There’s usually very little argument that striving to be “the first” is something worth aspiring to. The United States took tremendous pride in being the first to walk on the moon. And California routinely trumpets being the first in many things, from banning smoking in restaurants to enacting environmental protections. However, California is running down a path to be the “first” to set a standard in water quality that could easily place it last among the other 49 states.
In its quest to be the first to set a standard for hexavalent chromium, also known as Chromium 6, California, unlike the United States Environmental Protection Agency (U.S. EPA), is using outdated science. This approach has serious consequences that could easily spread beyond California’s boarders, posing new hazards and trade-offs never seen before in the advancement of safe drinking water.
After years of review, the U.S. EPA in 2011 delayed a federal risk assessment for Chromium 6 based upon new studies set to be completed in 2013. Those studies are now in and have been peer reviewed. The findings by the independent company Tox Strategies, in cooperation with numerous universities, indicate that California’s existing standard of 50 parts per billion for total chromium is sufficiently protective. The Tox Strategies studies found that at dosages likely encountered by humans, Chromium 6 converts to Chromium 3 in the human stomach as it oxidizes. Chromium 3 is an essential mineral important to human metabolism and digestion.
Not to be outdone, and in the face of facts to the contrary, on August 28 of this year, California’s Department of Health Services proposed a maximum contaminant level (MCL) for hexavalent chromium of 10 parts per billion. And the basis of their decision was a risk assessment by the California Office of Environmental Health Hazard Assessment which was based upon a controversial 2006 study by the National Toxicology Program that many experts have deemed outdated.
Human health concerns aside, the actual treatment of the water to get us to those extraordinarily low levels also poses new challenges for water suppliers and potential risks to neighborhoods surrounding treatment plants.
To begin, treating for Chromium 6 requires a very low level of acidity (pH) in the water. Neutralizing the acidity to extremely low levels requires large amounts of highly caustic sulfuric acid. According to studies by leading experts in a study for the National Water Research Foundation, it takes as much sulfuric acid to treat water for a small water system as it does a much larger system. Thus, large storage tanks will have to be constructed and protected in ordinary neighborhoods.
A second unintended consequence is that the identified treatment methods to reduce Chromium 6 below the proposed 10 parts per billion produces what’s known as residuals, the muck that is left behind after the water is treated. The residuals are of such a nature that they would have to be transported out of state.
The flawed risk assessment in California that led to the recommended MCL for Chromium 6 is leading the Golden State in a direction few anticipated when the Safe Drinking Water Act was passed in 1972. If California were to follow the U.S. EPA’s lead, these unintended consequences may not be realized.
California should reconsider setting a standard for Chromium 6 that is at odds with current scientific data. Simply put, California’s draft MCL for Chromium 6 is taking safe drinking water into uncharted territory, and dragging neighborhoods and consumers across the state with it. We should not, and cannot, go there. This is not a first worth striving for.
Peter S. Silva is former assistant administrator for the United States Environmental Protection Agency’s Office of Water. Richard Atwater is the executive director of the Southern California Water Committee.