California has been waiting for the last 2 years for news of a new drinking water regulation. At last, after the predictions and the pools in various labs and water district offices across the state, the books are closed and the verdict’s in: CDPH has proposed a Maximum Contaminant Level (MCL) of .01-milligrams per liter for Chromium-6. While this is not the final regulation, this is the first step towards solidifying the new MCL.
Chromium is an inorganic chemical that is used in many industrial processes including electroplating, wood treatment, pigments manufacture and cooling tower treatment for corrosion control. However, chromium is also a naturally occurring element. 
Chromium is classified as a carcinogen, an element which may cause cancer. The proposed MCL will work to lower the risks of developing cancer as a result of drinking water.
Since the 1970s, California has enforced a drinking water standard for total chromium, which includes chromium-3 and chromium-6. The California standard of 50 parts per billion (ppb) is more stringent than the federal standard for total chromium of 100 ppb. Now, the proposed MCL for chromium-6 is one-fifth of the previous standard.
On August 23, CDPH announced in the California Regulatory Notice Register the availability of the proposed 0.010-milligram per liter MCL for hexavalent chromium (chromium-6) for public comment. The final MCL will be adopted following the public review and comment process. CDPH will hold public hearings in Sacramento and in Los Angeles on October 11, 2013, to receive comments on the proposed regulations. All comments, whether written or presented at the public hearings, will be responded to in the final statement of reasons. Once final, the department will review the chromium-6 MCL at least every five years after its adoption. As technology improves, the standard may be changed.
For more information, you can view the CDPH press release here.