Many herbicides have been specially formulated to release over time or kill weeds before they grow. Most herbicides are formulated to dissolve in water, making this even more concerning when they get into our channels and move long distances.
When treating weeds near water, you must:
- Never use a herbicide not approved for use near water (refer to label).
- Never spray uphill from the water before it rains.
- Never over-apply herbicide near water – always use the appropriate amount as described on the label.
Finally, never use the products listed below near water. Using them near water is harmful to plants, animals and is even hazardous to humans!
Roundup
Roundup herbicide has been around since 1974 and is one of the most widely used herbicides in the United States. Claimed to be safe by the manufacturer, there is concern that Roundup is linked to a few cases of non-Hodgkin’s lymphoma.
However, when it comes to the restrictions of Roundup around water, it is due to the surfactant mixed into the product.
Surfactant is added to Roundup to help them stick to the plant. It also increases the surface area impacted by the herbicide and helps the product enter into the plant.
In Roundup, a surfactant called POEA (polyoxyethylene amine) is automatically mixed into the product. POEA is highly effective in helping the plant absorb roundup.
This helps it kill weeds but makes it extremely dangerous to fish and amphibians. POEA will quickly move through the skin and scales allowing Roundup to enter into their bodies and kill these organisms.
Roundup is considered a broad-spectrum herbicide. This means that it kills almost all plant life. Inadvertently spaying around bodies of water kills beneficial plants that surround these areas.
These plants are essential for limiting erosion. They also act as a biofilter that reduces other toxins from entering the water.
If you must use Roundup around a waterway, opt for one labeled for use in these areas. These products will not have the POEA surfactant and be relatively safe for both wildlife and humans. These products will also break down within a few hours after entering the water.
Crossbow
This product is a popular herbicide for clearing brushy, overgrown areas. Often areas around ponds will become overgrown, and property owners will turn to Crossbow. This is not safe, however.
Crossbow is an ester-based herbicide, which plants easily absorb. This characteristic also makes it easily absorbed by aquatic life. As it is described on the label, Crossbow is toxic to fish and other aquatic organisms.
As with other dangerous products, avoid spraying Crossbow within 15 feet of water. Additionally, never pour it in areas where water may rise after rain.
Overspray, or using too much Crossbow, causes it to runoff and be absorbed into the soil. This product quickly moves into shallow water tables and contaminates groundwater.
Aside from human and wildlife poisoning, Crossbow can remain in surface water for over a week. This persistence increases the chance of it coming into contact with non-target plants.
Atrazine
Atrazine is a product used frequently as a pre and post-emergent herbicide in lawns. The popularity of this herbicide is due to its ability to kill broad-leafed weeds without hurting certain grasses.
You must be careful when using Atrazine. It is absorbed quickly by soils and can remain there for over 2 months. This product moves through certain soil types (sandy and loamy sand) and can enter shallow groundwater areas.
Atrazine shows up frequently in drinking water samples. Its ability to poison drinking water is so well-recognized, the manufacturer advises not to use this product within 50 feet of wells. In addition, some atrazine products suggest being over 60 feet away from standing water.
Exposures of atrazine cause hormone issues in humans and wildlife. There is also an increased chance of cancer and heart complications from continuous exposure to atrazine.
To recap, only use herbicides near water that has been approved. This information will be included on the product label.
Avoid herbicides that are ester-based or have the word ester in the chemical name. Most of the esters are easily absorbed by plants and also aquatic organisms. Plus, they’re prone to vaporize in high temperatures.
Also, avoid herbicides that have a surfactant already mixed into the product. It is good to assume that most surfactants are not approved near water and toxic to aquatic life.
Lastly, do not use premixed or ready-to-use products. These types of products always are for use in areas where there is no water.
Signs of water contamination
Most herbicides are designed to dissolve in water. Therefore, there may not be any visual signs of contamination. A few signs of contamination to look for include:
- Water has an odd smell or color
- Foamy or milky colored water
- Dead fish or animals near the water
- Plants near the water have yellowing on the edge of leaves or are brown
- Chemical, salty or metallic taste from well water
- Oily film on settling on the surface
- Irritated skin, eyes, or nose after swimming
What you should do to limit water pollution
Federal and state laws are in place to protect surface water and drinking water. There are several things you can do if you think herbicides have contaminated water.
First, stop using the water source and notify neighbors. Contact your state’s Department of Environmental Management.
If you are unsure of the contaminant source, the state agency may want to collect a sample for testing or evidence.
Write down any signs that led to your concern about contamination. There is not a blanket test that identifies all contaminants. Therefore, any information you can provide the state agencies will be helpful.
After the herbicide contaminant has been determined, your state agency will guide how to correct the contamination and when the water will be safe to use again.
Conclusion
To recap, only use herbicides near water that has been approved. This information will be included on the product label.
Avoid herbicides that are ester-based or have the word ester in the chemical name. Most of the esters are easily absorbed by plants and also aquatic organisms. Plus, they’re prone to vaporize in high temperatures.
Also, avoid herbicides that have a surfactant already mixed into the product. It is good to assume that most surfactants are not approved near water and toxic to aquatic life.
Lastly, do not use premixed or ready-to-use products. These types of products always are for use in areas where there is no water.
