In early 2022, the Lake Bomoseen Association applied for an ANC permit to use ProcellaCOR which resulted in misinformation being spread online and in newspaper commentaries.

To help combat this misinformation, and to provide fact-based information on ProcellaCOR, the Vermont Department of Environmental Conservation (DEC), published a document in October of 2022 entitled “Permitting Aquatic Herbicide Projects in Vermont”.

The Vermont DEC describes that the purpose of this document is to:

1. Provide background information about DEC’s Aquatic Nuisance Control (ANC) permitting program, with a specific focus on aquatic herbicide projects;
2. Identify some of the recent findings related to ProcellaCOR; and
3. Provide a Q&A section on this topic reflecting common questions that DEC receives about our ANC permitting program

The document details Vermont statutes, the permitting application and technical review process, and the departments and agencies involved in the permitting process.

It also discusses key findings on ProcellaCOR EC, including:

• a pre- and post-treatment statistical analysis of the aquatic plant survey data from Vermont treated waterbodies (showing increases in native plants, and decreases in milfoil)
• an aquatic toxicity review memorandum performed by a Vermont DEC Environmental Scientist (concluding that “the potential for acute and chronic risks to fish, aquatic invertebrates, amphibians and other aquatic animals is considered low”)
• a macroinvertebrate survey conducted by New York DEC, finding that “No significant changes to the macroinvertebrate community assemblage were observed when comparing survey results pre- and post-herbicide treatment.”
• a review of ProcellaCOR’s confidential statement of formulation memorandum, performed by a Vermont State Toxicologist from the Vermont Department of Health concluding: “Based on a review of the confidential statement of formulation, it is reasonable to conclude that human exposure to the inert compounds contained in ProcellaCOR at the concentrations that would result under the conditions proposed by the applicants, is not likely to result in an increase in the level of concern for public health. Thus, the proposed treatment of Lake Bomoseen with ProcellaCOR is expected to result in negligible risk to public health, from both the active and inert compounds in ProcellaCOR.”)
• an acknowledgement from the Vermont DEC’s Drinking Water & Groundwater Protection Division,“DWGWPD does not have concerns with the use of ProcellaCOR provided the conclusions from VDH have not changed and that treatment concentrations do not exceed 5 PDUs.”

Finally, the document contains 16 frequently asked questions posed to the Vermont DEC about these topics with their answers.

This document can be viewed here: Permitting Aquatic Herbicide Projects in Vermont

We also highly recommend reviewing this presentation by the Vermont DEC entitled “ANC Permitting 101” which goes into great detail about the permitting process.

Vermont waterbodies have not “adapted” to milfoil, which is why tremendous effort – including at a significant cost – goes into controlling current infestations and preventing new ones. Milfoil has no natural controls to keep it in check as it does in its native regions. The US Department of Agriculture National Invasive Species Information Center lists Eurasian watermilfoil as an invasive species, the Vermont Agency of Agriculture, Food and Markets also designates Eurasian watermilfoil as a Class B Noxious Weed on their Noxious Weeds Quarantine Rule.

We’d encourage you to watch this documentary by the New York DEC: “Uninvited: The Spread of Invasive Species,” which you can view on YouTube. While the 53-minute documentary is worth watching in its entirety, if you fast-forward to the 38 minute mark, you’ll learn a lot about ‘Mother Nature’ and invasive species.

The documentary explains that nature cannot take care of itself after the balance is upset, typically a result of human activity. They offer a good example in the documentary of a reed (common reed or Phragmites) that was used as packing material 400 years ago on ships traveling from Europe. The reeds were thrown on shore and took root here in the US. This invasive reed is now destroying native plant species in wetlands, marshes and along lake shores.

In its native land, Phragmites has 170 different insects that feed on it, which keeps it in check, and that ecosystem is in balance. Here in North America, this plant only has five insects that eat it or have adapted to eat it. This imbalance allows common reed to grow uncontrollably, outcompeting native plant species. So, in over 400 years, nature has not adapted. In fact, the speaker says it would take thousands to hundreds of thousands of years for this reed to act like the plants it has displaced.

