Is Well Water Safe to Drink?

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If you’re buying a house with a well, or you’re considering installing a well at your property, you might have some questions about the quality of well water.

Unlike municipal water, well water is completely natural and untreated. Well water isn’t regulated by the Environmental Protection Agency (EPA) – but that doesn’t necessarily mean that the water is unsafe. It depends on the source.

In this guide, we’ve answered the question: “Is well water safe to drink?” We’ve shared the possible problems with well water, how to know that your well water is safe to drink, and which water treatment options are best for wells.

📌 Key Takeaways:

  • Well water may or may not be safe to drink – it depends on what the water contains.
  • Fluoride, iron, arsenic, pesticides, manganese, and microorganisms can all affect well water safety.
  • You can make well water safe for drinking by installing a water treatment system that removes or kills the contaminants in your water supply.

🚰 Is Well Water Safe For Drinking?

Private well water is usually safe to drink – but the safety of well water for drinking depends on the contaminants it contains.

Generally, wells are less susceptible to contamination than public drinking water systems because they’re protected by tens, even hundreds, of feet of rocks and soil.

However, well water can still be contaminated as a result of soil seepage or runoff, especially if the well is old, has poor construction, or is cracked or damaged.

Don’t assume that your well water is safe to drink. Test your water to find out what it contains, and if any contaminants are present at potentially dangerous levels, remove them with a suitable water treatment system.

water testing with tap score

🛑 What Are the Possible Problems With Well Water?

Well water safety may be compromised by harmful contaminants, aesthetic issues, and problems with plumbing and appliances.

Harmful Contaminants

According to the EPA, some of the possibly harmful contaminants commonly found in US well water include:

  • Microorganisms (like coliform bacteria and parasites)
  • Chemicals (like nitrate and nitrite)
  • Heavy metals (like arsenic and lead)
  • Organic chemicals from pesticides and herbicides
  • Radioactive elements (like radium and uranium)
  • Minerals (like fluoride)

In small amounts, these contaminants aren’t typically a threat to human health. But, because well water isn’t treated by local authorities, a well water source might contain levels of certain contaminants that greatly exceed the EPA legal limits for public drinking water sources.

Many of these contaminants can cause serious health problems, including kidney and liver damage, cancer, and reproductive issues, if they’re ingested in high quantities over a long period.

arsenic in groundwater map
Source: United States Geological Survey (

Aesthetic Issues

There are several aesthetic contaminants that are particularly common in well water, and can affect the taste, smell, and color of water.

Iron is an aesthetic contaminant you’re likely to find in well water. Iron gives water a brownish-orange tinge and a metallic taste.

Hydrogen sulfide, or sulfur, is another problem aesthetic contaminant in private well water systems, and can give water a distinct rotten egg odor and smell.

Aesthetic contaminants aren’t usually dangerous to health, but they can make water look, taste, and smell so unpleasant that you don’t drink as much as you should, which may cause mild dehydration.

Some aesthetic contaminants may also have health risks if they’re present in very large quantities or if they combine with other contaminants. For instance, iron may combine with bacteria to form iron bacteria, which may create conditions for other harmful microorganisms to grow.

Plumbing & Appliances

A number of contaminants, including the aesthetic contaminants mentioned above, can affect your water quality and damage your plumbing and appliances.

Iron doesn’t only give water a bad taste. When it interacts with oxygen in the air, it leaves reddish-orange rust deposits on surfaces Rust may corrode surfaces that can’t be reached easily, such as the inside of your pipes or the back of your appliances.

When your pipes and plumbing corrode, they may leach metals like copper into your water. This is particularly dangerous if you have an old plumbing system made from lead, since lead is an incredibly toxic heavy metal.

Plumbing and appliances can also be damaged by high levels of hardness minerals in well water. A USGS study of 2,100 private wells across the US found that the vast majority of these wells had hardness levels of more than 180 milligrams per liter (Mg/L).

Map detailing hardness of groundwater from domestic wells
Source: United States Geological Survey (

Excess minerals in hard water form surface deposits called scale. When scale builds up on pipes and in appliances over time, it covers pinhole leaks and corroded sections of pipe caused by corrosive water.

This may present a safety issue if you install a water softener in the future, which will remove the built-up scale, expose the leaks and corroded pipe sections, and possibly result in metal leaching into your water.

🚱 How Do Contaminants & Pollutants Get Into My Drinking Water Well?

