Emerging Contaminants: A Guide to What’s Not in Your Water Report

Emerging Contaminants: What’s NOT in Your Water Report

I’m sitting here at my kitchen table staring at the water quality report I just fished out of my recycling bin. Like most folks, I’d given it a quick once-over, noticed no red flags, and tossed it without a second thought. But after chatting with a neighbor whose well tested positive for something called “PFAS,” I’ve been wondering—what else might be lurking in my tap water that isn’t listed on this official-looking document?

Turns out, quite a lot.

The Invisible Threat

My water utility, like thousands across America, diligently tests for about 90 contaminants regulated under the Safe Drinking Water Act. Sounds impressive until you consider that over 85,000 chemicals are registered in the EPA’s Toxic Substances Control Act inventory (though only about 40,000 are actively used), with roughly 700-1,000 new chemicals reviewed by the EPA annually.

The gap between what’s regulated and what’s actually in our water has become my new late-night anxiety fuel.

“For decades, the American people have been exposed to the family of incredibly toxic ‘forever chemicals’ known as PFAS with no protection from their government,” said Environmental Working Group President Ken Cook in a recent statement when the EPA finally announced drinking water standards for these substances.

After weeks of research, conversations with water quality experts, and more than a few rabbit holes on scientific journal websites, I’ve identified three concerning unregulated contaminants likely flowing through America’s pipes—and potentially, my kitchen faucet.

1,4-Dioxane: The Stubborn Solvent

Back in the day, I worked in a lab where we handled plenty of nasty chemicals, but 1,4-dioxane wasn’t on my radar. Now I know this industrial solvent is practically the perfect water contaminant—it dissolves completely, doesn’t stick to soil, evaporates slowly, and stubbornly resists standard water treatment.

Commonly used as a stabilizer for chlorinated solvents, 1,4-dioxane shows up in countless products from paint strippers and antifreeze to personal care items. The EPA has classified it as a “likely human carcinogen,” and animal studies have linked it to liver and nasal cancers.

A 2021 analysis found that over 20% of public water systems across the United States contained detectable levels of 1,4-dioxane. According to the Environmental Working Group, water supplies for more than 7 million Americans in 27 states are contaminated with 1,4-dioxane at levels higher than what federal scientists consider a minimal cancer risk.

Despite the widespread presence of 1,4-dioxane, there’s no federal maximum contaminant level for it in drinking water. Only a handful of states have established their own guidelines, leaving most Americans in the dark about this contaminant.

Microplastics: The Tiny Invaders

Last week, I was washing my favorite fleece jacket when I remembered reading that a single wash can release up to 250,000 microplastic fibers. According to Earth Day’s fact sheet, the average American ingests more than 70,000 microplastics annually just from drinking water.

These microscopic plastic particles—typically defined as smaller than 5 millimeters—come from the breakdown of larger plastics, synthetic fibers from clothing, microbeads from personal care products (though many countries have now banned these), and even tire dust from roadways.

What makes microplastics particularly concerning isn’t just their ubiquity but their potential to absorb and concentrate other pollutants. Laboratory studies have shown they can cause inflammation, oxidative stress, and cell damage, though the World Health Organization notes that conclusive evidence of health impacts in humans is still lacking.

Despite these concerns, water utilities aren’t required to test for or remove microplastics from drinking water. The technology to effectively detect these particles at low concentrations is still developing, meaning they’re invisible not just on your water report but often to the utilities themselves.

PFAS: The “Forever Chemicals”

Perhaps the most notorious of the emerging contaminants are per- and polyfluoroalkyl substances, commonly known as PFAS. This family of thousands of synthetic chemicals has been used since the 1940s in everything from non-stick cookware and water-repellent clothing to food packaging and firefighting foam.

Their nickname—”forever chemicals”—is well-earned. The carbon-fluorine bonds that make them so useful are among the strongest in organic chemistry. These chemicals don’t naturally degrade in the environment—ever.

