Most of us judge our drinking water with our senses. If it looks clear, smells fresh, and tastes normal, it's easy to assume everything is fine.
Unfortunately, arsenic doesn't work that way.
Unlike chlorine, iron, or sulfur, arsenic gives no warning signs. It doesn't change the appearance of your water, leave an unusual taste, or produce an odor. The only way to know whether it's present is through laboratory testing.
It is important to understand that not all residences will have arsenic issues. Many public water systems actually meet federal drinking water standards at all times. However, arsenic is naturally occurring in the environment. It can be found in groundwater across much of the United States, so it's worth understanding, particularly for homeowners using private wells.
Whether you're reviewing your annual water quality report or testing a well for the first time, knowing the basics can help you make informed decisions about your household drinking water.
Looking for a countertop gravity-fed filtration system? The Big Berkey® Water Filter is our most popular stainless steel system for everyday household use.
Why Arsenic Is Different From Many Other Drinking Water Contaminants
Some water quality issues announce themselves immediately.
Hard water may leave mineral spots on dishes. Iron can stain sinks and laundry. Chlorine often has a recognizable smell or taste.
Arsenic is different.
Even when it's present, your water can look just as clean as ever. That's one reason it often goes unnoticed until a water test identifies it.
Another difference is its origin. While some contaminants are linked to aging infrastructure or industrial pollution, arsenic is frequently a product of local geology. In many areas, it's simply part of the rock formations beneath the ground.
Understanding that distinction helps explain why one neighborhood may have very different arsenic levels from another, even if the homes are only a few miles apart.
Where Does Arsenic in Drinking Water Come From?
Most arsenic found in drinking water originates underground.
As groundwater slowly moves through layers of rock and sediment, it can dissolve naturally occurring minerals, including arsenic. Over many years, trace amounts may accumulate in wells or groundwater supplies used for drinking water.
In some areas, too, human activities have affected arsenic concentrations. In certain areas, higher concentrations have been caused by historical mining, industrial activity, and past agricultural use. Despite this, in many areas of the country, the most prevalent cause remains naturally occurring geological conditions.
Because geology varies from one region to another, arsenic levels can differ significantly between communities. Two homes drawing water from different underground aquifers may have very different test results, even if they're located in the same county.
Is Arsenic Found Everywhere?
Technically, yes, but not at the same concentrations.
Small amounts of arsenic occur naturally throughout the Earth's crust. Whether it becomes a concern depends on local geology and the source of a community's drinking water.
Some regions of the United States are known for having naturally higher groundwater concentrations than others. These include parts of:
- California
- Arizona
- Nevada
- New Mexico
- Colorado
- Utah
- Texas
- Portions of the Midwest
- Several New England states
Living in one of these areas doesn't necessarily mean your water contains elevated arsenic. Public water systems routinely test and control water quality in compliance with Federal standards. But people with private wells in these areas may need to test their wells periodically because public water systems do not regularly test private wells.
Public Water and Private Wells: An Important Difference
Where your drinking water comes from plays a major role in how it's monitored.
If your home is connected to a municipal water system, your water provider performs routine testing for regulated contaminants, including arsenic. The results are typically summarized in an annual Consumer Confidence Report (CCR), which gives customers an overview of their local water quality.
Private wells operate differently.
Because they aren't regulated the same way as public water systems, routine testing is generally the homeowner's responsibility. If you've recently purchased a home with a well or if your water has never been tested for arsenic, arranging a laboratory analysis is a practical first step toward understanding your water quality.
Why Testing Matters
Since arsenic can't be detected by sight, smell, or taste, testing provides the clearest picture of what's in your water.
Homeowners often choose to test when:
- Purchasing a home with a private well
- Living in an area known for naturally occurring arsenic
- Learning that nearby wells have reported elevated levels
- Reviewing their household water quality for the first time
- Following recommendations from local or state environmental agencies
A certified laboratory can measure arsenic concentrations and provide results that help you determine whether any additional action is appropriate.
Understanding the EPA Standard for Arsenic
When people hear that arsenic can occur naturally in drinking water, the next question is usually, "How much is considered acceptable?"
The U.S. Environmental Protection Agency (EPA) has established a Maximum Contaminant Level (MCL) of 10 parts per billion (10 µg/L) for public drinking water systems. This federal standard is intended to limit long-term exposure and is one of many regulations that public water suppliers must meet.
If your home receives municipal water, your utility is required to monitor arsenic levels regularly and take corrective action if testing shows concentrations above the federal limit.
Private wells are different. Because they're not subject to the same federal requirements, it's up to the property owner to decide when and how often to have the water tested.
