Is Well Water Safe to Drink?

By: Jake Gallagher | October 23, 2023

The first question that pops up when you’re about to use well water or install a well in your home is, “Is well water safe to drink?” And the train of thought will lead to similar questions like, “Is it safe for the babies?” or “Will it affect my hair?”

The short answer is “yes.” Typically, groundwater is naturally clean and safe to drink. Because the soil on top acts as a filter, groundwater is usually free of microorganisms that may cause disease. However, it’s crucial to be aware that groundwater can become contaminated if the casings or caps for wells are not installed in the correct way. Human activities and environmental pollutants can also contribute to groundwater contamination.

What are these toxins, and what can you do to keep your well water safe and clean for drinking? Let’s find out.

What Makes Well Water Safe?

As long as you keep the water quality in check and treat the well water from time to time, well water is safe to drink! Almost 140 million people in the US pump out groundwater for daily household drinking water use.

Investing in a healthy private well pays off in terms of costs, the taste of water, and a rise in property value, but it requires regular maintenance. If you can’t do that, you’re better off with an industrially treated municipal water supply. Keep in mind that although the municipal water supply is apparently safe to drink, you might be ingesting treatment chemicals that are not always safe for your body. Having a private well means you’re in charge of what’s in the well water.

Possible Contaminants in Well Water and Their Harmful Effects

You will never delay your well water inspection once you learn about the damage these contaminants can do to your body. I have dedicated this section to explaining the serious health problems and other health concerns associated with the most common contaminants in well water, including naturally occurring chemicals, and how to remove them.

(Psst: For information about water filtration systems and other treatments, you can find details on all the water purification methods and techniques here.)


Consuming well water contaminated by total coliform bacteria, viruses, and protozoa can cause stomachache, nausea, vomiting, diarrhea, jaundice, and other gastrointestinal illnesses. In fact, such microorganisms are the leading cause of most waterborne diseases around the world. These harmful contaminants usually come from organic waste, such as human sewage or animal feces.


First, if you or your family members are experiencing chronic gastrointestinal disorders, immediately get your well water tested in a laboratory. It’s an inexpensive test that often costs less than $30, and the results can be expected within a week. Just make sure you collect the samples carefully to prevent any contamination of the sample. Better yet, consult the laboratory and learn about sampling protocols.

If your well water tests positive for microorganisms, you should treat it with chlorination, ultraviolet (UV) light, distillation, or ozonation to kill bacteria and other pathogens. 

Nitrates and nitrites

Nitrate and nitrite contamination in drinking water is another common concern among private well water owners. 

Harmful human activities, such as unsupervised waste disposal, expose clean groundwater to free ammonia that turns into nitrates and nitrites. One health concern associated with this toxin is the deadly methemoglobinemia—a disorder that targets children, specifically bottle-fed babies.

Some studies even suggest that drinking water contaminated with nitrates can cause cancer.


To stay clear of nitrate contamination, you will need to get your well water tested in a lab periodically. The Environmental Protection Agency (EPA) suggests that the safe limits of nitrates and nitrites are 10 mg/L and 1 mg/L respectively.

Ion-exchange technology and residential reverse osmosis devices have proven effective at removing these toxins


Arsenic occurs naturally as a mineral deposit in some regions, while in other locations it results from industrial practices, such as mining. For instance, groundwater in the regions of New Hampshire, Ohio, Michigan, and Maine have high levels of arsenic in bedrock.

This toxin can stop production of red and white blood cells and damage blood vessels. Moreover, it is associated with health issues like disturbed heartbeat, a “pinching” sensation in hands and feet, irritated respiratory system, and sore throat. Research shows that prolonged ingestion of inorganic arsenic can lead to cancer in the liver and skin.


According to the EPA, if your drinking water has an arsenic quantity greater than 10 ppb, immediately stop consumption and shift to another water source. Arsenic is not absorbed in the body through the skin, so if you’re using well water contaminated with arsenic, you can safely use it for bathing and cleaning purposes. However, I’d suggest you treat the water, as you’re still at risk of inadvertently ingesting arsenic. Better safe than sorry.

If you want to test your water for arsenic, contact a nearby laboratory or find a suitable lab through this database. Water testing will cost about $15–$30.

Arsenic can be a little tricky to remove, as its filtration can be hindered by other elements, such as iron and manganese, present in the water. This pesky contaminant exists in two forms, “arsenic 3” and “arsenic 5.” Its treatment involves converting arsenic 3 to arsenic 5 through oxidation, which is easier to filter out. I advise you to ask your lab to test the concentrations of both types of arsenic, so you can decide which water treatment process is best suited to your needs. 

The best arsenic removal methods include anion exchange, reverse osmosis, activated ammonia, ultra-filtration, and distillation.

Other heavy metals and trace elements

Other than arsenic, metals and metalloids, such as copper, lead, chromium, selenium, iron, manganese, calcium, magnesium, and other contaminants are naturally present in trace amounts in the ground. Increasing human activities, like mining and farming, are constantly adding to the concentration of total dissolved solids in the groundwater.

However, the most common causes of metal contamination in well water are deteriorating plumbing pipes and rusted fittings inside the well. If your well is 15 years old or older, the pipes might need some repairing, or even replacing.

Concentration of any of these metals exceeding safe limits can cause health risks such as kidney, liver, and intestinal disorders.

