The movie Erin Brockovich alerted the public to the great suffering the little town of Hinkley experienced due to hexavalent chromium in their drinking water. Sadly, Hinkley is not the only California community suffering from this devastating pollution. According to the Department of Public Health, from 1997 through 2008 hexavalent chromium was detected in 2,208 California drinking water sources. These sources are spread throughout 52 out of 58 counties, impacting an estimated 13 million Californians.

In order to protect public health, the California Legislature passed SB 351 (Ortiz) in 2001, requiring the development of a state drinking water standard for hexavalent chromium by January 2004. Despite this legal deadline, the state has yet to finalize this standard, leaving millions of Californians at risk from this dangerous chemical. 

Chromium occurs in the environment largely in two forms: trivalent chromium, which occurs naturally and is an essential human nutrient, and hexavalent chromium, which is produced predominantly by industrial processes and is the most toxic form of the element. Currently, chromium is regulated in drinking water as total chromium and the drinking water standard of .05 milligrams per liter measures the amount of both toxic (hexavalent) and non- or less-toxic (trivalent) chromium in the water. Basing the standard on the combined levels of both types of chromium does not adequately protect public health because hexavalent chromium is more toxic at much lower levels than the other form. A combined standard leaves us vulnerable to health effects from hexavalent chromium.

Where does hexavalent chromium come from?

Hexavalent chromium enters drinking water sources through discharges of dye and paint pigments, wood preservatives, chrome plating wastes, and leaching from hazardous waste sites. Not surprisingly, communities near chromium waste disposal sites or chromium manufacturing and processing plants are at particular risk of exposure. Probably the most impacted people are workers exposed on the job.

What are the health effects of hexavalent chromium?

Hexavalent chromium is a carcinogen and a reproductive toxicant for both males and females. As a result, it was added to California's Proposition 65 list of toxic substances (pdf) in December 2008. Exposure to hexavalent chromium occurs through breathing, ingesting, and contact with the skin. Although most of the known health impacts are related to inhalation, there is now strong data linking ingestion of hexavalent chromium, such as through drinking water, to severe health effects. In addition to cancer and reproductive harm, short and long-term exposures can lead to eye and respiratory irritation, asthma attacks, nasal ulcers, dermal burns, anemia, acute gastroenteritis, vertigo, gastrointestinal hemorrhage, convulsions, ulcers, and damage or failure of the liver and kidneys.

How are drinking water standards established?

A drinking water standard, also known as a maximum contaminant level or MCL, is an enforceable level for a contaminant in the water, which cannot be legally exceeded by a public drinking water provider. It is based on three things: health impacts, technical feasibility to detect and treat it, and the cost of the water treatment. Both the federal government and the state can establish legally enforceable drinking water standards for contaminants of concern.

In California, the establishment of drinking water standards is a two-pronged process. First Cal EPA's OEHHA does a scientific analysis to establish the level in drinking water at which no adverse health effects would be expected. Based on these findings, OEHHA establishes a Public Health Goal, or PHG. Then the Department of Public Health sets a drinking water standard as close to the PHG as possible - but also based on technical and cost considerations.

Note: Drinking water standards pertain to public water systems where the water is provided by a local government agency or private company. They do not pertain to private wells. Testing private well water and any necessary treatment is the responsibility of the well owner.

Is the proposed public health goal for hexavalent chromium protective enough?

Clean Water Action strongly supports the .02 ppb PHG for hexavalent chromium, which current science indicates is protective of the entire population, including vulnerable populations such as children, pregnant women, and the elderly. It will also drive the clean-up of California's contaminated sites which impact local water supplies and hold polluters accountable.