The Water Research Foundation has released a new report meant to help local water treatment plants decide the best method for removing Chromium-6 from their water. There are three main methods for doing so, each of which is most successful under different conditions. The report looks at several factors, especially water quality variables, helping managers make the best and most cost-efficient choice.
Chromium-6 is an inhaled carcinogen that became famous (at least more famous than most industrial contaminants) after the film Erin Brockovich, which tells the true story of a Cr-6 contamination in Hinkley, California. Though the EPA has set a maximum safe level of 100 micrograms/Liter of total Chromium, most water systems do not test for or filter Cr-6 specifically. As data mounts on the health risks of Cr-6, and on the high levels in several city water supplies, this will have to change.
There are three major treatment technologies for removing Cr-6 from water: Weak Base Anion resin (WBA), Strong Base Anion resin (SBA), and Reduction-Coagulation-Filtration (RCF). The report tests each of these methods against water samples from 10 different areas in California, Nevada, and Oklahoma. We have to think Norman, Oklahoma made the list because of a recent Environmental Working Group study of Cr-6 in U.S. waters, that found Norman to have the highest concentrations of any studied water system.
Water treatment managers have the task of not only keeping municipal water supplies clean and healthy, but doing so within a sometimes fairly restrictive budget. This study’s most useful product may be the comparisons of price between different methods under different conditions. The researchers found that the choice of technology can be the difference between a $5 million Cr-6 removal project and a $9 million one. In the real world, that amount of money could decide whether it happens at all.