Aquatic Nuisance Control Permitting
Aquatic Nuisance Control (ANC) permits are issued under 10 V.S.A. § 1455, which regulates the use pesticides (e.g., herbicide, lampricide), chemicals other than pesticides (e.g., chemicals not registered as a pesticide), biological controls, bottom barriers, structural barriers, structural controls, or powered mechanical devices in waters of the State to control an aquatic nuisance. An aquatic nuisance is considered an undesirable or excessive substance or population that interfere with the recreational potential or aquatic habitat of a body of water, which includes rooted aquatic plants, animals, or algal populations. The goals of this program are to allow for aquatic nuisance control activities to occur provided it can be found that adequate measures are taken to preserve and protect the quality of the receiving waters, to protect the public health, and to minimize the impact on the non-target environment.
Aquatic Plant Control
Aquatic Nuisance control (ANC) permits are typically issued for the control of aquatic plants. Projects that target an aquatic invasive species are more likely to be permitted as invasive species are considered one of the ten major stressors on Vermont’s surface waters as identified under the Vermont Surface Water Management Strategy (for more specific information on aquatic invasive species, please visit the Aquatic Invasive Species Program webpage). Control projects for native aquatic plant species are typically not permitted or are limited in scope to minimize the impact on the non-target environment. Minimizing impacts on native aquatic plant species is a goal of the permitting process because:
- Native aquatic plants can improve water clarity. Aquatic plants dampen wave energy, which slows shoreline erosion and allows fine particles to settle out of the water column. Rooted aquatic plants help to hold lakebed sediments in place. These actions can both improve water clarity and quality.
- Native aquatic plants are required by fish and wildlife. Aquatic plants provide physical structure and habitat. Fish and wildlife use aquatic plants as a place to nest, lay eggs, feed, and hide from predators. Aquatic plant beds make up the nursery grounds of a lake.
- Native aquatic plants can help prevent algae or cyanobacteria blooms. Aquatic plants help maintain stable lake ecosystems. Lakes with robust populations of aquatic plants help maintain a clear water stable state by being the primary point of uptake for nutrients. Without the presence of aquatic plants, nutrients can fuel algae or cyanobacteria growth instead.
Considerations for planning an aquatic plant control project:
Control projects must balance the purpose of a project (e.g., invasive species control, maintaining areas of high public use) with ensuring that the ecological integrity of the waterbody is maintained and risks to public health are negligible. Lakes and ponds are dynamic natural systems and excessive aquatic plant removal has the potential to negatively impact various aspects of an aquatic ecosystem. Consider the following when planning a project (many of these considerations will need to be identified when applying for an Aquatic Nuisance Control Individual Permit):
- What is the purpose of the project? Is it a lake-wide effort to control an aquatic invasive species or a targeted effort to maintain a specific area of water to improve public good uses (e.g., maintain an area for boating or swimming)?
- What are the tools available to achieve that purpose? There are many advertised control methods on the market, however some do not align with what is allowed in Vermont (e.g., the use of grass carp) or would be unlikely to be permitted (e.g., chemical control of native aquatic plants). For lake-wide aquatic invasive species management efforts, a combination of different management tools may be required.
- Are there less intrusive feasible alternatives to achieve the purpose of the project?
- If the purpose is Eurasian watermilfoil control, are there tools that are more selective at controlling the target plant species (e.g., using diver assisted suction harvesting instead of a mechanical harvester to target Eurasian watermilfoil)?
- If the purpose is to control aquatic plants around a dock, can the dock be extended (while remaining in compliance with Lake Encroachment Permitting) to a greater depth to avoid aquatic plant removal?
- Can the project be done with a method that does not require an ANC permit (e.g., pulling aquatic plants by hand/rake only)?
- What can be expected to be achieved by pursuing a control project? The density of aquatic plant growth is largely influenced by the depth and trophic state of the waterbody. With shallower and/or more nutrient rich waterbodies, it should be expected that aquatic plants will be more prevalent. While a project to control a lake-wide infestation of an aquatic invasive species can be a reasonable purpose and therefore a permittable project, eradication is a highly unlikely result from pursuing a control project.
- Do you have the right technical information? Depending on the project, an ANC application may require an aquatic plant survey. An aquatic plant survey helps provide an understanding of the species that are present in a waterbody, their location, and density. Aquatic plant surveys help inform and justify how management efforts could proceed.
- How long will a control project last? It should be anticipated that most projects will last in perpetuity to some degree. As mentioned, complete eradication of an invasive species is highly unlikely, and long-term maintenance is often required. Long-term measures that can reduce the frequency of control projects include:
- Shoreline and watershed management efforts aimed at reducing nutrient inputs. For shoreline property owners, this can be as easy as planting trees along the shoreline (check out the Lake Wise Program for more information on how you can help improve the resilience of your shoreline as well as the lake). For lake associations or municipalities, this could include watershed management efforts such as stormwater master planning or creating a lake watershed action plan (check out the Watershed Planning Program for more information on how to improve a lake’s watershed).
- Continual work on small projects to keep a balanced approach at achieving the project purpose. This helps maintain project outcomes over time and minimizes impacts on the ecological integrity of a waterbody.
- For a lake-wide effort to control a well-established population of Eurasian watermilfoil, the Agency of Natural Recourses has determined that the combined total surface area for all permitted Aquatic Nuisance Control projects (e.g., bottom barriers, diver assisted suction harvesting, herbicide) may only occur in up to 40% of a waterbody’s littoral zone annually. This approach has been adopted by the Agency due to a number of considerations, one of which is to retain structural habitat that can be provided by Eurasian watermilfoil for fish. While Eurasian watermilfoil is an aquatic invasive species, eradication from control efforts is rarely, if ever, likely to succeed. Therefore, concentrating annual control efforts helps reduce adverse impacts on the ecological integrity of the waterbody as impacts on the non-target environment cannot be entirely avoided.
Additional Review Resources for Proposed Herbicide Projects
- Permitting Aquatic Herbicide Projects in Vermont
- Internal DEC Aquatic Toxicity Review of ProcellaCOR Herbicide
- Vermont Department of Health Review of ProcellaCOR herbicide by the Vermont State Toxicologist
- Study of impacts on macroinvertebrate communities on the Peconic River, NY from a ProCellaCOR treatment Additioanl information available on the project webpage
- In April 2022, the Lakes & Ponds Program completed a statistical analysis of pre- and post-treatment aquatic plant survey data from waterbodies that have been treated with the herbicide ProcellaCOR EC. This herbicide is permitted to target Eurasian watermilfoil only. In sum, aquatic plant survey data has shown that after a ProcellaCOR EC treatment, a statistically significant decrease of the lake-wide frequency of occurrence for Eurasian watermilfoil (target aquatic invasive species) and coontail (non-target native species) occurred. Over the same period, a statistically significant increase of the lake-wide frequency of occurrence for the beneficial native species Illinois pondweed and American eelgrass occurred.
Exemptions and Additional Permits
An ANC permit is not required for the control of an aquatic nuisance when the project is done by hand only (e.g., handpulling, raking). However, control projects within a Class I or Class II wetland or in its associated buffer are still jurisdictional to the Wetlands Program under the Vermont Wetland Rules.
Please contact Misha Cetner: firstname.lastname@example.org or 802-490-6199