Chromium-6 in U.S. Tap Water
December 20, 2010

Chromium-6 in U.S. Tap Water: Progress in California

California Moving Slowly in the Face of Industry Resistance

State law required California to adopt a drinking water standard for hexavalent chromium, the “Erin Brockovich chemical,” by Jan. 1, 2004. But with a legislature that regularly disregards its constitutional deadline for adopting a state budget, it is hardly surprising that state agencies now lag more than six years behind in protecting residents from this cancer-causing contaminant.

In August 2009, the Office of Environmental Health Hazard Assessment (OEHHA), part of California’s Environmental Protection Agency, completed the first step in the process, releasing a draft “public health goal” for chromium-6 in tap water (OEHHA 2009). The agency proposed a goal of 0.06 parts per billion (ppb) to limit the increased lifetime cancer risk to one additional case of cancer for every million people chronically exposed at this level through drinking water.

The California EPA, however, did not take into account the special sensitivity of fetuses and infants, as recommended recently by federal EPA scientists (McCarroll 2010), or of people with common medical conditions that may increase uptake of hexavalent chromium. An exposure limit of 0.06 ppb may not adequately protect the health of many Californians.

Industry, meanwhile, has pushed back. Honeywell International, Inc., along with the Association of California Water Agencies, has filed requests for an additional external scientific peer review of the draft document. (In 2003, a federal judge in Newark, N.J. ordered Honeywell, a producer of aerospace systems, engineering services and consumer products, to carry out an estimated $400 million cleanup of chromium waste along Jersey City’s waterfront, citing “a substantial risk of imminent damage to public health and safety and imminent and severe damage to the environment.”) The American Chemistry Council, an industry trade group, sought to rewrite the charge of the second peer review committee and influence the composition of the group (ACC 2010), all in an effort to weaken the proposed public health goal.

Four of the five independent scientists taking part in this additional, industry-instigated review process, now complete, expressed strong support for the proposed public health goal for hexavalent chromium (OEHHA 2010).

Concentrations of chromium-6 in tap water signal concern

In California, the only state to require tap water tests for hexavalent chromium, current water pollution levels are a cause for concern. The chemical was detected in 2,208 out of more than 7,000 tap water systems analyzed as of 2008 (CDPH 2009). These tests could only detect hexavalent chromium down to 1 ppb, more than 16 times higher than the state’s proposed public health goal. About 10 percent of the samples had levels of 5 ppb or higher.

EWG’s tap water quality database, including more recent test information, shows that 13.7 million Californians could be drinking water contaminated with at least 1 ppb of hexavalent chromium (EWG 2009). With a more sensitive test, hexavalent chromium would be detected in far more water systems.

Currently, California’s tap water standard for total chromium is 50 ppb, half the federal standard. Both the federal and state standards combine hexavalent chromium and the essential nutrient trivalent chromium, and are more than 800 and 1,600 times higher, respectively, than the proposed California public health goal for chromium-6. The fact that these regulations lump a cancer-causing contaminant with an essential nutrient underscores the need for reform of water standards.

Inching towards a tap water standard

The California Safe Drinking Water Act of 1996 requires the California EPA to perform risk assessments and adopt goals for contaminants in drinking water based on public health considerations alone. These goals do not have the force of regulation and represent only the first step in creating a mandatory standard.

Once the California EPA has finalized its public health goal for hexavalent chromium, the California Department of Public Health (CDPH) must establish a state drinking water standard known as a Maximum Contaminant Level. These standards take economic factors and technical challenges into account and should be as close as feasible to the corresponding public health goal.

EWG urges the California EPA to promptly finalize its public health goal for hexavalent chromium and calls on the CDPH to take immediate action to establish a sound regulatory standard. Regulation of this extremely common contaminant is already six years overdue.