What You Need to Know About Arsenic in Drinking Water

Arsenic comes in different forms, some are harmful to your health and some are not. Arsenic is an element found naturally in the Earth's crust, which means it can be found in your well or spring water. This form is harmful to your health.

Health concerns: Is arsenic harmful to my health?

Health effects from drinking water with arsenic depend on two things:

  1. How much arsenic is in the water

  2. How many years you've been drinking the water

Drinking water with arsenic over a long period of time may cause an increased lifetime risk of bladder, lung or skin cancer. There also may be links to skin and cardiovascular diseases, diabetes or other cancers.

Source: How does arsenic get into my water?

Arsenic is a natural element found in the Earth's crust. As rainwater moves through natural rock formations underground, it can dissolve arsenic and carry it into aquifers that serve as sources of drinking water.

Testing: How do I know if arsenic is in my water?

You cannot see, smell or taste arsenic. Testing is the only way to know if arsenic is in your drinking water.

The Health Department recommends testing your well or spring for arsenic every five years. You can order an inorganic chemical test (Kit C) from the Health Department Laboratory, or you can use another certified drinking water lab to test for inorganic chemicals.

Test results: Is my result a problem?

The drinking water standard for arsenic is 0.010 mg/L (milligrams per liter). If the arsenic level in your water is more than (>) 0.010 mg/L, the Health Department recommends you stop drinking the water and install a treatment system to remove arsenic, drink bottled water instead, or get water from a known safe location.

Arsenic is known to cause cancer, so even amounts below the drinking water standard could affect your health. If the arsenic level is between 0.001 and 0.010 mg/L, consider treatment.

Need help understanding your drinking water test results? Find out how to read your results

Treatment options: Can I remove or lower the levels of arsenic in my water?

Arsenic levels in drinking water can be lowered by using one of the treatment systems listed below. 

  • Adsorptive filters: As the water flows through the filter, arsenic sticks to the filter, which contains a type of granular iron oxide. These filters allow for oxidation and removal in a single-filtration process.

  • Distillation units: These units boil water and then recondense the steam. The arsenic is left behind during this process, along with hardness and other minerals. These units can produce several gallons of arsenic-free water per day.

  • Reverse osmosis (RO): This system uses a synthetic membrane that allows water to go through but leaves arsenic behind. The membrane is continually rinsed. This system is typically installed under a kitchen sink (point-of-use or POU) but can also be installed as a whole house system (point-of-entry or POE). Install a system with an NSF/ANSI Standard 58 Certification

Other treatment systems require two steps to remove arsenic. First, the water must go through an “oxidation” process in order to change arsenic into a form that can be removed. Chlorine injection, specialized media or aeration can be used in this initial step. Treatment system options after oxidation are anion exchange and carbon block.

  • Anion exchange treatment: Anion exchange is a treatment like water softening but uses a different media that exchanges the arsenic for chloride. This is installed as a POE system.

  • Carbon block: This technology lowers total arsenic as the water passes through a solid carbon block. Install a carbon filtration system with an NSF/ANSI Standard 53 Certification

Re-test your drinking water for arsenic after any treatment system is installed to make sure levels are below the drinking water standard.

Financial assistance: Is there funding available to help me pay for my water system or treatment?

New Grant Opportunity for Vermonters

This summer, the Vermont Department of Environmental Conservation is offering grants to Vermonters who have failed drinking water systems. A failed drinking water system means:

  • You have an inadequate water supply (for example, your well runs dry in the summer).

  • Your water has high levels of some contaminants (for example, arsenic, bacteria or lead).

  • Your water supply is contaminated from known sources (for example, an underground fuel storage tank).

Find out if you're eligible and sign up today

Vermont Wastewater and Potable Water Revolving Loan Fund

This program, also known as the On-Site Loan Program, is available to certain Vermont residents for the repair or replacement of failed water supply and on-site wastewater systems. The On-Site Loan Program is funded and administered by the Agency of Natural Resources, Department of Environmental Conservation with loan underwriting and servicing provided by the Opportunities Credit Union in Winooski. Your drinking water supply has to be a failed system and you must be living in the residence on a year-round basis to be eligible. The family income cannot exceed 200% of the state median household income. For more information about eligibility and how to apply, call the On-Site Loan Program at 802-461-6051.

The NeighborWorks Alliance of Vermont

The NeighborWorks Alliance is made up of five local organizations offering full affordable housing services for income-eligible individuals. You may qualify for help from this program if you need money to install a water treatment system, drill a well, or repair or replace your septic system. For more information on eligibility, contact the local NeighborWorks Group in your region.

Single Family Housing Repair Loans and Grants

This program offers loans and grants to existing homeowners for well construction, repair and sealing. It's administered by the Rural Development office of the U.S. Department of Agriculture. The program is for low-income families who live in a rural area or a community with a population of 25,000 or less. The family income cannot exceed 50% of the median county income. Individuals who are 62 years of age or older may qualify for a grant or a combination of a loan and a grant. Younger applicants are eligible only for loans.

Burlington, South Burlington, Essex Junction, Winooski and parts of Colchester are ineligible for the program. Even if your property is in an eligible area, your eligibility is still subject to income limits. For more information or to find out if your property is in an eligible area, call the USDA Rural Development Office at 802-828-6022.

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Last Updated: September 29, 2023