Is Tap Water Safe To Drink?

Straight from the faucet? Does a water filter help? Should we invest in reverse osmosis?

This is the second of a two post series about the importance of clean air and water. Instead of writing about how important it is for leaders to work on improving and protecting our air and water quality (which it absolutely is!), I’m going to focus on small strategies that might help us survive our present environments.

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Tap water is relatively safe to drink.

But the question of how safe it is to drink tap water can be like diving down a deep, dark well. I am not an expert on water, but I have done some research over the years, and filtered it through my medically trained way of thinking. To simplify this topic to something readable and actionable, I’m going to return to the following summary refrain:

* The water we drink is amazingly clean by historic and world comparisons. But it also contains small amounts of thousands of chemicals - many of which can cause health problems with cumulative exposure. If we all drink water right out of the faucet, most of us will be fine, but a few of us will get sick over the years. Water filtration, especially using a reverse osmosis system, helps remove a lot of junk from our water before we drink it.*

You can stop reading here if you want. But I didn’t call this letter Examined so I could bring you some effortless fluff.

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What is in the water we drink?

Fortunately for us, we are living in an age of technologically cleaned and miraculously distributed water. Compared to most of human history, and especially compared to the dysenteric early days of towns and cities, we are doing great. But technology, chemistry, and engineering have also produced over 600,000 new chemicals, used in a wide array of manufacturing and industry. All of those chemicals cannot be properly tested for safety as they find their way into the Earth’s water cycle, and ultimately into our bodies. There is also the growing problem of microplastics showing up in everything, including the food we eat and the water we drink. Here are a select few of those 600,000 chemicals to consider:

Trihalomethanes and Haloacetic Acids - these groups of chemicals are formed when chlorine or other disinfectants are used to treat drinking water. TTHMs and HAAs can be carcinogenic, and harmful in pregnancy. But as with most things, the dose makes the poison, and depending on whether you follow the EPA guidelines (more lax), or environmental groups’ recommendations (more stringent), we should either be reassured or very concerned. More about that later in this post.

Nitrates - come from fertilizers, and often contaminate drinking water from agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Associated with higher cancer risk, just like the nitrates in most processed meats like cold cuts, deli meat, and hot dogs.

Per- and Polyfluoroalkyl Substances (also called PFAS) - these chemicals are termed “forever chemicals” as they persist in the environment over hundreds to thousands of years. In recent years PFAS have been found everywhere - in the soil, water, Arctic, and in the bodies of 99% of humans. Over 600 types are used in the U.S. in things like firefighting foam, cookware, cosmetics, carpet treatments and even dental floss. According to an article in Scientific American:

Scientists have found links between a number of (PFAS) and many health concerns—including kidney and testicular cancer, thyroid disease, liver damage, developmental toxicity, ulcerative colitis, high cholesterol, pregnancy-induced preeclampsia and hypertension, and immune dysfunction.

The EPA, now functioning again under a different administration, has announced a series of actions over the next three years to address the harms these chemicals are causing, and the potential for things to keep getting much worse with PFAS zombie-like lifecycles.

Lead - can get into our water supply mostly through the corrosion of old water pipes, according to EPA:

Lead pipes are more likely to be found in older cities and homes built before 1986. Among homes without lead service lines, the most common problem is with brass or chrome-plated brass faucets and plumbing with lead solder.

It’s not a bad idea to get your water tested for lead, although I have not done this yet. Lead can cause developmental problems with children’s brains, developmental problems in a fetus, and heart, kidney, and reproductive problems in adults. The story of Flint, Michigan is a case study.

Microplastics - another polluted legacy of modern life, plastics are showing up in everything from seafood, to the dust we breathe, to the water in our taps. One study found a range of 0-60 particles of plastic per liter of tap water in the U.S., with a mean of 9 plastic particles per liter. The study estimated that just from drinking tap water in the U.S., an average man would take in 6,000 plastic fibers a year.

The total microplastic burden in the human body is much higher. From the Plastic Health Coalition, a great article states:

Based on data currently available, scientists attempted to estimate the annual intake of microplastics by an average American citizen in 2019. This was estimated to range between 74,000 and 121,000 particles, depending on age and sex of the citizen, though the researchers believe this is an underestimation because only 15% of food consumed could be assessed. This study designated bottled water as one of the highest sources of plastic particle intake; bottled water contains about 100 microplastics per litre on average. More research has since been conducted, for example, plastic teabags and baby bottles have been found to release millions of microplastics and billions of nanoplastics into tea and baby formula. These studies suggest that our exposure has gravely been underestimated, but more research will need to be done to fully understand the extent of how much plastic we ingest and how much remains in our bodies.

Furthermore:

… researchers have hypothesized that human exposure to microplastics could lead to oxidative stress, DNA damage and inflammation, among other health problems. Particularly, when inflammation becomes chronic, this can pave the way to very serious health problems. However, it’s not only the plastic particles themselves that are potentially harmful: the surface of microplastics in the environment are colonised by micro-organisms, some of which have been identified as human pathogens.

