More than a year after an herbicide was first used in Lake George to combat an invasive plant species, scientists and activists say a study shows the chemical lingers or more than a year.
In July 2024, a Warren County Supreme Court Judge denied a request to prevent the use of ProcellaCOR to help manage Lake George’s eurasian watermilfoil populations.
Following that decision, the Lake George Park Commission had 48 hours to apply the chemical to two bays where the invasive species was prevalent.
More than a year later, President of the Lake George Association Brendan Wiltse and Lake George’s Water Keeper Chris Navitsky are taking this radio reporter, who is fortunately not prone to sea sickness, to look at one of the application sights.
Wiltse has been with the LGA since the start of the year.
“One point of caution with all of this is this is a relatively new herbicide. There aren’t many extensive studies of it in an actual lake environment. Especially in terms of understanding its persistence in the environment. And our work is showing that it’s persisting longer than we would have anticipated based on the limited number of laboratory and field studies that have been conducted to date. So, what that means for the lake, we don’t fully know. It’s more a set of concerns that we have this herbicide, which has toxic properties persisting in the environment that could have impacts on the ecology of the lake but we don’t know whether it actually will at this point in time,” said Wiltse.
Opponents of ProcellaCOR feared that Lake George’s depth and currents would cause the chemical to act differently than in lab settings. The LGA had offered to continue funding hand harvesting of the watermilfoil instead of moving forward with the herbicide.
While the LGA and Lake George Park Commission clashed over the ProcellaCOR application for years, they have since cooperated to maximize the lake's ecological management.
LGPC Executive Director Dave Wick says ProcellaCOR worked to completely wipe out the invasive plant where it was applied.
“Yeah, so we had two treatments in Lake George, one 2.3 acres, one 4 [acres], so out of a 28,000 acre lake that’s pretty small, of course. And we had 100% effectiveness in the two treatment sites and we’re thrilled with that and we’d fought for years ahead of that to control it under hand harvesting methods. So, yeah, we’re very pleased with the outcome,” said Wick.
He adds the LGPC is committed to using every tool at their disposal to keep Lake George clean and healthy.
“It’s been registered by EPA and DEC, it’s been used in 100s of lakes throughout the Northeast, all very successfully. No public health impacts, no ecological impacts identified. Even in the LGA’s study, they didn’t identify any specific ecological impacts. So, yeah, we don’t have any plans for ProcellaCOR treatment in the future, but it’s definitely still a tool in the toolbox should we need it again,” said Wick.
Still, use of the chemical gives the LGA pause.
A study by the LGA, Darrin Fresh Water Institute, and the Rensselaer Polytechnic Institute finds while the chemical dissipated from the water column within 72 hours it persisted in some lake sediment samples for at least a year.
Sheeps Meadow Bay is quiet, small, and sparsely populated with only a few homes.
Navitsky points out that the invasive plant is now absent from the bay.
“You would be able to see it [the watermilfoil]—there are patches over near that point which is sort of at the center of the bay. And then over just to the port side to the left in those, those are the two major patches of milfoil – some over in the southeast,” said Navitsky.
That means the herbicide is effective, and, Navitsky adds, ProcellaCOR does not pose a direct risk to humans.
“Well, I don’t think that there’s any human health concerns. That’s what the EPA studies have shown and I don’t think—we’re not making those statements at all. It’s just the concern is, again, initially is that this is persisting and that there is literature that says there’s concern that the milfoil plants may develop resistance if that [ProcellaCOR] remains in the environment and persists,” said Navitsky.
But, Wiltse says the LGA wants to study the implications of its persistence before any future applications are scheduled.
He adds the cheapest way to fight invasive species is by keeping them out of the lake in the first place.
“We think the appropriate next step is to go through the development of a rigorous aquatic invasive species management plan, and through that process, which would involve bringing in experts in this field, would bring in the public's perspective, because this is a shared resource the community. This is the community's Lake, and their perspectives should be taken into consideration with all of our management activities, and it would also be the process by which we could really explore that the knowns and unknowns the risks and rewards of all available management tools for addressing aquatic invasive species in Lake George,” said Wiltse.
