Your body is more than half water, and every cell, from your brain to your kidneys, depends on it. So the water you drink every day matters. Clean, pure water is one of the simplest and most important foundations of good health, and it is one of the first things I talk about with patients who want to lower their toxic load.

The good news is that most American tap water is treated to remove disease-causing bacteria and parasites. The less comfortable news is that “safe from germs” is not the same as “free of chemicals.” Here is what may be in your water, why bottled water is not the answer, and why I often suggest a countertop or under-sink reverse osmosis water filter for families who want cleaner water at home.

What Can Be in Tap Water?

Germs usually cause sudden, noticeable illness, like fever or stomach upset. Chemical contaminants work differently. They are usually present in very small amounts, they cause no symptoms you can feel, and the concern is what they may add to your total exposure over many years.

Depending on where you live and how old your pipes are, tap water can contain:

• PFAS (“forever chemicals”). A 2023 U.S. Geological Survey study tested tap water from homes across the country and estimated that at least one PFAS can be detected in close to half of U.S. tap water. In 2024 the EPA set its first national drinking water limits for several of these compounds.
• Disinfection byproducts. Chlorine keeps water free of germs, but it can react with natural organic matter to form trihalomethanes (THMs). A European analysis estimated that long-term THM exposure may account for thousands of bladder cancer cases each year in the European Union.
• Lead and other metals. Lead usually comes from older service lines, solder, and fixtures rather than from the treatment plant, so two homes on the same street can have very different results.
• Nitrates, arsenic, and perchlorate. These are more common in some farming regions and in private wells.
• Trace pharmaceuticals and industrial chemicals. Very small amounts of medication residue and solvents have been found in some water supplies.

Your local water utility publishes a yearly Consumer Confidence Report that lists what it tested for and what it found. It is worth reading. If you are on a private well, regular testing is your responsibility, and I strongly encourage it.

Is Bottled Water the Solution?

Short answer: probably not.

Bottled water is often just filtered municipal water, it is expensive, and it creates an enormous amount of plastic waste. It also brings its own exposure. In 2024, researchers at Columbia University used a new laser imaging method to look for very tiny plastic particles in bottled water. They found an average of roughly 240,000 plastic fragments per liter, and about 90 percent of them were nanoplastics, small enough to potentially pass into tissues.

Some plastics can also release compounds such as bisphenols and phthalates, especially when bottles sit in a hot car or in the sun. For daily drinking, I would rather you fill a glass or stainless steel bottle with well-filtered water at home.

I talk more about plastics and the body in this episode on belly fat and microplastics.

Filters vs. Purifiers: What Is the Difference?

Many pitcher and refrigerator filters are designed mainly to make water taste and smell better. Most rely on activated carbon, which is very good at reducing chlorine, many volatile organic compounds, and some pesticides. Higher quality carbon block filters can also reduce lead and some PFAS.

But carbon has limits. It does a poor job with dissolved inorganic contaminants such as nitrates, fluoride, and arsenic, and its performance drops as the cartridge fills up. A filter that is past its replacement date may be doing very little.

How a Reverse Osmosis Water Filter Works

Reverse osmosis (RO) uses pressure to push water through a semipermeable membrane with extremely small pores. Water molecules pass through, while most dissolved salts, metals, and larger molecules are left behind and flushed away.

Good home RO systems combine several stages:

1. Sediment pre-filter to catch rust, sand, and particles.
2. Carbon pre-filter to reduce chlorine and organic chemicals and to protect the membrane.
3. RO membrane to reduce dissolved contaminants such as lead, arsenic, nitrates, fluoride, and many PFAS.
4. Carbon post-filter to polish taste.

Because no single technology removes everything, combining carbon with reverse osmosis gives much broader coverage than carbon alone. That is the main reason I favor multi-stage RO for families who want the cleanest water practical at home.

The countertop system I have recommended is AquaTru. You can find it on my recommended products page.

