Under the Safe Drinking Water Act (SDWA) amendments of 1996 the Unregulated Contaminant Monitoring Rule (UCMR) was promulgated.  This rule requires the EPA to establish a list of up to 30 unregulated contaminants every five years, to be screened for in a representative sampling program.  All public water systems serving more than 10,000 people and a random sample of 800 systems serving 10,000 people or fewer will monitor those contaminants to determine their frequency and level of occurrence for 12 months.  The UCMR benefits the environment and public health by providing EPA and other interested parties with scientifically valid data on the occurrence of these contaminants in drinking water, permitting assessment of the population being exposed and the levels of that exposure. This information is the primary source of exposure data for the agency to determine whether to regulate these contaminants.

The Environmental Laboratories at Westchester County's Department of Labs and Research has participated in the first two cycles of the EPA’s Unregulated Contaminant Monitoring Rule (UCMR) and is preparing for the third cycle slated to start in 2011.

For general information on UCMR 2, go to EPA Safewater or call the Safe Drinking Water Hotline at (800) 426-4791.