe it was the best option when the drawdown could not be performed.

Select Board vice chair John Coutinho said the town has been negotiating to purchase the property that includes the well, which is located on an island, so that drawdowns would be possible going forward. He supported the herbicide option for this year, as did Lake Maspenock Preservation Association president Drew Logan, who also served as secretary of the Citizens Input Group.

Resident Cathy Sweeney said weeds are showing up already.

“We are seeing weeds in the North Basin much earlier than we usually do,” she said. “It’s all the way up on our beach. Usually we don’t see them until the end of maybe July. But we’re already seeing them up to the waterfront in our area, and I think they’re going to be quite a bit worse than usual. They are underwater, but they are growing and they are obvious.”

However, there has been a loud chorus of voices opposed to the use of chemicals.

“We could do what is expensive, expedient, short-sighted and disrespectful. This would leave poison soil, angry neighbors, unknown future health effects, disrupted natural balance and a daily uncomfortable feeling about contact with the lake,” said Carol Esler, a 36-year resident of the lake area. “Please let’s look more deeply into both our water and our actions. We could wait until the next drawdown. We don’t even know how the weeds will be this year. … Let’s not just throw more poisons at something we don’t like the looks of.”