There are several ways that contaminants and pollutants can get into private well water systems:

  • From surface runoff, such as from rainfall or snow melt, underground seepage, or washing contaminants into the well system. Harmful bacteria, heavy metals, and chemicals can all enter well water this way).
  • Through spills and improper waste disposal, which contaminate the local environment. Organic chemicals like pesticides and herbicides often enter well water systems from spills.
  • From human activities like mining and power production. Radionuclides, chemicals, and heavy metals can enter well water as a result of human activity.
  • Through leaking septic tanks or animal waste disposal systems, especially if a well is incorrectly positioned too close to one of these systems. Coliform bacteria like E. Coli and other microorganisms can enter a private well in this manner.
  • Natural contamination from the earth. Fluoride, manganese, iron, and other naturally occurring chemicals and minerals are found in the rocks and soils surrounding the well aquifer. The types and concentrations of natural contaminants in well water depend on the local geology.
  • As a result of leaching from well/plumbing systems, which may cause trace levels of lead, copper, and other metals to enter your well supply. This is especially likely if you have acidic well water (with a low pH).

☣️ Natural vs Unnatural Contaminants

Some well water contaminants are natural, which means they’re naturally found in the earth or rocks surrounding the well aquifer.

Other well water contaminants are manmade. There are also natural contaminants that are released by humans in large quantities, giving them an unnatural presence in the environment.

Some examples of natural contaminants are:

  • Hardness minerals (calcium and magnesium)
  • Iron
  • Sulfur
  • Manganese
  • Tannins
  • Sodium
Limescale Buildup
Calcium and Magnesium Build-Up in Water Pipe

Unnatural contaminants include:

  • PFOA and PFOS
  • Volatile organic compounds (VOCs)
  • BPA and BPS
  • Lead
  • Nitrate/nitrite
  • Pesticides and herbicides
Herbicide water contamination
Herbicide spraying can cause water contamination

Contaminants that are both natural and unnatural include:

  • Arsenic
  • Fluoride
  • Radionuclides
  • Microorganisms like coliform bacteria and viruses
  • Chromium
  • Aluminum

Don’t be deceived: natural contaminants aren’t always safe to drink. Some regions have dangerously high levels of natural contaminants.

For instance, arsenic, a cancer-causing contaminant, is found in very high levels in California’s groundwater, due to natural arsenic sources in the ground.

Here are some of the possible health effects associated with well water, and which contaminants cause these effects.

Gastrointestinal Illness – Microorganisms Like Bacteria

Gastrointestinal illnesses, which cause vomiting, diarrhea, abdominal discomfort, loss of appetite, and nausea, are caused by drinking water contaminated with microorganisms like harmful bacteria (e.g. E. Coli). Symptoms appear between 1 hour and 3 days after drinking bacteria-contaminated water. Gastrointestinal illness typically lasts up to 10 days.

Bacteria growth in water sample

Cancer – Arsenic and Radionuclides

Heavy metals like arsenic and radionuclides like radium have been linked to cancer when consumed in drinking water. According to, arsenic is linked to an increased risk of skin cancer and bladder cancer.

Internal Organ Damage – Lead

Many contaminants in well water cause internal organ damage if they’re consumed in large quantities over a long period. Contaminants that accumulate in the body over time, like lead, are most likely to damage the organs if ingested in ground water from a well over several years or decades. The kidney, liver, and intestines are particularly susceptible to damage from lead.

Skeletal Fluorosis – Fluoride

Skeletal fluorosis causes weakened, painful bones, and is the result of fluoride accumulation in the body. Fluoride is added to many public drinking water sources, and skeletal fluorosis is an unlikely consequence of drinking low levels of fluoride in water. However, high levels of fluoride aren’t safe to drink because of the fluorosis risk.

Person suffering from weakened, painful bones

Neurological Disorders – Heavy Metals, PFOS and PFOA, Pesticides

Neurological disorders are caused by drinking water containing high levels of heavy metals (like lead and arsenic), perfluorinated substances (like PFOS and PFOA), and certain types of pesticides. These contaminants can interfere with brain development in a number of ways and can cause memory problems, issues with processing information, and strokes.

Reproductive Problems – Pesticides, Organic Solvents, Heavy Metals

Reproductive problems and even infertility are caused by a number of common well water contaminants, including pesticides, organic solvents, and heavy metals. Exposure to these contaminants in the environment, including in drinking water, has been associated with low sperm count and difficulty conceiving.

⚠️ Signs Your Water is Making You Sick

Some of the signs your water is making you sick include:

  • Nausea
  • Vomiting
  • Fever/temperature
  • Stomach cramping
  • Diarrhea
  • Brain fog
  • Lethargy
  • Weakness
  • Muscle problems
  • Skin conditions

If you notice any of these symptoms in yourself or a family member, and they can’t be associated with an explanation (such as a viral sickness bug), stop drinking your well water and get it tested immediately.

