Chromium 6: Science, Not Arbitrary Deadlines, Should Drive Process to Set Drinking Water Standard

Last week, two environmental advocacy groups filed a lawsuit against the California Department of Public Health regarding the development of a hexavalent chromium (chromium 6) MCL. The Natural Resources Defense Council and Environmental Working Group said in their filing that there have been unacceptable delays in addressing chromium 6 in California’s drinking water, particularly since the California Legislature mandated CDPH adopt an MCL by January 1, 2004.

So, why HAS it taken so long? Has CDPH really delayed the process, and in doing so put Californians at risk for cancer and other health problems?

A look at the facts reveals the answer is no. CDPH is dedicated to “optimizing the health and well-being of the people in California,” and in my experience CDPH staff take that mission very seriously. The process to adopt a chromium 6 drinking water standard is being handled no differently. 

To understand why it has taken over a decade to get where we are today, it is important to look at what goes into developing a maximum contaminant level, and why it matters to you and me that the agencies involved do not rush through the process.

When California develops a drinking water standard, the first step is for the Office of Environmental Health Hazard Assessment (OEHHA) to draft a public health goal (PHG). A PHG is the number that identifies a level of a contaminant in drinking water (such as chromium 6) that OEHHA determines poses no significant public health risk when consumed over a lifetime. It is not a regulatory standard, and it does not take into account whether a lab can detect it in the water at that level, whether it can actually be reduced to that level, or how much removing it may cost the water system and its customers . Those questions are considered by CDPH when it develops the MCL.  But because state law says that CDPH must set the MCL as close to the PHG as “technologically and economically feasible,” OEHHA must establish the PHG before CDPH starts work on the MCL.

When the legislation was passed in 2001 to adopt a chromium 6 MCL by 2004, there was no corresponding PHG in place. OEHHA had already begun to focus on chromium 6 as a potential carcinogen when ingested (we have known for a long time it causes cancer when inhaled), but more information was needed to assess the specific health risks, as this would be the first chromium 6 PHG and MCL in the nation.

In addition, there was no statewide data on where and how much chromium 6 was in California’s water supply, which is why California’s water systems spent two years sampling their water sources and providing that information to CDPH.

A draft PHG was not released by OEHHA until 2009, and the final PHG was not published until 2011. But during that time a multi-year study by the National Toxicology Program was completed. OEHHA relied heavily on that study to establish the final PHG. There were also several comment periods for the public and other interested parties to provide input into the development of the PHG, which is required for any regulation in California.

Surely all parties would agree that having appropriate public participation only adds to the integrity of a final drinking water standard. In the case of the chromium 6 PHG, the length of time it took to set the final number actually resulted in a more conservative PHG, a revision that was supported by the same organizations that are now claiming the process has taken too long.

Now that the PHG is final, CDPH is working diligently to determine how water systems can effectively treat and remove chromium 6 from California water supplies. In order to complete this process, department staff is utilizing cost studies that were only recently completed to ensure water systems can protect public health at a reasonable cost to that same public. This includes what technologies may work best to remove chromium 6 from source waters, and at what levels it can be detected by laboratories.

Remember that many PHGs are set at levels below what labs can detect in the water. CDPH cannot set an MCL unless it knows it can be 1) reliably detected in the water, 2) removed from that water, 3) and done so at a practical cost, particularly to small systems. Asking a judge to set a “faster” deadline through a lawsuit does not protect the public; it distracts the experts from doing their job.

Ultimately, it is scientific literature and cost/benefit analyses that should be the drivers for adopting drinking water regulations, not a law passed with an arbitrary deadline. Regulations such as this will affect every Californian—don’t we deserve a process governed by science and not decided in a courtroom?

California’s local water providers are part of a proactive and diligent community that takes these matters seriously. Water agencies have been extremely cooperative in working with regulators to conduct additional sampling and testing of water, carry out pilot studies to better understand the challenges of low-level contaminant reduction and to provide whatever information regulators may need to establish new standards as efficiently as possible. Chromium 6 is no exception. The array of cooperative and voluntary steps taken by water agencies is as far from heel-dragging as one can get.

For further information, and to truly understand all of the steps taken OEHHA and CDPH have taken to develop the chromium 6 regulation, I encourage you to review CDPH’s extensive timeline on its website.

There is also a wealth of information on CDPH's MCL process here.