Arsenic occurs naturally in soil and rock formations and can dissolve into groundwater over time. It is colorless and odorless, which makes testing the only reliable way to confirm whether it is present in your home’s water supply. Although levels vary by region, arsenic has been detected in drinking water throughout the United States and parts of Canada.
For many families, understanding what may be in their water is an important part of maintaining a safe home environment. Knowing how arsenic reaches water sources and how testing works can help you make informed decisions about the next steps for your home.
In the United States and Canada, arsenic in municipal drinking water is regulated, and public water systems are required to test and maintain levels below established safety standards. However, private well water is not federally regulated. If your home relies on a well, regular testing is the only way to know whether arsenic or other contaminants are present.
Key takeaways:
- Arsenic typically enters drinking water through natural deposits, although agricultural activity or industrial processes can play a role.
- It cannot be detected by taste, smell or appearance.
- Only certified laboratory testing can confirm the presence and concentration of arsenic.
- Private well water is not federally regulated and is most likely to be at risk.
- Professional testing helps determine whether treatment is recommended.
Schedule your free water test.
What is arsenic poisoning?
Arsenic poisoning, also known as “arsenicosis,” occurs when you ingest or inhale more arsenic than can be eliminated through urine or sweat. This excess arsenic is treated the same way as phosphate — a critical element in nerve function, muscle contraction and more — inside your body.
Although arsenic exposure can occur when living near industrial sites, breathing in areas that have been treated with pesticides or eating contaminated food, drinking water is among the most common sources of arsenic.
Types of arsenic
There are two basic types of arsenic: organic and inorganic compounds.
- Organic compounds refers to arsenic combined with elements other than carbon; these aren’t currently linked to cancer and are generally nontoxic. They are most often found in seafood.
- Inorganic compounds refers to arsenic combined with elements other than carbon; these are recognized as cancer-causing elements and are often highly toxic. They can be found in tobacco products, industrial chemicals, meat and drinking water.
Now that you know why arsenic has earned its reputation, let’s find out how you can identify its presence in your own water supply.
What causes arsenic in water?
Because arsenic exists naturally in the environment, it can enter water supplies in a variety of ways. These include:
- Agricultural or industrial runoff
- Atmospheric deposits
- Erosion of natural arsenic deposits in the earth
In some areas, groundwater naturally contains arsenic. This is especially common in the western United States, but is less common in Canada.
What are the signs of arsenic in water?
One of the reasons arsenic can become dangerous is that it’s colorless, tasteless and odorless. Because of this invisibility, you may not have any specific reason to suspect the presence of arsenic in your drinking water. To further complicate matters, arsenic doesn’t cause mineral buildup, stains or other noticeable impacts to your fixtures and water-using appliances, meaning it’s more difficult to catch than hard water or other issues.
What are the side effects of arsenic in water?
The side effects of drinking arsenic-contaminated water over a short period can include nausea, vomiting and other gastrointestinal discomforts. You might also notice skin discoloration depending on the amount of arsenic ingested.
Over a longer period of time, side effects can become more severe. Eventually, long-term arsenic exposure could cause cancers of the lungs, skin, kidneys, prostate and more.
Testing your water for arsenic
Arsenic is virtually impossible to detect on your own. Here’s what you need to know about arsenic water testing — the only reliable way to know for sure whether this substance is in your drinking water:
H3: What are arsenic water tests?
The U.S. Environmental Protection Agency (EPA) and the Guidelines for Canadian Water Quality set standards for water safety, including rules about the amount of arsenic allowed in public water supplies. Arsenic tests conducted at water facilities help utility companies monitor water quality and adhere to these standards.
However, these tests can’t determine if arsenic enters the water supply after leaving the main facility, nor can they help protect private wells. For this reason, it’s smart for both city and well water users to know how arsenic water tests work.
H3: How to test your water for arsenic
Substances like arsenic or lead typically require your water sample to be sent to a laboratory (like Culligan’s IL EPA-certified lab) for further testing. For this reason, DIY water test kits are not typically recommended for arsenic identification.
Schedule your free water test.
