Polluters who contaminate drinking water and make people sick shouldn't get off easy. That has been the focus of my work for two decades, and I'm not planning to stop now. My work focused the attention of the world on a carcinogen called hexavalent chromium (hex chrome). In 1996, PG&E -- a multi-billion dollar corporation -- paid $333 million in damages to the people of Hinkley, Calif., for contaminating their drinking water and covering up the problem for decades while people got sick and died. This victory for was immortalized in film. But the story doesn't end there.

More than 500 California communities and 30 million state residents drank water contaminated with hexavalent chromium at levels above safe levels between 1998 and 2003. Hex chrome has been detected in nearly 60 percent of the drinking water sources sampled in California. These problems are especially widespread in the Central Valley and the Inland Empire regions of the state. The PG&E Kettleman case was settled in 2006 for $335 million. Another PG&E site in Topock, Calif., affected the Colorado River -- a drinking water source for millions of people. In Burbank, contamination by Lockheed Martin affected thousands, and in Riverside, TXI Corp's cement kiln contaminated the soil in the local community. Even Disney is responsible for chromium contamination in the San Fernando Valley.

Communities all over the United States and around the world have been poisoned by this chemical. I am currently working on a case in Midland, Texas, with enormous levels of hexavalent chromium in the well water. Chromium polluters include a "who's who" of major corporations. It doesn't take a genius to know that these polluters don't want people to realize the extent of the problem, because then they'd be on the hook for an expensive cleanup.

So it doesn't surprise me that five years after California regulatory agencies were required by law to set an up-to-date enforceable standard for hex chrome in drinking water, consumers are still not protected. I've fought these powerful interests for years, and I know first hand how good they are at delay tactics.

The good news is that Cal/EPA's Office of Environmental Health Hazard Assessment -- the public health agency that the governor tried unsuccessfully to eliminate in the last budget cycle -- has just come out with a proposed drinking water level that would protect Californians. The new assessment uses research from the National Toxicology Program to identify the levels of hex chrome that cause cancer and then calculates a safe level for vulnerable populations, including children. A public meeting was held Oct. 19 in Oakland to accept comments on this proposal; written public input is welcome until Nov. 2. You can send a message through the NRDC Action Center.

I read through the 140 page Cal/EPA document with mixed feelings. On the one hand, I felt vindicated -- but I also felt saddened. The National Toxicology Program concluded in its 2007 study that hexavalent chromium is considered carcinogenic not only by inhalation, but also by ingestion. Gosh, who knew? Maybe if someone had believed all these people in Hinkley, Calif., many years ago, many more lives would have been saved.  I was saddened by the descriptions of liver and kidney degeneration, blood abnormalities including anemia, testicular damage, infertility, miscarriage, fetal toxicity, chromosomal abnormalities and a litany of cancers. The clinical descriptions in the Cal/EPA document weren't abstract to me -- they brought back to me the names and faces of people that I know who have lived and died with these illnesses.

Roberta Walker, the original client in the movie, was poisoned once by Chromium 6 -- and may be again. PG&E recently tested Roberta's well at her new home and found levels of hexavalent chromium at 1.26 ppb, well over the proposed action level of .06 ppb.

I congratulate the long hard work of attorneys who fought on behalf of those poisoned by this chemical, and I applaud agencies and scientists for overseeing, setting and hopefully enforcing stricter standards. My fight for the people of Hinkley isn't over. To bring this dark chapter of history to a close, California must adopt a legally enforceable and truly health-protective standard for hex chrome in drinking water. I cannot personally protect every community with contaminated water, but if we have a uniform standard, I will be able to rest easier knowing that people won't be drinking this dangerous substance without knowing it. This chemical is a serious problem and one that I am glad to see being addressed. California has always led the way in setting standards that other states follow. We need to make prevention the goal of the future.

A version of this editorial previously appeared in The Sacramento Bee.