Arsenic in Well Water: 10 Things (2024) You Have to Know

Well water is highly susceptible to becoming tainted, and one of the most problematic assailants is arsenic.

Arsenic is naturally occurring, can’t be seen, smelled, or tasted, and causes life-threatening health issues.

Doesn’t sound good, right?

If your primary source of water comes from a well, then knowing how to detect arsenic and treat tainted water is a matter of life or death.

So, let’s get right down to business and cover everything you need to know about arsenic in well water, its potential side effects, and what you can do to keep yourself safe.

1. What is Arsenic?

Arsenic is a natural chemical that is categorized as a metalloid and represented by the symbol As and the atomic number 33.

Metalloids contain both metal and nonmetal properties, making them semi-metals.

There are two types of arsenic: inorganic and organic.

bulletInorganic arsenic refers to As III and As V, both of which are commonly found in water and dangerous for human consumption

bulletOrganic arsenic is considered less of a threat

The chemicals are highly toxic and have been used in warfare to create poison, chemical weapons, and toxic smoke screens.

An arsenic-based pesticide was even created to get rid of rodents causing damage to military operations.

As you can imagine, something that is used as a chemical weapon isn’t exactly a healthy substance to consume in daily life.

To avoid putting US citizens at risk, the Environmental Protection Agency (EPA) has created a maximum level of arsenic in drinking water; however, there is still controversy as to whether or not the levels should be adjusted (see next section for more information).

Part of what makes arsenic so dangerous is that it is difficult to detect.

Seemingly clean well water could actually be saturated with the toxic substance and could cause serious health issues.

So, let’s take a closer look at what is considered to be acceptable levels of arsenic in well water by the EPA and why there is controversy around the regulations.

2. What Are Acceptable Levels of Arsenic in Drinking Water

The EPA has decided that 10 micrograms per liter of water are considered safe–a ruling that was established in 2001.

But here’s the problem, 10 micrograms of arsenic per liter is still dangerous.

When water is consumed at or below the EPA’s designated levels, it will still increase your rate of cancer; however, the rates will be lower than if you consumed water with more than 10 micrograms per liter.

Regardless, that still doesn’t seem very safe, does it?

Ideally, no matter where your drinking water comes from, whether it be a well or faucet, the lower the arsenic levels, the better.

Since arsenic is naturally occurring and often found close to sources of water, it can be difficult, if not impossible, to completely prevent the chemical from entering the water source.

But natural occurrence isn’t the only reason arsenic gets into well water.

3. How Does Arsenic Enter Well Water?

Arsenic in private well water can be caused by a number of occurrences.

Some of the reasons behind the contamination are due to natural geology, while others are due to human activity.

Here are the main causes of arsenic in well water:

bulletGeological Sources

Arsenic is found in various rocks and geological formations, specifically if they are sedimentary or igneous rocks.

If these sources of arsenic are near groundwater or other bodies of water, it could make its way into a well.

Examples of specific types of rocks that commonly have arsenic are limestone, sandstone, and shale.


Mining is messy.

Operations create a massive amount of rock waste and tailings (residue of materials).

If the waste material contains arsenic, such as gold, zinc, and iron, it can easily contaminate nearby bodies of water via rainfall runoff.

bulletAgricultural Practices

Many fertilizers and imported pesticides used for commercial agriculture have high levels of arsenic.

As more and more arsenic is introduced to the land, it can eventually contaminate groundwater or be introduced to other sources of water due to rainfall runoff.

bulletAnimal Feed

Additives in animal feed sometime contain arsenic.

The chemical is known to enhance growth and prevent diseases caused by parasites.

When the feed passes through the animals, it creates waste with high levels of arsenic.

As a result, manure spreading and waste runoff due to rainfall cause the harmful chemical to enter water sources.

4. How Do You Test for Arsenic in Well Water?

So, there are plenty of causes behind arsenic in well water, but what tests can you do to ensure your water source is safe.

Unfortunately, testing for arsenic isn’t something you can do yourself, unlike testing water’s pH levels.

Instead, you will have to collect samples and send them off to a lab for testing.

That means it could take a few weeks until you know how safe your well water is.

Although collecting samples and shipping them off isn’t as convenient as DIY tests, it’s well worth the time and energy.

Once you have the results, you can compare them with EPA’s levels of arsenic in water that are considered to be safe (the lab should also determine whether levels are safe for consumption or not).

If you live in a high-risk area or are attempting to lower arsenic levels in your well water, you should perform tests at least once a year.

Once signs show that your well water is stable, you could reduce the frequency to once every few years.

Let’s check out potential short-term and long-term symptoms caused by arsenic poisoning.

5. What Are the Short-Term Symptoms of Arsenic Poisoning?

Arsenic poisoning is not a pleasant experience.

If you or someone in your household experiences any of the following symptoms, it’s a direct sign that your well water may contain arsenic, signaling you to act.

In extreme cases, short-term side effects can be fatal, so do not wait to seek medical treatment.

Here are the short-term symptoms of arsenic poisoning:

bulletAbdominal pain




bulletNumbness and tingling of the extremities

bulletMuscle cramps

When these symptoms manifest, and your primary source of water comes from a well, find a new source of drinking water until you can have your well tested.

Arsenic can stay in your system for several days (some forms of arsenic can last for several months), so talk to your doctor about the best options to detoxify your body.

6. What Are the Long-Term Symptoms of Arsenic Poisoning?

The long-term symptoms of arsenic poisoning are as severe as it gets.

If you experience any of the following symptoms, you need to seek medical attention immediately.