Of course, you don’t have to stop at arsenic testing. Many expert water tests can also tell you whether your water may be:
- Safe to drink
- Safe to bathe and clean with
- Harming your pipes
- Shortening the lifespan of your water-using appliances
- Responsible for stains on faucets, bathtubs and shower doors
- Causing skin irritation or hair dryness
H3: What is the safe limit for arsenic in drinking water?
The generally accepted limit for arsenic in drinking water is 10 parts per billion (ppb), or 0.010 milligrams per liter, according to EPA and Health Canada guidelines. Past this amount, water utility companies are required to take action to identify and fix the problem.
Arsenic water solutions
Although it might seem intimidating to hear that you could have arsenic in your drinking water, there’s no need to panic. Instead, brush up on these important facts about arsenic water solutions:
H3: Myths about removing arsenic from water
If you watch survivalist TV shows, you may think boiling water is the best way to remove any impurities or contaminants. While that might work for certain bacteria and viruses, it actually slightly increases the potency of arsenic in water via evaporation.
Similarly, chlorine disinfection cannot reduce or eliminate the presence of arsenic in your water supply; in fact, it can cause a handful of its own problems.
Arsenic water filters
The best, most reliable and most effective way to deal with arsenic in your water is to find a water filtration system for your home. These systems come in many different configurations, so it’s best to break them down like this:
- Point-of-use: An under sink reverse osmosis system is called a point-of-use system. That’s because these filters address arsenic and other potential contaminants at the specific tap where they are installed.* For this reason, they aren’t typically a standalone choice for arsenic, as it doesn’t address other taps, showers or your washing machine.
- Point-of-entry: A point-of-entry filtration system is installed where water lines enter your house. Also called whole-home systems, these filters can reduce the amount of arsenic in water throughout your home. Look for a system specifically designed to address arsenic.
Arsenic water testing FAQs
What type of test confirms arsenic levels?
Only certified laboratory testing can measure arsenic accurately. The best approach is to work with a professional water expert, who can collect a sample and submit it to a certified lab for analysis.
Does all tap water have arsenic?
Arsenic is not present in all tap water. In both the United States and Canada, municipal water systems are regulated and required to maintain arsenic levels below established safety standards.
Arsenic is more commonly detected in groundwater, which supplies many private wells. Because groundwater conditions vary by region, arsenic levels can differ significantly from one location to another.
Who should test their water for arsenic?
Testing is especially recommended for households that rely on private wells, homes located in areas with known natural arsenic deposits or properties that have not had their water tested in several years. If you’re unsure about your area’s risk level, a professional water test can provide clarity.
What is the safe limit for arsenic in drinking water?
The EPA and Health Canada have set a maximum contaminant level of 10 parts per billion for arsenic in public drinking water. Laboratory results are compared against this guideline to help determine whether further evaluation or treatment may be recommended.
Can boiling water remove arsenic?
No. Boiling does not remove arsenic. Because arsenic is a dissolved mineral, boiling can actually increase its concentration as water evaporates.
Is there an arsenic water filter pitcher?
Some water filter pitchers are designed to reduce certain contaminants, but not all models are certified to reduce arsenic. Because filter performance varies, it’s important to check for NSF/ANSI certification for arsenic reduction.
For households seeking more comprehensive treatment, under-sink reverse osmosis systems or whole-home solutions are often more reliable options.
Is it safe to shower in water with arsenic?
Arsenic is not easily absorbed through the skin, and it does not readily vaporize into the air. For this reason, exposure from showering or bathing is generally considered low.
The primary health concern associated with arsenic is long-term ingestion through drinking or cooking water.
What should I do if my water contains arsenic above recommended limits?
If your water test shows arsenic above recommended limits, a water specialist can review your results and recommend appropriate treatment options.
Reverse osmosis systems are commonly used to reduce arsenic at the point of use, while whole-home filtration solutions may be appropriate depending on your water conditions and household needs.
Test your water for arsenic
Because arsenic cannot be seen, smelled or tasted, testing is the only way to know whether it is present in your water.
A professional water test can determine whether arsenic is present and, if so, at what level. If results exceed recommended limits, there are effective treatment options available to help reduce arsenic in your drinking water.
Schedule a free in-home water consultation as a first step to better understand your water and explore solutions tailored to your home.
*Contaminants may not be present in your water.
