Chromium 6

Chromium 6 has been the subject of significant media attention and regulatory developments in recent weeks.

ACWA has developed key points about chromium 6 for our member agencies. The points and additional information can be found here. 

Background

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. In fact, chromium is the 11th most common element in the earth's crust.

There is currently no proposed or existing drinking water standard for chromium 6. There are, however, federal and state standards for total chromium in drinking water, which encompasses both chromium 6 and chromium 3, a mineral considered essential to human metabolism. The California standard for total chromium is 50 parts per billion (ppb), while the federal standard is 100 ppb.

California Developments

California's Office of Environmental Health Hazard Assessment (OEHHA) on Dec. 30 published a revised draft technical support document for a proposed public health goal (PHG) for chromium 6 in drinking water. The final PHG is 0.02 parts per billion (20 parts per trillion), reduced from the 0.06 ppb identified in the first draft released in 2009.

According to OEHHA, the change is due to consideration of early-in-life exposures for cancer potency.

ACWA submitted comments to OEHHA on the draft by the Feb. 15 deadline. ACWA's comment letter can be read here. 

A PHG is not an enforceable standard. State law requires the California Department of Public Health to use a PHG as guidance in developing a maximum contaminant level (MCL), which is the enforceable state standard for drinking water that public water systems must meet.

Background on chromium 6 and California's draft public health goal is available here.

Recent Federal Developments

The U.S. Environmental Protection Agency released a guidance document in January 2011 recommending that public water systems conduct enhanced monitoring and sampling for chromium 6.

EPA Administrator Lisa P. Jackson has characterized the new guidance document as one part of EPA’s response to emerging data suggesting that chromium 6 could pose health concerns if consumed over long periods of time.

More on EPA's guidance is available here.

Federal Legislation

U.S. Senators Barbara Boxer and Dianne Feinstein introduced legislation on Jan. 26 that would direct the Environmental Protection Agency to set drinking water standards for chromium 6. The bill, S 79, would require EPA to set a health advisory within 90 days of enactment, propose a drinking water standard within 180 days, and finalize the drinking water standard no later than one year after the legislation is enacted.

Environmental Working Group Report

The Environmental Working Group released a report in December indicating that chromium 6 had been detected in the tap water of 31 of 35 cities sampled nationwide. The highest levels sampled were in Norman, Okla.; Honolulu, Hawaii; and Riverside.

The complete EWG report can be found here.

ACWA has developed key points about chromium 6 for our member agencies. The points and additional information can be found here.

Chromium 6 Webinar

The association sponsored a webinar on chromium 6 in November that provided an update on state and federal developments, including a study currently under way to investigate the mode of action (MOA) for chromium 6 in drinking water.

An archived recording of the webinar can be viewed here.

Key Points for ACWA Members about Chromium 6

ACWA has developed key points about chromium 6 for its member agencies. ACWA members with questions are encouraged to contact Danielle Blacet, ACWA’s regulatory advocate.

Currents actions by California water systems to address hexavalent chromium in water

• Water systems throughout the state have tested for the presence of chromium 6 in their drinking water and reported the results to local and state officials. The sampling results are available here. Please note these results reflect CDPH’s current detection limit for purposes of reporting (DLR) for chromium 6, which is 1 ppb.

• While there is currently no drinking water standard specifically for hexavalent chromium (chromium 6), chromium 6 is currently regulated under the total chromium drinking water standard, or maximum contaminant level (MCL), of 50 parts per billion (ppb).  Consumers interested in the levels of chromium in their drinking water should refer to their water systems' annual Consumer Confidence Reports (CCRs).

• Many local water agencies are collaborating on research to determine effective treatment and disposal options for chromium 6 in the state’s drinking water sources.

Recent California Developments

• The Office of Environmental Health Hazard Assessment (OEHHA) July 27, 2011, released a final public health goal (PHG) for chromium 6 of 0.02 ppb (20 parts per trillion). 

• The PHG identifies a level of a contaminant in drinking water that OEHHA determines poses no significant public health risk when consumed over a lifetime. A PHG is NOT an enforceable regulatory standard.

• State law requires the California Department of Public Health to use the PHG as guidance in developing an MCL, the enforceable state standard for drinking water that public water systems must meet.

• CDPH has announced on its website that due to the recent EPA recommendations for enhanced chromium 6 monitoring, it is reviewing the chromium 6 DLR and the current holding time of 24 hours to determine whether CDPH methods should be revised to align with EPA’s recommendations.

• For more information on CDPH activities, please visit the Chromium 6 website at: http://www.cdph.ca.gov/certlic/drinkingwater/Pages/Chromium6.aspx.
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• OEHHA has developed chromium 6 talking points in conjunction with CDPH.

Recent Federal Developments

• EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of hexavalent chromium that will appear on the Integrated Risk Information System (IRIS) database; results are expected in 2011.

• In response to the study released in December by the Environmental Working Group (EWG), EPA Administrator Lisa Jackson announced that EPA would be taking a series of actions in the near future to address chromium 6 in the nation’s drinking water supply.

• EPA issued “recommendations for enhanced monitoring for Hexavalent Chromium (Chromium-6) in Drinking Water,” which can be found here. According to EPA, enhanced monitoring will enable public water systems to better inform their consumers about the levels of chromium 6 in their drinking water, evaluate the degree to which other forms of chromium are transformed into chromium 6 in their drinking water and assess the degree to which existing treatment is affecting the levels of chromium 6.

• U.S. Sens. Barbara Boxer and Dianne Feinstein have introduced a bill to mandate the adoption of a chromium 6 MCL within a certain time frame set by the legislation. The bill can be read here.