Unfortunately, we (humans) interfere with ‘Mother Nature’ all the time by introducing invasive species – knowingly or unknowingly. It is our responsibility to work to control or eradicate invasive species to protect the native species and the ecosystems they have unbalanced.

The goal of milfoil management programs is control, not eradication.

Left unchecked, milfoil will spread throughout the littoral zone (the area where light penetrates) of a lake, can form dense beds, and outcompete and suppress native plants, including rare, threatened and endangered species.

Unmanaged milfoil can also:

• Impede recreational activities like fishing, boating, kayaking, and swimming
• Decrease light penetration – limits photosynthesis and can cause algae blooms
• Decrease habitat complexity – reduces species biodiversity and impacts the food web
• Decrease oxygenation – lower oxygen can lead to algae blooms
• Increase sedimentation – a buildup of ‘muck’ and loss of water depth
• Increase nutrient loading – a release of phosphorus from the sediments causing algae blooms
• Accelerate eutrophication – enriching the lake with nutrients (phosphorus) which can lead to excessive plant and algae growth
• Affect pH and temperature levels – many aquatic organisms have a preferred pH and temperature range

As a perennial invasive aquatic plant, milfoil ‘keeps coming back.’ Whether an area was cleared of milfoil by hand-pulling, DASH, benthic barriers, or spot treatments of ProcellaCOR, milfoil is prolific, aggressive, and has the ability to grow in a wide range of environmental conditions. Uncontrolled milfoil can lead to fragments that can easily reseed newly controlled areas. By no means does this mean that the time, effort, and cost put into these control efforts is wasted, as the goal of these programs is to keep milfoil at manageable levels so that it’s not impacting lake health or recreational use.

Absolutely not. ProcellaCOR is highly selective to milfoil. The specimen label does list a few plants native to Vermont that can be impacted by ProcellaCOR, for example, coontail and watershield. When spot ProcellaCOR treatments are permitted for control milfoil in a lake, permit conditons take into consideration impacts to non-target plants and treatments, e.g.,  avoiding populations of these sensitive native species, use of low ProcellaCOR concentrations.

Vermont DEC performed a statistical analysis of ProcellaCOR use in Vermont lakes, and this analysis showed statistically significant decreases in milfoil, and statistically significant increases in native plants. These results reflect a successful treament regime –  when the invasive plant species is controlled, the native plants will take back that space. This analysis was completed using data from permit-required aquatic plant surveys from Vermont lakes treated with ProcellaCOR.

No, this is a gross distortion of the permitting process. This commentary was written in response to the Lake Bomoseen Association (LBA) submitting a permit application to use ProcellaCOR. All herbicide permit applications go through a rigorous process, involving numerous departments and scientists.

In the specific case of the LBA’s application, we have learned from the Vermont DEC that when this application was received, these 15 internal experts, along with additional scientists in the Vermont DEC, reviewed, and provided comments and input on this permit application:

• two scientists from the Vermont Department of Fish and Wildlife (DFW) Wildlife Division
• three scientists from the DFW Fish Division
• the DFW Public Access Area manager
• two DFW staff that oversee the Keho Camp
• two scientists from the Vermont Department of Health
• one scientist from the Vermont DEC Drinking Water Groundwater Protection Division
• the Vermont Department of Forests, Parks and Recreation regional State Parks manager
• two scientists from the Vermont DEC Wetlands Program
• one scientist from the Vermont DEC Monitoring and Assessment Program who is an aquatic toxicologist and member of the Vermont Pesticide Advisory Council

The Vermont DEC and DFW created a framework in 2018 for permitting both herbicide and non-herbicide milfoil control efforts. This framework has been in place since that time, and was used for all ProcellaCOR permits issued, for which both departments determined that all the projects presented an acceptable risk to the non-target environment.

The Vermont DEC also engages the Vermont Department of Health to review submitted pesticide applications to determine if a finding of negligible risk to public health can be made for the pesticide project proposed. In the memorandum for this review, the State Toxicologist determined that the use of ProcellaCOR “…is not likely to result in an increase in the level of concern for public health.”