Cryptosporidium and other bugs - I think you get the idea by now that water can be a vehicle for a lot of stuff. I’ve only mentioned a few chemicals and substances above, and I’m getting exhausted. But biological contaminants can also show up in water. Usually they are in minute amounts, and healthy individuals can deal with small ingestions. Chlorine and processing kills most bacteria, but cysts of the parasite Cryptosporidium are not easily killed. Water utilities monitor their sources like streams and rivers for parasites and cysts, and use filtration systems that remove any potential pathogens quite well. But immunocompromised individuals are at higher risk of getting sick if the water contains small amounts, and every once in a while an outbreak occurs. I try not to think about all the stuff in the community pool I love to swim in, so I’ll let the CDC state what I try to suppress awareness of:

Contaminated water may include water that has not been boiled or filtered, as well as contaminated recreational water sources. Several community-wide outbreaks of cryptosporidiosis have been linked to drinking municipal water or recreational water contaminated with Cryptosporidium.

Cryptosporidium parasites are found in every region of the United States and throughout the world. Travelers to developing countries may be at greater risk for infection because of poorer water treatment and food sanitation, but cryptosporidiosis occurs worldwide. In the United States, an estimated 748,000 cases of cryptosporidiosis occur each year.

The list goes on… pesticides, atrazine, hormones, pharmaceuticals, radium, 1,4-dioxane, arsenic, and metals like molybdenum. There is a plethora of chemicals that show up in minute amounts when water is tested. Cue refrain:

* The water we drink is amazingly clean by historic and world comparisons. But it also contains small amounts of thousands of chemicals - many of which can cause health problems with cumulative exposure. If we all drink water right out of the faucet, most of us will be fine, but a few of us will get sick over the years. Water filtration, especially using a reverse osmosis system, helps remove a lot of junk from our water before we drink it.*

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Who decides the acceptable levels of pollutants?

All public water systems in the United States are required to follow the standards and regulations set by the EPA. Owners of private wells are responsible for ensuring that their well water is safe from contaminants. Are these acceptable levels of pollutants in tap water reasonable? Are they reckless? It depends upon whom you ask, and how much risk you are willing to consider acceptable.

The Environmental Working Group is “an American activist group that specializes in research and advocacy in the areas of agricultural subsidies, toxic chemicals, drinking water pollutants, and corporate accountability.” EWG has gained a lot of attention in recent years, exposing pesticides in the foods we eat, and potential harm in the water we drink. I’m going to review what they say about water in 2 places near and dear to me - Philly and South Jersey.

To be fair, the “safe” standards EWG sets for drinking water quality are pretty much unattainable for public utilities. But they do show that perhaps we are being much too reliant upon water companies and the EPA to ensure a high enough level of safety with the tap water we drink. The world is polluted. But maybe we should invest in better filtration like activated charcoal filters, or reverse osmosis systems, for our drinking water if we don’t want to accept the small but cumulative risks of drinking water straight from the tap.

Ultimately, we decide what is acceptable to drink. Maybe this post will help.

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Two water analyses to consider: Philly and Jersey.

EWG analyzed water samples from all over the country, and you can see what they found by entering your zip code. I compared several cities like LA, NYC, Chicago, and New Orleans, and it is interesting to see the different chemicals that show up in different regions.

Here’s what Philly looks like. I’ll explain what you are seeing. The first chemical listed is bromodichloromethane. There is no legal limit for this byproduct of chlorination. But it does belong to that family of chemicals mentioned earlier called trihalomethanes, and the legal limit for TTHM’s is set at 60 parts per billion (ppb). However, EWG sets the bar really high, and estimates that the safe limit to protect people’s health would be just 0.1 ppb. So, according to EWG testing, Philly has about 3.5X as much of this stuff in the water as the legal limit. But if the standards were in line with what EWG scientists very conservatively assert as “safe”, then I’m drinking 322X as many TTHM’s as I should when I stick my mouth under the faucet.

That’s a huge difference between 3.5X and 322X… whom should we trust?

The database then lists these contaminants that are above health guidelines with additional chemicals that were detected in lower amounts, and gives a comparison of different filters’ ability to reduce these pollutants. Activated carbon is like a Brita filter, reverse osmosis is more costly and harder to install (unless you buy something like Aquatru, more about that later), and ion exchange filters. You can learn more about these types of filters through EWG as well.

It should be noted that activated carbon filters do pretty well, but not all are created equal, and they cannot remove as much as reverse osmosis. More on this later.

Not listed in these EWG water reports are levels of PFAS. They did a separate analysis on this, and a country-wide map. The EPA has recently set an upper limit of 70 ppb for PFAS + PFOS in drinking water. Philly is one of the worst places, but at 46 ppb still comes in below the EPA threshold. But scientists at EWG estimated that a truly “safe” level for PFAS would be 1 ppb. So if you ask them, Philly water has 44X the acceptable amount of PFAS.

And how about South Jersey, where I practice? Here are the EWG test results for Marlton, NJ:

* And other contaminants detected at lower levels:

In terms of PFAS, nearby Voorhees, NJ came in at 13 ppb. This is below the EPA threshold of 70 ppb, better than Philadelphia, but again higher than the 1 ppb EWG recommends.