Arsenic poisoning from well water can be deadly, and the longer you wait to receive treatment and remove the chemical from your drinking water, the more likely you are to develop life-threatening illnesses.

Here are the long-term symptoms of arsenic poisoning:

bulletSkin lesions

bulletPsychological disorders

bulletCognitive impairment

bulletGastrointestinal problems

bulletCancer (specifically liver, kidney, bladder, and skin)

Not a pretty list of symptoms, is it?

The sooner you can eliminate arsenic in well water, the less of a chance you’ll have of developing these illnesses.

Just because these side effects can take years and years to develop doesn’t give you leeway to put off addressing the issue.

7. How Do You Remove Arsenic in Well Water?

Removing arsenic in well water takes a bit of work and money, but it is possible.

The method of removal you choose to use will depend on the type of arsenic your water is contaminated with, the levels of the arsenic, and feasibility.

So, let’s look at what you can do.

Here are the primary ways to remove arsenic in well water:

bulletEliminate the source

If mining operations or agricultural practices are the cause of your well water having arsenic, then you need to go directly to the source.

Meeting with regulatory authorities, documenting evidence, and pursuing legal action will help ensure your drinking water is safe for consumption and that other people around the area avoid serious health issues.

bulletReverse Osmosis

Reverse osmosis is highly effective at removing arsenic in well water.

The process refers to moving water through a semi-permeable membrane, separating the liquid into two streams (one carrying the purified water and the other carrying the impurified water).

Arsenic is rejected by the semi-permeable membrane, so when the purified water is collected, it will be safe to drink.


Distillation refers to the process of heating water and collecting the steam.

Arsenic will not evaporate during the process, so all the liquid resulting from the steam will be free of the chemical.

The downside to distillers is that they cannot be hooked up to the well.

So, water would first have to be removed from the well and then added to the distiller.

bulletAnion Exchange

Anion exchange uses an exchange resin to remove arsenic from the water.

As the water is pressurized and sent through the resin beads, the beads exchange the toxic arsenic with non-toxic ions.

The problem with anion exchange is that the process can be very expensive and impractical for many people.

bulletDrill a New Hole

Depending on the severity of the arsenic levels and the sources causing it, drilling a new hole may be the most efficient and cost-effective solution.

When you’re picking a site for the new hole, work with a professional to avoid future arsenic complications.

8. How Can You Prevent Arsenic from Ever Entering Well Water?

If your well is free of arsenic, great!

But that doesn’t mean that it won’t one day become contaminated.

The good news is that there are a handful of steps you can take to ensure your well stays pure and safe.

Here are steps to prevent arsenic from ever entering your well water:

bulletChoose the right site: Where you decide to dig a well is crucial.

Check the local area for sites that may have high levels of arsenic.

For example, if you know a large-scale agriculture operation or a certain type of geological formation is located nearby, then you’ll be at high risk of contamination.

Always seek help from a professional when deciding where to build a well.

bulletDefend against rainwater runoff: Rainwater runoff is one of the primary ways well water gets contaminated.

The best defense against it is to properly landscape around the well.

A few tactics would be to install rain gardens, plant more vegetation, and reduce the amount of impervious surfaces nearby.

bulletAvoid using products with arsenic: You should never use products that contain arsenic around your well.

Be very mindful about which types of herbicides, pesticides, and fertilizers you’re using on your land.

bulletWork with the community: Teaming up with local community members is an excellent way to avoid arsenic contamination in the future.

Work with a team to educate the public, encourage frequent testing, and monitor nearby operations that could cause arsenic risks.

9. Can Boiling or Filtering Water Remove Arsenic?

Boiling water and using standard household filters, such as a Brita, do not remove arsenic from water.

The only way boiling water would work is if you used a distiller to collect and convert the steam into a purified liquid.

Likewise, the filtration process would have to use highly advanced systems, such as reverse osmosis or anion exchange, in order to work.

Standard household filters are better at removing sediment, particles, odors, tastes, and some organic compounds.

They may be able to reduce some heavy metals, but they won’t be able to handle arsenic.

So, even if you boil your contaminated well water for hours or run it through multiple filters, it is still not safe to drink and should be avoided at all costs.

10. Is It Safe to Shower with Well Water High in Arsenic?

Showering with well water that has arsenic is generally considered to be safe as long as the levels are not more than 500 parts per billion (ppb).

Arsenic is not easily absorbed by the skin, so the EPA’s recommended levels of 10 micrograms per liter of water do not apply.

Additionally, well water with arsenic is safe to use for brushing teeth, washing dishes and clothes, watering plants, and other household activities.

Skin cancer is one of the potential side effects of arsenic exposure; however, cancers caused by the chemical are due to long-term ingestion or inhalation.

Final Thoughts

Arsenic in well water is not something to ignore.

Because it’s impossible to see, taste, or smell, anyone that gets drinking water from a well should consistently have the water tested.

Failing to address the issue will put you and anyone else who relies on the well at serious risk of developing potentially fatal health issues.

So, put test well water for arsenic at the top of your to-do list, and ensure that you are consuming safe, clean water!

If you have any suspicions that you have been exposed to arsenic and are experiencing symptoms, find a new water source and seek medical attention immediately.

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Erika Gokce Capital

Disclaimer: we are not lawyers, accountants or financial advisors and the information in this article is for informational purposes only. This article is based on our own research and experience and we do our best to keep it accurate and up-to-date, but it may contain errors. Please be sure to consult a legal or financial professional before making any investment decisions.


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