Concord neighbors press Natural Resources Commission to limit chemical treatments for College Road pond

An abutter and a consultant clashed at the Natural Resources Commission meeting over a notice of intent to treat nuisance aquatic weeds in the swimming area of a pond at 18A College Road.

David Roche of All Habitat Services presented the application as an integrated management plan that relies primarily on mechanical harvesting and, as contingencies, limited spot treatments with herbicides he said are permitted by EPA and MassDEP — chiefly diquat and chelated copper, with imazamox (masamox) offered as a more expensive alternative. Roche said treatments would be “very limited use, very selective timing,” confined to the association’s swimming area, and that diquat binds quickly to plant material and is applied at parts-per-billion rates with an existing five-day irrigation restriction.

The nut graf: Dr. Victoria Chan Veil, an abutter and Harvard-trained physician-scientist, told the commission she strongly opposed an open-ended chemical license, citing long-term health and ecological concerns about diquat and urging mechanical removal and small-scale dredging instead. “You cannot put substances in one pot of water and say it doesn’t go into the other,” Chan Veil said, stressing the pond is closed and rain-fed. She asked the commission to limit the permit to mechanical measures and to exclude diquat.

Commissioners pressed for specifics. They asked the applicant to map precisely which parcels and water area would receive treatments, to document property-ownership consent for any treatment that would cross parcel boundaries, and to provide clearer information about application rates, the acreage targeted, and how mechanical harvesting would be used. Commissioner questions repeatedly emphasized the need for a treatment footprint map and for possible mechanical alternatives before approving chemical controls.

Roche said his firm performs both mechanical and chemical control, that the historical and most commonly used actives in the system are diquat and chelated copper, and that imazamox could be used as an alternative though it is costlier. He described the approach as minimizing chemical treatments (one or two per year in the swimming area) and said he would return with the pond map and additional details. He also said the existing order of conditions and the separate permit process still apply and that a new permit, if issued, would be valid for three years.

The commission kept the record open and continued the hearing to Nov. 6, requiring the applicant to provide: (1) a map showing the exact treatment area tied to parcel ownership; (2) clarification whether adjacent parcels would require written permission; and (3) more detail on mechanical alternatives and planned application levels. The commission also flagged the need to compare proposed application levels to chemical safety data and to document whether mechanical harvesting could feasibly address the nuisance weeds without chemical intervention.

The next procedural step is a return to the NRC on Nov. 6; staff requested any revisions be filed by the Friday before that meeting so the packet can be reviewed.