Microplastics in Tap Water: What Your Filter Isn't Catching

Your tap water almost certainly contains microplastics. A landmark 2017 investigation by Orb Media, conducted in partnership with researchers at the University of Minnesota, tested tap water from cities across five continents and found that 83% of samples contained microplastic fibers. The United States had the highest contamination rate at 94% of samples tested. Standard pitcher filters like Brita and PUR are designed to improve taste by reducing chlorine -- they are not designed to remove microplastic particles. The filters that actually work are reverse osmosis systems ($150-400), activated carbon block filters (not granular), and nano-filtration membranes. Our top picks: the APEC RO system (~$200) for best overall removal, the Berkey gravity filter (~$350) for no-install portability, and the Epic Pure pitcher (~$65) for a budget-friendly Brita replacement that's actually NSF-certified for microplastics.

And if you're thinking bottled water is the answer -- it's not. A 2018 study led by Sherri Mason at SUNY Fredonia found that 93% of bottled water brands contain microplastics, with an average of 10.4 particles per liter. That's roughly double what's found in tap water. The plastic comes from the bottle itself.

Below: the full research breakdown, why your current filter probably isn't working, which filtration technologies actually remove microplastics, detailed product reviews with prices, and the one thing you should definitely not do (boil it).

The Research: How Bad Is It?

The Orb Media investigation was the first large-scale study of microplastic contamination in drinking water. Working with researchers at the University of Minnesota School of Public Health, Orb collected 159 tap water samples from cities in 14 countries across five continents. The samples were analyzed using a standardized Nile Red fluorescence tagging protocol to identify and count microplastic fibers.

The contamination was global but not uniform. The United States had the highest contamination rate at 94.4% of samples, followed by Lebanon at 93.8%. European nations had the lowest rates -- but still averaged 72.2% of samples containing fibers. Samples were collected from sites including the US Capitol, the EPA headquarters, Trump Tower in New York, and the municipal water systems of cities including New Delhi, Beirut, Jakarta, Kampala, and Quito.

The fibers found were primarily synthetic -- nylon, polyester, and polypropylene -- consistent with the types of plastic used in clothing, packaging, and industrial processes. The most likely sources include wastewater treatment plant effluent (which cannot fully filter microfibers shed during laundry), atmospheric deposition, and degradation of plastic infrastructure in water treatment and distribution systems.

Bottled water is worse, not better

The intuitive response to learning about microplastics in tap water is to switch to bottled water. This is exactly the wrong move. A 2018 study led by Professor Sherri Mason at the State University of New York at Fredonia, commissioned by journalism organization Orb Media, tested 259 individual bottles from 11 major brands purchased in 9 countries.

The study found an average of 10.4 microplastic particles per liter of bottled water, with 65% of those particles being fragments rather than fibers -- suggesting the plastic is coming from the bottle and cap, not from the original water source. The most common polymer found was polypropylene, the same plastic used in bottle caps. Some bottles contained over 10,000 particles per liter. Brands tested included Aquafina, Dasani, Evian, Nestlé Pure Life, and San Pellegrino.

A subsequent 2019 study by the World Health Organization reviewed all available evidence and confirmed the finding: bottled water generally contains higher concentrations of microplastics than tap water. The WHO called for further research into health effects but stopped short of declaring a health emergency -- not because the evidence was reassuring, but because it was still incomplete.

Why Your Brita (Probably) Isn't Helping

Standard pitcher filters from Brita, PUR, and similar brands use granular activated carbon (GAC) to reduce chlorine taste and odor, along with ion exchange resin to reduce certain heavy metals like lead and mercury. They do an excellent job at what they're designed for: making tap water taste better.

But they are not designed -- or tested -- to remove microplastic particles. Here's why:

• Pore size is too large. Granular activated carbon has relatively large gaps between the carbon granules. Microplastic fibers and fragments can pass through these gaps. Carbon block filters (compressed carbon) have much smaller effective pore sizes and can trap particles that granular filters cannot.
• No microplastic certification. Neither Brita nor PUR standard pitcher filters carry NSF/ANSI 401 certification for microplastic removal. NSF 401 specifically tests for emerging contaminants including microplastics. If a filter doesn't carry this certification, there's no third-party verification that it removes microplastics.
• Designed for dissolved contaminants, not particles. Activated carbon adsorbs dissolved chemicals (like chlorine) onto its surface. Microplastics are solid particles, not dissolved chemicals. Particle removal requires mechanical filtration -- physically blocking particles from passing through -- which requires smaller pore sizes than most pitcher filters provide.

Does boiling water remove microplastics?

No. Boiling water does not remove, destroy, or break down microplastics. Microplastics are solid polymer particles that remain stable well above 100°C -- most don't begin to degrade until 200-300°C. Boiling water actually concentrates microplastics by evaporating some of the water while leaving all the particles behind.