A recent study by the U.S. Geological Survey found that at least 45% of the nation’s tap water contains one or more types of PFAS. These chemicals have been linked to serious health problems, including increased cholesterol, decreased vaccine response in children, thyroid disruption, and increased risk of certain cancers.

This widespread contamination has resulted in about 98% of Americans having detectable PFAS in their blood, according to CDC’s National Health and Nutrition Examination Survey data.

In April 2024, the EPA finally set national drinking water standards for six PFAS compounds. While this represents progress, it’s a small fraction of the thousands of PFAS chemicals in use, and compliance deadlines extend to 2029 and beyond.

Why Aren’t These Regulated?

When I first realized the scope of unregulated chemicals potentially in my drinking water, I immediately wondered—why haven’t these been addressed already? The answer involves a complex mix of scientific, economic, and political factors.

For a contaminant to be regulated under the Safe Drinking Water Act, the EPA must go through a lengthy process that includes multiple steps and can take decades to complete. For example, perchlorate was first listed as a candidate for regulation in 1998 but still isn’t regulated at the federal level.

Industry influence also plays a significant role. Many emerging contaminants are tied to profitable industries with substantial political clout and the resources to challenge regulations through litigation.

In our regulatory system, the burden of proof effectively falls on the public to demonstrate harm, rather than on manufacturers to demonstrate safety—a framework that inherently favors the status quo, even when that status quo may be causing harm.

What Can You Do?

After discovering all this information, I felt overwhelmed but not helpless. Here are practical steps I’ve taken that you might consider too:

Know Your Water Source

Understanding where your water comes from can help assess potential risks. Is your water drawn from a river downstream from industrial facilities? Is your groundwater near agricultural areas with heavy pesticide use or landfills? Local watershed groups often have information about specific contamination concerns in your area.

Consider Home Filtration

Different filtration technologies target different contaminants:

• For PFAS: Reverse osmosis systems and high-quality activated carbon filters (look for NSF/ANSI 53 certification) are most effective
• For 1,4-dioxane: Advanced oxidation treatment works best, though it’s not widely available for home use; some high-end reverse osmosis systems help
• For microplastics: Fine mechanical filters (1 micron or smaller) can remove larger particles, while reverse osmosis can remove most microplastics

Remember that no single filtration method removes all contaminants, and maintenance is crucial—an improperly maintained filter can become a source of contamination itself.

Support Better Regulation

Citizen pressure matters. Contact your representatives about supporting stronger water protections, faster regulatory action on emerging contaminants, and more funding for water infrastructure. Support environmental organizations working on water quality issues.

Reduce Your Contribution

Many emerging contaminants enter our water through everyday consumer products. Consider:

• Avoiding products with “fragrance” or “parfum” which may contain phthalates
• Choosing personal care products without “PEG” compounds which may contain 1,4-dioxane
• Reducing plastic use to minimize microplastic pollution
• Selecting cookware, clothing, and food packaging without PFAS (look for “PFAS-free” labels)

The Future of Water Testing

Despite the current regulatory gaps, there are reasons for optimism. Advanced detection technologies continue to improve, making it easier and more affordable to test for emerging contaminants. Public awareness is growing, putting pressure on utilities and regulators to address these invisible threats.

Some forward-thinking utilities are already going beyond regulatory requirements, voluntarily testing for and treating unregulated contaminants. And states like California, Michigan, and New Jersey have stepped in with their own standards where federal regulations lag.

What’s clear is that our understanding of what makes water “safe” continues to evolve. Today’s emerging contaminant may be tomorrow’s regulated substance. In the meantime, the best defense is awareness—understanding that your water report, reassuring as it may seem, isn’t telling the whole story.

The next time you receive that annual water quality report, give it more than a passing glance. But also remember what’s not listed there—the emerging contaminants silently passing through our pipes, waiting for science, regulation, and public awareness to catch up.

Now, if you’ll excuse me, I need to research water filters—and maybe buy a reusable water bottle while I’m at it..