  • Copper concentration exceeding 1.3 ppm (EPA limit) can cause vomiting, diarrhea, stomach illnesses, and cramping. If you identify bluish green stains on copper fixtures, that’s copper corroding away and entering your well water.
  • Lead is so harmful to the body that the EPA has set its safe limit to “zero.” It accumulates in the body over time and damages the central and peripheral nervous system—especially in children.
  • Iron greater than 0.3 g/L in well water will develop an unpleasant metallic taste. It gives a rustic orangish shade to water that can stain your laundry and dishes. High iron concentrations can damage the heart and liver and cause nausea and stomach pains.
  • Chromium exceeding 0.05 mg/L leads to skin rashes and disturbs the liver, stomach, and nervous system. If consumed for an extended period of time, it can even cause death.
  • Calcium and magnesium are responsible for the hardening of water and are treated using water softener. Interestingly enough, these minerals have shown positive health effects on the human body. But here’s the catch: drinking water with a high concentration of hard minerals for a long time can cause kidney stones, osteoporosis, and hypercalcemia. Make sure your hard mineral intake doesn’t exceed the safe limits determined by experts.


If your drinking water tests positive for metals and elements in quantities higher than the safe water benchmarks mentioned by USGS, the best solutions include replacing your well pipes and fittings, flushing the pipes to remove sediment contamination, and installing private purification systems.


Radionuclides like uranium, radon, and radium occur naturally in the bedrock. However, they are also often introduced to the ground from unregulated coal, oil, and nuclear industry waste disposal. Such contaminants are responsible for causing cancer in various organs.


You might need a professional to help eliminate radionuclides in your well water. Such water contaminants are usually removed using a GAC treatment in which water is filtered through “granular activated carbon.” Another suitable filtration method is aeration. It’s better to invest in a point-of-entry device that will clean all your well water instead of sink water filters that treat only a small portion of water.

Organic chemicals

Volatile organic compounds (VOCs) and synthetic organic chemicals (SOCs) can seep into the groundwater due to unmindful disposal of gasoline, pesticides, degreasing agents, dyes, paints, and pharmaceuticals. Long-term exposure to VOCs and SOCs damages kidneys, respiratory organs, and cardiovascular and reproductive systems.


Carbon filters, aeration, and reverse osmosis systems can help get rid of organic contaminants in well water.

The Causes of Well Water Contamination

You might remember from science class that water is an excellent solvent because it can dissolve many salts and chemicals. This is the reason why your groundwater is always susceptible to contamination.

Let’s discuss some of the major causes of water contamination and how you can avoid them. 

  1. Water runoff

The most common cause of well water contamination is the addition of nearby surface runoff in the well. During heavy rainfall or snow, contaminated water can seep through the surface and sneak into your well water source. The dirty surface water runoff brings with it harmful bacteria, viruses, parasites, organic chemicals, heavy metals—all sorts of toxicity present on the surface of the earth. Yes, I’m talking about human sewage, chemical fertilizers, animal waste, oil spillage, and other industrial pollution!

Although there’s nothing much you can do about preventing the dirty water from absorbing into the ground and entering your water source, you can treat the well water itself, seal the well head, and make it watertight.

  1. Location of the well

Another essential factor is the region where you’re located. Groundwater quality varies from place to place. Some locations offer squeaky-clean water, while other sites have a lot of mineral content in the ground, contaminating the groundwater with excessive salts.

For instance, groundwater in the northern US is quite saline because salt is regularly spread on roads to melt ice, which then absorbs into the aquifers.

If your well is situated near a farm where fertilizers and pesticides are used in abundance, it will catch some of those chemicals. Additionally, a well planted near a gas station, poorly designed septic tanks, underground storage tanks, landfills, or garbage dumps will most likely be full of contaminants and unsafe for drinking.

Before installing a well, you must thoroughly check the site and test the ground.

  1. Old structure and improper construction

Lead pipes and old pumps can also be a source of water contamination. Sometimes, old brass fixtures and rusting iron can leach harmful toxins into the drinking water. Faulty structures, such as inadequate concrete casings and leaky covers, can allow dirt to enter private wells.

If your private well is old and rusty, immediately replace the old copper and brass fittings with new ones and investigate your well structure regularly. Run the tap water for a few minutes every morning or if you haven’t used the water for several hours. This flushes out sedimented metal toxins in the water. 

Make sure you only use cold tap water for drinking and cooking purposes because metals and toxins dissolve more readily in hot water, making it more susceptible to contamination than cold water. 

The Importance of Testing Well Water Quality 

The only way to ensure that your water is safe to drink is to get it tested in a laboratory from time to time. You can overlook the subtle changes in the taste of water, its smell, and color, but lab tests will detect even the littlest of these harmful contaminants.

Private wells must be thoroughly checked at least once a year. But if you’ve just moved to a new home, had your well repaired, or experienced flooding and runoff contamination, or you haven’t used the well water for a while, don’t use it for cooking and drinking unless you get it tested and treated. For long-term safety, you must install a water filtration system or a water treatment system. 

Lastly, ensure that you test the drinking water both at the tap and the source. This way, you can determine the performance of your water filter or other private purification systems and immediately identify any malfunction before you or your family members become a victim of contaminated water.

You can always consult your local health department or certified well contractors to help you maintain the perfect drinking water quality. 

Final Thoughts

Just because your well water looks sparkly clean and tastes nice doesn’t mean it’s free of harmful contaminants. You can only know what’s inside by testing your water in a laboratory. 

Thanks to humans’ and industries’ harmful activities, groundwater and water quality are always susceptible to changes. So your take-home message is this: water from private wells is only safe to drink with frequent water testing and proper water treatment systems in place.

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