Frequent Questions

What is the "white stuff" that appears in a glass as ice cubes melt and where does it come from?

The "white stuff" is a concentration of minerals dissolved in the water. Water freezes from the outside in. Ice is pure water, so as the water freezes, any dissolved minerals in the water are forced to the center. As the water continues to freeze, the minerals concentrate in the center, forming the "white stuff" (Plain Talk About Drinking Water, American Water Works Association, 2001).

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