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Monitoring Unregulated Contaminants in Drinking Water

  • Unregulated Contaminant Monitoring Rule

    The EPA collects occurrence data for contaminants that may be present in drinking water, but are not currently subject to EPA drinking water regulations. Learn about the Unregulated Contaminant Monitoring Rule.

  • UCMR 5 Data Finder

    Use the UCMR 5 Data Finder to easily search for, summarize, and download available monitoring results. Learn how in this video demonstration.

Monitoring Unregulated Contaminants in Drinking Water

The Safe Drinking Water Act requires that the EPA establish requirements for public water systems (PWSs) to monitor for priority unregulated contaminants every five years and requires the agency to make the results publicly available.

  • Learn about the Unregulated Contaminant Monitoring Rule (UCMR)
  • Meetings and Materials
  • Reporting Requirements

Current and Previous UCMRs

  • UCMR 5 (2022-2026)
  • UCMR 4 (2017-2021)
  • UCMR 3 (2012-2016)
  • UCMR 2 (2007-2011)
  • UCMR 1 (2001-2005)
  • UCM-State Rounds 1&2 (1988-1997)

UCMR Laboratory Approval

  • UCMR 5 Laboratory Approval Program
  • EPA Approved Laboratories for UCMR 5
  • EPA Approved Laboratories for UCMR 3 and UCMR 4

Occurrence Data

  • UCMR 5 Data Finder
    • UCMR 5 Data Finder Walkthrough (video)
  • UCMR Archival Data Finder
    • UCMR Archival Data Finder Walkthrough (video)
  • UCMR Data Summaries
  • UCMR Occurrence Data Text Files

Related Information

  • Contaminant Candidate List (CCL) and Regulatory Determination
  • National Contaminant Occurrence Database
  • EPA Ground Water and Drinking Water Website
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on April 21, 2025
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