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Sodium is the sixth most abundant element on Earth and is widely distributed in soils, plants, water and foods. It is essential to human life.  Many people use the word “salt” when they intend to refer to sodium or to sodium chloride. When a salt such as sodium chloride dissolves in water it breaks up into positively- and negatively-charged ions. Sodium chloride breaks up into sodium and chloride ions in water. Every water supply contains some sodium and chloride.   A major source of sodium in the natural waters is due to the weathering of rocks and soils.

The concentrations of sodium in groundwater are dependent on the local geological conditions and wastewater contamination. Saline intrusion, mineral deposits, sewage effluents, and salt used in road de-icing can all contribute significant quantities of sodium to water.  Domestic water softeners contribute to sodium in the drinking water by replacing the calcium and magnesium that make the water hard.  These levels, though, are insignificant compared to the sodium ingested in the normal human diet.

Sodium Distribution in Ohio's Ground Waters


This map shows average concentrations of sodium in ground water in Ohio based on the type of aquifer.  This information was obtained from the Ohio EPAGround Water Quality Characterization Program



What are the Drinking Water Standards?

Sodium is included on the Drinking Water Contaminant Candidate List (CCL).  Sodium is currently not subject to any proposed or promulgated national primary drinking regulation (NPDWR).

What are the Treatment Options?

Water softeners are the most common source of sodium in home drinking water supplies.   If you are concerned about your water softener contributing to the sodium in your drinking water, talk with your doctor.  One way to reduce the sodium contributed by your water softener is to consider dedicating one or more cold water lines, for drinking purposes, by bypassing the water softener.

If a water softener is not installed or the cold water is already by-passing the water softener, you can consider:

  • Reverse Osmosis,
  • Distillation, or 
  • De-ionization

If salt water intrusion (high total dissolved solids) is the cause of the elevated sodium levels,  have a private water systems contractor inspect and evaluate your well to determine the source of the salt water.

What are the Health Effects?

A review of scientific data from U.S. EPA shows that the vast majority of sodium ingestion is from food rather than drinking water.  Sodium levels in drinking water from most water systems are unlikely to be a significant contribution to adverse health effects. 

A diet high in sodium intake has been identified as a risk factor for high blood pressure.  

References and Additional Resources  


Reviewed 05/29/2018