Herbicide application explained, could begin next week, Whitewater officials say

(Originally published Oct. 8, 2021.) 

By Kim McDarison

The City of Whitewater will soon be making aquatic herbicide application to over 100 acres of drawn down lakebed located on the city’s south side. 

Representatives from the city and Field and Stream Restorations, LLC, the Cottage-Grove based company that will be applying the herbicide, held a virtual meeting Wednesday, Oct. 6, to update the public about planning underway for herbicide application to control vegetation which has grown in the Cravath and Trippe lake beds. 

Plant growth in the lakes was initially attributed to fertilizers that had washed into the lakes from area properties, City Manager Cameron Clapper said in a presentation given to the public last month, making a nutrient rich environment in which invasive plants grew. To return the lakes to recreational use, Clapper said last month, the city began a restoration process, drawing down the lake water. 

That process, according to a representative from the Wisconsin Department of Natural Resources (DNR), began in May of last year. Since then, city officials have explained, vegetation has grown to heights that are taller than a human being, as described by Clapper during a State of the City address given virtually in September. The city has been working with the DNR to obtain dredging permits to clear the lake of invasive vegetation. Plans call for a controlled burning process to help remove the plants, but first, Clapper said during his September address, a chemical herbicide will be applied to the lakebed to weaken the plants.  

During Wednesday’s meeting, Whitewater Parks and Recreation Director Eric Boettcher introduced Field and Stream Restorations Senior Ecologist Steven Banovetz who gave a summary of the process, equipment and chemicals the company plans to employ during the herbicide application project. Additionally, Banovetz responded to several questions asked by Clapper and Whitewater City Council Member Brienne Brown. Whitewater City Council Member Lisa Dawsey Smith was also in attendance. A total of nine participants were in attendance during the meeting. 

An update from Boettcher

Boettcher noted that the project to restore the two lakes, Cravath and Trippe, had been underway for “quite some time now,” and that Wednesday’s meeting was meant to serve as an update of the continuing project. The application of herbicide is a step that will be followed, according to information shared by Boettcher in previous presentations, by some controlled burning of vegetation and dredging, after which the lakes will be refilled with water sometime next year, likely in the spring and summer.  

Boettcher further pointed to an outline produced by Field and Stream Restorations which offers an overview of the herbicidal process. 

The outline, he said, “describes where they are spraying and what they are spraying.” 

Looking at a map included as part of Wednesday’s presentation, Boettcher said: “The blue area is kind of where we are looking at treating. Again, this is the lakebed area; this does not go up onto residential shorelines. We are only allowed to treat the area on the lakebed.”  

A permit application sent by the city to the DNR was also shared during the meeting. 

“The DNR reviews all of this and then they are the ones that determine whether we can spray or not, and give us the permit in order to perform this work,” Boettcher said. 

Boettcher likened the process of herbicidal spraying to one a property owner might undertake in his yard. 

“How this kind of works is it is kind of like, if you think about it, a neighbor who sprays their lawn. When the spraying is done, they will mark the area they are spraying; they will post signage letting people know, and, kind of like when you have your neighbor spraying their lawn, they have an indication of what they are spraying, what they are doing, and how long to keep away,” Boettcher said. 

He next opened the floor to questions.

Questions and answers 

Clapper indicated that the questions he was asking were among those be believed would be of interest to people who might not have been able to attend the virtual meeting. 

Addressing his questions to Banovetz, Clapper asked: “What is the process, and especially, we talked about somebody going out and spraying, what does that look like, what kinds of equipment are they using, is this airborne, how does that work?” 

Banovetz said there were two reasons why the herbicide was useful: “One was, we thought that by refilling the lake and having 12-foot cottonwoods all over out in the water, what seemed like the public backlash would be: ‘we’ve spent two years doing all of this and we’ve got more standing biomass out there than we had before.’ So that was part of it. And a 12-foot cottonwood isn’t going to go away in a couple weeks, it may be two years.” 

He cited a goal of working to bring down unwanted vegetation so that it would “rot and fall down to the lake bottom, so that it’s tied up in the lake muds rather than in the water column when the water comes back. 

“If we leave those plants in the water column, in essence, they will become part of the nutrients in the water,” Banovetz said, which, he noted, would serve to feed and restore blooms of unwanted lake flora. 

Turning to herbicide application and methodology, Banovetz said his company would use a three-tiered approach, with each tier determined by its proximity to the shoreline, which, in turn, would determine the size of equipment used to make the application, and the types of chemicals that would be applied.  

