A glass of water containing that low an amount of sodium qualifies for the US Food & Drug Administration’s “very low sodium” category.

Why do water softeners contain salt and/or sodium?

The majority of water softeners utilize a resin bed, which you can see at their website, comprised of negatively charged plastic beads packed with positively charged sodium ions. As source water passes through the bed of beads, calcium and magnesium ions with stronger positive charges disrupt the sodium ions’ bonds with the beads and form their own bonds with the plastic beads.

Eventually after a water softener operates for a while the supply of sodium ions in the resin bed gets depleted and when that happens the resin bed must get recharged using a concentrated salt brine solution that more or less overpowers the collected calcium and magnesium and causes them to become dislodged from the plastic beads. Sodium molecules then take their place on the resin beads and the magnesium, calcium and excess sodium molecules get flushed out of the system.

After a properly completed flushing and rinsing, a water softener operating properly ought not produce water that has a salty taste since all of the actual salt (NaCl) should have gone out as waste water during back washing.

Measuring water hardness

Scientists typically measure water hardness using one of two scales: Grains per Gallon (GPG) and Parts per Million (ppm). One grain per gallon of hardness equals approximately 17.1 ppm of hardness.

You may also see ppm expressed as milligrams per liter (mg/L) in some literature.

Rating categories for water hardness

As a general rule,

• Water that contains less than 1 GPG or 17.1 ppm hardness gets labeled as ‘soft’.
   
• Water that contains between 1 and 3.5 GPG, or 17.1 to 60 ppm, hardness gets labeled as ‘slightly hard’.
   
• Water that contains between 3.5 and 7 GPG, or 60 to 120 ppm, hardness gets labeled as ‘moderately hard’.
   
• Water that contains between 7 and 10.5 GPG, or 120 to 180 ppm, hardness gets labeled as ‘hard’.
   
• Water that contains between greater than 10.5 GPG, or 180 ppm, hardness gets labeled as ‘very hard’.
   

The salt shaker on your kitchen table more than likely contains NaCl.

Other metals such as Mg (magnesium) and Ca (calcium) can also form salts in the presence of Cl (chloride), but they do not impart the same ‘saltiness’ to water and/or foods as NaCl.

Scientists have not, yet, determined the exact reason WHY different salts will taste salty, bitter or some other way, but evidence seems to point in the direction of Cl bringing saltiness to the table (pun intended) and the metals interacting with the Cl in their own unique ways causing each metal-chloride combination to have different taste characteristics.

Salty drinking water

We most often hear of this happening when one of two things has happened: 1) a water softener has developed a problem with its backwash cycle (i.e. too long a rinsing w/ salt charged water); 2) sea water (or salt water from surface runoff) has found its way into an aquifer accessed by private wells.

Regardless of how the salt got there, health experts believe that consuming too much salt, meaning NaCl, on a regular basis can have detrimental effects on a person’s health.

Testing for salt in drinking water

While simply tasting water typically serves as a surefire means of determining whether or not water contains unwanted levels of dissolves NaCl, do not drink water if you fear it has become contaminated with salt water. You will NOT like the outcome.

Use of a TDS (total dissolved solids) meter or an EC (electrical conductivity) meter will allow you to get a quick overview of your water’s potential salt concentration. While in most cases neither meter will give you a definite ‘this is salt’ verdict, water that contains elevated NaCl levels will have both a higher total dissolved solids and electrical conductivity reading than the same water sample without elevated salt levels… and even if not actually salt that either meter detects, the fact that either or both meters picked up something dissolved in the water should make you consider having a water professional test your water.