South Jersey results also differed from Philadelphia with more arsenic, radioactive radium, and metals showing up.

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What do simple water filters remove? Are reverse osmosis systems better? What’s up with that countertop reverse osmosis system?

Activated carbon filters are what most of us use when we filter water. They are easily purchased, and work pretty well to make tap water taste better. According to a summary from EWG:

Activated carbon chemically bonds with and removes contaminants as water flows through the filter. Activated carbon filters' effectiveness varies significantly. Some are certified only to reduce chlorine and improve taste and odor. Others can reduce the levels of contaminants such as asbestos, lead, mercury and volatile organic compounds, or VOCs. However, activated carbon does not remove common inorganic pollutants such as arsenic, fluoride, hexavalent chromium, nitrate and perchlorate.

Reverse osmosis (RO) systems have membranes with tiny holes large enough for H2O molecules to pass through, but not larger chemicals, plastics, and pollutants. I looked into installing an RO system a couple years ago, and I think it would have been about $1,500. With inflation bump that up higher now? The idea of a second little faucet spout being installed and then living next to the larger faucet spout needs to be reckoned with. Instead I bought a countertop reverse osmosis machine for $350 on Amazon. These are now $425. Inflation sucks.

Reverse osmosis systems sold for home installation typically include one or more activated carbon and sediment filters, allowing such systems to reduce or remove a large number of contaminants. The initial activated carbon treatment captures and removes chlorine, trihalomethanes and VOCs. Next, during the reverse osmosis filtration, tap water passes through a semipermeable membrane that blocks any particles larger than water molecules. As a result, reverse osmosis systems effectively remove many contaminants, such as arsenic, fluoride, hexavalent chromium, nitrates and perchlorate.

Wasted water is the primary drawback of reverse osmosis systems. These systems typically take in five times more water than they produce for use, and the unused “reject” water is flushed down the drain.

Additionally, reverse osmosis treatment removes minerals that improve the taste of water and are essential for health, such as iron, calcium and magnesium. Manufacturers of reverse osmosis systems may offer different options to address this problem, such as the addition of mineral drops for remineralization.

One reason I’ll keep talking about the Aquatru brand is that this RO system recirculates water as it’s filtering, and can produce 3/4 gallon of purified water for every 1 gallon of tap water used. That’s much more efficient than the 5:1 mentioned for other RO systems, and especially important in areas where water is a scarce resource.

Many people buy water in plastic bottles. This water is not much better, is sometimes worse than tap water, is very expensive, inefficient, and creates insane amounts of plastic pollution. Save your money and invest in filtration.

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Invest in a reverse osmosis system?

It’s up to you. Statistically you’re probably fine drinking tap water, especially if filtered at least with an activated carbon filter. I chose to get an Aquatru countertop reverse osmosis filter as I stated above. It cost a lot of money up front. But RO systems remove junk from water better than anything else, including stuff like microplastics and PFAS that are only going to get worse. [I also expect that future leaders (on the right) will keep weakening and trying to dismantle the EPA. It’s a well-documented fact that the previous administration rolled back over 100 environmental regulations concerning clean air, water, and toxic chemicals. Regardless of how you feel about abortion, guns, taxes, or immigration - the environment should be our top concern in my opinion. As we know, it isn’t.]

And so if you decide to get a countertop RO system instead of having an installer do one professionally for the house, the best (and only?) kind I could find was made by Aquatru. I store it on a workbench in my basement, since it has been banished from the kitchen because of other appliances taking up prime countertop real estate. I fill the removable tank with tap water, the RO machine does its thing, and within 5-10 minutes I can bring clean water up from the basement. Or just press the dispenser button to fill a glass. I have mineral drops that I can add to the filtered water, but I feel like we probably get enough trace minerals from the foods we eat, and other sources of water since I don’t exclusively drink just from this RO system.

Some men descend into their basements, tinker at a workbench, and emerge from the dark with accomplishments like a beautiful birdfeeder or fixed toy. I come up with a pitcher of clean water. Not so masculine I’m afraid, but that’s ok in 2022.

Here’s what my personal solution looks like:

Briefly skim this next part, it’s the filtration results from Aquatru, likely similar to other RO systems. I’m using it as an example for RO in general, sorry if this is sounding more like an advertisement! Basically they filter out 95-99% of stuff:

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And so concludes part 2 of this miniseries. I’ll end with the refrain, and I hope this has been helpful.

* The water we drink is amazingly clean by historic and world comparisons. But it also contains small amounts of thousands of chemicals - many of which can cause health problems with cumulative exposure. If we all drink water right out of the faucet, most of us will be fine, but a few of us will get sick over the years. Water filtration, especially using a reverse osmosis system, helps remove a lot of junk from our water before we drink it.*

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* Postscript - Thank you to the unknown reader who sent me the following message after the first post in this series: “I found this topic so fascinating, and the build up of CO2 in a closed car so shocking. I also upgraded my subscription. It’s kind of like getting a well-researched communication from a boutique/concierge doc, instead of getting ‘just take this pill.’ Keep the letters coming!”

~ I will, and thank you. And if you don’t mind, I think I’ll try using that “boutique letter” part!