What are Total Dissolved Solids (TDS)?
In its natural state, water is often contaminated with various minerals that occur in nature.

These contaminants include total dissolved solids. They are organic and inorganic contaminants that may be found in water naturally or by human activities.

Generally speaking, dissolved materials are calcium, magnesium, sodium or potassium cations. They can also be anions such as carbonate, bicarbonate, chloride, sulfate or even nitrate.


The Source

As stated above, they can be from human activity or they can be from natural sources: typically, soil erosion, runoff or decomposition of flora and fauna. In terms of human activities, road de-icing in Canada is one example of human actions that can promote the spread of TDS in Canadian waters.


Why monitor them?

Although water concentrated in total dissolved solids is not hazardous for human consumption, water highly concentrated in TDS may be an indicator of poor treatment. It is important to note that while TDS in water is not hazardous for human consumption, concentrations of 1000 mg/L and above are considered unfit for human consumption.


The World Health Organization, after various studies, has come to the conclusion that the acceptable TDS levels are as follows


Total dissolved solids in mg/L       


< 300


300 -600


600– 900

All right

900– 1200



Very Poor



To identify the amounts of dissolved solids in a sample, the easiest way is to use a total dissolved solids meter.


How to decrease the total dissolved solids in water?

The extraction of TDS is relatively easy. Depending on the type of TDS in the water, technologies such as reverse osmosis, nanofiltration, distillation and deionization have proven to be effective in reducing TDS concentrations.

Water and its Minerals
The variety of minerals that can be found in water through soil erosion is very diverse and changes from place to place.