Description: The 1996 Safe Drinking Water Act (SDWA) amendments require that once every five years EPA issue a new list of no more than 30 unregulated contaminants to be monitored by public water systems (PWSs). The second Unregulated Contaminant Monitoring Rule (UCMR 2) was published on January 4, 2007. UCMR 2 required monitoring for 25 contaminants between 2008 and 2010 using analytical methods developed by EPA, consensus organizations, or both. This monitoring provides a basis for future regulatory actions to protect public health.

    Number of Chemicals: 25