The California Environmental Protection Agency on Thursday set its public health goal for perchlorate a rocket fuel component that can cause thyroid disorders at six parts per billion. This is the first such level set in the country for the toxin.
As the next step in the process, the state's Department of Health Services will set a standard for the chemical, which is required to be as close as possible to the goal set by EPA..
Environmental groups said the recommendation was too low and still allows levels of perchlorate in drinking water that are high enough to be a threat to pregnant women and children. The chemical is found in Colorado River water that serves 15 million customers.
Because of its decades-long involvement with the defense industry, military and space programs, California has a particular problem with perchlorate.
Contamination from the toxin has shut down hundreds of wells that tap polluted groundwater, and perchlorate has been found in crops produced in affected areas.
Also, thousands of people have filed lawsuits, saying years of drinking water laced with the chemical have caused cancers and other illness.