What is Sodium Chloride?

Sodium Chloride is the chemical name for salt. When dissolved in water they dissociate to Sodium (Na+) and Chloride (Cl-)

These are not noticeable until they reach quite high levels.

NZ drinking water standards give guideline values of 200mg/L for Sodium and 250mg/L for chloride, after which water will begin to taste salty. Compare this to seawater which has around 3,500mg/L of salt.

How do sodium and chloride get into my water?

Salt is very soluble and if present in the ground will easily dissolve into passing water. It can be found in both ground and surface water.

As you would expect, this is more common in wells/bores which are near the sea, as salty water can intrude in the aquifer.

Occasionally if a house experiences seaspray and is collecting rain water, salt may be found in the supply as well.

What do Sodium and Chloride do?

Generally both of these are fairly harmless and in fact, we need a certain amount of salt for metabolic processes. The main issue is generally that salty tasting water is not palatable.

However high sodium intake has some links with hypertension and some people who may have been placed on a special low sodium diet by their doctor, may need to be more careful with Sodium levels in drinking water.

The other consideration for chloride is that it increases the conductivity of water and thus increases its corrosivity. In metal pipes, chloride reacts with metal ions to form soluble salts, which can increase the metal content of water as well as cause premature damage to pipes.

High chloride levels can come from contamination with sewage, so if found, it is worthwhile doing a bacteria test to be sure. Click here to arrange a test.

How can I remove sodium and chloride from my water?

Most of the time, you won’t need to.

However, if your levels are naturally high to have been increased by cation exchange, then these can be removed using reverse osmosis or distillation.

However in some cases, this can be expensive to do for a whole supply, and dilution with another water source may be an option.