Ongoing debate raises questions around ProcellaCOR’s use in lakes used for drinking water
By Gwendolyn Craig
Vermont regulators this spring denied an herbicide application to treat invasive aquatic weeds in the state’s largest inland lake. They cited public opposition, concerns about harm to native plants and other health and environmental issues.
The Green Mountain State’s posture was much different from their neighbors in the Empire State, where Adirondack Park regulators approved chemical treatment of Eurasian watermilfoil over the objections of residents around Lake George.
The Vermont permit denial faces a lawsuit as does the permit approval in New York.
Officials with the Vermont Department of Environmental Conservation declined to speak to the Explorer about the herbicide ProcellaCOR EC and the agency’s decision to deny putting it in Lake Bomoseen, due to the litigation.
But the Vermont permit application denial shows a stark contrast in how the Adirondack Park Agency, one of the permitters of the Lake George herbicide project, weighs public comments. The denial echoed some concerns brought by the lone APA board member who voted in opposition to the Lake George permits, Zoë Smith.
The APA and the state Department of Environmental Conservation authorized the Lake George permit, testing the herbicide in two bays to treat the invasive milfoil. The Lake George Park Commission, the state government applicant, oversaw the distribution of the herbicide at the end of June ,with a swimmer in view and a resident buzzing the contractor from a jet ski in an attempt to stop the project.
Opposition to the herbicide’s use in Lake George, a Class AA drinking water source recently featured by Travel and Leisure magazine as “the cleanest lake in the United States,” has come from hundreds of area residents, municipal leaders and nearly every environmental group in the park.
New York regulators have rejected recent public concerns about whether the herbicide’s active ingredient is a kind of “forever chemical,” and what its long-term impacts might be. Vermont news organizations reported similar concerns from residents around Lake Bomoseen.
All three New York agencies have amplified their position on the efficacy and safety of ProcellaCOR, which has been approved for use by the U.S. Environmental Protection Agency and the DEC.
The APA has already authorized more than a half dozen such permit applications in the Adirondack Park since 2020. The DEC has authorized more than 60 permits to use ProcellaCOR across the state.
The DEC said the state “is a national leader in emerging contaminant response and pesticide regulation,” and its reviews “ensure these products are fully protective of public health and the environment.”
Public concerns leads to herbicide denial in Vermont’s largest inland lake
Lake Bomoseen, the largest fully contained in the state, is 2,415 acres in Rutland County. It is less than an hour’s drive from Lake George, which is more than 10 times larger. Its shoreline includes a state park, two public boat launches, a municipal beach and private marinas and residences.
In February 2022, the Lake Bomoseen Association and the Lake Bomoseen Preservation Trust applied to use ProcellaCOR to treat Eurasian watermilfoil. The weed chokes out native plants and makes recreating difficult. Milfoil has infested the lake since at least 1982, records show.
Vermont authorities only permit such pesticides if there is no reasonable non-chemical alternative available and an acceptable risk to the non-target environment. There must be negligible risk to public health, a long-range management plan that minimizes pesticide use and; “a public benefit” without “undue adverse effect.”
Vermont has approved other applications of ProcellaCOR. While there are no mandatory water restrictions and the EPA has considered ProcellaCOR non-toxic for humans, past Vermont permits issued have required the applicant to supply drinking and cooking water to residents around a water body or its outlet stream for up to a mile downstream on the day of treatment if they rely on it as a potable water source. New York has no such requirement.
In the case of Lake Bomoseen, regulators found that there was unacceptable risk to native plants, the long-range management plan was insufficient and the public’s concerns outweighed the public good of the herbicide use.
All four municipalities around the lake opposed the application, the denial noted, as was a “significant portion” of the public.
The Vermont Agency of Natural Resources said the two lake associations seeking the permit were not enough to “wholly represent a favorable public interest in the project.”
The park agency’s approach: ‘Look at the science’
In New York, the APA board appears to consider public comments differently as demonstrated by its June meeting.
APA Board Member Arthur Lussi said he was aware of the Vermont denial and inquired about it.
