Chromium in Drinking Water

EPA Limit: 0.1 mg/L

The EPA MCL for total chromium is 0.1 mg/L. There is ongoing scientific debate about whether a separate, lower standard should be set for hexavalent chromium.

Where Does Chromium Come From?

Chromium occurs naturally in rocks and soil and can also come from industrial operations including steel manufacturing, chrome plating, and leather tanning. Both trivalent chromium (Cr-III) and hexavalent chromium (Cr-VI) can be present in water.

Health Risks

Hexavalent chromium (Cr-VI), the form made famous by the Erin Brockovich case, is a known carcinogen when inhaled and is associated with stomach cancer in drinking water studies. The current EPA MCL covers total chromium.

What Should I Do?

Reverse osmosis and strong base anion exchange filters can reduce chromium levels. Some states, notably California, have set lower advisory levels for hexavalent chromium specifically.