“We would be spraying the herbicides; it’s really the only logical, readily available method, from ground equipment. The ground equipment can range, on the small side, from a backpack on someone’s back, spraying an arc out in front of your walkway that you’re walking, as far as three or four feet from your feet. And you can spray maybe four or five feet in either direction as you’re walking. Imagine creating an arc in front of you with a fan tip. That’s kind of the smallest, most detailed type of application you could do, Banovetz said, adding that the backpack approach would be used in areas with sharp slopes, wet soils, and in and around trees that are hanging down onto the lakebed. The application would be used within five feet of the shoreline area. 

The next tier, according to Banovetz, would use single-person ATVs that would carry 25-gallon tanks of herbicide mounted to the vehicle. The chemicals would be applied to vegetation using a “boomless spray nozzle.” he said. The nozzle can spray chemicals about 15 feet in both directions from about five feet off the ground, he added.  

“Those, we would use in, again, small areas that it just doesn’t make sense to try and use anything larger,” he said, describing such areas as places where machinery might have to back up, or maneuver around obstacles. 

“The four-wheelers are pretty maneuverable that way, but unlike walking miles and miles a day, the ATV is certainly much easier than that. It can go a little bit quicker, and its going 15 to 20 feet wide versus maybe eight feet wide walking. So certainly our application rate and speed goes way up,” he said. 

A third tier would employ the use of a UTV, which, Banovetz said, was twice as wide as an ATV. “It’s almost like a mini pickup truck,” he said. 

The UTVs carry 100-gallon tanks and use what Banovetz described as a rod with nozzles that can spray product from 10 feet in the air, making a 35-foot wide area of application. The vehicle has tracking, he said, making it better able to go where smaller equipment might encounter difficulty with the terrain. 

“With 100 gallons, there are far fewer times you have to go back and refill, so again, our application rate is going to skyrocket with that tool as well,” he said.  

Said Banovetz: “Our intention is to do the shoreline with either the ATV or backpack by hand, until we are to a point where we feel like we are so well controlled, we can use the bigger machine and not worry about if a small breeze comes along, or a rut or something, where it takes our machine and moves it.

“There’s two ways that the spray could leave our intended area that we want it to be, either the wind could take it, or you could hit a bad rut or something if you were driving and instead of your boom spray pattern being horizontal with the ground, it all of a sudden becomes hard to tilt it, and it starts spraying more horizontally than down. That’s why we would look at creating kind of a buffer along people’s properties. The last thing we want is for someone to complain that we harmed one of their trees or some of their hostas, or something along the shoreline. Our effort will be to use the tool where we can ensure exactly the edge of where that herbicide is being sprayed.” 

Clapper asked: If someone was to look at their edge where they’ve got grass, and I know water came up to their grass before, where the grass ends, about how far from there are you expecting to go? How are you navigating that, and how close do you anticipate getting? 

Said Banovetz: “I’d like to be within five feet of that to accomplish our goal. I think there may be times, especially along the park, where there are some rock areas with noxious weeds in them that we’d like to hand backpack up into and capture some of those areas. We are going to be on the lake bottom, but there may be some associated landscapes within the city’s property that we may be able to treat within this. We would be less than five feet in those scenarios. If we approach somebody’s well manicured, well landscaped yard, we’re going to stay some distance away from that because the backlash is too difficult, but the goal of trying to remove the weeds from the lakebed is not more important than their comfort knowing that we respected their property rights.”  

Brown asked: “There are people at Whitewater Lake who have hand-planted native sedges and stuff like that in waters around there and so it may or may not be appropriate since I don’t know everybody around Trippe and Cravath, but if there were native things like that around, would your applicators be able to recognize that and try not to spray those?” 

Banovetz responded, saying: “Yes, we actually went around and mapped out where native plant populations were all the way around both lakes.” 

The map made by his team, he said, included areas where there were at least 20 native species. Areas in which a single native plant might be surrounded by invasive vegetation were not indicated. 

“So to find a single sedge, completely overwhelmed with canary grass or stinging nettle, we didn’t map that per se. We know it exists, so then really the direction could be from the council, if that’s of interest, we would need to backoff the property at least on some of the lakes in some areas 20 feet,” Banovetz said, adding, “If we want to save every native plant like that right on the edge of the shore, we could back off an additional distance from the shore.”  