Countertop vs. Under-Sink Systems

Traditional RO systems install under the sink and connect to your plumbing. Countertop units, such as the AquaTru system I have recommended in the past, sit next to the sink and need no installation. You fill a tank by hand, and the unit pushes water through its stages into a clean reservoir. They are a good fit for renters and for anyone who does not want to modify their plumbing.

Whichever style you choose, here is what to look for:

• Independent certification. Look for NSF/ANSI Standard 58 for reverse osmosis, plus Standard 53 for health-related contaminants such as lead. PFAS reduction claims should be backed by testing to NSF/ANSI 53 or 58 for PFOA and PFOS.
• Your own water report. Match the system to what is actually in your water.
• Filter costs and schedule. A great system with an overdue filter is not a great system.
• Waste water ratio. Newer designs waste far less water than older RO units.

What About Minerals?

Reverse osmosis is so thorough that it also removes beneficial minerals such as calcium and magnesium. The result is water with very low total dissolved solids (TDS). Some health experts, including the World Health Organization, have raised questions about relying on very low mineral water over the long term, especially when the diet is also low in minerals.

This is easy to address. Many RO systems now include a remineralization stage, or you can add a trace mineral product to your water. Most of all, get your minerals from food: leafy greens, nuts and seeds, avocados, beans, and quality sea salt or Himalayan salt in moderation. In my experience, people also tend to drink more water when it tastes good, and lightly remineralized water usually does.

Simple Steps for Cleaner Water Starting Today

1. Read your utility’s Consumer Confidence Report, or test your well.
2. Choose a certified filter that matches your water. For the broadest coverage, consider multi-stage reverse osmosis.
3. Replace filters on schedule. Put a reminder on your calendar.
4. Store and carry water in glass or stainless steel instead of plastic.
5. Never drink or cook with hot tap water, since it can pull more lead from pipes.
6. If your water has sat in the pipes overnight, run the cold tap for a minute before using it.

Clean water is one piece of a bigger picture of lowering your daily toxic load. You can learn more in my 7 Pillars of Health episode on hidden toxins, or start with the Detox and Cleanse guide.

Frequently Asked Questions

Is reverse osmosis water safe to drink every day?

Yes, for most people reverse osmosis water is safe for daily drinking. Because it removes most minerals, choose a system with a remineralization stage or add trace minerals, and eat a mineral-rich diet with plenty of vegetables, nuts, and seeds.

Does reverse osmosis remove PFAS?

Reverse osmosis is one of the most effective home options for reducing PFAS, including PFOA and PFOS. Look for a system with independent certification for PFAS reduction, and replace the filters and membrane on schedule.

Is bottled water safer than tap water?

Not necessarily. Much bottled water is filtered municipal water, and a 2024 study found hundreds of thousands of tiny plastic particles per liter in bottled water. Well-filtered tap water in a glass or stainless steel bottle is usually the better choice.

Do pitcher filters remove contaminants?

Many pitcher filters reduce chlorine and improve taste, and some certified models reduce lead. Most do little for nitrates, arsenic, or fluoride, so check the certifications on the box against your local water report.

How do I know what is in my tap water?

Read the annual Consumer Confidence Report from your water utility, which lists the contaminants it tested for. If you use a private well or have older pipes, a certified laboratory test gives you the most accurate picture.

References

1. Smalling KL, et al. Per- and polyfluoroalkyl substances (PFAS) in United States tapwater: Comparison of underserved private-well and public-supply exposures and associated health implications. Environment International. 2023.
2. Qian N, et al. Rapid single-particle chemical imaging of nanoplastics by SRS microscopy. Proceedings of the National Academy of Sciences. 2024.
3. Evlampidou I, et al. Trihalomethanes in drinking water and bladder cancer burden in the European Union. Environmental Health Perspectives. 2020.

This article is for educational purposes only and is not medical advice. Talk with your own doctor before changing your diet, starting a supplement, or changing any medication. These statements have not been evaluated by the Food and Drug Administration. Products mentioned are not intended to diagnose, treat, cure, or prevent any disease.

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