Goffstown lakes to be chemically treated for milfoil infestation
GOFFSTOWN — Glen and Namaske lakes will be closed to the public for 24 hours the first week of August to undergo chemical treatment to kill an invasive species of aquatic weed.
At the Board of Selectmen’s meeting Monday, Chairman Collis Adams said the Namaske and Glen Lake associations had contracted with Sutton, Mass.-based Aquatic Control Technology to treat portions of each lake for control of non-native milfoil.
“Portions will be treated with the U.S. EPA- (and) state-registered herbicide Navigate,” Adams said.
Namaske is scheduled to be treated Aug. 5 and Glen on Aug. 7. Swimming will not be permitted for 24 hours in either lake within 200 feet of the treatment areas, and the water is not to be used for drinking, irrigation or mixing sprays for plants.
“The shoreline of the lake(s) will be posted with signs warning of the temporary water-use restrictions that will be imposed, immediately prior to the treatment,” Adams said.
A notice with information about the treatments has been distributed to abutters of Glen and Namaske lakes, he said.
The variety of milfoil found in Glen and Namaske originates in the South and Midwest and thrives in freshwater bodies in New England east of the Connecticut River. Town Administrator Sue Desruisseaux said that both lakes have been infested with milfoil since the flooding of May 2006.
“We’ve tried hand-pulling (the milfoil) with divers, but that’s been insufficient,” Desruisseaux said. “Namaske Lake has been doing herbicide treatment for a few years now. Glen Lake is just starting up their herbicide treatment.”
Desruisseaux said the funding breakdown for the herbicide treatments is 40 percent from the state, 30 percent by the town, and an additional 30 percent from fundraising from the lake associations.
Marc Bellaud, president and aquatic biologist at Aquatic Control Technology, said Tuesday that milfoil has the ability to spread rapidly and choke out native vegetation in lakes and ponds.
“(Milfoil has) impacts on water quality, access (and) habitat value,” Bellaud said. “The state has been very aggressive in trying to manage milfoil in New Hampshire waterways .... It’s got a very aggressive growth pattern, and it’s pretty widespread already.”
Safe, effective herbicide
Bellaud said that Navigate, chemical name 2,4-D, has been determined by the state to be the most effective aquatic herbicide for treating the strain of milfoil found in New Hampshire, with minimal impact on other organisms.
“The plant absorbs the herbicide and it gets translocated through the plant and kills off the entire plant, including the root, but it’s not 100 percent effective, so we do see regrowth, usually the following season,” he said. “The state watches it closely, and they determine whether or not retreatment is needed in subsequent years.”
Bellaud said that Navigate is recognized as safe when used in accordance with the label.
“The concentrations (of the chemical used) will be very low, so they will work on the plants, but the herbicide won’t have an impact on aquatic organisms, fish, other wildlife, and won’t have an impact on humans either, at the rates that it’s used at,” he said. “It will pretty selectively control the milfoil and leave a lot of the native vegetation unharmed, so that can repopulate the area after the milfoil is controlled.”
Questions about the treatment process should be directed to Bellaud, who can be reached by phone at 508-865-1000, or via email at email@example.com.