Said Banovetz: “Our plan is fluid and adaptable. You notice from the blue map … that’s kind of the entire area that we could choose to spray. Some of it’s going to come down to the day we are spraying. We are going to do what we can based on wind direction and wind speed, how wet the soils are, if there is other feedback that would change that. Our original goal was to try and do the first 200 feet all the way around each lake. Certainly it’s much wider than that in Cravath Lake. So we left ourselves with the regulators a little more flexibility in case there were some areas we couldn’t get to and still wanted to try and reach a target of about 100 acres. 

“In terms of flexibility with the regulator, what I mean by that is if I don’t show it, I can’t really spray it under our permit. So it was easier to show too much blue than not enough blue, and then afford us a little adaptability to change the plan a little bit.” 

Banovetz said his team did not map “every square foot of both lakes,” calling that “a daunting task.” Instead, he said, his team would use discretion, and if they saw areas with highly desirable targets, such as cottonwoods, they would work to acquire those targets down to the roots.  

He identified portions on the map, specifically within the center of Cravath lake and on the south ends of both lakes, as areas that might not receive herbicide. 

“The soils get much harder to work with in terms of the creeks and the springs coming in, and when they get to a certain level of how wet and saturated they are, it gets hard to float equipment on them. Especially when you put 1,000 pounds in the rear end of a UTV or even the ATVs have 200 pounds in the rear. Those machines will start to sink,” Barnovetz said. 

Noting the four herbicidal products — Roundup Custom Aquatic Terrestrial Herbicide, Polaris AQ, Arsenal Herbicide, and Vastlan Herbicide — the company plans to use on the Cravath and Trippe lakebed, Clapper asked: Regarding the residue from the herbicides that will be applied, will the residue from those chemicals have a possibility in the spring of washing downstream? What kind of impact would that have on animals and aquatic life farther down Whitewater Creek? 

Banovetz said he did not believe any of the four chemical products, as noted by Clapper and as planned for application on the lakebed, would impact animals downstream. 

“By the time the water has come back up, or even in a hard rain event, these chemicals breakdown fairly readily. They are going to be sprayed to organic material that’s decomposing and rotting to the ground. If they were able to move so quickly and to do really any kind of measurable damage, they wouldn’t be labeled for use in aquatic environments,” Banovetz noted.  

He continued: “if you use a terrestrial herbicide and sprayed it in flowing water, it could potentially float on the water, move downstream, attach to vegetation and kill it. The goal with aquatic approved herbicides is that once they come in contact with water they’re … encapsulated and become inactive. Not that they’re not still an herbicide and still there, but they don’t have the same capacity to affect plant life and animal life like they did when they were first sprayed. 

“Herbicides, the same herbicide like Roundup, can be formulated for a terrestrial or land-based application and it’s effective and they use certain ingredients to make it work on land; they can take that same herbicide and they can put different additives with it so that it can be used in an aquatic environment, but not float or go off site and (cause) damage. That’s what makes it approved for aquatic use, because we all know that water can flow or that it could layer on the water and be blown across a lake and affect something on the other side.” 

Said Clapper: “I’m also thinking about someone having the concern — we’ve seen TruGreen lawn care and other companies that come out and take care of your lawns, and like Eric (Boettcher) said, put signs out that say, ‘hey, this is in process, doing its job, don’t walk out here … or roll around the grass for a day or two.’”  

Clapper asked: What about weather and rain; I think that might be some of the concern: we go to all this work and look at the forecast and then something crazy happens and the next day there’s a torrential downpour.  He asked if the city would need to reapply the herbicide. 

Said Banovetz: “Once the herbicide is applied to green living tissue … within an hour it is absorbed into the leaf, into the vascular system of the plant, so there isn’t a reapplication that would have to occur, unless you were negligently applying in the rainfall. Once it’s on and dried onto the leaf tissue, it’s there, it would be difficult to wash off. 

“Could we apply some of this herbicide and get a torrential rainfall and could some of it be detectable and move downstream? There’s always that possibility. 

“We’re using aquatic herbicides. My guess is after a hard rainfall after herbicide use in the farm fields around Whitewater, it would be detectable in the lake every time it rains, because you’re now washing things that are not aquatic approved. Not that that makes anybody happier, it’s not like this would be a real oddity, you know? The use of herbicides in our landscape is common everywhere.” 

Clapper asked Banovetz to talk further about the chemical products that will be used.   

