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.
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.
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:
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 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.
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
Eliminating sources of sodium and chloride is the best way to lower levels in your water. This includes:
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:
Funding is available to help you pay for water treatment or to fix your water system. Learn more about financial assistance programs and eligibility.
