The Carlisle Mosquito Online

Friday, October 7, 2005


Boards agree: no chemicals on pathways

After several months of discussions and controversy on what to do about the weeds that are growing on town pathways, town officials have agreed on a path forward: no chemicals will be used on paths in the town's right-of-way now or in the foreseeable future.

Last spring, the Bike/Pedestrian Safety Advisory Committee (Ped/Bike), which is responsible for building and maintaining the paths, and the Board of Selectmen, who have jurisdiction over the town's right-of-way along roadsides, had suggested that the herbicide Round-up and an organic citric acid preparation be tested on a weedy stretch of path. The Board of Health vigorously opposed any use of Round-up.

At this point, however, there is more agreement on what not to do about the weeds, than on how the town can build and maintain trouble-free paths. At the Selectmen's meeting last week, Selectman Tim Hult summarized the main points of agreement reached among Ped/Bike, and the Selectmen, the Board of Health, the Historical Commission, and the citizen-sponsored Carlisle Pesticide Awareness Group (CPAG):

• The Board of Health will not support the use of any chemicals on town paths.

• The Selectmen will not oppose the position taken by the Board of Health.

• The appearance of the paths, especially in the town center, must be appropriate for the town's semi-rural character.

• A new surface material must be selected before new paths are built, and existing paths may need to be resurfaced.

Surfacing materials

Former Ped/Bike chair Deb Belanger later amplified on the available surfacing materials. If cost were no issue, everyone's first choice would be Stabilizer, a commercial surfacing material which contains psyllium, an organic fiber. Unpaved paths in the Minuteman Parks in Lexington and Concord are surfaced with Stabilizer and have remained solid and weed-free for years. The problem is the high cost.

An alternative possibility, said Belanger, is the use of very finely crushed stone, with or without a polymer surface spray which increases the binding of the stone particles to make an impenetrable surface. The finer the crush, the better the binding. When crushed, granite particles have a high angularity and compact very tightly. Current paths were built using crushed stone, but the crush was not fine enough to bind well.

Polymer sprays are EPA-approved at the federal level for use in wetlands, stated Belanger, but state and local authorities have not ruled on their use.

Path forward

Early next spring Ped/Bike plans to test crushed stone and crushed stone with polymer spray on sections of town paths. While more affordable than Stabilizer, crushed stone has a "less historic look," Belanger suggested, and the town may yet need to consider using Stabilizer in the town center.

"We need to get back on track building new paths," she said. "We have lost a year out of our five-year plan."

2005 The Carlisle Mosquito