Said Banovetz: “We chose four different herbicides. Often times you use more than one herbicide because the herbicides are designed to work on the plant cellular systems in different ways. One may disrupt the way an enzyme is made or used, another may be a growth hormone that causes a plant to overgrow itself, so there’s a couple different ways and modes at which they try to specifically create an herbicide that will disrupt a particular unique cellular function within just plants. It’s important to note that, because what they try to do to get a label, and to get the ability to use the product, they have to show that it doesn’t kill insects, and mammals, and other forms of life. So they try to find plant-unique cellular systems to disrupt.” 

Such techniques are used to ensure the products will kill plants, but will not necessarily harm the animals living around them, he said. 

Banovetz continued: “The next layer we looked at, there are some herbicides that are considered contact only. Roundup is one of those. If it doesn’t generally hit green leaf tissue, there’s nothing much more that it will do. It will degrade fairly quickly. The soils, bacteria will break it all down, the sunlight breaks it down. Moisture helps with that. There are other herbicides, what we call residual, where the herbicide may stay around for a while in the soils, continuing to actively work on humans’ best interest, to control the weedy plants that you applied it for. The common lawn herbicide 2, 4-D, Weed B-gon, is the common name for it, is a residual herbicide. It sits in your lawn for two to three months, continuing to provide dandelion control let’s say.  So we are using both of those — both the contact only and a residual — but in the first 50 feet from the shoreline, we are not using a residual because the chances are that maybe let’s say a big willow tree growing right on the edge of the shoreline may have roots underneath the lakebed or within the lakebed. And if we put a residual herbicide down, eventually, it may find its way to those willow roots and could negatively affect that willow tree.” 

He said the plan in the lakebed called for the use of contact-only herbicide in the first 50 feet from shore. 

“When we get farther out from 50 feet, we are going to switch over and use Polaris, which has a residual quality to it. And the value to that is that we are going to have an extended length of time for weed control beyond just the initial application. I’m no expert in this, so I can’t say that the Polaris will be there in June of 2022, but I’m quite sure it will be there late into November and December, perhaps, if we have a cool winter, it may still be somewhat active to the next spring. The advantage to that is that if the lake levels don’t come up as quick as you’d hope and maybe there’s some residual herbicide activity there, we can keep the lakebed cleaner longer and perhaps have a more aesthetic lake refilling process,” Banovetz said.  

Clapper asked about people who might be sensitive to odors, what precautions should they take? 

Banovetz suggested sensitive people keep their windows closed or perhaps choose to spend the day doing something away from Whitewater. 

“Our herbicides are applied with a lot of water, so it’s not like we’re creating a mist that might come out of an airplane that will float across the lake and landscape. Nothing we are using will become volatile,” he said. “I cannot guarantee that someone might be able to smell something that may smell like herbicide, or an unusual oder the days we are spraying,” he added.  

Clapper asked: “Animals that are living in the area, the birds, the fish, any of our mammal or other critters, turtles, frogs, this is not intended to and has low risk of hurting those animals, correct?” 

“Correct. If there was any risk, real risk at all, it wouldn’t be labeled for the type of application we are doing. That science has been settled long before our work here,” Banovetz said.    

Said Boettcher: “I can also add to that that the Wisconsin DNR would not allow us to apply anything that was not meant for this purpose. They are pretty strict on what we can and can’t do.”  

Banovetz agreed, saying: “I have created permits and had the DNR turn me down and say, ‘we need you to use this and this in this situation.’ They actually do do their research, they know what they are talking about, and they help guide us; they are not just there to approve or disapprove.”  

“I do believe that due diligence has been done by all the parties involved in making this happen. Concerns are understandable and legitimate. This is chemicals applied in a natural area,” Clapper said.  

Benovetz said on Wednesday that while he was still waiting for final approval of the permit from the DNR, he anticipated that the first day of spraying could begin in 7-10 days. How long it might take to complete the task of spraying 100 acres was weather dependent, he said, adding that with perfect breeze-free weather, it could be completed in as few as three or four days. Typically, he said, weather affects some portion of each day, which would increase the time needed to complete the full application. 

Those interested in learning when spraying will begin can look for notification on the city’s website, Clapper said. 

An earlier story about the permitting process and the meeting, including documents filed with the DNR is here: https://fortatkinsononline.com/trippe-cravath-lakes-chemical-aquatic-application-public-meeting-set-for-oct-6/. 

The city’s website is here: https://whitewater-wi.gov/1. 

A link to the full meeting provided by the City of Whitewater on Vimeo is here: https://vimeo.com/624918894.