MILTON - Representatives from Three Ponds Protective Association told Milton selectmen on Monday that a weed-fighting herbicide treatment applied to a portion of Northeast Pond in July largely eradicated the invasive weed in that portion of the lake.
European Naiad was first identified in Milton Three Ponds two years ago when the infestation was discovered in September 2015 by an area volunteer.
TPPA co-President Wayne Sylvester said about $35,000 had been spent mitigating the European Naiad last summer and that at least another $25,000 would be needed next year to fund diver-assisted suction harvesting to further eradicate the nuisance plant.
The herbicide treatment done on 41 acres on the Maine side of Northeast Pond on July 26 did its job, Sylvester said, leaving only trace amounts of the weed near the entry of the Salmon Falls River into the pond.
Funding for the eradication effort has come from Maine and New Hampshire DEPs and the towns of Milton and Lebanon with oversight and coordination of the effort thanks to the TPPA.
Next year no herbicide treatment is expected to be needed, Sylvester said, but the suction method to remove adults plants will continue.
As of Oct. 6 the eradication of the plant had reduced its footprint on Milton Three Ponds by 50 percent.
"I'm pretty confident that with our volunteers (and more from New England Milfoil) this weed will come under control," Sylvester added.
At the end of the discussion selectmen approved to maintain about $8,000 in the town funds already approved for the plant's eradication effort to remain available for the TPPA next summer.
TPPA officials also noted that some 1,600 boats had been inspected over the summer at the Town Beach and at Everetts Cove Marina in Lebanon, Maine, to combat any further contamination by invasive plants into Milton Three Ponds.
European naiad, which can overtake native lake habitats by shading and outcompeting ecologically valuable aquatic plants, grows from an annual seed into 7-foot long plants. A productive, one-acre infestation can generate tens of millions of seeds per season. Dense infestations can alter water chemistry and oxygen levels.
It can devastate native plants and fish species if left unchecked, scientists say.