Chromium, including hexavalent chromium, is an odorless and tasteless metallic element that occurs naturally in rocks, animals, plants, and soils. It occurs naturally in most water supplies. The forms most common in natural waters are trivalent chromium (chromium 3) and hexavalent chromium (chromium 6).
Chromium 3 is an essential human dietary nutrient found in many vegetables, fruits, meats, grains, and yeast.
Chromium 6 occurs naturally in the environment due to erosion of natural chromium deposits. Chromium 6 is used in industrial and manufacturing processes such as electroplating, tanning, and pulp processing. It can be found in consumer products such as spray paints, tanned leather and stainless steel.
Total chromium, the combination of both trivalent and hexavalent chromium, is currently regulated under the Safe Drinking Water Act. However, there is no national regulatory standard solely for hexavalent chromium. In 2014, California independently developed a regulatory standard for hexavalent chromium of 10 parts per billion. Of the hundreds of samples of drinking water in Washington State analyzed for hexavalent chromium, none exceeded this California regulatory standard.
Under the Unregulated Contaminant Monitoring Rule (UCMR) 3, the U.S. Environmental Protection Agency (EPA) gathered thousands of samples nationwide to test for hexavalent chromium and continues to evaluate the risks from consuming water with low levels of hexavalent chromium. The EPA will use this information to determine whether hexavalent chromium should be regulated under the Safe Drinking Water Act. The following links provide you with more information:
- Basic Information from USEPA about Chromium in Drinking Water: https://www.epa.gov/dwstandardsregulations/chromium-drinking-water
- California Regulatory Standard for Hexavalent Chromium: http://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/Chromium6.shtml
- Information for Consumers About Hexavalent Chromium: http://www.drinktap.org/water-info/whats-in-my-water/hexavalent-chromium.aspx