The California Department of Public Health has submitted a final regulation setting a limit of 10 parts per billion for hexavalent chromium in public drinking water supplies.
Known as chromium 6, the toxic metal species makes its way into groundwater naturally from geological formations or through industrial pollution and can be found in water supplies across the state. Currently, chromium-6 (hexavalent chromium) is regulated under the 50-micrograms per liter (µg/L) primary drinking water standard (maximum contaminant level, MCL) for total chromium. The current federal drinking water standard for total chromium is with 100 ppb even higher. Concerns about chromium-6's potential carcinogenicity when ingested resulted in a state law that requires CDPH to adopt a chromium-6-specific MCL.
The new standard:
The CDPH announced Tuesday that it has submitted a final regulation setting a limit of 10 parts per billion for hexavalent chromium in public drinking water supplies, a level that will require more than 100 water systems to treat their raw water for the contaminant.
If approved as expected by the Office of Administrative Law, the nation's first-ever drinking water standard for hexavalent chromium would take effect July 1. Public health Director Ron Chapman said the limit "will protect public health while taking into consideration economic and technical feasibility as required by law."
The 10 ppb Cr(VI) standard was already proposed last year in August as part of the rulemaking process. CDPH announced the availability of the proposed MCL for public comment and received more than 18,000 comments. The proposed final regulation documents include a summary and response to comments received. It is 500 times greater than a non-enforceable public health goal set earlier by the state Environmental Protection Agency, sparking criticism from environmentalists that the new limit isn't stringent enough.
The "long-delayed action today simply does not provide enough protection for people's health," said Avinash Kar, an attorney with the Natural Resources Defense Council, which sued the department to force it to issue a standard. "The department both inflated water treatment costs and underestimated the benefits of a stronger standard."
A number of water districts, on the other hand, complained that the new limit isn't scientifically justified and would be prohibitively expensive to meet.
Rich Atwater, executive director of the Southern California Water Committee, said communities in the Coachella Valley and others across the state with naturally occurring chromium 6 in their aquifers "will be spending an extraordinary amount of local customers' water bills on state-of-the-art new treatment systems."
Los Angeles and other cities already have been treating industrially contaminated groundwater supplies in the San Fernando Valley to a level of 5 ppb of chromium-6, so they will not have to use new treatments to comply with the standard. Related Information California Department of Public Health: Chromium-6 in Drinking Water ACWA Association of California Water Agencies: Chromium-6 U.S. EPA: Recommendations for enhanced monitoring for Hexavalent Chromium in Drinking Water
U.S. EPA: Basic Information about Chromium in Drinking Water U.S. EPA: Chromium in Drinking Water U.S. EPA: IRIS Toxicological Review of Hexavalent Chromium (External Review Draft) Environmental Working Group: Hexavalent Chromium Environmental Working Group: Chromium-6 in U.S. Tap Water Environmental Working Group: EWG Urges EPA: Protect Public from Chromium-6 in Tap Water Related EVISA Resources Link Database: Toxicity
of hexavalent chromium (chromate) Link Database: Industrial Use of chromate Link Database: Occupational exposure of hexavalent chromium Link Database: Legislation for hexavalent chromium at the workplace Link Database: Methods for chromium speciation analysis Brief summary: The role of elemental speciation in legislation Brief summary: Speciation and Toxicity Related EVISA News April 11, 2012: EPA calls for more study on hexavalent chromium in drinking water December 27, 2011: EPA ruling on hexavalent chromium in water expected soon July 31, 2011: California sets goal for limiting hexavalent chromium in drinking water January 19, 2011: EPA Issues Guidance for Enhanced Monitoring of Hexavalent Chromium in Drinking Water October 7, 2010: US EPA offers chance to speak out against hexavalent chromium September 15, 2010: EPA accuses chromium industry of withholding lung cancer study May 17, 2007: Hexavalent Chromium in Drinking Water Causes Cancer in Lab Animals June 8, 2006: Scientific journal adds fuel to ongoing chromium debate
last time modified: April 17, 2014