Ames Water Safe from Chromium-6 Concerns
In light of a report issued recently by the Environmental Working Group, the Ames Water Plant wants to reassure our consumers that drinking water in Ames is free from Chromium-6 concerns.
In 2014, the City of Ames performed testing for Chromium-6 as part of a larger package of analyses required by the US EPA under the third round of the Unregulated Contaminant Monitoring Rule (UCMR-3). The results ranged from 0.17 to 0.25 parts per billion.
The US EPA has not established a Maximum Contaminant Level (MCL) for Chromium-6. Only one state, California, has set its own health standard specifically for Chromium-6 at 10 parts per billion. The results in Ames water were 40 times lower than the exceedingly protective California standard.
If you’re having difficulty conceptualizing just what “0.25 parts per billion” means, think about it this way: That is the equivalent to finding one specific second of video in a movie that is 126 years long!!
Chromium compounds can exist in several different forms. (For those with a scientific curiosity, the variation comes from differences in oxidation states, or valences.) The most commonly found forms in the environment are Chromium-6, Chromium-3, and unoxidized Chromium. Chromium-3 is actually considered an essential micro-nutrient.
Chromium-6 is also known by several different names, including: hexavalent chromium, chromium VI, chrome 6, Cr(VI), Cr+6, or hex chrome. Hexavalent chromium is also popularly known as the “Erin Brockovich chemical.”
The results for all contaminants detected in Ames drinking water are published annually in Ames Water’s Water Quality Report.