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Home » Water Education & Testing » How to Remove Arsenic in Well Water

How to Remove Arsenic in Well Water

By: David Trinh
Last Updated:
how to remove arsenic in well water

You don’t need us to tell you that arsenic isn’t for human consumption, but did you know that approximately 2.1 million people in the United States drink water from wells contaminated with high arsenic levels?

Needless to say, that’s a scary statistic for well water users. Depending on where you live, there’s a high probability that your water contains arsenic. States such as Maine, New Hampshire, and Arizona are notorious for high arsenic levels because of their bedrock structure.

Although arsenic naturally occurs on land, water, and in the air, the good news is that you can remove and prevent it from getting into your well water.

In this guide, we’ll give you more details about the impact of arsenic on health and teach you how to remove arsenic in well water.

Arsenic Overview


Arsenic is a chemical that stands on its own in nature, but it can also mix with other metals and sulfur. Without realizing it, you probably come in frequent contact with arsenic, even if it isn’t through your well water. For example, tobacco, pesticides, and wood preservatives can all contain this toxin.

Comparing Arsenic 3 and Arsenic 5

We’ll try not to get too technical here, but there are seven different kinds of arsenic. When it comes to well water, Arsenic 3 (arsenite) and Arsenic 5 (arsenate) are the ones that are the most pertinent to you. If you have to have arsenic in your water, it’s best to have the Arsenic 5 variety because it’s easier to remove. If you end up having Arsenic 3, you’ll first need to oxidize it to Arsenic 5 before getting rid of it.

The Arsenic Health Debacle

A little bit of arsenic once in a while isn’t likely to do you harm. In fact, foods like rice often contain traces of it. Nevertheless, if you consume arsenic over the long term, it can cause issues such as:

  • Cancer of the bladder, lung, and kidneys
  • Cardiovascular disease
  • Diabetes
  • Congenital disabilities
  • Early death

However, before these major side effects kick in, you might notice more minor side effects. Symptoms of too much arsenic consumption include:

  • Nausea
  • Vomiting
  • Diarrhea
  • Stomach pain

Understanding How Arsenic Arrived in Your Water

Tap water

The quality of well water depends on the underground environment around it. So, if you live in states with naturally occurring high arsenic concentrations in the bedrock, such as New Hampshire and Arizona, you’re automatically going to need to take extra precautions from letting this metal pass through your faucet.

However, the arsenic doesn’t have to come from the immediate area around your well. Instead, rain and melted snow can carry arsenic for miles, landing it in your drinking water. Other common sources of arsenic contamination are industrial pollution and farmers using pesticides on their crops.

That said, researchers believe that arsenic in small amounts likely won’t ever do you harm. For this reason, according to the Environmental Protection Agency (EPA), it’s okay for water to have up to 10 parts per billion (ppb) of arsenic per liter. That means that even municipal water consumers might have some arsenic in their water.

Since wells typically belong to private properties, owners don’t have to abide by the EPA’s 10 ppb rule. Nevertheless, you’re here because you’re understandably concerned about arsenic in your well water. So, let’s talk about how you can test for it.

Testing for Arsenic in Your Well Water


Unlike other unwanted substances that can enter your well water, arsenic is odorless and tasteless. Therefore, you must test your water to find out if this chemical is present. Testing well water for arsenic every three to five years is ideal, assuming that your initial test produced a result of under 10 ppb.

However, if your arsenic test comes back borderline to high, you should survey your well water more frequently.

Ideally, you should hire a private company specializing in arsenic testing or a state-certified health service organization. When you receive the results, it’ll indicate whether arsenic is present in your drinking water. If it’s there, it’ll tell you the concentration.

That said, you can opt to use a home water testing kit to check arsenic levels. The kits come with testing strips. You’ll need to hold the strip underwater for a few seconds, then determine the concentration, if any, of arsenic-based on a color code.

Nevertheless, it’s important to note that arsenic home testing kits aren’t always reliable. Therefore, if you live in a high-risk area or your kit indicates that you have a borderline high arsenic concentration in your water, it’s best to have a professional perform the test as well.

Are you ready to drink clean water? Whether you find out that you have a high concentration of arsenic in your water or you simply don’t like the thought of drinking trace amounts of it, we’ll show you how to remove arsenic in well water.

How Do You Remove Arsenic from Well Water?

Arsenic is a metal, so many filtration systems don’t have the right design to keep it out of your tap water. Therefore, if you plan to use a filter for your water, make sure to investigate what it does—and doesn’t—siphon out.

You’ll need to do research on the best water filtration systems for well water.

Below are some of the best techniques you can use to remove arsenic in your well water.

Ion Exchange


Using ion exchange is a popular way to prevent arsenic from entering your well water. These systems work by using the support of another substance, such as sodium, to swap out arsenic particles before they contaminate the water you drink.

Ion exchanges can detect when the resin bed is full of arsenic. Once this occurs, regeneration happens. In layman’s terms, it flushes out the resin bed, removing all of the arsenic it gathered.