Finally, in late March of 2023, all three departments: Vermont Department of Environmental Conservation, Vermont Department of Fish and Wildlife, and Vermont Department of Health officially formalized the agreed upon framework which you can see here: “Aquatic Nuisance Control (ANC) Individual Permit Application Internal Review Procedure”.

For a thorough explanation of the Aquatic Nuisance Control permitting process, see this presentation by the Vermont DEC entitled “ANC Permitting 101”.

No. As you can hear in his testimony to the House Committee on Environment and Energy on March 15th, 2023, Lakes and Ponds Program Manager Oliver Pierson dispels the myth that the two departments don’t work together, and that the Vermont DFW opposed the Lake Bomoseen permit application:

“This process which we’ve developed which we call the aquatic nuisance control internal review procedure is unique. I’m not aware of any other examples in our own permit issuing where the authority to issue the permits voluntarily seeks out the input of other State departments who may have slightly different missions and mandates, but we’re all in this for similar long-term outcomes and does our best to incorporate those into our permitting decisions. And I think it’s worth noting that since we’ve issued the ProcellaCOR permit on Lake Iroquois, and with all of our ProcellaCOR applications since then, as I’ve said, we’ve received input from Fish and Wildlife. With that input, you’ve established permit conditions you may prohibit certain parts of the lake from being treated because there’s rare, threatened, or endangered species. You may say that this part of the lake doesn’t need herbicide because they haven’t demonstrated that the invasive is interfering with aquatic habitat because we’ve taken that feedback from our sister department into consideration, and that’s influenced our permitting decisions. Most recently, for the Lake Bomoseen permit application, we received feedback from Fish and Wildlife, saying that with a few conditions, such as not treating north of the Grady bridge, and a few other conditions, that as long as we implement those conditions, in the permit, they do not object to this application. Again, I’ll let them speak for themselves tomorrow, but I think that is an important point to make that all this division that’s being portrayed between DEC and Fish and Wildlife, when you look at the facts, isn’t as divisive as it might appear to be. We are really working together to issue these permits in a collaborative manner where their feedback is taken into consideration.”

Earlier in his testimony, before this detailed explanation, Oliver stated:

“I can’t speak to what happened prior to 2018, but what I can say, since 2018, there has not been an example of Fish and Wildlife objecting to an herbicide permit issued in Vermont.”

We’d also like to note a response from Secretary Julie Moore on March 20th, 2023 to an individual who made misrepresentations and false accusations about the relationship between the departments, and ‘clandestine’ groups and meetings to the House Environment and Energy Committee:

“I received a copy of the email message you sent to members of the House Environment and Energy Committee last week; I am deeply concerned with the misrepresentations made in your message. Staff at the Agency are dedicated to working in collaboration with other agencies and the public to protect Vermont’s environment and the accusations in your letter represent either an unwillingness to conduct basic due diligence or a willful disregard for the facts.

The Agency’s Lakes and Ponds Program has organized an Aquatic Nuisance Control Pre‐Rulemaking Focus Group to foster discussion and solicit input to a rulemaking on the ANC rulemaking process. Information on this focus group, including participating entities, proposed timeline, and minutes, is available at https://dec.vermont.gov/watershed/lakes- ponds/permit/control/aquatic-nuisance-control/anc-pre-rulemaking-focus-group. Given the emotional and sometimes accusatory discussion on this topic, the group collectively agreed to abide by the “Chatham House Rules,” which simply states that group participants “are free to use the information received, but neither the identity nor the affiliation of the speaker(s), nor that of any other participant, may be revealed.” This agreement and process allows for robust discussion and constructive disagreement, without resulting in polarizing public exchanges that stifle genuine progress.

In addition, your continued attempts to suggest a schism between the scientists in the Fish and Wildlife Department and those in the Department of Environmental Conservation reveals a basic lack of understanding regarding the collaborative and consultative process involved in management of the public trust and the importance of scientists’ ability to discuss and sometimes disagree with one another. FWD has been included in and engaged in every meeting of the Pre‐Rulemaking Focus Group and all substantive meetings with the Lake Bomoseen Association. The idea that DEC is actively undermining their colleagues is a fiction that does a disservice not only to DEC but also to FWD, and would seem to suggest you believe I am failing in my capacity as the leader responsible for overseeing both departments in ensuring all concerns are being heard and being given equal consideration.