Why Long-Term Exposure Gets the Most Attention
For most people, arsenic doesn't cause immediate symptoms after drinking a single glass of water.
Instead, researchers focus on long-term exposure. Drinking water with elevated arsenic levels over many years has been associated with an increased risk of certain health conditions.
According to the EPA, scientific studies have linked prolonged exposure to possible effects involving:
- Changes to the skin
- Cardiovascular health
- Diabetes
- The nervous system
- Certain types of cancer
These associations depend on several factors, including the concentration of arsenic, the duration of exposure, and individual health characteristics. For information about your own health, it's always best to consult a qualified healthcare professional.
Can You Remove Arsenic by Boiling Water?
It's a common assumption and an understandable one.
After all, boiling is often recommended to address certain water quality concerns.
Arsenic, however, behaves differently.
Because it's an element dissolved in the water, boiling doesn't remove it. As water evaporates during boiling, the concentration of dissolved arsenic may even increase slightly.
If testing indicates elevated arsenic levels, a filtration system specifically designed to reduce arsenic is generally the more appropriate approach.
Practical Steps Homeowners Can Take
It's okay to be overwhelmed by the news that arsenic can be found in drinking water. In many cases, some simple measures will help you to learn more about the quality of your household water.
Start by identifying where your water comes from. If you're connected to a public water system, review your annual Consumer Confidence Report to see what your utility reports for regulated contaminants.
If your home uses a private well, arrange for testing through a certified laboratory, especially if you've never had the water analyzed or you live in an area known for naturally occurring arsenic.
If testing identifies elevated arsenic levels, you may also want to explore point-of-use water filtration systems that have been evaluated for arsenic reduction. As with any filtration product, following the manufacturer's maintenance schedule is an important part of ongoing performance.
Choosing the Right Berkey® System
Many homeowners prefer countertop filtration because it doesn't require permanent plumbing modifications and can be used in a variety of kitchen layouts.
Berkey® gravity-fed water filtration systems are designed to provide a convenient countertop solution for everyday household use. When equipped with Black Berkey® Replacement Filters, these systems are designed to help address a broad range of common drinking water contaminants, including arsenic, while also helping improve the taste and odor of drinking water. Performance has been evaluated through third-party laboratory testing for numerous common drinking water contaminants.
Of the available options, the Big Berkey® is popular among households because it offers an ideal balance of capacity and countertop space. Larger water systems are typically better suited for families that use water regularly, whereas those with smaller households may be more satisfied with compact systems.
| System | Capacity | Recommended For | Product |
|---|---|---|---|
| Travel Berkey® | 1.5 Gallons | Singles & Couples | View Product |
| Big Berkey® | 2.25 Gallons | Most Families | View Product |
| Royal Berkey® | 3.25 Gallons | Larger Families | View Product |
| Imperial Berkey® | 4.5 Gallons | High Daily Water Use | View Product |
| Crown Berkey® | 6 Gallons | Large Homes & Offices | View Product |
Frequently Asked Questions
Can I tell if my water contains arsenic?
No. Arsenic has no noticeable taste, odor, or color. The only way to tell if it's present is to have it tested in the lab.
Does every private well contain arsenic?
No. The amount of arsenic depends significantly on the area's geology. The levels of naturally occurring contaminants in some wells are very low, while in others they may be elevated.
Is municipal water tested for arsenic?
Yes. The federal drinking water regulations require public water suppliers to regularly test for arsenic and publish the results in Consumer Confidence Reports.
How often should private wells be tested?
Frequency of testing is based on local conditions and recommendations from state or local agencies. Laboratory testing of your well is recommended if it has not been tested before for the presence of arsenic, or if arsenic has previously been found in nearby wells.
Does boiling water help?
No. Boiling doesn't remove arsenic from drinking water.
Which Berkey® system is best for most households?
The Big Berkey® is a great solution for many households, combining the daily capacity, countertop size, and convenience they desire. Larger models are available for households with higher daily water needs.
Where can I buy replacement filters?
You can shop genuine replacement elements on our Berkey® Replacement Filters page.
Final Thoughts
Arsenic is unusual among drinking water contaminants because it doesn't announce its presence. The water may appear clear, taste normal, and have no noticeable odor, yet laboratory testing may reveal naturally occurring arsenic.
Fortunately, understanding your water doesn't have to be complicated. It is important to be familiar with the water quality information available in your area, consider testing a private well if necessary, and select a filtration system that suits your family's needs.
If you're considering a gravity-fed countertop filtration system, the Big Berkey® remains a popular option for everyday household use. When equipped with Black Berkey® Replacement Filters, it's designed to help address many common drinking water contaminants while supporting better-tasting, better-smelling drinking water, all in a convenient, electricity-free countertop system.