A recent newspaper article (see link below) has stirred interest in hexavalent chromium in the community. As the article mentions, hexavalent chromium has been detected in some Utah water systems at levels ranging from 0.06 to 0.77 ug/L. Chromium occurs in water mainly in a valence state of +3 (trivalent) and +6 (hexavalent). The hexavalent form has been identified as being the more toxic form. The EPA and the State of Utah only regulate total chromium which contains both valence states. The current EPA maximum contaminant level for total chromium is 0.1 mg/L or 100 ug/L (parts per billion). There is no current limit for hexavalent chromium.
California has chosen to set a regulated limit for hexavalent chromium at 10 parts per billion, with a future goal of 0.02 parts per billion. Many environmental groups point to the California rule as a positive example, and are requesting the EPA to lower MCL limit.
Chemtech-Ford can test for Hexavalent Chromium by method SM 3500 Cr B to a reporting limit of 10 parts per billion. We can test for Total Chromium by ICP/Mass Spec 200.8 to a reporting level of 0.5 parts per billion. This would include all valence forms. A detected result by 200.8 would not be able to identify which valence form was seen.
If you have questions regarding testing hexavalent chromium, please contact us at 801.262.7299, and we will be happy to provide any additional information.
Link for Ogden Standard Examiner article