For more than 40 years, RoundUp weed killer was marketed as safe—so safe it became America’s most popular herbicide. Then science caught up, linking glyphosate, RoundUp’s active ingredient, to cancer, kidney damage, and reproductive harm. 

Today, glyphosate is turning up in places it was never meant to be: streams, rivers, rainfall, and even our tap water.

Yet national drinking water standards still rely on studies from the 1980s that not only permit glyphosate in our water, but also allow it at levels other countries (and even some U.S. states) consider dangerously high. 

So why is America lagging so far behind in protecting its water? How did we even get here? And what does glyphosate contamination really mean for you and your family?

Let’s dive in…

U.S. farmers spray up to 300 million pounds of glyphosate each year across croplands to control weeds. When rain hits those fields, it doesn't just water the crops—it can wash glyphosate into nearby streams, rivers, and eventually, the water treatment plants that supply your tap. 

But it’s not only farms. Glyphosate is also sprayed on lawns, schoolyards, parks, and roadsides because it’s cheap, accessible, and effective.

Distance doesn’t guarantee safety. 

In addition to washing into waterways, wind can carry microscopic droplets of glyphosate there too. This likely helps explain why the U.S. Geological Survey (USGS) researchers found glyphosate in 94% of streams and rivers tested, including urban waterways far from farm country.

And it’s not just runoff. 

Glyphosate can also sneak into waterways through another surprising route: wastewater treatment plants.

While more common in Europe than the U.S., household products like laundry detergents and cleaners can contain a class of additives known as aminopolyphosphonates that can be converted to glyphosate in wastewater treatment plants. 

This newly recognized pathway helps explain why glyphosate pollution sometimes persists in rivers even where herbicide use drops.

Unlike many chemicals that break down quickly in water, glyphosate has a persistence problem.

That lingering exposure is now tied to mounting health risks.

The following health effects are showing up in courtrooms, research labs, and medical studies:

• Cancer risk: Approximately 2,400 lawsuits allege glyphosate exposure caused cancer, with courts awarding billions in damages.

• Kidney damage: Studies link higher exposure levels to chronic kidney disease and reduced kidney function.

• Reproductive harm: Animal studies suggest glyphosate may impair fetal development.

• Metabolic disruption: Including connections to diabetes, obesity, and disrupted metabolism.

• Endocrine disruption: Evidence suggests glyphosate can interfere with hormone systems, potentially affecting thyroid health, fertility, and immune function.

• Universal exposure: Found in 60-80% of Americans tested, including in urine, blood, and breast milk.

Even as the evidence piles up, scientists and regulators can’t agree on just how dangerous glyphosate really is.

In 2015, the World Health Organization's cancer research arm (IARC) classified glyphosate as "probably carcinogenic to humans." The EPA disagrees, maintaining it's "not likely to be carcinogenic."

The difference comes down to approach:

• IARC: Evaluates whether a substance can cause cancer under any circumstance.

• EPA: Focuses on whether it will cause cancer at typical exposure levels.

This fundamental disagreement explains why, as you’ll see below, safety standards vary so dramatically.

Yes, glyphosate is regulated in U.S. drinking water.

The EPA set a Maximum Contaminant Level of 700 parts per billion (ppb) back in 1992. The problem is that the standard was based on toxicity studies from the 1980s, before we knew about cancer risks (among other things).

Today, other states and countries have reached very different conclusions about how much glyphosate is actually "safe."

While the U.S. still clings to a decades-old limit, other states and countries have moved ahead, setting or suggesting far stricter protections.

The EPA's standard hasn't changed since the Clinton administration, even as scientific understanding has evolved.

For example, those original 1980s studies that formed the basis for today's 700 ppb limit didn't test for cancer and did not include special protections for children.

Here's what other standards consider that the EPA doesn't:

• EPA: Sets limits based on what an average adult might tolerate short-term, ignoring cancer risk.

• Minnesota: Tightens the limit with extra protection for vulnerable populations as well as cancer risk.

• EWG: Goes further, applying a cancer risk standard with an added 10× margin of safety for children, driven by the aim for “one-in-a-million” cancer risk.

• EU: Uses the precautionary principle, applying the lowest possible threshold across all pesticides.

Glyphosate has been detected in tap water supplies in Iowa, Alabama, Florida, Oklahoma, and Arkansas—all states with heavy agricultural activity. That suggests farm regions and southern states are especially vulnerable to contamination.

Families relying on private wells near agricultural areas face the highest risk—and the least protection—since wells aren’t routinely tested or regulated for glyphosate.

But it’s not just rural America.

USGS researchers have found glyphosate in 94% of U.S. streams and rivers tested, including river basins near urban centers. Wind drift, wastewater pathways, and runoff mean the chemical can show up in city water systems miles from the nearest farm.

All of this raises the most important question: if glyphosate can show up almost anywhere, how do you keep it out of your glass?

Ordinary carbon filters aren’t built to remove herbicides. To keep glyphosate out of your glass, you need specialized filtration.

That’s where Clearly Filtered comes in.

Powered by breakthrough Affinity® Filtration Technology, our entire line of advanced water filtration systems—from our best-selling filtered water pitcher to our bottles, 3-stage under-sink system, and universal inline fridge filter—removes up to 99.9% of glyphosate, along with up to 365+ other contaminants that ordinary filters overlook.

Protect yourself and your loved ones by upgrading to Clearly Filtered today.