Arsenic Water Testing

Private well owners could be at risk from harmful exposure to arsenic in their drinking water. You can’t see, taste or smell arsenic, so test your water and take action if you learn that your well has arsenic.

Should you be concerned about arsenic in your well water?

Yes. EVERYONE should test their well water for arsenic and other contaminants. If you are on a public water system (your water enters your home from a city or town pipe), ask your water provider for its “consumer confidence report” or “water quality report.” Learn about other sources of arsenic exposure by reviewing this website.

Private well users should be particularly concerned if you live in an area where:

  • Higher arsenic occurs naturally;
  • Run-off from local industrial sites, orchards, farming or past land-use practices may have added arsenic to soil and water;
  • Development or a change in your neighborhood is taking place.

Many people in this country are exposed to low levels of arsenic through food, water and other sources that may increase their risk of diseases like cancer, heart disease and diabetes later in life.


In the U.S., high concentrations of naturally occurring arsenic are more common in the West, Midwest, parts of Texas, and Northeast, but can occur almost anywhere. This map shows the probability of arsenic in private well water greater than 10 parts per billion (ppb), the federal maximum contaminant level for arsenic in public water supplies (New Hampshire and New Jersey have adopted 5 ppb as their regulatory limit for public water systems). Note: 1 ug/L is the same as 1 ppb. Remember, arsenic is not just a problem in those regions, so test your well for arsenic no matter where you live. Data and map from U.S. Geological Survey

How do you know if there’s arsenic in your well water?

By Testing it. Remember, you can’t see smell, or taste arsenic. If your water comes from a private well, it’s your responsibility to get your water tested to make sure it is safe to drink.

Federal law does not require private well users to test or treat their water for contaminants, so unless your local city or town has a law to require well water safety, it is completely up to you to be sure that your family’s water is healthy for drinking.

Even if your neighbor’s well has no arsenic, everyone’s well water needs testing since arsenic levels vary from well to well.

WHAT YOU CAN DO

Drink Safe Water

Be Proactive

Lowering your arsenic exposure now could improve your long-term health.

How do you test your well for arsenic?

Collecting a water sample and sending it to a lab will tell you how much arsenic is in your water and whether you should use a treatment system to reduce your exposure.

FOLLOW THESE STEPS:

  1. The U.S Environmental Protection Agency (U.S. EPA) maintains a website that provides links to private drinking water well programs in every state. Click on your state to get more information on water testing and treatment.
  2. Find an accredited testing laboratory or request a test kit from your state lab, by contacting your state laboratory accreditation program for a list of licensed laboratories in your area.
  3. Contact your private drinking water well program, or your state health department, or your local health department for a list of common contaminants in your area and the water tests you should order.
  4. Select a laboratory and call to order an arsenic test kit and any other water tests. Ask your lab contact: “Are you accredited to analyze drinking water compliance samples?” Make sure the laboratory’s “reporting limit” for arsenic is no more than 5 ppb. Some labs may have a reporting limit of 10 ppb, meaning that even if your water has 9 ppb arsenic, the lab might report the results to you as “not detected.”
  5. To test for arsenic: an arsenic test kit usually costs less than $30. The laboratory will mail a test kit and directions to your home.
  6. Collect your water sample from the tap that you drink from the most often: for most households that is the kitchen sink.
  7. Follow the directions for collecting a water sample carefully to be sure that your test results are accurate.
  8. Mail or bring the sample back to the lab. For an arsenic water test only, you do not need to refrigerate or overnight ship the sample, but if you’re testing for other contaminants be sure to follow the instructions for storing and shipping the water sample.

You will receive your test results in the mail or by email. Once you get the results, consider having another test done to confirm them.

Depending on where you live, help with testing your well and understanding the test results might be available from your:

If you are buying a new home:

  • Ask about a water test, and learn whether the buyer or the seller is responsible for the water test or for treatment if the test shows that the water is not safe to drink.
  • Some states, local governments, or mortgage lenders require a drinking water test before a property with a well is purchased or sold, but those required tests don’t always include arsenic.

Be sure to always:

  • Test your well water before you use it for the first time.
  • Test regularly and at least every 3-5 years for arsenic.
  • Test your water after you install an arsenic removal treatment system.

Is Arsenic in Water Regulated?

Yes. The U.S. EPA requires public water systems to reduce arsenic levels in water to 10 parts per billion (ppb) or lower. Federal law does not require private well users to test or treat their water for contaminants, although local or state requirements may exist where you live (New Hampshire and New Jersey require public water systems to reduce arsenic levels in water to 5 ppb). It is your responsibility to learn what is in your water and take steps to be sure your water is safe to drink.


A Summary of Arsenic Levels

  • 0 ppb U.S. EPA’s Maximum Contaminant Level GOAL for arsenic in public water (not enforced).
  • 2 ppb Average arsenic levels in U.S. drinking water.
  • 5 ppb New Jersey’s and New Hampshire’s Maximum Contaminant Level (enforced in public water systems). More cautious than federal limits.
  • 10 ppb U.S. EPA’s Required Maximum Contaminant Level (enforced in public water systems). Set in 2001 based on cost and feasibility.
  • 1000-3000 ppb Fatal levels of arsenic exposure.

Use Be Well Informed With Your Test Results

The New Hampshire Department of Environmental Services has developed an online tool – Be Well Informed – to help you interpret your water testing results. Enter the results of your water test into the tool and it will provide water treatment options and information on health risks based on your unique water characteristics. You don’t need to live in New Hampshire to use this tool.

follow directions on test kit

What do my test results mean?

If your water test says you have arsenic levels greater than the U.S. EPA Maximum Contaminant Level, then learn about treatment options. If your levels are at or below 10 parts per billion, it is still worth considering installing a treatment system to remove arsenic since no amount of arsenic exposure is totally safe.

When you receive your water test results, call your state drinking water agency for treatment recommendations and then contact a water treatment professional.

The New Hampshire Department of Environmental Services has developed an online tool – Be Well Informed – to help you interpret your water testing results. Enter the results of your water test into the tool and it will provide water treatment options and information on health risks based on your unique water characteristics. You don’t need to live in New Hampshire to use this tool.

How do you remove the arsenic?

“Point-of-use” (e.g., under the sink or at the tap) treatment can be both effective and relatively inexpensive; but treating all of the water used in your home (“point-of-entry”) might be needed. The options that are best for you depend on:

  • knowing what other contaminants are in your water in addition to arsenic;
  • how you use the water in your home;
  • other factors such as your comfort level with taking responsibility for maintaining a treatment system.

Go to the Water Treatment Page for more details.

EVEN IF YOUR WATER TEST SHOWS ZERO ARSENIC or “NOT DETECTED,” MAKE SURE YOU:

  • Test every 3-5 years, preferably at different times of the year, e.g., spring and fall, since arsenic levels may vary seasonally with the level of the water table.
  • Review this site to understand your total arsenic exposure.
  • Follow the WHAT YOU CAN DO action steps to help you lower other arsenic in your world.

“If your drinking water comes from a private well, we recommend you test your water to be sure it is safe to drink. You can’t see, taste or smell arsenic in drinking water, so the only way to know if your well has arsenic or other common contaminants is to test it. New England, the Midwest, and the Southwest are naturally more likely to have high arsenic in the groundwater, but it’s important for everyone to test their well for arsenic every 3-5 years.”

Paul Susca, New Hampshire Department of Environmental Services

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