A 2024 study published in Environmental Science & Technology Letters by researchers at Guangzhou Medical University found an interesting nuance: in hard water (water with high calcium carbonate content), boiling can cause calcium carbonate to crystallize around microplastic particles, forming incrustations that can then be removed by simple filtration through a paper or metal mesh filter. However, this effect only occurs in hard water and still requires a filtration step after boiling. Boiling alone, without subsequent filtration, does not remove microplastics regardless of water hardness.

What Actually Removes Microplastics

Three filtration technologies have been shown to effectively remove microplastic particles from drinking water. They work through different mechanisms, at different price points, but all share one thing in common: pore sizes small enough to physically block microplastic particles from passing through.

1. Reverse osmosis (RO)

Reverse osmosis forces water through a semi-permeable membrane with pore sizes as small as 0.0001 microns (0.1 nanometers). For context, the smallest microplastic particles found in drinking water studies are typically 1 micrometer (1,000 nanometers) or larger. An RO membrane's pores are roughly 10,000 times smaller than the particles it needs to catch. RO systems remove 95-99% of dissolved solids, heavy metals, bacteria, and virtually all microplastic particles. They are the gold standard for comprehensive water purification.

2. Activated carbon block filtration

Carbon block filters compress activated carbon into a dense block with controlled pore sizes, typically in the range of 0.5-10 microns depending on the specific filter. High-quality carbon blocks with sub-micron pore sizes can effectively trap microplastic particles through mechanical filtration while also adsorbing dissolved chemical contaminants like chlorine, VOCs, and some pesticides. The key is that the carbon must be a block -- compressed -- not loose granules.

3. Nano-filtration

Nano-filtration membranes have pore sizes between 0.001 and 0.01 microns, placing them between ultrafiltration and reverse osmosis in terms of filtration precision. They effectively remove microplastics, most bacteria, and many dissolved contaminants while typically requiring less pressure (and energy) than RO systems. Nano-filtration is more common in commercial and municipal settings but is available in some home systems.

Filter Comparison: What Works vs. What Doesn't

The 3 Best Filters for Microplastic Removal (Detailed Reviews)

Each of these filters uses a fundamentally different approach -- reverse osmosis, gravity-fed carbon block, and pitcher carbon block -- but all effectively remove microplastic particles. The right choice depends on your budget, living situation, and whether you can install an under-sink system.

How to Choose the Right Filter

If you own your home and want the best filtration

Install the APEC reverse osmosis system under your kitchen sink. At ~$200, it's less than a year of bottled water and removes virtually everything -- microplastics, heavy metals, fluoride, arsenic, pharmaceuticals. Installation takes 1-2 hours with basic tools. Filter replacements cost ~$50-70 per year. This is the gold standard.

If you rent or don't want to install anything

The Berkey gravity filter sits on your countertop and works without plumbing, electricity, or water pressure. Pour water in the top, clean water comes out the bottom. The filters last ~6,000 gallons -- roughly 3 years for a couple. Higher upfront cost ($350) but extremely low ongoing cost. Take it with you when you move.

If you want the easiest, cheapest switch from Brita

The Epic Pure pitcher looks and works like a Brita but uses a carbon block filter that's actually NSF-certified for microplastic removal. At $65, it's the lowest-cost entry point into real microplastic filtration. Perfect for individuals and small households. The only adjustment: it filters slightly slower than a Brita (denser carbon block = better filtration = slower flow).

The Bigger Picture: Where Do Tap Water Microplastics Come From?

Microplastics enter the water supply through multiple pathways, and no single intervention eliminates them all at the source. Understanding the origins helps explain why even treated municipal water still contains these particles:

• Wastewater treatment plants. When you wash synthetic clothing (polyester, nylon, acrylic), each load releases hundreds of thousands of microfibers into the wastewater. Treatment plants catch most solid waste, but microfibers are too small for many filtration stages. Studies estimate that a single wastewater treatment plant can release up to 65 million microplastic particles per day into waterways.
• Atmospheric deposition. Microplastics are found in the air -- from tire wear, clothing fibers, construction dust, and degrading plastic waste. These airborne particles settle into reservoirs, rivers, and catchment areas. A 2019 study published in Nature Geoscience found microplastic contamination even in remote Pyrenees mountain regions, confirming atmospheric transport over long distances.
• Water treatment infrastructure. Ironically, the pipes, tanks, and equipment used to treat and distribute water can themselves be sources of microplastic contamination. Plastic pipes (PVC, PE) and plastic-lined storage tanks can shed particles, particularly as they age.
• Agricultural runoff. Biosolids (treated sewage sludge) applied as fertilizer contain concentrated microplastics from wastewater. Rain washes these particles into groundwater and surface water that feeds municipal water systems.

The point is not to be fatalistic -- it's that filtration at the point of use (your kitchen) is the most practical and effective way to reduce your exposure. You can't control what's in the municipal supply, but you can control what makes it into your glass.

Frequently Asked Questions