APA Project Analyst Aaron Ziemann said Vermont regulators determined the herbicide project was not an acceptable risk for the environment, considered the public benefit and public good and felt the proposal treated too much of the lake’s littoral zone — the shallows.
Jerry Delaney, the executive director of the Adirondack Park Local Government Review Board, said “we have seen chemicals deemed safe that were over time used irresponsibly, or variables that weren’t anticipated become a problem.” He encouraged the agency to keep investigating the herbicide.
When the Lake George permits came to a vote, Smith asked if other board members were concerned that the local governments around the lake did not want the herbicide used.
“I think that’s a hard question,” said APA Chairman John Ernst. “Our job is to try and look at the science, understand the science and make a decision based on the science, and we want to listen to public comments, and we want to make sure we take them seriously, but the numbers of them aren’t necessarily a determining factor.”
APA Board Member Mark Hall added that he “has to make a decision with the science as I know it, not on the emotions. I think we’re all concerned for multiple reasons, but it’s hard to project what’s going to happen 20 years out.”
Smith, who is the director of Paul Smith’s College Adirondack Watershed Institute, said she did not feel the Lake George application followed the agency’s own permit requirements, either. The Lake George Park Commission chose bays for a pilot study that had not been treated for milfoil in a while and were not sites of the densest beds.
There are alternatives to using the herbicide as well, she noted, adding there were many opposition letters in the hundreds received.
“That raises some red flags I guess,” she said. “So I don’t feel comfortable.”
Ernst said he didn’t think they were ignoring those concerns but voted for the permits.
Smith broke with the majority while Benita Law-Diao and Ken Lynch were absent.
“Everything that went into this decision today for the Queen Lake in the Adirondack Park was a big one, and I think everyone did a great job,” said Brad Austin, an APA board member and state government representative with Empire State Development.
Ernst said the Lake George Park Commission had applied for the permits before, the board approved them, but then there was a lawsuit brought by the Lake George Association.
“We looked at it again to make sure we were doing our jobs,” Ernst said. “I think it was the right thing to do.”
Repeated calls for formal hearings
Environmental organizations disagreed, bringing up their repeated criticism that the agency has discontinued airing issues in an adjudicatory hearing. The last one was authorized in 2007 and held in 2010 and 2011.
Such formal hearings are meant to address outstanding questions and concerns on a permit before an administrative law judge. It is the only way the APA can deny a permit.
The APA has eschewed the adjudicatory process since, despite dealing with multiple controversial projects, many generating reams of comments. The Lake George herbicide application was one.
David Gibson, of Adirondack Wild: Friends of the Forest Preserve, said the agency appears to have “an orchestrated bias” against such hearings.
“Some of your staff are indefinitely tying your hands from ever denying a project or from ever making substantial modifications to any project, and if you’re OK with that, please come clean and say so,” Gibson said.
Ernst said he was sure there would be a return to hearings.
Jackie Bowen, conservation director of the Adirondack Council, echoed Hall’s use of the word “emotional” to describe public comments and said such a remark “minimizes their role.”
Lake George Waterkeeper Chris Navitsky, employed by the Lake George Association suing over the permit, said many of the property owners around the treated Blairs Bay and Sheep Meadow Bay will have no choice now, but to drink, swim and paddle in lake water.
“Most frustrating, I feel, is the apparent disregard to the details and technical science comments that have been presented,” Navitsky said.
Differing definitions around ‘forever chemicals’
At the APA’s May meeting, Navitsky introduced a Minnesota Department of Agriculture Interim Report that classified the active ingredient in ProcellaCOR as a PFAS, or “forever chemical.” These substances are difficult to break down in the environment, and some have been linked to causing cancer and disease. The active ingredient is called florpyrauxifen benzyl.
Navitsky called for a halt on all of the agency’s herbicide permits. The Lake George Association offered to pay for manual harvesting of the weed this year to divert the herbicide project, at least while regulators found out more information.
At the June meeting, Ziemann, the APA staffer, said the Minnesota “report does not negate the background work that has already happened federally, statewide and across the country.”
Asked what the herbicide degrades into, Ziemann responded: “product aggregates.”
“What do those degrade into and what are the impacts of that? That’s what concerns me. I don’t know if anyone knows,” Smith said.
