Sodium and Chloride in Drinking Water

Sodium and Chloride in Drinking Water

Both sodium and chloride are found naturally in the Earth’s crust, which means they can be found in your well or spring water. However, high levels of sodium and chloride typically mean that your drinking water may be contaminated with road salt, fertilizers, leaking septic systems, or malfunctioning water softeners.

Health Concerns: Are sodium and chloride harmful to my health?

Consuming water containing chloride and/or sodium alone is typically not harmful to your health. However, if sodium and chloride are in your water, that may mean other contaminants, such as bacteria, nitrates or lead, may be in your water. Plus, high levels of sodium and chloride may cause your water to taste bad. 

If you or someone in your household is on a low-salt diet, talk with your health care provider about the level of sodium in your water. The U.S. Environmental Protection Agency recommends no more than 20 mg/L (milligrams per liter) of sodium in drinking water for people restricted to a total sodium intake of 500 mg/day (milligrams per day).

High sodium and chloride levels can also corrode your plumbing fixtures. 

Source: How do sodium and chloride get into my water?

Sodium and chloride are found naturally in the Earth’s crust. As rainwater moves through natural rock formations underground, it can dissolve salts and carry them into aquifers that serve as sources of drinking water. However, high levels of sodium and chloride are typically caused by contamination from:

  • road salt 
  • fertilizers
  • septic systems
  • malfunctioning water softeners

In New England, we would expect levels of sodium to be less than 15 mg/L and chloride to be less than 30 mg/L.

Testing: How do I know if there is sodium or chloride in my water?

Testing for sodium and chloride is the only way to know how much is in your water. 

The Health Department recommends testing your private water source for sodium and chloride 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 sodium is 250 mg/L (milligrams per liter) and for chloride is 250 mg/L. These standards are called secondary maximum contaminant levels, or SMCLs, because the levels are based on aesthetic (color and taste) reasons rather than health effects.

If you have levels of sodium and chloride above the drinking water standard, your water would likely taste salty and may pose a risk to people who are on sodium-restricted diets. You may consider treatment to improve the taste and appearance of your water. 

High levels of sodium and chloride could also mean that you have other problems with your well that could allow other contaminants into your water if not fixed (see treatment options below).

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 sodium and chloride in my water?

Eliminating sources of sodium and chloride is the best way to lower levels in your water. This includes: 

  • Inspecting the area around your wellhead for possible sources of contamination, such as road salt piles and storage sheds, driveways and roads where road salt is used, fertilized areas, septic systems, and waste from pets and farm animals. 
  • Removing any visible sources of contamination whenever possible.
  • Making sure the wellhead is properly sealed and separated from sources of contamination whenever possible. 
  • Making sure rain and melting snow are directed away from your wellhead.

Watch a video of common well problems and solutions

It is also important to ensure that any salt-based water softeners are properly maintained and serviced regularly. If your softener is not backwashing, it can leach additional salt into your drinking water. Most conventional water softeners will add small amounts of sodium to the water, but sodium levels above 100 mg/L and chloride levels above 25 mg/L typically indicate a problem. 

If you would like to get rid of the salty taste in your water, you can install one of these systems at your kitchen sink:

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

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.