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Are There Side Effects of Drinking Tap Water?



You know that drinking water is good for you — but what if your water source has quality issues you don’t know about?

The good news is that homes across North America can generally count on safe drinking water. That’s thanks to a variety of laws, treatments and testing options designed to prevent waterborne diseases and contamination.

However, as you’ll see, water safety is a bit more complicated than that. If your tap water has certain contaminants, taking a drink could still sometimes lead to noticeable side effects such as upset stomach, headaches, decreased blood pressure and more.*

Let’s take a closer look at the drinking water supply and what it means for your body.

When Does Tap Water Cause Side Effects?

Most of the time, tap water causes more positive health effects than negative ones. . After all, it helps prevent dehydration — and that can solve problems ranging from thirst and dry mouth to dizziness and tiredness.

Water does more than just keep you hydrated. How exactly water behaves in your body depends on what it contains. That’s because “pure water” doesn’t exist in nature, and the various treatment solutions for municipal water, well water and even bottled water don’t necessarily remove everything.

Some of this content can be good or at least not concerning, such as the minerals that give tap water its flavor. Other impurities can cause aesthetic issues like an unpleasant taste, odor or appearance, while still others may present a health risk. Contaminants that cause these issues can get into private or public water supplies in a variety of ways — sometimes just traveling through nature — and may not be noticeable for a while.*

Here are a few potential issues that may occur with tap water and the side effects they may cause:


There can be all kinds of minerals in your tap water. As water passes through rocks, sand and soil on its way to your main water source, it can pick up and carry these minerals straight to your tap.

Fortunately, the most common minerals found in water are unlikely to cause significant health concerns. For example, iron in water only causes gastrointestinal disturbances at high levels generally not found in drinking water — and it helps increase your intake of the healthy minerals your body needs. However, too much iron in your water can lead to rust-like stains on sinks, toilets and tubs or even a metallic taste. Calcium and magnesium are other frequent issues, and while you can drink them without concern, they do cause hard water, which can affect your home and plumbing.


Nitrates occur naturally in your body and many of your favorite foods. However, they also exist in certain fertilizers, industrial waste, septic systems and more — often in higher concentrations. Nitrate issues are more common in well water, particularly in areas with a lot of agricultural activity. For example, nitrate can often be present in areas where livestock are raised. Runoff from crop fertilization is another common source. If these sources pollute your water supply, you can end up with high levels of nitrates, which may cause health concerns. Symptoms include gastrointestinal disturbances, decreases in blood pressure and increased heart rate; infants under six months of age are generally at the most risk.


Copper is found in everything from the Earth’s crust to the plumbing in some homes. Unfortunately, that means it can get into your water supply in both of those ways and more.

Your body does need a certain amount of copper, but too much can cause nausea, vomiting, liver damage and kidney disease. That’s why it’s smart to look for signs of copper contamination in your water system, such as metallic tastes or blue-green stains on your sinks and fixtures.


If your home has lead pipes, you might have this metal in your water supply, too, as lead pipes can corrode over time. Even treated municipal water may have this kind of contamination since treatment occurs before water travels through your plumbing.

Lead poisoning isn’t as common as it once was, particularly because newer homes don’t have this kind of piping. Where it does occur, this health problem can cause side effects at every stage of life, including brain damage in unborn babies, learning disabilities in children and cardiovascular effects in adults.


Fluoride exists in nature and is added to the drinking water supply in North America to help protect public health. This mineral helps reduce the risk of cavities. That means it’s one of those occasions where an additive to your water is actually taking care of your body.

Too much fluoride can result in fluorosis, or tooth discoloration, particularly in young children. However, the amount of fluoride in the public water system — and, more rarely, in private wells from natural sources — isn’t generally a health concern.

PFAS Chemicals

Sometimes called “forever chemicals,” these contaminants earn their name by lasting a long time in the environment — and in your body. Health effects can range from decreased fertility to increased cancer risk. These chemicals can’t be detected by color, odor or taste, which means you can’t identify a problem on your own.