Note: Many drinking water contaminants don’t have any obvious health effects, but that doesn’t mean that they’re not harmful.

🔎 How to Tell If Well Water Is Safe to Drink

Knowing whether your water is safe to drink can be tricky. Many well water contaminants are invisible, so they don’t give water an unpleasant taste or smell, or unusual color.

That means you won’t be able to tell if your water is safe to drink by sniffing it, looking at it, or tasting it.

The safest way to tell if your water is safe to drink is to arrange for water testing.

water testing with tap score

🧪 Test Your Water

If you’ve never tested your well water, get your well tested as soon as possible for a broad range of drinking water contaminants. This will tell you exactly what your water contains.

After this initial testing, you should get your well water tested regularly for specific contaminants because your local geology can change from time to time, and new contaminants can be introduced to your well aquifer without changing the water quality.

What To Test For In Well Water

I recommend testing your well water for the following contaminants:

  • Hardness and alkalinity
  • Aluminum
  • Arsenic
  • Chromium
  • Copper
  • Barium
  • Lead
  • Iron
  • Mercury
  • Manganese
  • Nickel
  • Silver
  • Potassium
  • Zinc
  • Titanium
  • Sodium
  • Total coliform bacteria
  • Fluoride
  • Nitrate
  • Chloride
  • Sulfate
  • Pesticides
  • Herbicides
  • Total dissolved solids (TDS)

Many water testing laboratories provide testing packages for well water that allow for testing of all these contaminants at a discounted price.

Additional contaminants to test for, if you believe you may have a local pollution issue or you just want to be certain of what your well contains, include:

  • VOCs
  • Radionuclides
  • SVOCs
completed tap score water test

When To Test Your Water

If you’ve never had your well tested before, or you’re moving into a new home with a well, get your water tested as soon as possible.

According to the CDC, after initial testing, you should get your well tested once every year for total dissolved solids, nitrates, coliform bacteria, and alkalinity.

There are other occasions when you should get your well tested:

  • When you carry out a repair or replacement in your well system
  • If you’re alerted that your local ground water has been polluted
  • If local land disturbances or flooding have potentially contaminated your well
  • If your water quality (such as taste, odor, or color) has changed

Who Should Carry Out the Testing?

Before you consider private testing, contact your local health department. In some cases, your local health department will test private wells in the area for free, or at a discounted price.

These tests will typically analyze water for nitrates, bacteria, pH, and volatile organic compounds.

If you’re looking for more thorough testing than offered by your local health department, look into private testing by a state-certified laboratory.

The Environmental Protection Agency has a list of state-certified laboratories that allows you to search for laboratories based on where you live.

I recommend Tap Score, a health services company founded at the University of California in Berkeley, which offers three tiers of well water testing depending on the contaminants you need to test for.

water testing with tap score

🌀 How To Make Well Water Safe To Drink

The most effective water treatment methods for private wells are water filters and other private purification systems.

Water Filtration Systems

The most common of water filtration systems are listed below.

Whole House Water Filtration Systems

Whole house water filters use a combination of filter media to remove a range of contaminants from private wells.

A whole house filtration system may use filter cartridges, such as activated carbon filters, or a mineral oxidation process, like air injection, to remove sediment, iron, sulfur, manganese, heavy metals, organic contaminants, and other dissolved minerals.

Whole house filters trap contaminants in their filter media. Depending on the type of water filtration system you buy, you’ll need to replace the filters or set the unit to regenerate or backwash when the media becomes saturated with contaminants.

👨🏼‍🔧 You can learn more about whole house water filters in my best well water filtration system guide.

Springwell whole house water filter system
Springwell Whole House Water Filter System

Water Softeners

Unlike whole house water filtration systems, water softeners don’t filter contaminants out of water. Instead, these systems use ion exchange to replace hardness minerals with equal amounts of sodium ions.

A water softener is primarily used to tackle water hardness, although some systems can be used for iron removal, too.

If you don’t want to alter the taste of your water, consider a water conditioner. Water conditioners don’t change your water quality. Instead, they alter the composition of hardness minerals, preventing them from forming scale without actually softening your water supply.

👨🏼‍🔧 Learn more about the best water softeners for well water in my dedicated guide.

Reverse Osmosis Systems

Reverse osmosis systems remove more contaminants than the average whole-house water filter. The complex design of a reverse osmosis water filter enables it to trap contaminants of all sizes, allowing only tiny water particles to pass through.

All reverse osmosis filters use several filtration stages, including a carbon water filter, a pre-filter, and a semi-permeable membrane. The membrane is made up of thousands of tiny pores, which deflect contaminants in water flowing through the system. These contaminants are then sent down a drainpipe with wastewater.