Ziemann said when the herbicide degrades, it does “not pose impacts,” and “that’s the available data, and that’s what we base our determinations on and our review on.”
The Explorer spoke with experts on “forever chemicals,” and found analysis challenging.
The Nelson A. Rockefeller Institute of Government of SUNY, a public policy think tank, has been tracking all the different definitions of PFAS and noted that even New York uses Minnesota’s definition when it comes to food packaging.
The institute found that of 49 PFAS-related bills introduced across the country in 2023, three different definitions were used. The majority considered a PFAS “as organic chemicals having at least one fully fluorinated carbon atom, with many, if not most, referring to them as a class of chemicals.”
The EPA most recently decided to take a case-by-case approach for deciding what chemicals are considered a “forever chemical.”
The Explorer asked the DEC why New York uses different PFAS definitions depending on the scenario, and if it has considered using its food packaging definition for herbicides in drinking water sources.
The DEC said the definition used for food packaging is a “screening tool” that “does not apply to DEC-regulated pesticides.” Pesticides are evaluated by the DEC and Department of Health (DOH).
“EPA, DEC, and DOH experts did not identify any concerns regarding the toxicity or persistence of the active ingredient, florpyrauxifen-benzyl, when used as labeled in the ProcellaCOR EC product,” the DEC said.
Concerns around ProcellaCOR in drinking water
DEC said ProcellaCOR, registered in New York in 2019, goes along with the EPA’s review of current federally registered pesticides. EPA found such pesticides did not contain “active or inert ingredients with structures similar to “prominent PFAS.” The DEC has approved permits for ProcellaCOR in 17 water bodies that have a drinking water classification.
PFAS experts, one from the University of Oregon and one from Boston University, were not as concerned about the herbicide as a “forever chemical,” but said they would prefer drinking water without it.
Tom West, a professor of environmental health at Boston University, studies PFAS in pharmaceuticals and said the definition Minnesota used in its report has nothing to do with its toxicology. It’s a structural definition that chemists have introduced categorizing chemicals that have “one fully fluorinated carbon,” he said.
“The other part of the molecule I’m more worried about,” West said. “I don’t think I would particularly want it in my water, but I’m not so worried about the PFAS question.”
Jamie DeWitt, a professor in the Department of Environmental and Molecular Toxicology and the director of the Environmental Health Sciences Center at the University of Oregon, said it’s important to remember the purpose of pesticides.
“No pesticide designed to kill a living organism is truly safe because it’s designed to be toxic.”
Jamie DeWitt, director of the Environmental Health Sciences Center at the University of Oregon
She pointed to a European Food Safety Authority report that showed “a data gap” in a study about the effects of florpyrauxifen-benzyl on the endocrine system of rats.
Male rats developed mammary gland tumors during the two-year study. Researchers think the tumors were unrelated to the chemical and “agreed not to propose classification regarding carcinogenicity.” The report noted that “a significant consumer intake is not expected and the consumer risk is expected to be low.”
“I don’t know if this is going to assure your readers or frustrate them even more,” DeWitt said. “Having it in my water would not make me happy.”
Even though the manufacturer met all the testing requirements for the chemical’s approval, DeWitt said, there are still criticisms of the chemical review process. DeWitt studies immunotoxicity, but that evaluation isn’t included in every review. She thinks it should be.
“Not all potential forms of toxicity that can arise from exposure to pesticides are evaluated by those seeking registration for the pesticide,” she said. “They only have to do a certain number and type of tests, and many times those types don’t detect the type of toxicities that end up emerging as pesticides are used over time.”
DeWitt said ProcellaCOR’s active ingredient appears to degrade quickly, something that the Lake George Park Commission tracked and reported. The herbicide had fallen to undetectable levels about a day after it was applied.
Top photo: Town of Caroga (New York) officials treated Caroga Lake with ProcellaCOR in June 2024. Photo by James M. Odato
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Well written article; I has wondered about the Vermont connection. Seems to me the DEC hasn’t dug as deeply into potential problems with ProcellaCor as they should. If Gwendolyn Craig can find this information, why can’t the DEC, Dept of Health and APA find it and specifically address it.