Bees, like this one in the Harwich Elementary School garden, are on the decline, and some blame the widespread use of glyphosate. FILE PHOTO

CHATHAM — By order of selectmen, town groundskeepers will no longer use glyphosate, the active ingredient in herbicides like Roundup, to control weeds in parks, athletic fields, mulch beds and along walkways.

The board’s vote Monday came at the request of Laura Kelley of the group Protect Our Cape Cod Aquifer (POCCA), who has argued against the use of pesticides that might contaminate the region’s shallow groundwater supply, which is also the source of most of the Cape’s drinking water.

Selectmen further voted to direct the board of health to review regulations that would prohibit town employees from applying a broader range of chemicals to town properties.

The change does not apply to private property owners, though Kelley said it would set a good example for homeowners and businesses to consider alternative ways to control weeds.

Parks and Recreation Director Dan Tobin told the board that the town uses a relatively small quantity of glyphosate each year, mostly to control weeds in places where it’s difficult to remove them. The amount is equivalent to about a gallon of glyphosate concentrate, or a 2.5-pound bag of concentrate granules, each year.

“It’s a very limited amount of pesticide we use,” he said. Tobin said he became aware of POCCA’s request by seeing the agenda for the selectmen’s meeting, and did not have time to fully research with other department heads what a prohibition on glyphosate use might mean for the schools, the cemeteries, the Seaside Links Golf Course and other green spaces.

In August, a California jury awarded $289 million in damages to a groundskeeper who developed cancer after repeated use of Roundup. The defendant, the chemical giant Monsanto, successfully lobbied to have the award reduced to $78 million

“Proof being, these products are harmful,” Kelley said. A University of Texas study earlier this year also linked glyphosate to a decline in bee populations.

Orleans resident Whiting Rice, who also works with POCCA, said the board of health in Marblehead formulated a bylaw in 2005 that includes a list of chemicals that cannot be used on property under the town’s control. While other towns have tried to use home rule petitions to ban pesticides in their towns, those efforts have been overturned by the state attorney general’s office, which upholds the regulatory authority of the state’s pesticide board.

Rice said there are inconsistencies with the way the state regulates pesticide use. It is prohibited to use certain chemicals near a preschool center where there are children under age six, but legal to use around older children. “That means your school department can use all the pesticides they want,” he said. “We don’t think that’s a good thing.”

Tobin told selectmen that the town has used glyphosate for years as part of landscape maintenance, but always according to the manufacturer’s guidelines. Certain members of the town’s groundskeeping team are specially trained and certified to apply the pesticide, he said.

“I get very concerned about the chemical issues that we’re having in our world in general,” Selectman Shareen Davis said. Board member Jeffrey Dykens agrees.

“We have to be concerned about our sole-source aquifer,” he said. Even if glyphosate hasn’t been directly linked to health or environmental problems, “I think we should act on the side of prudence,” he said.

Board member Cory Metters said a voluntary move by the town to limit its own use of glyphosate makes sense.

“Philosophically, this is something I can support,” he said.

Selectman Peter Cocolis said the California jury award and the bee study are sufficient proof that it’s time for the town to act. He admitted that he’s got an old container of Roundup in his own garage.

“You must wait for toxic waste day and recycle it properly,” Kelley said.

Resident Suzanna Nickerson urged the selectmen to stop town groundskeepers from using Roundup.

“It puts our aquifer at risk, our town employees at risk, our wildlife and children at risk,” she said. Applying pesticides can hurt an entire ecosystem of organisms, “not just the one that you don’t want,” she added.

On a motion by Dykens, the board voted unanimously to direct the town manager to have staff voluntarily discontinue the use of glyphosate on town-owned properties by all town departments, and to investigate the use of potential alternative methods of weed control.

Present at the meeting were representatives of Chatham-based Pure Solutions, a business that offers organic lawn care. They offered to provide town officials with a list of substances that they use instead of herbicides like glyphosate.

The board also voted unanimously to have the board of health review the Marblehead bylaw and to make a recommendation within three months on the possibility of adopting a similar bylaw.