I recognize your passion on this subject but disagree with your divisive approach. Rather than casting aspersions on the dedicated staff in DEC and FWD, I suggest that you focus your time and energy on the substantive issues under consideration before the legislature.”

So, why are these claims still being made? It may be that they are misinterpreting, whether intentionally or unintentionally, a memo dated April 8th, 2022 from an individual biologist in the Fish Division of Fish and Wildlife to the DEC Lakes and Ponds department opposing the permit after comments were solicited on the Lake Bomoseen application. As you can hear from Oliver’s testimony, this lone biologist expressed an opinion that was not shared by the Vermont Department of Fish and Wildlife. Fish and Wildlife did not oppose the treatment under the conditions they shared with the DEC. It’s important to distinguish comments from an individual and the leadership of the department.

We’ll again suggest that you read the framework / procedure agreed upon by the Vermont Department of Environmental Conservation, Vermont Department of Fish and Wildlife, and Vermont Department of Health to collaboratively review permit applications: “Aquatic Nuisance Control (ANC) Individual Permit Application Internal Review Procedure”.

No. This quote is from email correspondence between an individual biologist from the Fish Division of the Vermont Department of Fish and Wildlife and Misha Cetner from the Vermont DEC, and has been repeated numerous times, and in numerous mediums.

Lakes and Ponds Program Manager Oliver Pierson addressed this statement directly in his March 15th, 2023 testimony to the House Committee on Environment and Energy, saying this:

“The example that has been read twice today about the Lake St. Catherine situation where it’s been quoted twice by a [Vermont DFW] fisheries biologist that Lake St. Catherine’s aquatic plant management has been quote “nothing short of a disaster.” That’s one individual in Fish and Wildlife. We’ve heard from others in Fish and Wildlife that it has not been a disaster, it has simply led to a change from a decrease in largemouth bass, but an increase in smallmouth bass. Fish and Wildlife will be here tomorrow, I’ll let them speak for themselves, but I think it’s fair to say that we don’t agree, nor does Fish and Wildlife’s leadership, with the statement that aquatic plant management has been quote unquote, ‘nothing short of a disaster at Lake St. Catherine’.”

It should also be noted that the DEC took this claim very seriously, leading to the following reply from Vermont DEC Lake & Shoreland Ecologist Misha Cetner later that day:

“I take your comments on the St. Catherine warmwater fish populations quite seriously as that is not a casual statement. Do you have data that supports this? If so, that needs to be incorporated into the overall discussion. Is this observation in St. Catherine only or is it seen in the other lakes with EWM control?”

There was no response from the biologist to this direct questioning from the DEC.

Often cited along with this comment is a report entitled “2021 Bass Inventory and Management – District 2”, which was compiled by the fish biologist referenced above. This report contains data on electrofishing surveys performed on Lake St. Catherine from 1988 – 2021, with the data showing a decrease in largemouth bass, and an increase in smallmouth bass populations. It should be noted that this report does not contain bass data prior to 1988, so there can be no comparison between bass population data from 1988 to 2021 to the pre-milfoil era of Lake St. Catherine (prior to the early 1970s).

In the ‘Discussion’ section of this report, the author notes:

“Following a 15-year study of the black bass population in Lake Morey, VT, Kirn (1996) concluded that the introduction and rapid expansion of Eurasian watermilfoil (Myriophyllum spicatum) (EWM) in the lake was a major factor that lead to the development of a high-quality Largemouth Bass fishery there. Similar observations have been made in other Vermont lakes with established EWM populations (Good 2019).”

The author is citing a study, and his own observations, that milfoil infestations in lakes have a positive impact on largemouth bass populations.

So, this would lead you to the logical conclusion that lakes which experienced increases in their largemouth bass populations because of their milfoil infestation would also see a reversal of those unnatural largemouth bass population increases when they began milfoil control programs. Meaning, if the rapid expansion of milfoil was a major factor in increasing largemouth bass populations, the control of that milfoil would bring the population back down to its natural level that had been previously supported by the lake’s native aquatic plants.

