Does Your Water Contain an Unsafe Level of Arsenic?

Today, I’ll continue my review of some of the more common drinking water contaminants with a look at Arsenic. I’ll touch on how Arsenic can affect water quality and share information on things you can do to minimize your family’s exposure to the contaminant.

Arsenic, a naturally occurring element, is found in the Earth’s crust. Two ways it typically gets into our drinking water supply are: 1) through the erosion of natural deposits, and 2) from runoff from orchards and certain factories. Consuming water containing Arsenic at levels above 0.00 mg/L can cause adverse health effects.

Fortunately, Arsenic is one of the drinking water contaminants regulated by the EPA. This means public water companies are required to monitor their water supply for Arsenic and work to ensure the water they provide their customers does not exceed the legal limit for the contaminant. However, even with this standard in place, it’s still possible for your tap water to contain excessive amounts of Arsenic. Using data from the EPA, I estimated as many as 288 thousand Americans were exposed to water with potentially unsafe Arsenic levels at least once in 2019.

How Arsenic Can Affect Water Quality and Your Health

Both natural processes (e.g., erosion of naturally occurring deposits in the Earth’s crust) and human activities (e.g., waste disposal) can contaminate our water supply with Arsenic.

What is Arsenic, exactly? Arsenic, often referred to as a metal, is an element that has properties of both a metal and a non-metal. Historically, Arsenic was used in wood treatment and pesticides.

How can drinking water that contains Arsenic affect your health? If you consume water that contains elevated levels of Arsenic for an extended period, you may develop skin damage or problems with your circulatory system, and you may have an increased risk of getting cancer.

At what level can Arsenic cause health problems? Arsenic is known to cause adverse health effects when its concentration in drinking water is above 0 mg/L.

In an effort to protect our health, the EPA established legally enforceable standards to limit the amount of Arsenic in our drinking water. Public water companies are required to ensure the concentration of Arsenic in the water they provide their customers is kept at or below 0.01 mg/L.

Given available treatment technology, water utility companies should be able to provide drinking water that meets this quality standard. However, over 230 public water systems violated the regulatory limit for Arsenic in 2019.

Does Your Drinking Water Contain a Harmful Amount of Arsenic?

Public water companies are required to provide customers with an annual water quality report, also known as a Consumer Confidence Report (CCR). Inside this report, you’ll find important information about your drinking water, including where it comes from, and whether it tested positive for any regulated contaminants like Arsenic.

Most Populated Areas with Violations for Arsenic in 2019

Water System
Moore, OK
Columbus, NE
Columbus, City of
Arvin, CA
Arvin Community Services Dist
Sunland Park, NM
Camino Real Regional Utility Authority
Andrews, TX
City of Andrews

If you’re curious to know how much Arsenic was found in your city’s drinking water, grab a copy of the latest CCR and look for the section of the report that covers “Inorganic Chemicals.” Here, you’ll find test results for Arsenic as well as other contaminants like Antimony, Barium, and Cadmium.

How to Interpret Your Water Quality Report

When looking at your water quality report, you can expect to see test results for Arsenic reported in Parts per Billion (ppb). 1 mg/L equals 1,000 ppb, so 0.01 mg/L is equivalent to 10 ppb.

Below is an example of what you might see on your annual water quality report if Arsenic is detected in your town’s drinking water:

Example Water Quality Report

MCLG (1)MCL (2)Average
Your Water

Definitions from the EPA:
1. Maximum Contaminant Level Goal (MCLG) – The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.
2. Maximum Contaminant Level (MCL) – The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consideration. MCLs are enforceable standards.

In this example, water samples contained an average of 13 ppb of Arsenic, exceeding both the public health goal level (MCLG) and the legal limit (MCL) for the contaminant.

Will You Be Notified If Your Water Contains an Unsafe Level of Arsenic?

In addition to providing you with an annual quality report, your water company is required by the EPA to notify you if they identify a problem with your drinking water.

If your water company delivers water that could negatively impact your health, they have to notify you of the situation within the timeframe set by the EPA. Depending on the severity of the issue, the company is given 24 hours to 30 days to provide this notice.

If your city’s water exceeds the Maximum Contaminant Level (MCL) for Arsenic, your water company must notify you within 30 days of the violation. Typically, you will receive this notice via the media or through the mail.

What Can You Do to Remove Arsenic from Your Tap Water?

Fortunately, if you want to limit your family’s exposure to Arsenic, there are several affordable yet effective options for removing the contaminant from your tap water.

But how can you tell which products work and which ones don’t? Well, if you want peace of mind, I recommend choosing a water treatment product that is certified by NSF International (NSF) to be effective at removing Arsenic from water.

What does the NSF certification represent? When a product is NSF certified to remove Arsenic, you can rest assured that:

  • the manufacturer’s contaminant reduction claims have been verified;
  • the system was tested to confirm it adds nothing harmful to the water;
  • the system has been found to be structurally sound;
  • the product’s advertising, literature, and labeling have all been verified as accurate;
  • and there is testing in place to determine whether the quality of the product is consistent over time.

Do all NSF certified water filters work against Arsenic? Water treatment devices can earn certification for meeting one or more NSF standards or protocols. But only certain NSF certified products, like Reverse Osmosis devices that meet NSF standard NSF/ANSI 58 for Arsenic, are certified to reduce the amount of the Arsenic in your water.

One such product, OptimH2O Reverse Osmosis + Claryum by Aquasana, is NSF certified to remove up to 97.6% of the Pentavalent Arsenic found in your tap water. This device requires installation underneath your sink, so the manufacturer recommends enlisting the help of a professional to make sure it gets done right.

3 steps for selecting the right water treatment system for your family:

  1. Review your area’s annual water quality report to find out what’s in your drinking water.
  2. Determine which contaminants you’d like to reduce from your water.
  3. Select a water treatment product that is NSF certified to work effectively against those contaminants you’d like to reduce from your tap water.

Just remember, no matter which water treatment product you choose, you need to make sure to perform the routine maintenance suggested by the manufacturer. This will help keep the device in proper working order and limit your family’s exposure to Arsenic.



I’ve moved several times over the years, so I know just how stressful it can be to relocate. I want to help put your mind at ease. That’s why I research and write about all the things I think you should consider when moving to a new town.

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