The Lake George Association is deploying the resources of the Jefferson Project to conduct the most detailed study yet of the impacts of ProcellaCor on a body of fresh water.
“It is very unfortunate that ProcellaCOR was put in Lake George at all, particularly when The Jefferson Project’s validated computer models were available to predict the flow of water, which would likely impact the efficacy and spread of the pesticide,” said Dr. John E. Kelly III, LGA Board Chair and a founder of the Jefferson Project. “But now that it has been applied, we must take the opportunity to scientifically measure the effects for better-informed lake management decisions.”
According to Kelly, the LGA has contracted with an independent, university-based laboratory to analyze water, plant and soil samples collected from the waters of northern Lake George, at and within proximity of the precise locations where the Lake George Park Commission applied the aquatic herbicide ProcellaCOR in an attempt to eradicate Eurasian milfoil on June 29.
The state-of-the-art lab, based at the University of Connecticut, will also analyze samples collected from sites where the herbicide may have settled after being displaced through a multitude of possible hydrodynamic processes, such as winds and currents.
The sampling will help the LGA map the transit of the herbicide through the waters as well as to gauge its longevity, said Kelly.
“We’re looking at such questions as: Where did the ProcellaCOR go? What did it do? Was it effective? Did it kill the intended invasive species? What else did it do? And what are the vestigial remains of ProcellaCOR and its ingredients?” said Kelly.
Kelly said the LGA plans to present its initial findings to the public sometime within the next few weeks.
Water Samples
One of the Jefferson Project’s vertical profilers was anchored in Blair’s Bay and another in Sheep Meadow Bay, even before the chemical was applied by the Lake George Park Commission, said Lake George Waterkeeper Chris Navitsky.
Kelly noted: “By utilizing the vertical profilers and our computer models, we know where every cubic meter of water in that bay is moving at any point in time. We know the wind direction. We know how the water was moving throughout the water column, and at what speed, on June 29, at the depths at which the ProcellaCOR was applied, at the time it was applied.”
According to the Lake George Park Commission, its contractors collected water samples from eleven sites in Blair’s Bay and Sheep Meadow Bay, at the surface and near the bottom of the lake.
“We’ve collected hundreds and hundreds of samples, testing more frequently than the Park Commission does, and not only from the Park Commission’s sites, but over a broader area, from places where the Park Commission did not look. We went outside its designated treatment and dilution zones to places where our circulation models told us the water – and likely ProcellaCOR – would go, and go pretty quickly,” said Kelly.
The Jefferson project’s circulation models, which have been validated by data and by independent, peer-reviewed research, show that the waters in the bays of Lake George remain static for much shorter periods of time than is commonly thought, especially when activated by winds, stream inputs and thermal effects.
According to Kelly, “If the concentration of residual chemicals is high enough, milfoil outside the intended treatment zones would die. That would indicate that you should also look for collateral damage to native species.”
And at low concentrations, the herbicide might actually stimulate the growth of Eurasian milfoil, Kelly acknowledged.
Kelly said we should also be concerned if ProcellaCOR is swept from the bays into the main lake where the water is deep.
“At those depths, the ProcellaCOr would be unable to decompose from exposure to sunlight. It would have a half-life of many days, weeks or even months. And at this point, we don’t know the consequences of that,” said Kelly.
Where did the herbicide go?
According to the Lake George Park Commission, its own sampling showed that no ProcellaCOR could be detected within 24 hours of its application, either in the treatment areas or in the Park Commission’s designated dilution zones.
In response, a spokesperson for the LGA stated, “ProcellaCOR does not break down that rapidly, especially when there’s no sunlight, so it had to go somewhere. That’s what we’re trying to discover.”
Chris Navitsky said he also wondered if the absence of any detectable concentrations of the herbicide after a relatively short period of time was an indication that it was washed from the bays and beyond the dilution zones.
An arsenal of tests
The LGA is not only analyzing water samples, Kelly said.
“We’re conducting a whole arsenal of tests, plant surveys included,” said Kelly.
Using RPI’s submersible Remote Operated Vehicles (ROVs), which are equipped with cameras and sampling capabilities, the areas targeted for milfoil eradication were surveyed before and immediately after treatment, as well as more recently.
“We’re now in the process of studying not only the efficacy of the treatment, but the persistence of ProcellaCOR and its ingredients on the plants and in the soils of the lake bed,” said Kelly.
Dissolved oxygen sensors in both bays are measuring
how much oxygen is available for other species in the food chain, Kelly said.
“If large amounts of plant material die, we should see a dramatic change in the levels of dissolved oxygen,” Kelly explained.
The LGA’s research will continue through the summer and into next year, said Kelly.
Data will inform future treatments
According to Kelly, the LGA plans to make its data public. “We intend to sit down with all stakeholders – the public, the municipalities, the Lake George Park Commission, the APA and the DEC and share and explain this data,” said Kelly. “My hope is that we, collectively, can come to some preliminary conclusions as to the results of this experiment, and that these conclusions will inform the next experiment, should there be one.”