Unlike one of the filtration systems we’ll cover here, ion exchanges have a high tolerance for varying pH levels; if your water has a pH between 6.5 to 9.0, you can use this system. While ion exchanges are beneficial for people looking to soften their water and remove nitrate, the system targets arsenic by pushing water through pressure-packed columns that have a strong-base anion.

Installing an ion exchange system is an investment; you can expect to spend anywhere from $300 to $1,200. The price fluctuation will depend on how complex the system is. As a general rule, the more prone your well water is to arsenic contamination, the more complex the system you should purchase.

If you’re leaning towards buying an ion exchange system, you may want to have a professional check the amount of total dissolved solids (TDS) in your water. If the number is higher than 500 milligrams per liter, the system won’t be as effective. Similarly, a TDS of more than 50 milligrams per liter of sulfate will also have a negative impact on how your ion exchange functions.

As is the case with any arsenic filter, you’ll need to keep the system maintained; your system will need salt about four times per year. You’ll also need to replace the resin after six to eight years.

Reverse Osmosis

If the term “reverse osmosis” gives you flashbacks to high school chemistry, you’re not alone. Since many years may have passed from your last chemistry class, here’s a refresher: reverse osmosis is the process of filtering out unwanted molecules via the use of a partially permeable membrane to separate them.

In other words, a reverse osmosis system will gather the harmful arsenic in your well water, making sure it doesn’t land in your cup. Many filters go into making this system effective. In fact, you can even install some whole home reverse osmosis systems at your water’s entry point. That means that a single system can generate clean water for your entire home.

Many well water owners gravitate towards reverse osmosis systems because they’re so effective at eliminating arsenic. In fact, research shows that this filter can remove as much as 98% of arsenic particles. The catch, however, is that this number is for the Arsenic 5 variety. If you have Arsenic 3 in your water, it may only remove 50 – 80% of it. For this reason, it’s critical to know the type of arsenic in your water before you pick a treatment method.

As an additional advantage, reverse osmosis systems can remove other metals, bacteria, and sediment in your water.

Luckily, purchasing a point of use reverse osmosis system won’t break most banks—for a mere $150 – $400, you could significantly improve the quality of your family’s life. The machine itself lasts for over ten years. However, you’ll need to change the filters regularly to ensure it maintains optimal performance.


CO-Z distiller

Here’s some good news—the Arsenic 3 and Arsenic 5 varieties found in well water aren’t typically damaging to the external layer of your skin. Therefore, you can opt to purchase a filtration system that will offer you arsenic-free drinking water without having to install filters throughout your entire home. In this case, using a water distiller is a great choice.

The great part about distillers is their quick setup—within a few minutes, you’ll have access to clean drinking water from your faucet. Another advantage is their portability. The only thing you’ll need is a nearby power source.

Distillation works remarkably well for removing arsenic from well water because arsenic can’t evaporate. Therefore, when you plug in a distiller, water enters a boiling chamber. Here, clean water evaporates and dispenses into a carafe. Arsenic and other substances that don’t turn into liquid remain in the boiler’s dispenser.

One of the most significant benefits of the distillation method is that it offers among the cleanest water of all the options we’ve covered. However, the downside is that it often takes a few hours to distill. Therefore, you’ll need to plan in advance to ensure you’ll have water when you need it.

Affordability is another feature that attracts people to distillers. For as little as $100 – $150, you can purchase this portable device. It’s a great option for campers and people who frequent places that use well water without knowing how well-maintained they keep the well.

Finally, using the distillation technique might be the right fit for you if you want a low-maintenance system. Certain varieties of distillers include a carbon filter. However, distillers work well without the filters, so many people choose not to invest time and money into using them.

Activated Alumina

If you have a high level of arsenic in your water, especially if it’s the Arsenic 3 variety, it’s critical that you use a system that’s durable enough to handle it. Activated alumina systems harness the power of alumina to whisk away several contaminants, including arsenic.

However, activated alumina involves a more complicated process than that—you’ll need to feed the system chlorine bleach or hydrogen peroxide. It’ll then use the chemicals in these compounds to create oxidation, allowing the absorption of arsenic.

That said, before you run out to buy an activated alumina system, you’ll need to check the pH of your water. It should hover right around 7, which is the pH of water in its purest state. If the pH is far from this golden seven number, you’ll first need to treat the pH imbalance in your water. Otherwise, your alumina system won’t work well.

Many activated alumina systems produce as much as 10 gallons of water per minute. They’re also excellent tools for removing iron in your water, which can be another harmful metal, especially for young children.

Activated alumina systems are the least expensive of all the arsenic filtering methods we covered here. You can purchase a system for well under $100—usually in the $40 – $70 range. That said, like most of the other methods, you’ll also need to factor in the lifelong costs of replacing its filter.

If you’re concerned about other harmful chemicals or materials in your water, we recommend using activated alumina in conjunction with a larger household filtration system. That way, you’ll maximize the number of contaminates you remove from your well water.

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David Trinh
David is an expert in all things plumbing, heating, cooling, and water treatment. He got his start in the plumbing business working on fixing all types of home improvement issues including water leaks, broken toilets, appliance installation, and more. Over time, he learned a ton about installing and choosing the correct water treatment products for homeowners.

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