Reversing a Bush administration decision, the Environmental Protection Agency announced today that it the developing a regulation for perchlorate, a naturally occurring and man-made chemical that research shows may impact the normal function of the human thyroid.

The federal agency said that monitoring data shows more than 4 percent of public water systems have detected perchlorate and between 5 million and 17 million people may be served drinking water containing perchlorate. The science that has led to teh decision has been peer reviewed by independent scientists and public health experts including the National Academy of Sciences, the EPA said.

Perchlorate is both a naturally-occurring and man-made chemical that is used in the manufacture of rocket fuel, fireworks, flares and explosives, and may be present in bleach and in some fertilizers. This decision reverses a 2008 preliminary determination by the previous administration, and considers input from almost 39,000 public comments.
  
Looking ahead: Drinking water standard for VOCs

Also In a separate action, the agency is also moving towards establishing a drinking water standard to address a group of up to 16 toxic volatile organic compounts (VOCs) that may pose risks to human health. The VOC chemicals to be addressed include trichloroethylene (TCE) and tetrachloroethylene (PCE), as well as other regulated and some unregulated contaminants that are discharged from industrial operations.

The VOC standard will be developed as part of EPA’s new strategy for drinking water, announced by the administrator in March 2010. A key principle of the strategy, according to the EPA, is to address contaminants as groups rather than individually in order to provide public health protections more quickly and also allow utilities to more effectively and efficiently plan for improvements.

“Clean water is critical to the health and prosperity of every American community and a fundamental concern to every American family. EPA is hard at work on innovative ways to improve protections for the water we drink and give to our children, and the development of these improved standards is an important step forward,” said EPA Administrator Lisa P. Jackson. “Our decisions are based on extensive review of the best available science and the health needs of the American people.” 
 
More information on the EPA”s drinking water strategy