Applying Herbicides in and Around Water

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[EMILY ROJIK] Invasive and unwanted plants seem to grow anywhere, and herbicides are often required to manage them efficiently and effectively.

But what if the plants are growing in a wetland or in or near a body of water?

Is it safe to use herbicides in an aquatic setting?

Hi.

I'm Emily Rojik, a Penn State Extension educator specializing in natural area vegetation management.

In this video, I will discuss the regulations around using herbicides in aquatic sites in Pennsylvania and how to select the right products.

Please note that other states may have different regulations on this topic.

First, let's define aquatic applications.

According to Pennsylvania law, an aquatic application is the use of a pesticide on standing or running water.

So applying herbicide to control vegetation in a body of water, which includes ponds, lakes, reservoirs, streams, and rivers, as well as surface water in a wetland is considered an aquatic application.

Before an herbicide product is legally registered for sale, the manufacturer must put it through extensive testing overseen by the US Environmental Protection Agency or EPA.

This testing is to determine the herbicide's effectiveness and its level of toxicity to humans, animals, and the environment.

This includes the level of toxicity to aquatic wildlife, including vertebrates like fish and frogs, and invertebrates like aquatic insects and crustaceans.

To be registered with the EPA for aquatic use, pesticide products must go through additional testing so we understand their effects when intentionally applied to aquatic sites.

Herbicides that are approved for use in aquatic settings are referred to as aquatic labeled herbicides.

Look at the product label before using an herbicide to treat plants that are growing in a body of water.

The label must have aquatic listed as an application site.

This is also true for anything that's added to the spray mixture to increase its effectiveness, such as surfactants.

However, you cannot simply buy aquatic labeled herbicides and additives and start applying them to water.

Before herbicide can be applied to any body of water in Pennsylvania, the property owner must apply for a Chapter 91 permit, also referred to as a joint permit.

This permit is jointly administered by the Pennsylvania Fish and Boat Commission and the Pennsylvania Department of Environmental Protection, or DEP.

You can find the permit application on the website of either the Fish and Boat Commission or DEP, or by doing an internet browser search.

The title of the form is Application for Use of an Algaecide, Herbicide, or Fish Control Chemical in PA Waters.

Follow the instructions in the form to properly complete and submit it.

A property owner must secure this permit before applying herbicide directly to surface water.

While you do need to have a Chapter 91 permit, you do not need to be a certified pesticide applicator to apply an herbicide to water on your own property in most cases.

An applicator certification is required for certain situations.

See other extension videos on who can apply pesticides for information on when applicator certification is required.

We've been looking at the procedures for open bodies of water.

Now, let's consider wetlands.

What is a wetland?

A site where the soil is saturated or water logged for long periods of time and contains plant species that are typically associated with wet soils is considered a wetland, even if there is no open water on the surface.

Applying herbicide in a wetland is not technically an aquatic application if no surface water is being treated.

This means that a Chapter 91 permit is not required.

However, a wetland is still considered an aquatic site, so only aquatic labeled herbicides may be used.

There is an exception to this.

If the wetland is being treated during a period when the soil is not saturated and the herbicide label allows for applications to seasonally dry wetlands, then you can use an herbicide that is not aquatic labeled.

Finally, let's consider sites that are close to water.

You are generally permitted to use herbicides that are not aquatic labeled up to the water's edge if the soil is not saturated, as long as your herbicide label does not state a buffer zone or a setback requirement.

For example, this label includes distances of 50, 25, or 15 feet that you must stay away from the water's edge, depending on the type of application you are conducting.

Even if it is legal to use a non-aquatic labeled pesticide, it's best practice to use an aquatic labeled product when working close to water.

This minimizes the potential for harming aquatic wildlife if the herbicide accidentally gets into the water.

In this video, you learned that herbicides can be safely and effectively used to control unwanted vegetation in and near bodies of water and in wetlands.

Just follow the regulations and read the herbicide label carefully to ensure it is a successful application that you and the aquatic creatures will be happy with.