The U.S. Environmental Protection Agency released its third list of drinking water contaminants known or anticipated to occur in public water systems, which may require regulation. EPA will continue to evaluate and collect data on the contaminants, and determine by 2013 for some of them whether or not to propose drinking water regulations.

The contaminant candidate list (CCL 3) includes 104 chemical contaminants or groups and 12 microbes. Among them are contaminants, pesticides, disinfection byproducts, pharmaceuticals, chemicals used in commerce, waterborne pathogens and algal toxins. The agency’s selection of the contaminants builds upon evaluations used for previous lists and is based on substantial expert input and recommendations from different groups including stakeholders, the National Research Council and the National Drinking Water Advisory Council.

The agency evaluated approximately 7,500 chemicals and microbes and selected 116 candidates for the final list based on their potential to pose health risks through drinking water exposure.

More information on the contaminant candidate list, visit http://www.epa.gov/safewater/ccl.