Salt (sodium chloride) in drinking water

Sodium is an essential mineral in our diet. It is commonly found in the form of sodium chloride (salt). Salt has no smell and it dissolves easily in water and gives water a “salty” taste at levels greater than 180 milligrams per litre.

Normally in Australia the greatest amount of salt consumed in our diet comes from food and salt added to food rather than from drinking water. In Australia, the average daily consumption of salt through food and drink is estimated to be around 4 grams. However this can be greatly influenced by individual dietary habits.

Is Sodium (salt) in drinking water a concern?

Sodium is essential for normal functioning of the human body. It can be found in all body tissues and fluids, and it is not generally considered harmful at normal levels of intake from combined food and drinking water sources.

However, the following people should be aware of the level of sodium (salt) in drinking water when the level is greater than 20 milligrams per litre:

• Persons who are monitoring their salt intake for high blood pressure
• Persons with cardiovascular or heart disease
• Persons with kidney problems or
• Persons on low sodium diets.

If you have one of these conditions, you should talk to your doctor to see if your medication needs to be adjusted based on the level of sodium (salt) in your drinking water.

Parents of infants less than 6 months of age, who are not connected to a scheme drinking water supply, should also be aware of the level of sodium (salt) in their drinking water. This is because the recommended daily intake of sodium for babies is lower than for adults. Although an elevated level of sodium (salt) will not make your baby sick, it is recommended that bottled water be used to reconstitute infant formula. Please talk to your local District Nurse to discuss this matter further.

How does sodium get into drinking water?

Sodium can be released naturally into water through mineral deposits in ground and surface water and seawater spray off roofs used to collect rainwater.

What are the safe levels in drinking water?

The Australian Drinking Water Guidelines (external site) have an aesthetic guideline level for sodium (salt) based on taste of 180 milligrams per litre. No health-based guideline value has been set for sodium (salt) as you will not be able to drink a large quantity of water with salt levels high enough to cause you harm.

Are elevated levels of sodium commonly found in drinking water in WA?

No, however, some private supplies and remote communities which obtain drinking water from bores in high salinity areas may have concentrations of sodium above the aesthetic guideline value.

How can I tell if sodium levels in my drinking water are elevated?

The immediate indicator that your drinking water is high in sodium is that it will taste salty. However, you may not be able to taste lower concentrations.

In Western Australia, drinking water scheme providers test for sodium in their supplies and results are reported to the Department of Health. You will be able to find the level of salt in your scheme drinking water supply by either contacting the drinking water provider or by looking at the annual water quality reports on the provider’s website.

If you are not connected to a scheme drinking water supply, you can have your water tested by a chemical laboratory. If you are interested in this, please refer to the Drinking water monitoring and testing webpage.

Can I reduce the level of sodium in my drinking water?

Sodium (salt) cannot be easily removed from drinking water and cannot be removed through boiling or conventional filtration.

Reverse osmosis, ion exchange or distillation systems can reduce sodium levels but these systems may be expensive to operate.

If you find that your drinking water is unpalatable or you cannot use it because of a medical condition, you may wish to consider alternative water supplies such as home treated rainwater, a bulk water supply or bottled water. People with sodium related medical conditions should also always check bottled water information labels for the sodium content as the sodium (salt) level in different brands may vary.

Summary

• Salt is essential for normal functioning of your body.
• Food is the major source of salt in your diet.
• Sodium (salt) will give drinking water a salty taste at a concentration greater than 180 milligrams per litre.
• People who suffer from high blood pressure, cardiovascular disease, heart disease, kidney problems or are required to be on a low sodium diet should be aware of the sodium (salt) level in their drinking water.
• Elevated levels of sodium (salt) will not make babies ill but it is recommended you talk to your local District Nurse if you bottle feed your baby.
• If you are not connected to a scheme drinking water supply, you can have your water tested by a chemical laboratory.
• Reverse osmosis, ion exchange or distillation systems can reduce sodium (salt) levels in drinking water.