Skip to main content
U.S. flag

An official website of the United States government

The world's most acidic water is found in a mine in California

Detailed Description

The most acidic waters ever measured are percolating through an underground mine at Iron Mountain, near the northern California town of Redding. Hot acid solutions, more concentrated than battery acid, are dripping from colorful mineral stalactites in the abandoned copper and zinc mine at Iron Mountain, in northern California. The pH of the drip water was -0.7. The beaker shown here holds 2 liters. Such high concentrations of acid and metals can have severe environmental effects when they enter a river system, since they may kill all aquatic life except microorganisms, for up to several miles downstream.

Such high concentrations of acid and metals can have severe environmental effects when they enter a river system, because they may kill all aquatic life except microorganisms, for up to several miles downstream.

Sources/Usage

Public Domain.