While many emerging contaminants like PFAS aren’t yet addressed by federal regulations protecting the public water supplies, the good news in the U.S. is that the Environmental Protection Agency recently announced a new regulation covering six PFAS chemicals. However, the final rule won’t take effect until 2027, and it allows public water systems five years to reduce PFAS exposure if they exceed the set limits. Plus, private well water will not be covered.

FAQs About Tap Water

Remember, it’s nearly impossible to keep up with every potential contaminant on your own — not to mention the health effects associated with each one. That’s why it’s smart to brush up on the underlying information and let your local water quality expert help with the rest.

Here are a few things to know about tap water:

What Are The Types of Contaminants?

Water quality issues can generally be broken down into general categories including:

  • Physical: This includes sediment and particles.
  • Chemical: Chemical contaminants include everything from toxins and metals to pesticides and other man-made substances.
  • Biological: This category includes living organisms such as bacteria and viruses.
  • Radiological: Radioactive substances, such as radium and uranium, fall into this group.

Keep in mind that this is only a frame of reference — a way of thinking about how various contaminants may end up in your water. When it’s time to choose specific water treatment solutions, you’ll need more specific information about your own tap water.

What’s The Difference Between City and Well Water?

The most significant difference between city and well water is treatment. In North America, various organizations and laws work together to protect both public and environmental health by monitoring, treating and testing the public water supply. That’s part of why you can generally count on safe drinking water. However, private wells aren’t covered by these protections — so if you have a well, that means water quality is your responsibility.

Another noteworthy difference is the water source. While city water may come from groundwater (such as aquifers) or surface water (such as lakes or reservoirs), wells are most commonly fed by groundwater.

Can You Drink Too Much Water?

Although it’s technically possible to get overhydrated and cause an electrolyte imbalance in your body, this is most common in athletes or those with certain medical conditions and isn’t a common concern for most.

It’s more important to think about “too much water” if you happen to be drinking contaminated water. For example, maybe a sip of water with high lead levels won’t immediately cause an issue — but you certainly don’t want to be drinking it all day, and should probably switch to bottled water until a solution is in place.

Is Hard Water a Health Concern?

The contaminants we’ve covered here are examples of drinking water problems that could impact your health through ingestion. However, some water problems like hard water can also cause issues for your home, such as stains on your sinks and bathtubs.

Additionally, while hard water doesn’t cause problems when ingested, it can lead to a different kind of health concern because it dries out your skin and hair. That can lead to itchiness, irritation and more.

Can You Test Your Own Water?

There are all kinds of DIY water testing kits on the market. However, you have to perform these tests yourself and interpret sometimes-complex results — so if you want comprehensive answers and personalized recommendations, it’s best to have a professional water test.

How To Improve Tap Water Quality

Once you’ve had a water test, you’ll know which contaminants — if any — are present in your water supply. The next step is to take action, and that often means choosing a water treatment solution like a reverse osmosis filtration system.

Reverse osmosis (RO) is a process that addresses a wide range of impurities. RO systems often include additional stages of filtration as well, helping with some of the biggest water concerns, including:

  • Arsenic
  • Lead
  • Fluoride
  • Minerals
  • PFAS chemicals
  • Viruses
  • Bacteria
  • Pesticides

You should also look for third-party certifications that tell you exactly what the system can address, how effective it is and what it should be used for.

It’s important to note that, although RO systems address some of the minerals responsible for hard water (such as calcium), they aren’t intended to solve hard water problems. To address dry skin and hair, mineral buildup, soap scum and other hard water issues, you’ll need a water softener.

Both city and well water users can benefit from filtration and softening. It all depends on what’s in your tap water.

Make Your Tap Water More Reliable

Although tap water is generally safe, issues can still remain. That’s why it’s important to have regular water tests and choose treatment solutions that align with your home’s unique needs.

It all begins with a free, in-home water test and consultation. Schedule yours today.

*Contaminants may not be present in your water.

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