Electrical Conductivity of Water Range and Significance

Electrical Conductivity of Water is useful as a general measure of water quality. Each water body tends to have a relatively constant range of conductivity that, once established, can be used as a baseline for comparison with regular conductivity measurements.

In general, the range of specific conductance of natural waters should approximate that of total dissolved solids based on a correction factor. The relationship between ionic concentration and conductance can be easily determined for most streams after an appropriate number of samples have been analyzed for dissolved solids and electrical conductance.

The relationship is usually linear and therefore can be described by a straight line formula (EC)K = DS, where EC is the conductance in mhos, DS is the dissolved solids in mg/L, and K is the conversion factor. For natural waters, the range of K is usually between .55 and .75, the higher values generally being associated with high sulfate waters.

The use of electrical conductance as a water quality indicator is good for estimating the amount of mineralization and is commonly used for total dissolved solids. Conductance can be used for assessing the effect of diverse ions on chemical equilibrium, physiological effects on plants or animals, corrosion rates, etc.

All in all, much of the Total Dissolved Solids discussion applies to Electrical Conductance.

Chemical Water Quality Parameters
pH of Water
Relation of Acidity and Alkalinity in Water
Primary Anions and Cations in Water
Dissolved Gasses in Water
Primary Nutrients in Water and Eutrophication
Toxic Constituents in Water
Pesticides in Water
Oil in Water

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Physical Water Quality
Chemical Water Quality
Biological Water Quality
Water Basics 101