For the last few days, this sign has greeted people who come to Sears Island. Officials from the Friends of Sears Island have worked to find out more about the herbicide application. Credit: Abigail Curtis / BDN

SEARSPORT, Maine — Members of the Friends of Sears Island are distressed that a corporation gave no warning before spraying herbicide earlier this month along a portion of a road where hikers, dog-walkers, trail runners and others like to recreate.

The nonprofit serves as the land management entity for the island, which is owned by the state of Maine. It’s one of the largest undeveloped islands on the Eastern Seaboard, and much of it has been put into conservation, including the area along Cell Tower Road where the herbicide was applied.

At first, officials from the Friends of Sears Island did not know who or what had applied the herbicide, which turned formerly green vegetation in the middle of and alongside the dirt road a sickly brown color. They did not see any signage posted to alert people as to the nature of the chemical that had been used.

But eventually they learned that the herbicide had been applied by a contractor for the American Tower Corp., a Boston, Massachusetts-based company that owns wireless and broadcast communications towers in several countries. American Tower owns a nearly 5-acre parcel at the southern tip of the island, where a cell phone tower is located behind a tall chain link fence. It also has an easement along the road leading up to the tower, which is where the friends group believes the herbicide was sprayed. Cell Tower Road is open for public use by pedestrians.

Before making contact with American Tower, the Friends of Sears Island moved to warn visitors that they did not know what chemicals had been applied. Rolf Olsen, the vice president of the friends group, figured that it wasn’t right that neither the state nor the nonprofit were given any advance notice about the chemical application.

“This is alarming to us for a number of reasons, but mainly because we don’t know what substance was applied, so we have no idea if it is safe for the many people who walk that road virtually every day, with children and pets in tow,” Olsen said last weekend. “Right now, the urgency is finding out who contracted with whom to spray what on property that’s owned by the people of Maine.”

Matt Peterson, the vice president for communications at American Tower Corp., told the BDN that the herbicide sprayed near the tower facility is not problematic.

“After reaching out to our vendor, there is nothing that we are aware of that would cause concern for people or their pets accessing the area,” Peterson wrote Tuesday in an email. “We will be connecting soon with Rolf and Friends of Sears Island to discuss any concerns and review best practices at the site.”

Olsen said officials from American Tower told him this week that as soon as the chemical they used had dried, it was safe for children and animals to use the area. They also said they had sprayed only on their property, but that doesn’t sound right to him. Photos seem to clearly show that the area along the road had been sprayed, he said.

“It seems pretty clear to us that the site depicted … is not within the boundaries of [American Tower Corp.’s] 4.98-acre site on Sears Island,” Olsen wrote Thursday in an email to the company. “We will prepare a more thorough and formal response to this claim.”

Moving forward, Olsen said that the official from American Tower Corp. offered to facilitate contact between the herbicide applicator hired by the company and a team that would include representatives of the Maine DOT, the Friends of Sears Island, the Maine Board of Pesticides Control and the Maine Coast Heritage Trust, which holds the conservation easement.

That will help, but still doesn’t feel exactly satisfactory to Olsen.

“I don’t know what little streams or water flows might wash the stuff into Penobscot Bay,” he said.

Moreover, the role of the Friends of Sears Island is to maintain the trails, provide interpretive programs and to otherwise encourage visitors to enjoy a safe and pleasant experience on the island, he said.

“We don’t want to get involved in advocacy or challenging herbicides or pesticides,” he said. “But this clearly was in our face and we had to deal with it.”