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Water: Unregulated Contaminant Monitoring Rule 3

Unregulated Contaminant Monitoring Rule 3 (UCMR 3)

The third Unregulated Contaminant Monitoring Rule (UCMR 3) was signed by EPA Administrator, Lisa P. Jackson on April 16, 2012. The UCMR 3 requires monitoring for 30 contaminants using EPA and/or consensus organization analytical methods during 2013-2015. EPA, the States, laboratories and public water systems (PWSs) will participate in UCMR 3.

Federal Register Notice

The UCMR design divides contaminants into three types of monitoring. UCMR 3 includes monitoring under each of the three lists, as follows:

  • Assessment Monitoring uses common analytical method technologies used by drinking water laboratories. For UCMR 3, all PWSs serving more than 10,000 people and 800 representative PWSs serving 10,000 or fewer people will monitor for 21 List 1 contaminants during a 12-month period from January 2013 through December 2015.
  • Screening Survey monitoring uses specialized analytical method technologies not as commonly used by drinking water laboratories. All PWSs serving more than 100,000 people, 320 representative PWSs serving 10,001 to100,000 people and 480 representative PWSs serving 10,000 or fewer people are required to monitor for seven List 2 contaminants during a 12-month period from January 2013 through December 2015.
  • Pre-Screen Testing uses newer method technologies not as commonly used by drinking water laboratories. For UCMR 3, EPA will select 800 representative PWSs serving 1,000 or fewer people that do not disinfect. These PWSs with wells that are located in areas of karst or fractured bedrock, will participate in monitoring for two List 3 viruses during a 12-month period from January 2013 through December 2015.

EPA will pay for the analysis of all samples from systems serving 10,000 or fewer people and will arrange for the collection of samples from the systems that participate in the Pre-Screen Testing.

Additionally, EPA coordinates a Laboratory Approval Program for the contaminants. UCMR 3 requires laboratories have EPA approval to analyze PWS samples.


  • Basic Information – Basic information and audience specific fact sheets outlining various aspects of the regulation
  • Methods & Contaminants – List of contaminants and corresponding analytical methods
  • Laboratories – Information describing the Laboratory Approval Program and list of laboratories approved to analyze samples
  • Reporting – Information on reporting requirements, data elements and the electronic reporting system, Safe Drinking Water Accession and Review System (SDWARS)

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