Point-of-use RO water filters, such as under-sink RO filters, are more common than whole-home filters.

With that said, whole house RO filtration is becoming more commonplace nowadays. I’ve shared the top whole house reverse osmosis water filters in this guide.

RO system on counter with dedicated faucet
POU Reverse Osmosis System

Disinfection Systems

The aim of disinfection is to make well water safe for drinking by removing microorganisms like bacteria and viruses from the tap water supply. Disinfection can only be used to kill or remove live organisms in water, and can’t be used to remove impurities like metals and chemicals.

You can find two popular disinfection options below.

Chemical Treatment

Chemical treatment mimics the disinfection process that takes place in large-scale public water treatment facilities.

Chemical treatment systems inject measured amounts of chemicals like chlorine into an untreated well water supply. This water is stored in a tank to allow the chemicals time to take effect before being delivered around your home.

Chemical treatment requires ongoing maintenance because the chemicals will eventually run out, and will need to be topped up every few months. This form of disinfection also involves adding chemicals to water, and comes with an element of risk.

UV Treatment

UV treatment is a low-maintenance alternative to chemical treatment. A UV purification system uses ultraviolet light to alter the DNA of disease-causing pathogens, killing them and preventing them from reproducing.

You can install a UV lamp at your home’s point of entry. When water flows through the chamber, the ultraviolet light provides instant disinfection. UV lamps are space-saving, taking up a fraction of the space that a chemical injection system would need.

Most UV lamps need replacing after one year of use, but some can last for up to three years before a replacement is needed.

whole house uv water filter
Viqua UV Treatment System Diagram

📋 How To Choose The Best Treatment Method For Your Unique Situation

Once you know more about your water quality, you can decide on which treatment method is most suitable for your well water system.

To decide on a water treatment method, follow these steps:

1. Assess Your Water Test Results

Test your well and analyze the results. Decide which impurities are most concerning in your drinking water, which have the biggest effect on your water quality, and which you’d like to remove.

You may decide at this stage that you need several treatment systems (for instance, you want to tackle hard water and heavy metals with a water softener and a whole house filtration system).

2. Determine Your Water Usage

Once you have a list of contaminants that you want to remove, work out how much water you use on a weekly basis. The easiest way to do this is to view your monthly water bill and work out an average based on several bills.

It’s important to choose the right system capacity for your drinking water (and washing water, cooking water, etc.) needs, so make sure you select a treatment system that delivers the right amount of water to your home.

3. Consider Your Water Pressure And Flow Rate

Finally, a water system shouldn’t have a noticeable effect on water’s flow rate in your home. You should still receive near-instant water to your faucets and appliances, even with a water filter intercepting your waterline.

Make sure the filter won’t slow down your water flow too much. Customer reviews can be helpful in letting you know how a system affects flow rate.

4. Compile What You Know To Decide On Suitable Water Treatment

Finally, compile what you know about your water quality, water usage, required water pressure and flow rate, and use this data to find a drinking water system that meets all of your requirements.

📑 Final Word

Your well water might be safe to drink – but it might contain certain contaminants that compromise water safety, like heavy metals, chemicals, and microorganisms.

Luckily, there are plenty of water filters and other private purification systems that can be used to make well water safe to drink. You don’t have to gamble with your health just for the convenience of using a private well!

💡 Frequently Asked Questions

How long does it take to receive well water test results?

If you test your well with a private testing company, it can take up to 7 days to receive your test results. Most companies will email your results directly to your inbox, but some will post your results if that suits you better.

How can I prevent my private well from being polluted or contaminated?

There are several things you can do on your own property to reduce the risk of ground-water contamination and protect your drinking water quality:

  • Make sure septic systems are installed at least 50 feet away from the well
  • Keep pesticide and herbicide storage, or petroleum storage, at least 100 feet away from the well
  • Keep manure stacks at least 250 feet away from the well
  • Regularly check underground storage tanks that hold gasoline, diesel, or oil for leaks
  • Get your well inspected regularly, and fix any damaged components when you notice them
Required distance of well water from septic tank
Source: Mississippi State University Extension

What is the best treatment for ground water?

The best treatment for ground water depends on your water quality and parameters. Generally, well owners find that a combination of a drinking water filter system and a disinfection system is best. Some well owners may also need to soften their drinking water with a water softening system.

  • Brian Campbell
    Founder, Water Treatment Specialist

    Brian Campbell is a water treatment specialist and water expert based in Denver, Colorado. He's always been obsessed with water quality, and has spent years testing all kinds of treatment devices from simple pitchers and portable devices to complex whole home systems.

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