Operator terms · Water

What is water hardness?

Water hardness is the amount of dissolved calcium and magnesium in water. Hard water leaves scale in pipes and heaters and uses more soap; soft water does not. Hardness is not a health concern, but operators track it because it affects treatment, corrosion, and customer complaints.

Last reviewed 2026-08-03

Where it comes from

Water picks up calcium and magnesium as it moves through rock and soil, so groundwater is often harder than surface water. The more of these minerals, the harder the water.

Why operators track it

Hard water scales up pipes and equipment and drives customer complaints, while very soft water can be corrosive. It is a water-quality measure, not a health limit.

Common questions

Is hard water unsafe?
No, hardness is not a health concern; it is a nuisance and equipment issue.
What causes hardness?
Dissolved calcium and magnesium picked up from rock and soil.
Why does it matter to operators?
It affects scaling, corrosion, treatment, and customer complaints.

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