A mix of older Islanders, young families, Tisbury town officials and teenagers gathered Sunday to protest the Eversource plan to apply herbicides under power lines on Martha’s Vineyard this week.

About 60 people joined the demonstration outside the Eversource facility on the Edgartown-Vineyard Haven Road.

“This is people coming out and saying, in the most bipartisan way, that this is not acceptable. We can’t have people spraying such dangerous herbicides — not only Eversource, but everybody. This stuff is toxic. We know it’s carcinogenic,” said Keith Chatinover, a senior at the Martha’s Vineyard Public Charter School.

Keith, who is also a member of the Islandwide community action group We Stand Together, helped organize the hour-long demonstration after the Tisbury board of health issued a letter late last week advising that an Eversource contractor will begin spraying herbicides Oct. 16 through Oct. 20.

“Please be advised that spraying could occur at any time on the dates indicated,” the letter read in part. “Although the contractor plans to do targeted application of herbicides, as a precaution you may want to keep your doors and windows closed and be sure that pets are kept inside during the application period.”

The letter quickly circulated on Island social media and elsewhere.

The herbicide spraying has been approved by the state department of agriculture and has attracted widespread debate and opposition on the Island in recent weeks.

Susanna Savoy said she was pleased to see the turnout.

“People really are up in arms about it,” she said, holding a sign that read We Have Bees. Her husband Mike’s sign read “No Spray Zone — Single Source Well Water.”

“The power lines cut right through our property and we have a shallow water well that’s our primary source for drinking water. I’m not happy,” he said.

“We’re pretty freaked out about it,” added Ms. Savoy. “We live right on the water and it’s downhill from the power lines to our well and to Tashmoo.”

Mary DeFreitas, who brought her two small children to the demonstration, lives near the power lines in Vineyard Haven. She said after receiving the advisory letter and reading descriptions of the herbicides on the town website, she decided her family will live with in-laws for the week.

“What do you do when you have kids who like to play outside?” she said, as her daughter cheerfully brandished a large stick. “I don’t want to jeopardize the future of my children because somebody is being cheap.”

The listed herbicides for possible use include Arsenal, Rodeo, and Garland 4.

Tisbury selectman Tristan Israel also expressed concern for the future, particularly in light of past uses of chemicals later found to be highly toxic.

“In our 1944 town booklet, the moth committee proudly wrote that they sprayed 33.5 pounds of lead on West Chop to control moths,” he said. “In 1944, who knew? It sounded good.”

But when it comes to the herbicides to be applied this week, Mr. Israel said: “We do have some knowledge today. They’re putting stuff into the ground that is poisonous and is very close to our water table.”

Even though Eversource arborists have pledged to apply the herbicides minimally and carefully, he said, “I’m not willing to play Russian roulette with the future.”

Tisbury selectman Melinda Loberg was also in the crowd, along with her husband Michael Loberg, a member of the board of health, and board chairman Malcolm Boyd.

A bill pending on Beacon Hill aims to give towns the right to ban specific herbicides. Mr. Israel said Island towns should also take action.

“I think that each town should file its own home rule legislation,” he said.

Passing motorists — including at least one driver of a VTA bus — honked in solidarity with the protesters, who carried handmade signs with messages such as Mow Don’t Spray and Goats Eat Brush.

“This is another example of a company that makes so much money off people, and doesn’t care,” said Jo Maxwell of Oak Bluffs, who joined the protest with her husband David Joyce.

“They can use goats. They can brush cut. But they’d rather poison us,” she said.

While unhappy about the spraying plans, Ms. Maxwell found something to like about Sunday’s protest.

“It’s just nice to know that you can be with other Islanders who care about things, without extraneous stuff,” she said.