The Alarming Scale of Glyphosate Use in the U.S. Waterways
Glyphosate, the active ingredient in Roundup®, is best known as a weed killer for farms and gardens. But what many people don’t realize is that it’s also being sprayed directly into lakes, ponds, and canals across the United States often in shockingly large quantities.
Take Florida’s Lake Okeechobee, for example. In a single year, over 12,000 pounds of glyphosate-based herbicides—roughly the weight of a school bus—were dumped into the water to control invasive plants like water hyacinth and hydrilla. And this isn’t an isolated case. From Midwestern fishing ponds to suburban stormwater basins, glyphosate remains a go-to solution for aquatic weed control.
But here’s the problem: While the weeds may disappear temporarily, the long-term consequences for our water quality, wildlife, and even human health are far worse than the original problem.
The Domino Effect of Glyphosate Spraying
When glyphosate kills aquatic plants, those plants don’t just vanish; they sink to the bottom and begin to rot. This decomposition process consumes oxygen, creating dead zones where fish and other aquatic life can suffocate. In some cases, rapid weed die-offs have led to mass fish kills, leaving lakes littered with floating carcasses.
But the damage doesn’t stop there. As the dead plants decay, they release phosphorus and nitrogen nutrients that fuel toxic algal blooms. Lake Okeechobee, already struggling with farm runoff, has seen massive blue-green algae outbreaks in recent years. Glyphosate treatments, while not the primary cause, add another "drop in the bucket" of phosphorus that worsens the problem.
Does Glyphosate Really "Break Down Quickly"?
Herbicide manufacturers often claim that glyphosate degrades rapidly in the environment. But research tells a different story. Glyphosate binds tightly to sediment, where it can linger for months or even years. Its breakdown product, AMPA, is even more persistent, with a half-life of 2–3 years in lakebeds.
A U.S. Geological Survey study found glyphosate and AMPA in the majority of tested streams and rivers, proving that this chemical doesn’t just disappear—it accumulates.
The Human Health Risks
Glyphosate is at the center of over 125,000 lawsuits alleging links to non-Hodgkin’s lymphoma. In 2015, the World Health Organization’s cancer research agency classified it as a "probable human carcinogen." By 2020, Bayer (which acquired Monsanto, Roundup’s original maker) agreed to a $10 billion settlement to resolve these cases—one of the largest product liability payouts in history.
Yet, despite these red flags, glyphosate is still being sprayed into waters where people swim, fish, and even draw drinking water.
A Better Way Forward
The good news? We don’t have to choose between weedy lakes and poisoned water. Mechanical harvesting, nutrient management, and biological controls (like grass carp) offer safer, more sustainable alternatives—such as using an aquatic weed harvester.
Sources:
1. North American Lake Management Society – Use of Herbicides in Lakes
2. The News-Press (Florida) – Example of Glyphosate Use on Lake Okeechobee
3. LakeMat (aquatic management company) – Drawbacks of Aquatic Herbicides (oxygen depletion and sediment)
4. Aquarius Systems (aquatic services) – Glyphosate and Algae Blooms in Lake Okeechobee
5. Aquarius Systems – Advantages of Mechanical Harvesting (nutrient removal, etc.)
6. U.S. Geological Survey – Glyphosate in Streams Study (widespread detection in water)
7. NPR News – Bayer to Pay $10 Billion in Roundup Settlement (125,000+ lawsuits, WHO classification)
8. Wisconsin DNR – Glyphosate Fact Sheet (environmental persistence and regulatory info)
9. Hamburg Township, MI – Aquatic Weed Control Program FAQ (cost of mechanical vs. chemical)
10. Aquarius Systems – Mechanical Harvesting Benefits (selectivity, long-term effects)
11. Aquarius Systems – Integrated Approach (Harvest then Herbicide)
12. Aquarius Systems – Composting Harvested Weeds
13. Aquarius Systems – Herbicide Suspension in Florida .