What’s Actually In Your Tap Water (And Why Filtering Isn’t Always The Answer)

I used to grab a glass straight from the tap without a second thought. Coming from Ireland, I figured our water was fine — treated, regulated, monitored. Then I started paying closer attention to what was actually being measured, what wasn’t, and what the regulations don’t cover. The picture turned out to be more uncomfortable than I expected.

According to Simply Younger’s review of the EPA’s own data and the emerging contaminant science, the question isn’t really am I drinking enough water — it’s what’s in the water I’m drinking, and what is it doing to me over time?

The Contaminants the EPA Itself Just Flagged

In March 2026, the US Environmental Protection Agency added microplastics and pharmaceuticals to its Contaminant Candidate List — the formal list of substances being evaluated for potential federal regulation in drinking water. The new draft list also includes PFAS and disinfection byproducts. Listing isn’t the same as regulating — it means the agency is now obligated to evaluate the contaminants, decide whether they pose a public health risk, and consider whether a national standard is warranted. This process can take years.

PFAS: The Forever Chemicals Already in Roughly Half the Country’s Water

PFAS are synthetic compounds used in non-stick cookware, waterproof clothing, and firefighting foam. They don’t break down in the environment or the human body. EPA testing indicates around 176 million Americans drink tap water contaminated with PFAS; the EWG suggests closer to 200 million. In 2024, the EPA finalised first-ever federal limits on six PFAS compounds at 4 parts per trillion, with compliance required by 2029. In 2025, the agency announced plans to roll back limits on four of the six and extend the compliance deadline for the remaining two to 2031.

Why Your Filter Probably Isn’t Catching What You Think

Standard pitcher filters are built primarily to improve taste and reduce chlorine. What they generally don’t do is reliably remove PFAS, microplastics, pharmaceutical residues, or many trace contaminants. Reverse osmosis, activated carbon block filters, and ion exchange resins each handle different categories with different effectiveness. But there’s a tradeoff almost nobody talks about: when you strip contaminants aggressively, you also strip naturally occurring minerals — calcium, magnesium, potassium — that contribute to how your body absorbs and uses water. RO water is exceptionally clean and nearly mineral-free. Remineralisation is essential.

Pharmaceuticals: The Contamination Most People Have Never Considered

Pharmaceutical compounds — antibiotics, hormones, anti-anxiety medications, painkillers — enter the water supply through human waste and agricultural runoff. Conventional water treatment plants weren’t designed to remove them. Trace amounts of dozens of pharmaceutical compounds have been detected in drinking water across the US and Europe for years. The EPA has now released human health benchmarks for 374 pharmaceuticals — not enforceable limits, but a signal that this contamination is no longer being quietly ignored.

Frequently Asked Questions

What contaminants are actually in tap water?

US tap water can contain PFAS, disinfection byproducts (trihalomethanes and haloacetic acids formed when chlorine reacts with organic matter), pharmaceutical residues (antibiotics, hormones, painkillers from wastewater), microplastics, lead (from older pipes), nitrates, and agricultural runoff chemicals. The specific profile varies significantly by municipality. Your utility is required to publish an annual Consumer Confidence Report detailing detected contaminants and whether they fall within regulatory limits.

Does a standard Brita filter remove PFAS?

Standard activated carbon pitcher filters like Brita do not reliably remove PFAS. Reverse osmosis systems are generally the most effective residential option for PFAS removal, typically achieving 90–95% reduction. Certain high-performance activated carbon block filters are also certified for PFAS reduction. Always check the NSF/ANSI certification for the specific contaminants you’re targeting.

Is reverse osmosis water actually good for you?

Reverse osmosis produces exceptionally clean water with very effective contaminant removal. The tradeoff is that it also removes beneficial minerals like calcium, magnesium, and potassium. Drinking large volumes of demineralised water can dilute electrolyte concentrations in the body, impairing cellular hydration. Health authorities including the WHO recommend remineralising RO water before consumption. Adding a pinch of unrefined sea salt or using a remineralisation filter stage addresses this.

How do I find out what’s in my local tap water?

Every US water utility is legally required to publish an annual Consumer Confidence Report (CCR) detailing the source of your water, detected contaminants, and how levels compare to regulatory limits. For contaminants not covered by current regulations — including many PFAS compounds, microplastics, and pharmaceuticals — the CCR will not show testing results. The Environmental Working Group’s Tap Water Database provides broader contaminant data by zip code for comparison.

This article is for general informational purposes only and is not medical advice. If you have specific health concerns, please consult a qualified healthcare professional.