Milton Three Pond's battle with the invasive plant European Naiad, now in its fourth year, begins its summer of 2018 assault in earnest on Monday when Maine Department of Environmental Protection officials will comb areas of the three ponds to determine the effectiveness of last summer's eradication efforts.
John McPhedran of Maine's DEP will be part of the group. He said on Friday one of their chief areas of concern is a 41-acre patch on Northeast Pond that was treated with an herbicide last July. Earlier this year Wayne Sylvester, Three Ponds Protective Association co-president, told Milton selectmen the treatment had been largely successful,
McPhedran said on Monday they'll be verifying the results of that treatment, and also trying to determine the success of other efforts employed in the eradication effort such as suction treatments and hand pulling efforts by divers that were also undertaken.
McPhedran cautioned that it may be difficult to differentiate the native Naiad, which is not a threat, and the European Naiad on Monday, because one of the easily observed variables is the European Naiad's faster growth. If the two separate Naiad species appear fairly uniform on Monday, they may have to come back later in the month.
Money being used in the effort is coming from both Milton and Lebanon as well as New Hampshire's Department of Environmental Services and Maine's Department of Environmental Protection.
McPhedran said that if another herbicide treatment is necessary, Maine's DEP will pick up the tab as part of their Continued Rapid Response effort.
Both Milton and Lebanon, which share the lake, will pay $5,000 this year, Sylvester said in an email on Friday.
The MTP infestation was first discovered in early September 2015 by an area volunteer citizen scientist.
European naiad can overtake native lake habitats by shading and outcompeting ecologically valuable aquatic plants, European naiad 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.
As part of the battle to mitigate further contamination of the MTP boat ramps at Everetts Cove Marina in Lebanon and Milton Town Beach are inspecting boats and urging boat owners to make sure their craft are clean and free of the weed before entering the water.
McPhedran said while progress is apparent in the fight against European Naiad, this is "still likely a long-term effort."
He also said European Naiad has been spotted in Spaulding Pond, which also has been affected by intrusion of milfoil as well. He said Maine DEP divers would be returning there for further eradication efforts this summer, too.