As you have read previously, this logical conclusion has been described by the author as ‘nothing short of a disaster’. It certainly appears that the author is advocating for lakes to remain heavily infested with milfoil to support “high-quality Largemouth Bass fisheries”, without regard for the overall long-term health of the lake.

Finally, see this excerpt from the document “Rapid Response Plan for Eurasian Watermilfoil in Massachusetts” developed for the Massachusetts Department of Conservation and Recreation by ENSR International which discusses how intermediate densities of aquatic plants (including milfoil) can be beneficial for fish, but dominance of milfoil can result in replacement of native plants, alter the food web, and decrease fish and macroinvertebrate abundance.

“Aquatic macrophytes [aquatic plants] can provide food, shelter and spawning habitat for a wide variety of fishes (Lillie and Bud 1992). Intermediate densities of aquatic macrophytes, even including EWM, enhance fish diversity, feeding, growth and reproduction (Dibble et al. 1996). However, dominance by EWM tends to replace native macrophytes, altering the food web and creating food shortages for many fishes (Engel 1995). Beds of EWM can also impede predation, shelter overly dense assemblages of panfishes, and cover spawning areas, leading to potential decreases in sportfish abundance (Engel 1995). Large piscivorous fishes spend more time foraging for prey as plant density increases, thus reducing growth rates through unfavorable energetics (Savino and Stein 1982). EWM beds have been shown to decrease fish abundance compared to native vegetation, and Keast (1983) found that beds of native vegetation supported up to four times as many fish and up to seven times as many macroinvertebrates. Decreases in macroinvertebrate abundance were observed as EWM coverage increased in a Michigan study examining six lakes (Cheruvelil et al. 2001). In another Michigan study involving 13 lakes (Schneider 2000), EWM was implicated in undesirable population features for centrarchid fishes (bass and sunfish). The depletion of oxygen in waterbodies with dense milfoil coverage can also result in fish avoidance, and, in extreme, cases fish kills (Holland and Huston 1984, Lillie and Bud 1992, Engel 1995).”

No. ProcellaCOR is injected by hoses at subsurface depths of the lake from a boat.

A term like spraying may be purposefully used to evoke an image of applicators in hazmat suits using aerosol spray wands around a lake, which is not how ProcellaCOR is applied. Other scaremongering terms like poison, toxic, and chemicals may also be used purposefully to influence those who are not fully informed on the topic of this herbicide to steer away from a rational discussion of their use, safety, and effectiveness.

Note: There are no recreational or household restrictions for lake water usage after a ProcellaCOR application, but the State of Vermont recommends that the lake not be used for recreation or household use on the day of the treatment.

No, it’s not likely that herbicide applications lead to cyanobacteria blooms. Herbicides work by targeting specific aspects of a plant’s internal cellular processes. This allows them to kill one kind of plant, but not another. Freshwater algae and cyanobacteria do share many cellular processes with terrestrial plants. A number of recent papers indicate that both algae and cyanobacteria are sensitive to many different herbicides (for example, Gomes and Juneau 2017, Singh et al. 2016, Hernadez-Garcia and Martinez-Jeronimo 2020). Just how much they are affected depends on the herbicide, when/how it is applied, and environmental conditions at the time of application. Applicators must take this into account and apply herbicides that target the nuisance plant primarily and limit effects on non-target species. Applied properly, herbicides should not change phytoplankton community structure to favor cyanobacteria.

Cyanobacteria grow in aquatic environments with many other inhabitants. Competition for light, nutrients, and space to grow has led many species to develop abilities that allow them to access what they need better than others can. When you look at the phytoplankton communities in lakes affected by cyanobacteria blooms, they are not conspicuous because of the lack of other algae like diatoms and green algae. On Carmi, St. Albans, and Missisquoi, there are major spring diatom blooms and masses of green algae in summer along the shorelines. They also support large communities of aquatic plants. This is true even during persistent bloom events and over many years despite persistent blooms. Cyanobacteria dominance at a certain time of the year is more likely connected to other characteristics like temperature and nutrients than to the use of herbicides. You can read more about cyanobacteria from retired aquatic biologist Angela Shambaugh in her FOVLAP website article here: “Cyanobacteria”.